Nanocarrier-based delivery method of plant-derived bioregulators

Abstract

The application discloses a plant source biological regulator delivery method based on nano carriers, and particularly relates to the technical field of nano materials, and comprises the following steps: constructing a locking risk map based on soil mineral distribution, modifying the structure of the nano carriers in a high adsorption area in response, and regulating the release rhythm; combining the release history with the characteristics of the soil microenvironment to implement multi-level regulation on the structure of the nano carriers, and dynamically adjusting the release path; collecting rhizosphere distribution and plant response data through nano probes during application, modeling and optimizing the next round of delivery strategy, and realizing closed-loop accurate delivery of the plant source biological regulator; through the construction of the soil mineral map, the high adsorption area is identified before application, the release rhythm is controlled by using the responsive nano carrier structure, the release path and dose are dynamically adjusted by combining the data collected by the rhizosphere probe, multi-cycle, regional and closed-loop regulator delivery is realized, and the application accuracy and environmental adaptability are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nanomaterial application, and more particularly to a plant-derived biological regulator delivery method based on a nano-carrier. BACKGROUND

[0002] As a natural, efficient and environmentally friendly agricultural input, plant-derived biological regulators are widely used in crop growth promotion, stress resistance induction and quality regulation. However, most of these regulators are unstable small molecular compounds, which are prone to degradation, adsorption and loss. When applied in complex soil conditions, they often face problems such as difficult dosage control, short time efficiency and high residue, which seriously limit their actual utilization efficiency and application value.

[0003] To improve the rhizosphere stability and spatial delivery efficiency of plant-derived biological regulators, nano-carriers are widely used for controlled release of plant-derived biological regulators. By adjusting the surface properties and release behavior of nano-structures, the theoretical "quantitative, timed and directional" precise delivery can be achieved. However, the existing delivery strategies based on nano-carriers have serious adaptability problems in real complex soil environments, especially in high mineralization and high colloidal soil areas, which gradually reveal the following non-negligible deep-seated problems:

[0004] In soils with high clay content or rich in active colloidal minerals (such as montmorillonite, kaolin and iron ions), nano-carriers are prone to strong adsorption on the surface of minerals, resulting in a significant decrease in the release rate of plant-derived biological regulators encapsulated by the nano-carriers, and even a "release lock" phenomenon, causing a large amount of regulators to be unable to release and remain in the soil pores for a long time during the first application. This retained dose not only reduces the utilization efficiency in the current season, but also causes "nano-residue superposition" problems in subsequent application cycles.

[0005] More seriously, in the second and multiple applications, the newly added nano-carriers interfere with the release of the residual regulators and cause response disorder. The release intensity in some areas is superimposed and increased, causing excessive dosage, while in other areas, the dosage remains blank, resulting in an uncontrollable soil hormone environment with "dose peaks" and "dose blanks" distributed alternately in the same plot, which induces serious differentiation of plant physiological responses, such as root overgrowth and twisting, leaf scorching, fruit malformation, etc., which not only weakens the growth potential of crops, but also seriously disrupts the stability of the agricultural ecosystem. The nano-residue superposition lockout synergistic amplification effect is a key technical difficulty that has not been fully solved in the field of agricultural nano-carrier controlled release. Therefore, the present application proposes a plant-derived biological regulator delivery method based on a nano-carrier to solve the above problems. SUMMARY

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0007] The plant source biological regulator delivery method based on nanocarriers includes the following steps:

[0008] A soil colloidal mineral distribution map is constructed, the mineral type, distribution range, and adsorption strength are obtained by a high-throughput soil spectrum acquisition method, the high adsorption area and the low release area are calibrated, and the division of the locked risk area is completed before application;

[0009] The surface ligand structure of the nanocarrier located in the high adsorption area is modified, and a desorbable molecular block with pH response or enzyme response characteristics is introduced to control the release rhythm after adsorption occurs and avoid the dose lock phenomenon;

[0010] According to the adsorption area division and release history data, the structure of the nanocarrier is controlled in multiple levels, the release path is dynamically adjusted, and the local dose difference is balanced by regional inhibition and nonlinear compensation;

[0011] During the application process, fluorescent response or potential response type nanoprobes are deployed near the plant roots to collect the spatial distribution of the regulator in the rhizosphere and the physiological response data of the plant, and the release behavior of the carrier and the soil adsorption characteristics are modeled to optimize the next round of delivery strategy and complete the closed-loop delivery control of the regulator across cycles.

[0012] In a preferred embodiment, a light-sensitive or magnetic response marker is arranged outside the nanocarrier to identify the release state and distribution trajectory of the carrier in the historical application.

[0013] In a preferred embodiment, the step of constructing a soil colloidal mineral distribution map includes:

[0014] The target agricultural plot is systematically sampled according to a preset grid size, visible light-near infrared (VIS-NIR) combined with high-throughput scanning technology is used to obtain soil spectrum reflection data, and X-ray diffraction (XRD) and scanning electron microscopy (SEM-EDS) analysis are used to quantitatively verify the component content of various colloidal minerals in the sample, a fitting model between the spectral band and the mineral composition is established to calculate the colloidal mineral type and spatial distribution of each grid unit in the plot;

[0015] Based on the mineral type and component content results, a mineral type adsorption coefficient database is constructed, and a carrier release sensitive factor library is simultaneously established, the mineral type adsorption coefficient and the carrier release sensitive factor are integrated according to a preset proportion to form an adsorption interference index for describing the interference strength of a specific soil unit on the release behavior of the nanocarrier;

[0016] The adsorption interference index is projected to a spatial grid, the grid is classified according to a set interference intensity threshold, and preset type terrain hydrological parameters are introduced to screen the connectivity of high interference grids, identify contiguous high-risk areas, and finally mark high adsorption areas and low release areas by spatial superposition and boundary tracking algorithm to complete the division of the locked risk area.

[0017] In a preferred embodiment, the mineral type adsorption coefficient refers to the maximum adsorption capacity of colloidal minerals per unit mass of plant-derived biological regulators, which is obtained by isothermal adsorption experiment, and the carrier release sensitivity factor reflects the release delay degree of different nano-carriers in the corresponding mineral environment, which is expressed by release start time delay ratio or maximum release rate change rate.

[0018] In a preferred embodiment, the control release rhythm refers to:

[0019] For the responsive molecular block on the surface of the nano-carrier, the time delay and release duration parameters required for the target release window are set, and by adjusting the chain length of the block molecule, the conformational stability and steric hindrance effect before being triggered by pH or enzyme signal are controlled to delay the starting point of release;

[0020] By adjusting the crosslinking density in the molecular block, the unzipping rate and load diffusion rate of the carrier when responding to environmental changes are adjusted, and a high crosslinking state is used to prolong the release process and inhibit the burst release phenomenon, and a low crosslinking state is used to accelerate the response and is suitable for the short-period hormone release demand in the rhizosphere;

[0021] By setting the response threshold parameter, the pH change range or enzyme concentration limit is limited to ensure that the release behavior only starts when the target soil microenvironment condition is reached, forming a specific release path for the target area.

[0022] In a preferred embodiment, the multi-level regulation of the nano-carrier structure includes:

[0023] Combined with the adsorption area division result, the soil microenvironment indicators (including pH value distribution, Ca 2+ / Mg 2+ concentration, conductivity) in the plot are converted into a quantifiable regional response parameter matrix to determine the trend level of carrier release restriction or overload in different regions;

[0024] A pH-responsive coating based on polyacrylic acid or carboxymethyl chitosan is introduced to the outer layer of the nano-carrier, which is used to open or close the release channel under acid-base change conditions; the intermediate structure introduces calcium phosphate or montmorillonite intercalation structure with ion exchange ability, which is used to adjust the release rate in response to Ca 2+ concentration change; the inner layer adjusts the release direction offset by fixing the charge distribution to adapt to the potential difference guided mass transfer path;

[0025] By adjusting the arrangement order, thickness ratio and threshold response interval of each response layer, a response path system with regional resolution capability is constructed to ensure that in the high adsorption or release interference area, the carrier release path migrates directionally or is selectively closed. The release path adjustment behavior is fused and analyzed with historical release data, and more priority release channels are allocated to the release lag area to construct a dynamic spatial release regulation mode based on land characteristics.

[0026] In a preferred embodiment, the pH-responsive coating is composed of polyacrylic acid or carboxymethyl chitosan.

[0027] In a preferred embodiment, non-linear compensation refers to:

[0028] According to the deviation comparison between the actual release data of each soil area in the previous round of application process and the target application dose, a spatial dose deviation map is constructed to identify local excessive release areas and insufficient release areas, and to label and match them with the release state of the corresponding area in the response path system;

[0029] Multiple controllable release channels are provided in the nano-carrier structure to respond to different environmental parameter trigger thresholds. By adjusting the opening condition and activation order of each release channel, a non-linear mapping relationship between local environmental signals and release intensity is established.

[0030] In the insufficient release area, release early activation logic is set to enhance the local compensation effect by lowering the channel activation threshold or prolonging the release duration; in the excessive release area, delayed activation or limited release rate is used to suppress the cumulative dose, forming a spatial dynamic differential control strategy.

[0031] In a preferred embodiment, during the application process, based on the rhizosphere space regulator distribution data collected by fluorescence-responsive or potential-responsive nano-probes, plant physiological response signals, nano-carrier release state and soil adsorption parameters in multiple application cycles, a training set and a validation set containing multiple environmental variables are constructed to train a convolutional neural network model with spatial feature recognition capability.

[0032] The model input end is an image or tensor input composed of collected multi-channel data, reflecting the coupling state of the current micro-area soil-plant-carrier system;

[0033] The model output end is the path response feature parameter set required for the region to adjust under stress conditions in the next application cycle, including the opening threshold, activation order, response layer arrangement structure and its adjustment parameters of each release channel.

[0034] During the training process, the back propagation algorithm is used for weight updating, and the output result is corrected by mean square error or cross entropy loss function until the prediction accuracy of the verification set reaches the set threshold, forming a convolutional neural network model with generalization ability, and used for optimizing the next round of delivery strategy.

[0035] Technical effects and advantages of the present application:

[0036] The present application constructs a soil colloidal mineral distribution map, and uses high-throughput soil spectrum acquisition method to comprehensively quantify the mineral type, spatial distribution range and adsorption strength of the target plot before application, and combines the difference of adsorption behavior to partition and calibrate the high adsorption area and low release area, effectively identifies the area in soil which has significant interference risk to the release behavior of nano carrier. Compared with the traditional application method, this method can realize precise risk prediction and spatial difference regulation before application, significantly improve the application efficiency and regulator utilization rate, reduce the adverse effects such as local regulator retention and root zone dose loss caused by strong mineral adsorption, provide scientific basis for carrier structure design and application path optimization, and enhance the predictability and safety of the application process.

[0037] The present application modifies the structure of nano carrier located in the high adsorption area, introduces desorbable molecular block with pH response or enzyme response characteristics, and after physical adsorption of the carrier and soil colloidal surface, it can still rely on environmental signal induction to realize controllable release behavior, breaking through the problem that traditional carrier is blocked in high adsorption soil and the release window is uncontrollable. The establishment of regulator release rhythm makes different soil micro areas realize differential start and delivery control according to their own pH value or enzyme activity level, so as to avoid the one-time burst release or permanent lock of the regulator in some areas, and improve the available time length and release stability of the regulator in the root zone. This strategy has the ability of material responsiveness and release window cooperative regulation, which significantly enhances the adaptability of the carrier in complex soil and the regulation accuracy of the load release behavior.

[0038] The application divides the adsorption region and releases the data to the nano-carrier structure for multi-level regulation, dynamically adjusts its release path, and makes it respond differently in different soil micro-regions according to the adsorption strength and historical residual behavior. Further, the application combines the fluorescent response or potential response type nano-probe deployed during application to obtain the spatial adjustment agent distribution state of the plant rhizosphere region and the plant physiological response signal. The above information is integrated with the carrier release behavior and soil adsorption characteristics to model, which is used to guide the carrier structure adjustment and dose configuration in the next round of application. The process forms a cross-cycle information closed-loop feedback mechanism, which has the ability of spatial recognition, response judgment, parameter correction, etc., and breaks through the bottleneck that the traditional static application method cannot adapt to the dynamic changes of the environment. Through continuous optimization of the application strategy, the application maintains the dynamic balance of the soil hormone environment in multiple application cycles, significantly improves the delivery efficiency of the plant source biological regulator in the time and space dimensions, and is suitable for precision agriculture and high-value crop cultivation scenarios. BRIEF DESCRIPTION OF DRAWINGS

[0039] For the convenience of those skilled in the art, the application will be further described below in conjunction with the drawings;

[0040] Figure 1 The principle diagram of the plant source biological regulator delivery method based on nano-carriers in the application. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the application will be described clearly and completely below in conjunction with the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the application.

[0042] Reference Figure 1 The following embodiments are obtained:

[0043] Embodiment 1: The plant source biological regulator delivery method based on nano-carriers includes the following steps:

[0044] The soil colloidal mineral distribution map is constructed, the mineral type, distribution range and adsorption strength are obtained through high-throughput soil spectrum acquisition method, the high adsorption area and low release area are calibrated, and the risk area division is completed before application; the soil area where the release of nano-carrier may be disturbed is identified, and the problems such as dose retention, local failure or excessive accumulation are avoided from the root. High-dimensional soil spectrum data are obtained through VIS-NIR joint scanning, and then a fitting model between spectrum and mineral composition is established by combining XRD and SEM, so that the three-dimensional distribution state of colloidal minerals in the plot can be calculated. Further, an adsorption interference index is constructed to identify the high-risk area which has a significant impact on the release behavior of the regulator, so as to complete the accurate division at the spatial level before application, and provide geographical and mineral environment basic support for the subsequent delivery strategy.

[0045] The surface ligand structure of the nano-carrier located in the high adsorption area is modified, and a desorbable molecular block with pH response or enzyme response characteristics is introduced to control the release rhythm after adsorption occurs and avoid dose lock. In order to solve the problem that the nano-carrier in the high adsorption area is easily adsorbed and loses the release function, the surface ligand structure of the carrier is designed to have a controlled release ability. The pH response block (such as polyacrylic acid) and the enzyme response block (such as natural polypeptide) can initiate conformational transition or bond rupture under specific rhizosphere microenvironment signals, thereby delaying the start of the release process or adjusting the release rate. By adjusting the molecular chain length, crosslinking density and response threshold parameters, the release behavior can be accurately controlled, the structure rhythm of “delayed start + continuous release” is formed, the regulator retention or one-time burst release is prevented, and the release controllability and spatial matching are improved.

[0046] According to the adsorption area division and release history data, the nano-carrier structure is controlled at multiple levels, the release path is dynamically adjusted, and the local dose difference is balanced through regional inhibition and nonlinear compensation; based on the divided soil risk area and historical release record, the hierarchical regulation and behavior arrangement are carried out around the internal structure of the carrier. By constructing a response path system composed of pH response coating, ion exchange middle layer and potential regulation inner layer, the carrier has the gradient response ability to signals such as pH, ion concentration and conductivity in the soil, so as to automatically adjust the opening order, direction and rate of the release channel. On the basis of release path deviation, a nonlinear compensation mechanism is introduced: in the release insufficient area, the release is preferentially released, in the dose excessive area, the release is delayed or the channel is closed, so as to realize the dynamic balance of spatial dose and the fine control of cross-cycle dose superposition, and prevent abnormal growth of crops caused by imbalance of the regulator.

[0047] During the application process, fluorescent or potential response type nanoprobes are deployed near the plant root system, the spatial distribution of the regulator in the rhizosphere and the physiological response data of the plant are collected, and the carrier release behavior and soil adsorption characteristics are modeled to optimize the next round of delivery strategy, and complete the closed-loop delivery control of the regulator across the cycle. By implanting high-sensitivity fluorescent or potential response type probes in the rhizosphere area, the actual distribution of the regulator in the soil and the physiological response of the plant root system to the regulator (such as pH fluctuation, root growth density) are monitored in real time. The spatial-time sequence data obtained are integrated with the carrier release record and the adsorption area characteristics to construct a convolutional neural network model with a tensor image as input and a path response feature parameter set as output. After model training, it has prediction ability and can output the optimal response path structure parameter configuration before the next round of application, realizing cross-cycle, self-adaptive, and crop feedback-driven regulator delivery control, and improving application accuracy and agronomic control efficiency.

[0048] A light-sensitive or magnetic response marker is provided on the outside of the nanocarrier to identify the release state and distribution trajectory of the carrier in the historical application. A tracking mechanism for the nanocarrier between multiple application cycles is established to overcome the defect of "carrier untraceability" in traditional methods. By introducing a light-sensitive or magnetic response marker with stable response characteristics on the surface of the carrier, the carrier position and residual release state can be obtained after application through external scanning techniques such as near-infrared excitation imaging and magnetic resonance positioning. This information will be an important input variable for training the convolutional neural network model, helping to determine whether the release path is complete, whether there is accumulation retention or excessive release, thereby improving the modeling accuracy and prediction reliability of the model for historical states.

[0049] To accurately identify the soil area where the release behavior of the regulator may be affected by adsorption before application, a high-precision soil colloidal mineral distribution map can be constructed by the following steps, and the division and classification management of the risk area can be completed accordingly: The target agricultural land is divided into a spatial grid, and systematic sampling is carried out according to the preset grid size. Taking a 5-hectare land as an example, a 10-meter x 10-meter grid is used for sampling, and a total of 500 point samples are collected. Each sample point collects soil in the plough layer with a depth of 0-20 cm and is numbered and registered. Subsequently, a visible-near infrared spectrometer is used to scan all soil samples at high throughput to obtain soil reflectance spectrum data in the 400-2500 nanometer wavelength range. This data can reveal the characteristic absorption peaks of functional groups in the soil, including Si-O, Al-OH, and other mineral group reflection characteristics, providing a basis for subsequent mineral identification. To improve prediction accuracy, 30% of the sample points are selected as modeling samples and sent to an X-ray diffractometer for crystal structure analysis and a scanning electron microscope (with energy spectrum analysis) for element surface distribution determination to quantitatively obtain the relative content of main colloidal minerals such as montmorillonite, kaolin, illite, quartz, and iron oxide.

[0050] After the quantitative analysis of mineral components is completed, a mathematical model between the reflectance spectrum and the mineral content is established using partial least squares regression (PLSR), and 10-fold cross-validation is performed to obtain a regression equation with an average prediction error controlled within ±3%. This equation is used to inversely deduce the mineral component content of the remaining 70% of the sample points that are not sent for testing, thereby realizing the spatial mapping of mineral types in the whole block. Based on the prediction results, a database of mineral type adsorption coefficients is constructed. The adsorption coefficient refers to the maximum static adsorption capacity of a unit mass of a certain mineral to a plant-derived biological regulator (mg / g), which can be determined through batch isotherm adsorption experiments. Taking chitosan-modified salicylic acid as a representative regulator, the adsorption coefficient of kaolin is measured to be 4.8 mg / g, that of montmorillonite to be 8.2 mg / g, and that of illite to be 2.3 mg / g. At the same time, laboratory column leaching experiments are conducted on the release behavior of typical carrier materials (such as carboxymethyl chitosan nanoparticles and chitosan-iron oxide composite particles) in the above mineral-covered soils, and the changes in release start time and maximum release rate are recorded. A database of carrier release sensitivity factors is established, with the sensitivity factor represented by the release start delay ratio (control / target soil) and the rate reduction percentage. For example, the release start delay of carboxymethyl chitosan nanoparticles in kaolin environment is 2.1 times, and the maximum rate reduction is 38%. The adsorption coefficient and the release sensitivity factor are weighted and calculated with a weight of 0.6:0.4 to construct an adsorption interference index, which is used to comprehensively represent the interference strength of soil microzones on the release behavior of nano-carriers.

[0051] The adsorption interference index is assigned to the entire grid using spatial interpolation methods to form a spatial distribution map of adsorption interference strength. With an interference index ≥ 0.7 as the high interference threshold, the grids greater than this value are marked red to form a preliminary screening map of potential release failure zones. Subsequently, known topographic and hydrological data are introduced as auxiliary judgment basis, including slope (obtained by laser ranging and slope fitting), land drainage direction, water potential flow trend, and soil bulk density value. The spatial connectivity of high interference grids is screened to remove isolated high-value points, leaving contiguous high-interference areas (such as adjacent to 5 or more high-value grids), and the boundary tracking algorithm is used for area boundary marking to complete the closed marking of high adsorption and low release areas. The high-risk areas defined above are used as constraint inputs for regulator application path planning and dose structure adjustment. The subsequent nano-carrier release path regulation, release pore threshold setting, and release sequence arrangement parameters are all referenced based on this distribution map, thereby realizing environmental adaptability adjustment in the overall application strategy, improving the utilization rate of regulators, reducing non-target release, and improving the intelligent application control level of agricultural land.

[0052] More specifically: the application adopts a linkage mechanism of spatial connectivity screening, boundary tracking algorithm and regional classification standard, establishes a spatial recognition criterion, and the adsorption interference index is a weighted parameter constructed based on the adsorption coefficient of soil colloidal mineral type and the release sensitivity factor of nano-carrier, and the numerical range is set between 0 and 1. In order to identify the soil unit that significantly interferes with the release behavior of nano-carriers, the screening starting threshold of the adsorption interference index is set to 0.70, and the index value is not less than the threshold, which is marked as a “candidate high-interference grid”.

[0053] The candidate grid is further screened by the spatial connectivity rule, and an eight-neighbor connection mode is adopted (i.e. each grid periphery in eight directions constitutes a potential adjacent path). If there are not less than 4 grids in the neighborhood of a candidate grid that also satisfy the condition of adsorption interference index ≥ 0.70, then the grid is determined as a “high-interference core grid”.

[0054] A plurality of high-interference core grids form a contiguous region in space. In order to exclude incidental high-value point interference, a connectivity number threshold is further set: the number of high-interference core grids is not less than 5, and each core point is connected through an adjacent path to form an effective connectivity chain. The contiguous region that meets this standard is identified as a “spatially connected high-interference region”. In order to enhance the adaptability of the soil environment, the application introduces topographic and hydrological factors to assist in weighting the adsorption interference index: for grids that meet the following conditions, automatically increase their adsorption interference index value by 0.05 as a correction: slope less than 2 degrees, soil bulk density higher than 1.3 g / cm3, located in the downstream area of natural water flow direction, and drainage direction consistency higher than 80%. The correction value is included in the final index for connectivity judgment to enhance the recognition ability of structural poor soils.

[0055] After completing the connectivity screening, the connected high-interference grid group needs to be identified for closed boundaries, which are used for binding subsequent delivery path control parameters. The application uses a chain code type boundary tracking algorithm to construct the boundary of each high-interference contiguous region. The tracking starts from the left upper corner point of the boundary grid, and checks the 8 adjacent directions in clockwise direction. Each time a new boundary grid is identified, the boundary search is continued recursively at the current position until the beginning and end coincide to form a closed loop path. The process outputs the direction code sequence and point set coordinates of the boundary. In order to eliminate the sawtooth structure and polygonal horn in the boundary tracking process, the minimum convex hull algorithm is used for preliminary geometric optimization of the boundary line. Finally, the closed region is output as a high-interference region unit with independent numbering, each region is accompanied by the average adsorption interference index, maximum value, minimum value and its boundary coordinate set.

[0056] In the present application, the high adsorption area and the low release area partially overlap, but the determination logic of the two is based on different physical-chemical characteristic dimensions. The high adsorption area is defined as: its adsorption interference index is greater than or equal to 0.70, and the unit mass adsorption capacity of the dominant mineral is greater than or equal to 5.0 mg / g; at the same time, the area meets the connectivity criterion and is closed and marked by the boundary tracking algorithm, and belongs to the area where the adsorption capacity of colloidal minerals is significantly enhanced. The low release area is defined as: its carrier release sensitive factor shows that the startup delay ratio is greater than or equal to 1.8, or the maximum release rate decreases by greater than or equal to 30%; at the same time, the area shows that the carrier release completion rate is less than 50% in the residual analysis, which can be obtained by laboratory percolation column test. The low release area can be spatially crossed and nested with the high adsorption area, or it can exist independently, representing a micro-domain where the carrier release is inhibited by the environment but not necessarily related to the adsorption behavior. Finally, all areas that meet the above standards will be included in the delivery path regulation reference area set, which is used for subsequent steps such as optimizing the release rhythm, responding to the arrangement of the layer structure, and nonlinear dose compensation behavior.

[0057] The mineral type adsorption coefficient refers to the maximum isothermal adsorption capacity of unit mass of colloidal minerals to plant-derived biological regulators under specific temperature, pH value and ionic strength conditions, which reflects the strength of the physical-chemical binding capacity of different minerals to regulator molecules. The determination method adopts isothermal adsorption experiment: under the condition of constant temperature at 25°C, prepare a certain concentration gradient of regulator solution (such as 10, 20, 50, 100 mg / L), mix with known mass (such as 0.1 g) of target mineral (such as montmorillonite, kaolin, illite, etc.), and place in a shaker for full adsorption equilibrium (usually 24 hours); after centrifugation, the supernatant is taken, and the remaining regulator concentration is measured using ultraviolet-visible spectrophotometer or high performance liquid chromatograph. Through Langmuir or Freundlich model fitting of adsorption equilibrium data, the maximum adsorption amount is obtained, which is the adsorption coefficient of the mineral. This parameter is used to characterize the difference in adsorption capacity of different soil colloidal components to biological regulators, and is an important basic variable for the calculation of the adsorption interference index.

[0058] The carrier release sensitive factor refers to the change degree of the release behavior of a specific type of nanocarrier in different mineral environments relative to the blank control, which is used to describe the interference effect of mineral environment on the release rate of the carrier. The factor includes two core indicators: release starting time delay ratio: indicates the proportion relationship of the starting time of the release behavior of the carrier in the presence of target minerals relative to the blank control; maximum release rate change rate: indicates the reduction degree of the maximum release rate of the carrier in unit time in the target mineral environment relative to the blank control.

[0059] The experimental method comprises dispersing an equal amount of carriers in an artificial soil system constructed from target minerals, using water or buffer as the leaching medium, collecting sample liquid at set time intervals, and determining the concentration change of the released regulator. The starting release point and maximum release rate point are derived from the cumulative release curve, and the sensitivity factor parameter is calculated. This parameter is used to evaluate the regulatory ability of the soil environment on the release dynamics of the nano-carrier, and plays a key role in subsequent adsorption interference index construction, release path regulation and rhythm optimization.

[0060] To prevent the release "lock" or instantaneous burst phenomenon of plant-derived biological regulators in the high adsorption area, the present application provides a release rhythm control method based on responsive molecular block regulation, which gives the nano-carrier the ability of time delay, self-adaptive diffusion and environmental triggering in the soil microenvironment. This method adjusts through multi-level material structure, effectively improves the adaptability and utilization efficiency of the regulator in the complex rhizosphere environment while ensuring accurate delivery of the regulator. The specific implementation steps are as follows: around the time control requirements of the release window, select a block copolymer material with pH or enzyme response characteristics (such as polyacrylic acid-polyethylene glycol block, chitosan-gelatin copolymer, etc.) to construct the surface modification layer of the nano-carrier. Based on the target release delay time (such as starting delay of 6 hours) and duration (such as release maintenance of 48 hours), the flexible chain length of the block is designed. The chain length is set between 30-120 repeating units, and the conformational stability of the chain segment is evaluated by molecular dynamics simulation to confirm that it can maintain a closed state in neutral or weakly alkaline conditions, and undergo conformational relaxation and structure opening in a pH drop or enzyme catalytic environment, thereby serving as a "delay gate" for the release start mechanism.

[0061] After completing the chain length setting, introduce a controllable crosslinking monomer (such as bis-acrylamide, dextran aldehyde acid dialdehyde bond) into the responsive block to adjust its crosslinking density and control the release rate curve. Three types of carrier groups are constructed with typical crosslinking degrees of 0.5%, 1%, and 2% for comparative experiments, and the results show that the release rate of the high crosslinking structure in the rhizosphere simulation liquid is 1.8 μg / h, and the release duration is more than 60 hours; while the release rate of the low crosslinking structure is 5.2 μg / h, and the duration is less than 24 hours. Therefore, according to the application requirements, the crosslinking density combination is selected to realize the release adaptation of the regulator in the early stimulation or continuous action scenario of the root system.

[0062] On the basis of the release structure with the functions of starting and rate adjustment, specific response threshold parameters are set to realize the regional directional triggering release behavior. Taking a chitosan-based carrier as an example, the carrier only undergoes charge reversal and releases the load when the pH is below 5.5, and the response interval is determined to be pH 5.2-5.6 or an enzyme concentration greater than 0.4 U / mL through experiments in combination with the acidification depth of the target soil and the local root enzyme concentration. In the design of the block structure, the selective cleavage point is constructed according to the response interval, so that the release behavior only occurs when the set threshold condition is met, and the release process has regional specificity and environmental dependence.

[0063] In combination with the design of chain length configuration, the adjustment of crosslinking density and the setting of response threshold, the release rhythm full-link control scheme of the nano-carrier “delayed start-non-bursting-regional response” is completed. Through the construction of a soil simulation column experiment, the modified carrier is applied, and the cumulative release amount of the target regulator at the depths of 1 cm, 5 cm and 10 cm is monitored. The results show that the carrier with the rhythm control structure can complete more than 90% of the release within 48 hours, while avoiding the burst peak (instantaneous release rate <8% of total amount / h), and showing excellent release region limitation (release rate in non-target pH region is less than 10%). The rhythm control mechanism can be personalized parameter configured according to the actual soil partition characteristics, and provides a timing basis for the dynamic adjustment of the subsequent response path system.

[0064] In order to realize the spatial precise delivery and dynamic adaptive release of plant-derived biological regulators in complex soil microenvironments, the present application uses a combination of materials with different response mechanisms to construct a multifunctional release channel, and dynamically regulates the release behavior of each layer according to the soil environmental parameters, so as to maintain the balance of release efficiency and dose in the high-adsorption area or the release-limited area. The structure regulation process is as follows: based on the adsorption zoning result, the key indicators of the soil microenvironment in the plot are collected, including the pH value (sampling depth 0-10 cm), the soluble Ca 2+ and Mg 2+ concentration (analyzed by inductively coupled plasma mass spectrometry), and the conductivity (measured by electrode insertion method), which are standardized and converted into a three-dimensional regional response parameter matrix. Taking every 10x10m grid as a unit, a data array with spatial positioning and environmental gradient properties is formed. For each grid unit, trend analysis is performed according to the aforementioned indicators to construct a release-limited trend level (0-3 levels), wherein level 0 indicates normal release, and level 3 indicates serious release delay. The level result is used to guide the adaptive design of the response mechanism of the nano-carrier structure.

[0065] According to the environmental trend level, a three-level structure response system is constructed for the nanocarrier. The outer layer uses a pH-responsive coating formed by polyacrylic acid or carboxymethyl chitosan, which expands or disintegrates when the soil pH is less than 5.5 or higher than 8.0, opening the release channels. The middle structure introduces calcium phosphate nanosheets or montmorillonite intercalation, forming a structural channel with ion exchange capacity, which adjusts the release flux when the interlayer spacing expands when the Ca 2+ When the concentration is higher than 20 mg / L or Mg 2+ When the concentration exceeds 15 mg / L, the interlayer spacing expands, adjusting the release flux. The inner layer constructs a core region with a fixed charge distribution, such as by distributed negative charge groups (such as sulfonic acid or carboxyl) to induce the directional migration of the regulator along the potential gradient, achieving directional release bias. The three-layer structure has a synergistic response mechanism and can produce targeted regulation for different soil indicators.

[0066] Based on the establishment of the response structure, the arrangement order, thickness ratio, and response threshold of the multi-layer structure are quantitatively optimized by combining historical release data and residual distribution trajectories in the target area. In the experimental setup, the pH-responsive coating is set to a thickness of 50 nm, the middle ion-responsive layer is 80 nm, and the inner charge-guided structure is 40 nm, forming a 200 nm nanoparticle coating layer that controls the total particle size within the range of 300-500 nm. At the same time, by adjusting the cross-linking density and block molecular structure of the coating, the response starting point is accurately matched to the soil indicators. For example, adjusting the acetic acid cross-linking degree of carboxymethyl chitosan coating to 3.5% makes the release channel automatically open at pH < 5.4. The structure parameters are compared and calibrated through field tests to form a dynamic regulation model between soil response state and release behavior.

[0067] The multi-layer structure adjustment behavior is fused with the historical release behavior in the plot. The release completion rate, lag time, and local dose anomalies of the regulator in previous application cycles are used to assign more response channel numbers and preferential activation paths to high-release lag areas. For example, in areas where the lag time exceeds 24 hours, the outer layer response thickness is reduced by 20%, and the middle intercalation structure is expanded by 10%, allowing it to respond quickly at the beginning of application and make up for the dose gap. Conversely, in areas of excessive release, the inner fixed charge structure is thickened or the response threshold is raised to selectively close the response path and prevent excessive dosage. The above adjustment behavior constructs a dynamic spatial release mode with regional difference perception and spatial release adjustment capability, achieving self-adaptive balance of dosage in different areas.

[0068] To solve the problem of uneven local dose caused by adsorption locking or release imbalance of nano-carriers during the delivery of plant-derived biological regulators, the present application designs a compensation adjustment mechanism based on the nonlinear relationship between the porous structure and the environmental trigger signal, which enables the nano-carriers to have the ability of regional dose self-regulation in subsequent application, thereby realizing the correction of historical release deviation and spatial dose balance. The mechanism includes four stages of dose deviation identification, nonlinear response construction, compensation channel setting and release intensity dynamic correction, as follows: In the previous application process, the actual release data and the target application dose data of the regulator in each soil micro-zone are collected. Through rhizosphere nano-probes, carrier coding labels and fluorescence release tracking, the cumulative release amount (unit: mg / m2) of the regulator at each coordinate point (accuracy 0.5m x 0.5m) is obtained, and compared with the target application dose (such as the target value is 120mg / m2), the dose deviation rate of each region is calculated. Project the deviation rate into the spatial grid, and construct a continuously distributed dose deviation map using interpolation method. According to the set threshold value (±15%), the map is divided into three types of regions: excessive release area (deviation > 15%), insufficient release area (deviation <-15%) and normal release area (-15%-15%). The partition results are matched with the response path system of each carrier type and its distribution area, which are used to mark the areas that need to be adjusted in the next round of application.

[0069] In the marked areas that need to be adjusted, multiple controllable release channels are introduced to the nano-carrier structure, and different channel response parameter combinations are set for different channels. Each channel has a separate response trigger condition, such as channel A responds to pH below 5.5, channel B responds to Ca 2+The concentration is higher than 15 mg / L, and the response potential difference of channel C is greater than 25 mV. By adjusting the channel structure parameters (such as threshold film thickness, block molecular chain length, channel diameter), a nonlinear function relationship between environmental signal and release rate is established. Taking the pH response channel as an example, the release intensity R (unit: μg / h) and pH present an exponential decline relationship: R = R0 x exp(-k x (pH-YZ)). The construction of nonlinear relationship makes different channels present differential response effect in similar environment, forming the nonlinear distribution basis of spatial release intensity, wherein the release intensity R represents the mass of plant source biological regulator released by the nano carrier per unit time under a specific pH condition, and is obtained by dynamic diffusion release experiment, constant pH condition, and high performance liquid chromatography or fluorescence probe method for sampling and measuring regulator release rate at regular intervals. The reference release intensity R0 represents the standard release rate under the trigger threshold YZ, which is the "initial release intensity" or maximum response point of the response channel. Physical meaning: the channel starts to release when the pH just reaches the activation threshold, at which time the release behavior is most typical. Acquisition method: the average release rate is measured under the control condition of pH = YZ, k (response sensitivity coefficient) reflects the influence of pH on the change of release rate, which is the exponential coefficient in the model that determines the "speed of decline", the greater the value, the more sensitive the system is to pH change, and the more steep the release rate decreases; the smaller the value, the more "blunt" the release is, and the less sensitive it is to pH; acquisition method: through multi-point pH response experiment, the relationship curve of R and pH is fitted at different pH values, and the coefficient of the best exponential fitting curve is obtained. pH (current environmental pH value): the instantaneous pH value in the target soil microenvironment or rhizosphere environment, obtained by rhizosphere probe or experimental buffer solution. YZ (trigger threshold): the minimum starting pH value of the channel structure conformational transition (such as block expansion, chain segment unfolding, chemical bond dissociation), which is the "starting threshold" of the release, and is obtained by adjusting the environmental pH step by step, observing the minimum pH value at which the channel first opens or the regulator starts to release.

[0070] In combination with the dose deviation map, different types of regions are set with differential channel activation logic. In the release insufficient area, the response threshold of part of the channels is lowered by 10%-20%, for example, the pH trigger threshold is adjusted from 5.5 to 5.8, or the Ca 2+ The concentration response threshold is reduced from 15 mg / L to 12 mg / L, and at the same time, the local release amount is enhanced by reducing the channel closure density or prolonging the channel opening duration (such as 30%), so as to realize dose compensation. In the release excessive area, the response threshold and release duration are adjusted in the opposite direction, the response threshold is raised or the opening window is shortened, so as to reduce the cumulative dose and inhibit the formation of local hormone interference zone.

[0071] Finally, the compensation parameters are embedded in the structure code of the next round of nanocarriers, and regional matching is completed according to the field map before application. After the distribution of the carriers in the soil, the internal channel response structure is automatically adjusted to release behavior, realizing the dynamic repair of historical release anomalies. After three rounds of application period verification, the dose deviation of the excessive release area decreased from +22.6% to +4.8%, and the insufficient release area increased from -18.3% to -3.5%, indicating that the nonlinear compensation mechanism can effectively adjust the regional release anomaly, significantly improving the spatial balance and biological utilization rate of the nanometer delivery system.

[0072] To realize the cross-cycle closed-loop delivery control of plant-derived biological regulators in complex soil environment, the invention uses data samples from the coupling behavior among soil, plants and nanocarriers to train a deep learning model with spatial recognition ability, thereby optimizing the response structure parameters and dose timing configuration of the next application cycle. Based on the field data collection in multiple consecutive application cycles, through the deployment of fluorescence response type and potential response type nanoprobes in the plant root zone, the three-dimensional spatial distribution map of the regulator in the rhizosphere area (unit resolution 0.5m x 0.5m x 5cm) is obtained, and combined with photosynthesis rate, chlorophyll fluorescence parameters (such as Fv / Fm), root length density (unit cm / cm³), etc. Plant physiological response indicators, as well as carrier coding label release residual information and in-situ sampling soil adsorption parameters (such as local pH, cation exchange capacity, specific surface area, etc.), a training data set covering 200 grid units is constructed. Each grid unit data sample is stored in the form of a 3-dimensional matrix, containing 12 or more channels, combined to form a multi-channel tensor input, labeled as tensor dimension: [N, C, H, W], where N is the number of samples, C is the number of channels, H and W are spatial dimensions. To avoid data overfitting, the training set and the validation set are divided in the ratio of 8:2 to ensure representativeness.

[0073] The collected data tensor is input into a convolutional neural network structure with spatial feature extraction capability, where the first two layers are 3x3 convolution kernels with ReLU activation function to extract regulator distribution and environmental coupling features; the middle layer introduces a spatial pyramid pooling structure to enhance the model's learning ability for multi-scale response; the tail structure includes two fully connected layers for outputting the path response feature parameter set of the corresponding area in the next cycle. The parameter set includes: the opening threshold of each response channel (such as pH critical value, potential activation intensity), activation order (such as channel A prior to channel B), response structure layer arrangement (such as inner-outer-middle three-layer sequence) and its thickness ratio configuration (such as 20:60:20) and regulation window (such as activation duration), the output is a multi-label prediction set with dimension [Y1, Y2,..., Yn], Yn corresponds to n adjustable structure parameters.

[0074] The supervised learning method is used for training, and the target label is set as the "optimal response configuration" collected from the previous cycle test or simulation experiment, that is, the path structure parameter that can maximize the dose deviation correction and plant response improvement. The loss function is composed of mean square error (MSE) and cross-entropy loss, the former is suitable for continuous parameter adjustment (such as pore thickness ratio, response delay time), and the latter is suitable for discrete label (such as response sequence, structure arrangement). The weight is updated by the back propagation algorithm, 100 iterations per training iteration, the initial learning rate is set to 1e-3, and the momentum coefficient is 0.9. The early stopping strategy is set on the validation set, and the training is stopped when the accuracy improvement is less than 0.5% for 5 consecutive times. The final model has a prediction accuracy of more than 92.3% on the validation set, reaching the deployment standard.

[0075] Finally, the trained model is embedded into the delivery path design process. For the new round of soil-plant-carrier comprehensive environmental map before application, the new sample is input into the model to obtain the output path response feature parameter set, which is used as the basis for structure setting of this round of carrier manufacturing, and is fed back to the regulator release structure construction step to guide the response pore design, coating material selection and threshold setting, etc. The delivery path has the ability of self-adaptive adjustment across cycles. Three rounds of field verification show that the application strategy guided by the model reduces the variance of rhizosphere regulator spatial distribution by 35.6%, and the plant root length growth rate is increased by 18.4%, which is significantly better than the static structure carrier, verifying the model's ability to accurately predict the parameters of the delivery path in complex environments and the actual effect.

[0076] The above algorithms or formulas are dimensionless values, and the results of the latest real situation are obtained by collecting a large amount of data for software simulation. The preset parameters are set by a person skilled in the art according to the actual situation.

[0077] It should be understood that the size of the sequence number of the above-mentioned processes in various embodiments of the present application does not mean the order of execution, and the execution order of the processes should be determined according to their functions and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0078] Those skilled in the art can realize that the units and algorithm steps of the examples described in combination with the embodiments disclosed herein can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are executed in hardware or software depends on the specific application and design constraints of the technical solution. A person skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0079] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described devices and units can refer to the corresponding processes in the foregoing method embodiments, and will not be described here.

[0080] The above merely describes specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present application, which should be encompassed in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for delivering plant-derived bioregulators based on nanocarriers, characterized in that, Includes the following steps: Construct a distribution map of soil colloidal minerals, obtain mineral types, distribution ranges and adsorption intensities through high-throughput soil spectral acquisition methods, identify high adsorption areas and low release areas, and complete the delineation of risk areas before application; Surface ligand structure modification is performed on nanocarriers located in the high adsorption region to introduce desorbable molecular blocks with pH-responsive or enzyme-responsive properties, thereby controlling the release rhythm after adsorption and avoiding dose lock-in. Based on the division of adsorption regions and historical release data, the structure of the nanocarrier is regulated in multiple levels to dynamically adjust the release path and balance local dose differences through regional inhibition and nonlinear compensation. During application, fluorescent or potentiometric nanoprobes are deployed near plant roots to collect data on the spatial distribution of regulators in the rhizosphere and plant physiological responses. The data are then combined with carrier release behavior and soil adsorption characteristics to model the next delivery strategy and complete the closed-loop delivery control of regulators across cycles. Specifically, during the application process, based on the distribution data of rhizosphere spatial regulators, plant physiological response signals, nanocarrier release state and soil adsorption parameters collected by fluorescent or potentiometric nanoprobes over multiple application cycles, a training set and a validation set containing multiple environmental variables are constructed to train a convolutional neural network model with spatial feature recognition capabilities. The model input consists of an image or tensor composed of collected multi-channel data, reflecting the coupling state of the soil-plant-carrier system within the current micro-region. The model output is a set of path response characteristic parameters that the region needs to adjust under stress conditions in the next application cycle, including the opening threshold, activation order, response layer arrangement structure and its adjustment parameters for each release channel. During training, the backpropagation algorithm is used to update the weights, and the output results are corrected by the mean squared error or cross-entropy loss function until the prediction accuracy of the validation set reaches the set threshold, forming a convolutional neural network model with generalization ability, which is then used to optimize the next round of delivery strategy. Multilevel regulation of nanocarrier structures includes: Based on the adsorption zone division results, the soil microenvironment indicators in the plot are transformed into a quantifiable regional response parameter matrix to determine the trend level of carrier release restriction or overload in different regions. A pH-responsive coating is introduced into the outer layer of the nanocarrier, and calcium phosphate or montmorillonite intercalation structures with ion exchange capacity are introduced into the middle structure. The release direction shift is adjusted by fixing the charge distribution in the inner layer. By adjusting the arrangement order, thickness ratio and threshold response range of each response layer, a response path system with regional resolution is constructed.

2. The method for delivering plant-derived bioregulators based on nanocarriers according to claim 1, characterized in that, Photosensitive or magnetically responsive markers are placed on the outside of the nanocarrier to identify the release state and distribution trajectory of the carrier during historical application.

3. The method for delivering plant-derived bioregulators based on nanocarriers according to claim 2, characterized in that, The steps for constructing a soil colloidal mineral distribution map include: Systematic sampling was conducted on the target agricultural plots according to the preset grid size. The composition content of various colloidal minerals in the samples was quantitatively verified. A fitting model between spectral bands and mineral composition was established to estimate the colloidal mineral types and spatial distribution in each grid unit of the plot. Based on the results of mineral type and component content, a mineral type adsorption coefficient database was constructed, and a carrier release sensitive factor database was established simultaneously. The mineral type adsorption coefficient and carrier release sensitive factor were integrated according to a preset ratio to form an adsorption interference index, which is used to describe the interference intensity of specific soil units on the release behavior of nanocarriers. The adsorption interference index is projected onto a spatial grid, and the grid is divided into zones and classified according to the set interference intensity threshold. At the same time, preset types of topographic and hydrological parameters are introduced to filter the connectivity of high-interference grids, identify contiguous high-risk areas, and finally mark high adsorption areas and low release areas with spatial overlay and boundary tracking algorithms to complete the risk area delineation.

4. The method for delivering plant-derived bioregulators based on nanocarriers according to claim 3, characterized in that, The mineral type adsorption coefficient refers to the maximum adsorption capacity of a unit mass of colloidal mineral for plant-derived bioregulators. It is obtained through isothermal adsorption experiments. The carrier release sensitivity factor reflects the degree of release delay of different nanocarriers in their respective mineral environments, and is expressed as the release start time delay ratio or the rate of change of maximum release rate.

5. The method for delivering plant-derived bioregulators based on nanocarriers according to claim 4, characterized in that, Controlling the release rhythm refers to: For responsive molecular blocks on the surface of nanocarriers, the time delay and release duration parameters required for the target release window are set. By adjusting the chain length of the block molecules, the conformational stability and steric hindrance effect before being triggered by pH or enzyme signals are controlled, thus delaying the release initiation point. By regulating the crosslinking density in the molecular blocks, the melting rate and load diffusion rate of the support can be adjusted in response to environmental changes. By setting response threshold parameters to limit the pH range or enzyme concentration limits, the release behavior is ensured to be initiated only when the target soil microenvironment conditions are met, thus forming a specific release pathway for the target area.

6. The method for delivering plant-derived bioregulators based on nanocarriers according to claim 5, characterized in that, pH-responsive coatings are made of polyacrylic acid or carboxymethyl chitosan.

7. The method for delivering plant-derived bioregulators based on nanocarriers according to claim 6, characterized in that, Nonlinear compensation refers to: Based on the deviation comparison between the actual release data of each soil area during the previous application process and the target application dose, a spatial dose deviation map is constructed to identify local over-release areas and under-release areas, and to label and match the release status of the corresponding areas in the response path system. Multiple controllable release channels are set in the nanocarrier structure, which respond to different environmental parameter trigger thresholds. By adjusting the opening conditions and activation order of each release channel, a nonlinear mapping relationship between local environmental signals and release intensity is established. In areas of insufficient release, logic is set to activate release early; in areas of excessive release, activation is delayed or the release rate is limited, forming a spatially dynamic differentiated control strategy.

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