A growth hormone functionalized nanocarrier, and a preparation method and application thereof

Abstract

The application provides an auxin functionalized nanocarrier and a preparation method and application thereof, and relates to the technical field of plant disease and pest control. The nanocarrier comprises a nanostructure core and a signal molecule on the surface of the nanostructure core, wherein the signal molecule is a plant auxin or an analogue thereof. By constructing an auxin signal interface on the surface of the nanocarrier, the nanocarrier can be recognized outside plant cells and regulate the endogenous polar transport system in plants, so that the nanocarrier is driven to migrate along the transport path in the plant body in a directional manner, and long-distance delivery from the aboveground part to the root or target tissue is achieved. The nanocarrier can load pesticides or other functional components, and underground target control can be achieved through foliar application. Compared with the prior art, the auxin functionalized nanocarrier provided by the application can significantly improve the utilization efficiency of active ingredients, reduce the pesticide application amount, and improve the control effect and ecological safety.

Description

Technical Field

[0001] This invention relates to the field of plant disease and pest control technology, and in particular to a auxin-functionalized nanocarrier, its preparation method, and its application. Background Technology

[0002] Existing pesticides and functional molecules have low delivery efficiency in plants, especially for root targets (such as root-knot nematodes). Traditional application methods mainly rely on soil irrigation or foliar spraying, making it difficult for active ingredients to effectively reach underground tissues, resulting in low pesticide utilization and serious environmental pollution.

[0003] Although nanocarrier technology can improve the stability and slow-release properties of pesticides, most nanomaterials have limited migration ability in plants and are difficult to enter the vascular system for long-distance transport, usually remaining on the leaf surface or cell wall region.

[0004] Plants possess a polar transport system centered on endogenous auxin, enabling long-distance directional transport. However, current technology lacks artificial nanocarrier systems capable of coupling with this endogenous transport system.

[0005] Therefore, developing a nanocarrier capable of directional migration using plant endogenous transport mechanisms is of great significance for improving pesticide utilization efficiency and realizing precision agriculture. Summary of the Invention

[0006] Therefore, the purpose of this invention is to propose an auxin-functionalized nanocarrier, its preparation method and application. By constructing an auxin signaling interface on the surface of the nanocarrier, it can be recognized and driven by the plant's endogenous polar transport system, thereby realizing long-distance directional transport and targeted enrichment of active ingredients in the plant.

[0007] The technical solution of this invention is implemented as follows: In a first aspect, the present invention provides an auxin-functionalized nanocarrier, the auxin-functionalized nanocarrier comprising porous nano-starch and a shell encapsulating the porous nano-starch; The shell is obtained by covalently grafting signal molecules onto chitin derivatives; The signaling molecules are auxins and / or auxin-like substances; the signaling molecules are distributed on the surface of the nanocarrier in an exposed state, and are used to interact with receptors in the extracellular environment of plants, thereby regulating the endogenous polar transport pathways of plants and driving the nanocarriers to migrate directionally along the transport direction in the plant; the auxin-like substances are naphthaleneacetic acid or indolebutyric acid; The average particle size of the nanocarrier is 30-100 nm, preferably 50-60 nm, in order to limit or avoid endocytosis within plant cells and maintain its transport state in the extracellular space.

[0008] The chitin derivative is chitosan oligosaccharide and / or chitosan.

[0009] Preferably, the shell is prepared by covalently grafting a signal molecule onto a chitin derivative via an EDC / NHS system; The mass ratio of the porous nano starch to the shell is 1~2:1~2; The porous nano starch is used to load active ingredients to obtain a nanocarrier core; The active ingredient is selected from at least one of pesticides, nucleic acids, proteins, or plant regulators.

[0010] In a second aspect, the present invention provides a method for preparing the auxin-functionalized nanocarrier as described above, comprising the following steps: S1: In a reaction medium with a pH of 4.5 to 6.5, the signal molecule is covalently grafted onto the chitin derivative through an EDC / NHS system to obtain the shell. In one specific embodiment of the present invention, the reaction medium with a pH of 4.5 to 6.5 is MES (2-morpholinoethanesulfonic acid) buffer. In another specific embodiment of the present invention, the EDC / NHS system typically uses a pH 5.5 MES buffer. In yet another specific embodiment of the present invention, the EDC concentration in the EDC / NHS system is 0.02 to 0.05 M, and the NHS concentration is 0.01 to 0.04 M. S2: Blend porous nano starch and shell, collect the precipitate, and obtain the auxin-functionalized nanocarrier.

[0011] Preferably, the method for preparing the porous nano starch includes the following: (1) Dissolve starch in an organic solvent, add ethanol for shearing, collect the precipitate, and obtain pretreated starch; (2) Dissolve the pretreated starch in a buffer solution with a pH of 4.5 to 6.5, add a compound enzyme for hydrolysis, collect the precipitate, and obtain the porous nano starch; Add 5-20 μL of compound enzyme to every 2-10 g of starch; the enzymatic hydrolysis time is 2-10 h. The complex enzyme is α-amylase and / or amylase; The organic solvent is dimethyl sulfoxide.

[0012] Preferably, in step S1, the mass ratio of the signal molecule to the chitin derivative is 1~5:3~4; In the EDC / NHS system, the EDC concentration is 0.02~0.05 M and the NHS concentration is 0.01~0.04 M; The reaction temperature for covalent grafting is 20~26℃, and the reaction time is 5~50 h; in a specific embodiment of the present invention, the reaction is carried out at room temperature, where room temperature refers to the range of 20~26℃.

[0013] Preferably, in step S2, porous nano starch and shell are blended and dissolved in a buffer solution with a pH of 4.5 to 6.5, and the shell encapsulates the porous nano starch through electrostatic interaction.

[0014] A third aspect of the present invention provides the application of auxin-functionalized nanocarriers in the preparation of nanopesticides; wherein the auxin-functionalized nanocarrier is the auxin-functionalized nanocarrier described above, or the auxin-functionalized nanocarrier prepared by the above preparation method.

[0015] Preferably, the signaling molecules constructed on the surface of the auxin-functionalized nanocarrier enable the nanopesticide to be recognized and driven by the plant's endogenous polar transport system, thereby enabling the pesticide active ingredients to be transported, targeted, or delivered over long distances within the plant.

[0016] A fourth aspect of the present invention provides a nanopesticide, the nanopesticide comprising the above-mentioned auxin-functionalized nanocarrier and a pesticide loaded on the auxin-functionalized nanocarrier, or the auxin-functionalized nanocarrier prepared by the above-mentioned preparation method and a pesticide loaded on the auxin-functionalized nanocarrier. Porous nano starch was used to load pesticides to obtain the core of the auxin-functionalized nanocarrier; The pesticide is selected from at least one of abamectin, fluopyram, and thiazophos. Pesticides are blended with porous nano starch in solution form, so that the pesticides are physically loaded into the structure of the porous nano starch.

[0017] In one specific embodiment of the present invention, abamectin is loaded onto porous nano starch. The abamectin is dissolved in an organic solvent and blended with the porous nano starch. A suitable organic solvent can be selected according to the characteristics of the pesticide. In addition, fluopyram and thiazophos can also be blended with porous nano starch in solution form, so that they are physically loaded into the structure of porous nano starch, respectively, to obtain the core of auxin-functionalized nanocarriers loaded with fluopyram and thiazophos, which can be used to realize long-distance directional transport and targeted enrichment of fluopyram and thiazophos in plants.

[0018] A fifth aspect of the present invention provides a method for targeted transport of a target component within a plant, comprising applying an auxin-functionalized nanocarrier prepared by the above-described preparation method and a target component loaded on the auxin-functionalized nanocarrier to the above-ground parts of a plant, thereby causing the target component to migrate to the roots and / or target tissues via the plant's endogenous transport system. The target ingredient is selected from at least one of the following: insecticide, acaricide, fungicide, herbicide, plant growth regulator, fertilizer, nucleic acid molecule or protein.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: The auxin-functionalized nanocarrier provided by this invention can achieve long-distance directional transport of target active ingredients within plants and increase root accumulation by ≥5 times. Using the auxin-functionalized nanocarrier can significantly improve the utilization rate of active ingredients; experiments show that when pesticides are selected as active ingredients, the amount of pesticide used can be reduced by ≥30%. Furthermore, the auxin-functionalized nanocarrier can achieve underground target control through foliar application, effectively improving the control of pests and diseases, reducing environmental toxicity, enhancing ecological safety, and simultaneously promoting plant growth and further increasing yield.

[0020] The auxin-functionalized nanocarrier provided by this invention can achieve a non-endocytosis mechanism through size control, which greatly improves the biocompatibility and controllability of the carrier. Attached Figure Description

[0021] Figure 1 The image shows a scanning electron microscope (SEM) image of AVM@IAA-7 NPs prepared in Example 1 of this invention.

[0022] Figure 2 The image shows a scanning electron microscope (SEM) image of AVM@IAA-13 NPs prepared in Example 1 of this invention.

[0023] Figure 3 This is a scanning electron microscope image of AVM@IAA-18 NPs prepared in Example 1 of the present invention.

[0024] Figure 4 This is a scanning electron microscope image of AVM@IAA-20 NPs prepared in Example 1 of the present invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0026] Unless otherwise specified, the experimental methods used in the embodiments of this invention are all conventional methods.

[0027] Unless otherwise specified, all materials and reagents used in the embodiments of this invention are commercially available.

[0028] EDC, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride; NHS, N-hydroxysuccinimide; IAA, auxin; NPA, naphthyl-o-carbamoylbenzoic acid.

[0029] Chitosan oligosaccharide was purchased from Beijing Innocare Technology Co., Ltd.

[0030] Example 1 - Preparation of auxin-functionalized nanocarriers (1) Preparation of porous nano starch Starch was dissolved in an organic solvent and treated under heating conditions. Porous nano-starch particles were then obtained through precipitation and enzymatic hydrolysis. Specifically, corn starch (5 g) was dissolved in dimethyl sulfoxide (50 mL) at 90 °C, and ethanol (500 mL) was added dropwise for high-speed shear precipitation (10000 rpm, 3 min). After freeze-drying, the product was dissolved in disodium hydrogen phosphate-citrate buffer (50 mL, pH 5.5), and 10 μL of α-amylase (4000 U / g) and amyloglucosidase (5000 U / g) were added for hydrolysis for 6 h. The product was purified by centrifugation (12000 rpm, 10 min), washing, and vacuum drying.

[0031] (2) Active ingredient loading 500 mg of abamectin was dissolved in 50 mL of ethyl acetate and then mixed with 50 mg of porous nano starch. The mixture was magnetically stirred at 300 rpm for 12 h to allow it to be physically loaded into the porous structure.

[0032] (3) Auxin modification In a 50 mL MES buffer at pH 5.5, IAA (53 mg, 88 mg, 140 mg, 175 mg) was covalently grafted onto chitosan oligosaccharide (161 mg, molecular weight ≤2000) via an EDC / NHS-mediated amidation reaction (EDC: 287.5 mg, 1.5 mmol; NHS: 119 mg, 1 mmol). The reaction was carried out at room temperature for 24 hours, followed by dialyzing and lyophilization to obtain IAA-grafted chitosan oligosaccharide.

[0033] (4) Assembly Porous starch nanoparticles (50 mg) loaded with active ingredients were mixed and dissolved with IAA-grafted chitosan oligosaccharide (50 mg) in 50 mL of MES buffer at pH 5.5. The mixture was magnetically stirred at 300 rpm for 12 h. The auxin-functionalized nanocarriers were collected by centrifugation, washed and dried, and were named AVM@IAA-7 NPs (IAA dosage 53 mg), AVM@IAA-13 NPs (IAA dosage 88 mg), AVM@IAA-18 NPs (IAA dosage 140 mg), and AVM@IAA-20 NPs (IAA dosage 175 mg).

[0034] Example 2 - Performance Parameter Testing Test Method: The mean hydrodynamic diameter and polydispersity index (PDI) of the nanocarriers were determined using dynamic light scattering. The instrument was a Malvern Zetasizer Nano ZS90 (Malvern Panalytical, UK), with a scattering angle of 90° and a test temperature of 25 ℃. Samples were diluted with ultrapure water to a suitable concentration, gently mixed, and allowed to stand for 5 min to eliminate air bubbles. Approximately 1 mL of sample was added to a disposable polystyrene cuvette, and the measurement was started after equilibration for 2 min. Each sample was measured three times consecutively, with at least 10 measurement cycles per cycle. The average of the three measurements was taken as the final result. Data analysis was performed using the instrument's accompanying Zetasizer software, and the results are expressed as mean hydrodynamic diameter and polydispersity index (PDI).

[0035] The Zeta potential of the nanocarrier was determined using electrophoretic light scattering. The instrument used was a Malvern Zetasizer Nano ZS90 (Malvern Panalytical, UK). Samples were diluted with ultrapure water to the appropriate concentration, gently mixed, and allowed to stand to remove air bubbles. A suitable amount of sample was added to a disposable folded capillary electrophoresis cell (DTS1070) and measured at 25 °C with an equilibration time set to 120 s. Each sample was measured in triplicate, with at least 10 measurement cycles per cycle, and the average value was taken as the final result. Data were automatically analyzed using Zetasizer software, and the Zeta potential was calculated using the Smoluchowski model.

[0036] The morphology of the nanocarriers was observed using transmission electron microscopy (TEM). The instrument used was a JEOL JEM-2100F (Japan Electronics Corporation). After appropriate dilution, a small amount of sample was dropped onto a copper mesh carbon film and allowed to dry naturally at room temperature. Once the sample was completely dry, it was observed and images were acquired under an accelerating voltage of 200 kV to analyze the morphology and particle size distribution characteristics of the nanocarriers.

[0037] The in vitro drug release behavior of nanocarriers was investigated using dialysis. A certain amount of drug-loaded nano-formulation was placed in a pretreated dialysis bag, sealed, and then placed in an Erlenmeyer flask containing an appropriate amount of release medium. Release experiments were conducted under constant temperature and shaking conditions at 25 °C. At preset time points, a certain volume of release medium was removed, and an equal volume of fresh release medium was added to maintain a constant volume of the release system. After appropriate processing, the samples were analyzed using high-performance liquid chromatography (HPLC) to determine the concentration of avermectin, which was used to calculate the drug loading, release rate, and root enrichment factor. A C18 column was used, and the detection wavelength was 245 nm.

[0038] The performance of the auxin-functionalized nanocarriers (AVM@IAA-20 NPs) was tested, and the results are as follows: (1) The average particle size is about 55 nm and the PDI is 0.18; (2) The Zeta potential is -3.2 mV; (3) The grafting density of auxin is approximately 0.5 mmol / g; (4) The drug loading is approximately 41%; (5) The release rate is approximately 90% after 48 hours under acidic pH 5.0 conditions; (6) The enrichment factor of the loaded effective components in the roots is about 10 times; Depend on Figures 1-4 The results show that the auxin-functionalized nanocarrier provided by the present invention, with a particle size controlled in the range of 50–60 nm, can effectively avoid endocytosis, maintain extracellular transport, and exhibit good delivery performance.

[0039] Comparative Example 1 - Preparation of Nanocarriers (1) Preparation of porous nano starch Corn starch (5 g) was dissolved in dimethyl sulfoxide (50 mL) at 90 °C, and precipitated by high-speed shearing (10000 rpm, 3 min) with ethanol (500 mL) added dropwise. After freeze-drying, the product was dissolved in disodium hydrogen phosphate-citrate buffer (50 mL, pH 5.5), and hydrolyzed for 6 h with 10 μL of α-amylase (4000 U / g) and amyloglucosidase (5000 U / g). The product was purified by centrifugation (12000 rpm, 10 min), washing, and vacuum drying.

[0040] (2) Active ingredient loading 500 mg of abamectin was dissolved in 50 mL of ethyl acetate and then mixed with 50 mg of porous nano starch. The mixture was magnetically stirred at 300 rpm for 12 h to allow it to be physically loaded into the porous structure.

[0041] (3) Assembly Porous starch nanoparticles (50 mg) loaded with active ingredients were mixed and dissolved in 50 mL of MES buffer at pH 5.5. The mixture was magnetically stirred at 300 rpm for 12 h. The nanocarriers were collected by centrifugation, washed and dried, and denoted as IAA-0 NPs.

[0042] Example 3 - Plant Transport Experiment Experimental Methods: Tomato seedlings (20 days old) with uniform growth were used. Different samples were applied to leaves (5 mL) according to the formulations in Table 1. Specifically, NPA (10 µM) was physically mixed with avermectin-loaded auxin-functionalized nanocarriers (AVM@IAA-20NPs) (avermectin concentration 100 μg / mL) and applied to the leaves. IAA (2 μg / mL) was physically mixed with nanocarriers (IAA-0 NPs) (avermectin concentration 100 μg / mL) and applied to the leaves. The remaining auxin-loaded auxin-functionalized nanocarriers (AVM@IAA-7 NPs, AVM@IAA-13 NPs, AVM@IAA-18 NPs, AVM@IAA-20 NPs) and nanocarriers (IAA-0 NPs) were applied to the leaves individually. After tissue extraction at different time points, the avermectin content in leaves, stems, and roots was determined by high-performance liquid chromatography (HPLC).

[0043] When auxin-functionalized nanocarriers were sprayed onto plant leaves, they migrated to the stem in a short period of time and then accumulated in the roots, resulting in a maximum increase of 72.32-fold in root accumulation at the centimeter scale for leaf-to-root directional transport. When a polar transport inhibitor was added, this transport significantly decreased, indicating that transport is dependent on the auxin pathway.

[0044] Table 1. Residual levels of auxin-functionalized nanocarriers loaded with avermectin in different plant parts under different treatments.

[0045] Example 4 - Prevention and Control Application Experimental Methods: Pot Experiment. 1.5 kg of air-dried, steam-sterilized soil (sand / nursery soil, 1:1, v / v) was added to 10.5 × 7 × 7.5 cm plastic pots. Uniformly growing tomato seedlings (20 days old) were selected. The next day, three 6-8 cm deep holes were drilled around the base of each tomato plant, and 600 second-instar root-knot nematode larvae were inoculated. The auxin-functionalized nanocarrier (AVM@IAA-20 NPs) was applied foliarly (50 mg·L⁻¹). -1 5 mL), with ivermectin (10 mg·L⁻¹) -1 A 50 mL root drenching solution served as a positive control, while water served as a blank control. Each group had five replicates, and the treatment was administered only once. Seedlings were planted in a greenhouse and received routine water and fertilizer management. Root knot counts were recorded after 60 days to calculate the control effect.

[0046] Field Experiment: The field experiment was conducted at the experimental farm of the College of Tropical Agriculture and Forestry, Hainan University (N19°30′25″, E109°28′54″). The soil at the experimental site was clay loam with a pH of 5.96±0.09 and an organic matter content of 7.81±0.29 g / kg. Root-knot nematode infection had been recorded at this site. All treatments used a randomized block design with three replicates per treatment. Each plot was 6 m × 10 m in size, and 60 plants were planted per treatment (20 plants per plot). The auxin-functionalized nanocarrier (AVM@IAA-20 NPs) was applied foliarly at a dose of 50 mg·L⁻¹. -1 10 mL), with avermectin (10 mg·L⁻¹) -1 A root irrigation of 100 mL was used as a positive control, while water served as a blank control. Treatments were administered every 15 days for a total of two treatments. All plots followed standardized agronomic practices; irrigation was carried out according to local agricultural practices to maintain adequate soil moisture; and fertilization was performed according to routine management protocols to ensure normal crop growth. Root knot counts were recorded after 60 days to calculate the control effect.

[0047] The auxin-functionalized nanocarriers (AVM@IAA-20 NPs) were used to control root-knot nematodes. Through foliar application, abamectin was efficiently delivered to the roots, achieving a 79.71% control rate in indoor potted plants and a 60.71% control rate in the field, while reducing pesticide input by half.

[0048] Table 2. Effects of auxin-functionalized nanocarriers loaded with avermectin on auxin control in pot experiments

[0049] Table 3. Control efficacy of auxin-functionalized nanocarriers loaded with avermectin in field trials

[0050] Example 5 - Safety Evaluation Test method: Acute toxicity of earthworms was assessed using artificial soil assays according to OECD 207 guidelines.

[0051] Soil biological tests showed that its toxicity was 3.2 times lower than that of commercial pesticide formulations, and its environmental safety was higher.

[0052] Table 4. Results of acute toxicity assay of auxin-functionalized nanocarriers loaded with avermectin to earthworms.

[0053] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. An auxin-functionalized nanocarrier, characterized in that, The auxin-functionalized nanocarrier includes porous nano-starch and a shell encapsulating the porous nano-starch. The shell is obtained by covalently grafting signal molecules onto chitin derivatives; The signaling molecules are auxins and / or auxin-like molecules; The chitin derivative is chitosan oligosaccharide and / or chitosan.

2. The auxin-functionalized nanocarrier according to claim 1, characterized in that, The shell is prepared by covalently grafting signal molecules onto chitin derivatives via an EDC / NHS system. The mass ratio of the porous nano starch to the shell is 1~2:1~2; The porous nano starch is used to load active ingredients to obtain a nanocarrier core; The active ingredient is selected from at least one of pesticides, nucleic acids, proteins, or plant regulators.

3. A method for preparing an auxin-functionalized nanocarrier as described in claim 1 or 2, characterized in that, Includes the following steps: S1: In a reaction medium with a pH of 4.5 to 6.5, the signal molecule is covalently grafted onto the chitin derivative through an EDC / NHS system to obtain the shell. S2: Blend porous nano starch and shell, collect the precipitate, and obtain the auxin-functionalized nanocarrier.

4. The method for preparing auxin-functionalized nanocarriers according to claim 3, characterized in that, The method for preparing the porous nano starch includes the following: (1) Dissolve starch in an organic solvent, add ethanol for shearing, collect the precipitate, and obtain pretreated starch; (2) Dissolve the pretreated starch in a buffer solution with a pH of 4.5 to 6.5, add a compound enzyme for hydrolysis, collect the precipitate, and obtain the porous nano starch; Add 5-20 μL of compound enzyme to every 2-10 g of starch; the enzymatic hydrolysis time is 2-10 h. The complex enzyme is α-amylase and / or amylase; The organic solvent is dimethyl sulfoxide.

5. The method for preparing auxin-functionalized nanocarriers according to claim 3, characterized in that, In step S1, the mass ratio of the signal molecule to the chitin derivative is 1~5:3~4; In the EDC / NHS system, the EDC concentration is 0.02~0.05 M and the NHS concentration is 0.01~0.04 M; The reaction time for covalent grafting is 5 to 50 hours.

6. The method for preparing auxin-functionalized nanocarriers according to claim 3, characterized in that, In step S2, porous nano starch and shell are blended and dissolved in a buffer solution with a pH of 4.5 to 6.

5. The shell encapsulates the porous nano starch through electrostatic interaction.

7. The application of an auxin-functionalized nanocarrier in the preparation of nanopesticides; wherein the auxin-functionalized nanocarrier is the auxin-functionalized nanocarrier as described in claim 1 or 2, or the auxin-functionalized nanocarrier prepared by the preparation method described in any one of claims 3 to 6.

8. The application according to claim 7, characterized in that, The signaling molecules constructed on the surface of the auxin-functionalized nanocarrier enable the nanopesticide to be recognized and driven by the plant's endogenous polar transport system, thereby enabling the pesticide's active ingredients to be transported, targeted, or delivered over long distances within the plant.

9. A nano-pesticide, characterized in that, The nanopesticide includes the auxin-functionalized nanocarrier as described in claim 1 or 2 and the pesticide loaded on the auxin-functionalized nanocarrier, or the auxin-functionalized nanocarrier prepared by the preparation method described in any one of claims 3 to 6 and the pesticide loaded on the auxin-functionalized nanocarrier. Porous nano starch was used to load pesticides to obtain the core of the auxin-functionalized nanocarrier; The pesticide is selected from at least one of abamectin, fluopyram, and thiazophos. Pesticides are blended with porous nano starch in solution form, so that the pesticides are physically loaded into the structure of the porous nano starch.

10. A method for targeted transport of a target component within a plant, characterized in that, The method includes applying the auxin-functionalized nanocarrier prepared by the preparation method according to any one of claims 3 to 6 and the target component loaded on the auxin-functionalized nanocarrier to the aboveground parts of a plant, so that the target component is migrated to the roots and / or target tissues through the plant's endogenous transport system. The target ingredient is selected from at least one of the following: insecticide, acaricide, fungicide, herbicide, plant growth regulator, fertilizer, nucleic acid molecule or protein.

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