32 results about "Membrane lipids" patented technology

The invention discloses a targeted delivery method of a plant-derived biological regulator, and relates to the technical field of bioengineering, and the targeted delivery method comprises the following steps: in the application process of an electroporation technology, monitoring and acquiring cell membrane lipid change data information in real time through a biosensor technology; the method comprises the following steps: preprocessing original data acquired by a biosensor, and organizing and storing the preprocessed data according to rules to form a structured data set; the system can accurately control the state of the plant cell membrane by monitoring the lipid change of the cell membrane in real time and combining intelligent evaluation and dynamic adjustment of the electric field parameters. When membrane lipid is oversaturated, the electric field intensity and the pulse frequency are dynamically adjusted, membrane damage is reduced, cell integrity is protected, and meanwhile effective delivery of allogenic materials is ensured. According to the method, the stability and the accuracy of an electroporation technology are improved, the targeted delivery of the plant-derived biological regulator is optimized, and the application potential of the plant-derived biological regulator in the fields of agriculture and biomedicine is expanded.

The invention discloses a functional lipid compound for nano-liposome wrapping and a preparation method, and relates to the technical field of functional lipid compounds, the functional lipid compound comprises (a) a polyphenol-lipid covalent conjugate which is composed of a polyphenol active unit selected from curcumin, dihydroquercetin or derivatives thereof, and (b) a lipid covalent conjugate which is composed of a polyphenols active unit selected from curcumin, dihydroquercetin or derivatives thereof and a polyphenols active unit selected from curcumin, dihydroquercetin or derivatives thereof; the conjugate is covalently linked to a phosphatidyl ethanolamine or cholesterol skeleton through a cleavable linking group, and the conjugate can be integrated into a nano-liposome membrane and has the functions of structural support and biological activity; (b) a microenvironment-responsive functional phospholipid, which is a phospholipid derivative having a functional group responsive to an inflammatory microenvironment specific stimulus modified on a hydrophilic head group or a hydrophobic chain of a phospholipid molecule, the specific stimulus being selected from local pH < = 6.5, reactive oxygen species (ROS) concentration > = 10 [mu] M or matrix metalloproteinase MMP-2 / 9 overexpression; and (c) a bionic exosome membrane lipid component, wherein the bionic exosome membrane lipid component comprises sphingosine-based glycolipid or sulfated cholesterol separated from the plant-derived exosome.

The invention discloses a preparation method of a high-activity mitochondrial targeting MAPS polypeptide preparation, and relates to the technical field of biologication.The preparation method comprises the steps of S1, polypeptide design and synthesis, S2, thiol oriented cross-linking, S3, cutting and purification, S4, liposome assembly and S5, freeze-drying preparation molding.The preparation method has the advantages that by designing an amphipathic alpha-spiral polypeptide structure, the high-activity mitochondrial targeting MAPS polypeptide preparation is obtained; a stable helical conformation is spontaneously formed in a physiological environment by utilizing the alternative arrangement characteristic of hydrophobic and hydrophilic residues; the hydrophobic surface of the conformation can effectively interact with the mitochondrial membrane lipid bilayer, so that the transmembrane resistance is reduced; meanwhile, the hydrophilic surface is combined with the high negative membrane potential of the mitochondrial inner membrane through charge interaction to form a directional driving effect, so that the active transfer efficiency of the polypeptide under the mitochondrial membrane potential is remarkably improved; in addition, the integrated mitochondrial positioning signal further specifically recognizes the mitochondrial outer membrane transporter, the polypeptide is assisted to be accurately anchored to the targeting site, and non-specific diffusion is reduced.

The invention relates to a genetically engineered bacterium with high capric acid tolerance as well as a construction method and application of the genetically engineered bacterium. The genetically engineered bacterium takes escherichia coli as a starting strain, an aaS gene is knocked out, and meanwhile, a mla Z gene and a mla Y gene are overexpressed; wherein the Gene ID (Identity) of the nucleotide sequence of the aaS gene is 947315; the Gene ID (Identity) of the nucleotide sequence of the mla Z gene is 882402; and the Gene ID (Identity) of the nucleotide sequence of the mla Y gene is 882401. The aaS gene in the escherichia coli is knocked out, and the mla Z and mla Y genes are overexpressed at the same time, so that the membrane lipid strength of the escherichia coli engineering bacteria is effectively enhanced, and the genetically engineered bacteria show better robustness and higher tolerance in the fermentation process of a high-concentration substrate capric acid. When the capric acid is fed to the maximum concentration of 3.0 g / L, the yield of the trans-2-decenoic acid can reach 1.47 g / L, the conversion rate is 49.13%, and the yield is remarkably improved.

The present disclosure relates to the field of biotechnology, and in particular to method for modifying a high-yield L-lysine-producing strain engineering and application thereof. The present disclosure provides a recombinant strain obtained by knocking out the cbrB gene and / or the cbrC gene in the genome of E. coli. Fermentation of the recombinant strain can increase the yield and conversion rate of L-lysine and reduce the mortality rate of the strain during the fermentation process. The present disclosure has significant application value. Through experimental studies, it was found that these two genes have a synergistic effect on E. coli. L-lysine hydrochloride imposes osmotic stress resistance on the strains, and silencing the related gene proteins can alter the membrane lipid composition (increasing a proportion of unsaturated fatty acids), maintain membrane fluidity, improve tolerance to lysine hydrochloride, and reduce the mortality rate in the late stage of fermentation.

The invention relates to the technical field of biological medicine, and particularly discloses a macrophage membrane coated plateau encephaledema drug carrier and a preparation method and application thereof, and the macrophage membrane coated plateau encephaledema drug carrier is composed of a nanoparticle core and a macrophage membrane shell layer wrapping the core; the nanoparticle core comprises an ROS-responsive carrier material and carbon monoxide release molecules MnCO entrapped in the ROS-responsive carrier material; the content of phosphatidylserine in the shell layer of the macrophage membrane is not less than 5 mol% of the total phospholipid of the membrane. According to the invention, a bionic delivery system of ROS response type MnCO nanoparticles coated with a macrophage membrane is constructed, phosphatidylserine on the surface of the membrane is utilized to actively activate a microglial cell Trem2 receptor, a positive feedback cycle of targeting phagocytosis-CO release-Trem2 up-regulation is formed, and at the same time, fatty acid oxidative metabolism reprogramming is promoted by means of degraded membrane lipid, so that the biomimetic delivery system is used for preparing the ROS response type MnCO nanoparticles. And multi-mechanism synergistic efficient brain-targeted therapy is realized.

Nanolipoprotein particles having at least a scaffold protein component and a membrane lipid component and related compositions, methods and systems are described. The membrane lipid component includes at least one or more membrane forming lipids, one or more polymerized lipids and / or one or more polymerizable lipids.

This invention discloses a method for isolating and preparing Chlorella exovesicles. Specifically, Chlorella, conventionally cultured to the early logarithmic growth phase, is induced to develop in a nitrogen-limited medium. The culture medium is then concentrated using a tangential flow filtration system. Finally, the concentrate is subjected to density gradient centrifugation with iodixanol. After centrifugation, components within the density range of 1.10–1.12 g / mL are collected to obtain the Chlorella exovesicle product. This invention achieves concentrated and precise collection of Chlorella exovesicles by regulating membrane lipids during the early induction culture of Chlorella, combined with TFF concentration and density gradient centrifugation. This method effectively eliminates impurities, achieving a recovery rate of over 60% and a purity of 2.56 × 10⁻⁶. 10 The particle / μg method provides an efficient, controllable, and scalable solution for the industrial-scale separation and preparation of microalgal exovesicles.

The invention discloses a photoresponsive antibacterial hydrogel, which comprises a photosensitizer, acrylamide, potassium 3-sulfopropyl methacrylate, chitosan quaternary ammonium salt, an additive and a cross-linking agent, and the structure of the photosensitizer (PD-Se) is shown in the specification. A photosensitizer (PD-Se) is added into hydrogel, the positive charge characteristic of QSA hydrogel remarkably improves the local enrichment concentration of PD-Se in thalli by enhancing the binding force with the bacterial surface, unsaturated fatty acid in a bacterial membrane lipid bimolecular layer is oxidized after photoinduced ROS is generated, guanine bases in a DNA double-helix structure are attacked at the same time, and therefore the bioactivity of the bacterial membrane lipid bimolecular layer is improved. The gel is endowed with photodynamic antibacterial ability, has an excellent sterilizing effect on escherichia coli, staphylococcus aureus and methicillin-resistant staphylococcus aureus, and can be used for preparing hydrogel dressing for wound repair.

This application relates to the field of plant genetic engineering technology, specifically disclosing the application of a sterol synthesis-related gene in the response regulation of plant salt tolerance. This application clarifies the sterol synthesis-related gene. SMT2 This study expands our understanding of the role of sterol biosynthesis in plant stress response by revealing the function of calcium signaling under salt stress; it also unveils a novel mechanism by which sterol-membrane lipid interactions regulate calcium signaling, providing a new perspective for research on plant salt stress signal transduction; furthermore, this application provides new salt tolerance gene resources. SMT2 Genes can be used for molecular breeding of salt-tolerant crops, to breed salt-tolerant crop varieties, or to develop salt-tolerant molecular markers.

The present application relates to a kind of high capric acid resistant genetically engineered bacteria and its construction method and application.The genetically engineered bacteria take E. coli as starting strain, knock out aaaS gene, simultaneously overexpress mlaZ gene and mlaY gene;Wherein, the Gene ID of aaaS gene nucleotide sequence is 947315;The Gene ID of mlaZ gene nucleotide sequence is 882402;The Gene ID of mlaY gene nucleotide sequence is 882401.The present application effectively strengthens the membrane lipid intensity of E. coli engineering bacteria by knocking out aaaS gene in E. coli and simultaneously overexpressing mlaZ and mlaY gene, so that genetically engineered bacteria show better robustness and higher resistance in the fermentation process of high-concentration substrate capric acid.Trans-2-decenoic acid yield can reach 1.47g / L when capric acid is added to the highest concentration of 3.0g / L, and the conversion rate is 49.13%, which significantly improves the yield.

The invention discloses a saccharomyces cerevisiae genetic engineering strain and application thereof. Based on a chassis strain SquMC13 with high squalene productivity, a sclareol synthesis route is modularly reconstructed, precursor carbon flow distribution is dynamically regulated and controlled, cell wall and membrane system steady states are adjusted, membrane lipid composition is adjusted, a cell cycle is intervened, and a product efflux system is enhanced, so that the problem of cytotoxicity caused by product accumulation is relieved to a certain extent. According to the invention, a plurality of saccharomyces cerevisiae engineering strains with high yield of sclareol are constructed, including Scl14, Scl24, Scl31, Scl38, Scl71 and Scl75, the result of the strain Scl75 is most prominent, the yield of sclareol fermented by a 250 mL shake flask is up to 4.1 g / L, efficient, stable and green biosynthesis of sclareol is realized, and a new strategy and theoretical basis are provided for microbial preparation of complex diterpenoid compounds.

The invention provides a fruit tree dormant branch cold resistance comparison method, and relates to the technical field of fruit tree cultivation, and the method comprises the following steps: alternately executing polarization mode operation and impedance mode operation on the same detection site of a fruit tree dormant branch; wherein when the polarization mode operation is carried out, a first wave band laser and a second wave band laser are emitted to a detection site at a preset incident angle, and a transmission light intensity data set is acquired; when impedance mode operation is carried out, sweep-frequency current is injected into a detection site, and an impedance component data set of a characteristic frequency point is collected; calculating the intercellular ice crystal density according to the transmission light intensity data set; calculating a membrane lipid phase shift angle according to the impedance component data set; when the intercellular ice crystal density is greater than an activation threshold value, calculating an ice crystal-membrane lipid synergy ratio based on the intercellular ice crystal density and a membrane lipid phase shift angle; calculating a cold-resistant synergy index according to the intercellular ice crystal density and the change rate of the membrane lipid phase shift angle; and judging the cold resistance grade according to the cold resistance synergy index value.

The invention belongs to the technical field of cell viability on-line discrimination, and particularly relates to a mass spectrum-based cell viability measurement method and a mass spectrum-based cell viability measurement system. The invention provides a label-free endogenous metabolite-based cell viability measurement scheme and a label-free endogenous metabolite-based cell viability measurement system, aiming at the defects that the prior art depends on an exogenous label and cannot be synchronously carried out on line with single cell mass spectrometry. The method comprises the following steps: acquiring continuous single cell metabolome data through single cell electrospray ionization mass spectrometry, identifying a single cell event and a time window by taking ubiquitous membrane lipid as a first characteristic ion, extracting an endogenous metabolite reflecting cell activity in the window as a second characteristic ion, and calculating a signal-to-noise ratio; generating an activity label according to a preset threshold value and counting the cell viability of the group, wherein the system correspondingly comprises a data acquisition module, an event identification module, a marker extraction module, a threshold value judgment module and a viability counting module. According to the invention, synchronous, on-line and label-free accurate measurement of the cell viability in single cell metabonomics analysis is realized, and exogenous interference and data deviation are effectively avoided.

The application discloses a preparation method of a flaky magnetic material for enriching exosomes. The flaky Fe3O4 magnetic material with high specific surface area is taken as a starting point, and a surface of the flaky Fe3O4 magnetic material is coated with silicon dioxide to enhance dispersibility and chemical stability of the flaky Fe3O4 magnetic material, and to provide controllable silicon hydroxyl reaction sites for subsequent surface chemical modification. On this basis, amino active groups are introduced to the surface of the magnetic material through 3-aminopropyl triethoxysilane (APTES), and DSPE-SS-PEG2000-CHO containing a disulfide bond structure is further covalently connected to the surface of the magnetic material. Due to a membrane lipid insertion mechanism, non-antibody-dependent capture of a lipid bilayer exosome can be realized. The flaky magnetic material disclosed by the application shows universality and high affinity advantages, and can realize high affinity capture of a lipid structure of an exosome.

The present invention relates to the technical field of skin care products, and provides a biomimetic sebum membrane lipid nanoparticle with a repairing function, a preparation method, an application, and a product. The biomimetic sebum membrane lipid nanoparticle is composed of the following ingredients by weight: wax ester 8%-10%, triglyceride 15%-20%, squalane 3%-6%, sterol 0.1%-2%, ceramide 0.05%-0.25%, lecithin 1%-5%, antioxidant 0.1%-1%, polyol 5%-22.5% and the balance water; the weight content of phosphatidylcholine in the lecithin is ≥45%, and the particle size of the biomimetic sebum membrane lipid nanoparticle is ≤200nm. The sterol added in the present invention has a synergistic effect with the lecithin, so that the biomimetic sebum membrane lipid nanoparticle has a better repairing effect, and adding it to cosmetics can more effectively promote the transdermal penetration and absorption of water-soluble active substances in the formula.

The application discloses a kind of L-lysine high-yield production strain modification method and its application, belong to the field of bioengineering technology.The application obtains recombinant bacteria by knocking out CbrB gene and / or CbrC gene on the genome of escherichia coli, and the yield and conversion rate of L-lysine can be improved by fermenting the recombinant bacteria, and the mortality in the fermentation process of strain can be reduced.The application has important application value.The application finds through experiment that the influence of the two genes on escherichia coli has synergistic effect, L-lysine hydrochloride has osmotic pressure stress effect on strain, and silencing related gene protein can change membrane lipid composition (increase the proportion of unsaturated fatty acid), maintain membrane fluidity.Improve the tolerance to lysine hydrochloride, reduce the mortality in later fermentation stage.

This invention relates to the field of exosome delivery vector technology, specifically to a method and system for targeted delivery of CRB1 based on exosomes. The method includes acquiring a CRB1 inactivated cell recognition fragment, generating corresponding exosome image sequences, labeling membrane lipid insertion paths, constructing a targeted fusion conformation, completing the preparation of fused exosomes, and analyzing delivery distribution. This invention uses protein signal loss and nucleic acid breakage as dual indicators to screen cell states, combines image sequences to confirm the consistency of exosome origin, introduces membrane structure markers to define insertion boundaries, optimizes the fusion conformation through spatial structure pairing and charge polarity reversal, improves intermembranous chimerism matching and stability, and compresses the offset range based on the trajectory distribution of delivery particles on the target cell surface, enhancing target aggregation tendency and particle distribution density, thereby strengthening target recognition ability and membrane structure adaptation during delivery.

The invention provides a golden pomfret preservation method, which comprises: (1) preparing a preservation solution: adding tragacanth and chitosan into water, uniformly stirring and mixing, then adding a clausena lansium seed extract, a hypericum japonicum extract and a fig leaf extract, uniformly stirring and mixing, and finally adding glycerin, and uniformly stirring and mixing to obtain the preservation solution; and (2) performing fresh-keeping treatment on the golden pomfret, namely removing fish scales, gills and viscera from the fresh golden pomfret, washing the golden pomfret with clear water, soaking the golden pomfret in a fresh-keeping solution, draining the golden pomfret, and sub-packaging the golden pomfret subjected to fresh-keeping into food sealing bags for preservation. The fresh-keeping liquid is prepared from the clausena lansium seed extract, the herba hyperici japonici extract, the fig leaf extract and other raw materials, can keep good antibacterial performance, can also form a film to obstruct gas and reduce the respiratory action of fish cells, can also reduce the digestion degree of nutrient substances of fish and reduce the metabolic process, and has the effects of improving the immunity of the fish and improving the quality of the fish. And formation of active oxygen and peroxidation of membrane lipid are avoided, so that the fresh-keeping effect is improved, and the refrigeration shelf life is effectively prolonged.

This invention discloses a feminine care oil capsule based on oil-soluble chimeric collagen and its preparation method, relating to the field of cosmetic technology. The oil phase contents include: 0.5–2.0 wt% oil-soluble chimeric collagen, 95–98 wt% plant oil-based carrier, 0.3–3.0 wt% biomimetic sebum membrane lipid composition, and 0.1–0.5 wt% antioxidant; wherein the biomimetic sebum membrane lipid composition is composed of ceramide, cholesterol, and free fatty acids in a molar ratio of (0.8–1.2):(0.8–1.2):(0.8–1.2). By constructing oil-soluble chimeric collagen molecules, which are stably dispersed in the plant oil-based carrier and self-assembled into nanomicelles, the technical problem that traditional water-soluble collagen cannot be applied to anhydrous oil phase systems is solved. Combined with the scientific formulation of the biomimetic sebum membrane lipid composition, it effectively enhances the vulvar skin barrier repair ability and moisturizing durability. With the specific preparation process and soft capsule dosage form, it achieves high stability of active ingredients, precise dosage, and no preservatives added.

The disclosure provides methods of preventing or treating cognitive impairment or a decline of cognitive function in a subject in need thereof, the method comprising administering an effective amount of at least one compound to the subject, wherein administration of the compound reduces cellular and / or plasma membrane lipid content.

The invention provides a non-ribosome polypeptide compound as well as a synthetic gene cluster BNP37 and application thereof, the structural sequence of the polypeptide compound is X0-X1-X2-X3-X4-X5-X6-X7-X8-X9-X10-X11, the polypeptide compound is a linear peptide or a cyclic peptide, and the cyclic peptide is a lactam cyclic peptide formed by connecting any one of X1, X3 and X5 with X11, or a lactam cyclic peptide or a lactone cyclic peptide formed by connecting X2 with X11. The compound disclosed by the invention can cause discharge of important ions in bacterial cells by targeting Gram-negative bacterium outer membrane lipid A and Gram-positive bacterium teichoic acid, so that bacterial death is caused. The compound disclosed by the invention has strong in-vivo and in-vitro antibacterial activity on a plurality of multi-drug-resistant gram-negative pathogenic bacteria such as escherichia coli, klebsiella pneumoniae, acinetobacter baumannii, pseudomonas aeruginosa, enterobacter cloacae and neisseria gonorrhoeae and a plurality of multi-drug-resistant gram-positive pathogenic bacteria such as staphylococcus aureus and enterococcus faecium.

The invention discloses preparation and application methods of a nutrient solution for preventing and treating low-temperature freeze injury of tomatoes, and belongs to the technical field of agricultural fertilizers. The nutrient solution for preventing and treating the low-temperature freezing injury of the tomatoes is prepared from the following raw materials in parts by mass: 5 to 10 parts of triacontanol, 3 to 10 parts of gamma-aminobutyric acid, 10 to 25 parts of proline, 3 to 7 parts of linolenic acid, 30 to 40 parts of potassium nitrate, 5 to 10 parts of potassium silicate, 15 to 20 parts of calcium superphosphate, 20 to 30 parts of calcium chloride, 1 to 5 parts of zinc sulfate, 1 to 5 parts of copper sulfate, 5 to 10 parts of manganese sulfate and 150 to 250 parts of water. The nutrient solution for preventing and treating the low-temperature freezing injury of the tomatoes is beneficial to solving the problem that the yield and quality of the tomatoes are easily influenced by low-temperature stress, and can promote plants to synthesize antifreeze proteins and osmotic regulators, reduce the membrane lipid phase transition temperature and greatly improve the stress resistance of the plants.

The present application relates to the field of plant physiology and biomarker, and particularly relates to a cell membrane lipid marker combination for characterizing cold tolerance of citrus fruits and application in detection. The present application provides a set of cell membrane lipid marker combination for characterizing cold tolerance of citrus fruits, which comprises 39 kinds of membrane lipid components such as PC(O-38:5), ShexCer(35:0;20), PE-Cer(41:6;20), LPE(36:3), PC(32:0), TG(16:0_18:0_18:1), LPC(20:3) and the like. The process for extracting, purifying and detecting the membrane lipid components of citrus fruits is established, and a cell membrane extraction and detection kit convenient for small sample operation is developed, so as to provide a rapid and simple evaluation method for breeding of cold-tolerant varieties of citrus fruits and selection of reasonable storage temperature after harvesting.

The invention relates to the technical field of medical treatment, and particularly discloses a red breaking liquid for bloody body fluid cell wax blocks. The red breaking liquid is prepared from absolute ethyl alcohol and distilled water, and the volume concentration of the absolute ethyl alcohol is 20%-30%; according to the method, the ethanol aqueous solution in a specific concentration range is adopted as a splitting system, efficient and selective splitting of the red blood cells in the bloody body fluid is realized, and cell membranes of the seedless red blood cells can be quickly destroyed by utilizing the dissolution effect of ethanol on cell membrane lipid and the hypotonic characteristic of the solution, so that contents of the seedless red blood cells are released and are easily eluted. Meanwhile, the morphological integrity and cell membrane antigenicity of nucleated cells (including tumor cells) can be protected to the greatest extent, and the problem of cell damage or antigen shielding possibly caused by a conventional hemolytic agent is avoided.

The present invention belongs to the field of plant molecular biology, and particularly relates to a loquat membrane lipid desaturase gene EjFADC1 and its application. The full-length coding region sequence of the cDNA of the EjFADC1 gene is shown in SEQ ID No.1, and the amino acid sequence of the protein encoded by it is shown in SEQ ID No.2. This gene is induced to express by low temperature and is closely related to the cold tolerance of loquat. The overexpression vector of the EjFADC1 gene was transferred into wild-type Arabidopsis thaliana by the agrobacterium-mediated floral dip method. The results show that overexpression of the EjFADC1 gene in wild-type Arabidopsis thaliana can enhance the cold tolerance of Arabidopsis thaliana. This gene can be used for the breeding of cold-tolerant loquat varieties and has good application prospects.

The invention provides a yarrowia lipolytica engineering strain with high yield of beta-carotene and construction of the yarrowia lipolytica engineering strain, and belongs to the technical field of synthetic biology and metabolic engineering. According to the invention, a multi-copy geranyl-geranyl pyrophosphate synthase gene, a compartmentalized localization expression beta-carotene synthetic pathway related enzyme gene, a diacylglycerol acyltransferase gene, a cell cycle regulation transcription factor, an oxidative stress regulation related gene, and a cell wall and membrane lipid homeostasis regulation related gene are integrated; and regulating foreign protein folding and expression related genes to obtain the yarrowia lipolytica engineering strain for efficiently biosynthesizing beta-carotene by taking glucose as a substrate. The yield of beta-carotene of the constructed yarrowia lipolytica engineering strain is high, the yield at the shake flask level can reach 3253.2 mg / L, and the yield can be increased to 26.5 g / L when fed-batch fermentation is carried out on a 5L scale. The method has great practical significance and economic value for industrial and commercial application of high-value terpenoid products.

The invention relates to membrane lipid coated nanoparticles and methods of use thereof. Disclosed herein are nanoparticles and methods of making the same, the nanoparticles comprising a virus-containing inner core; and an outer surface comprising a cell membrane derived from cells. The virus is an oncolytic virus, and the cell membrane is derived from, for example, red blood cells.

Disclosed is a process of making a nanoparticle comprising an inner core comprising a virus and an outer surface comprising a cellular membrane derived from a cell via extrusion.

The application provides a fruit tree dormant branch cold resistance comparison method, relates to the technical field of fruit tree cultivation, and comprises the following steps: alternately performing polarization mode operation and impedance mode operation on the same detection site of the fruit tree dormant branch; when the polarization mode operation is performed, first wave band laser and second wave band laser are emitted to the detection site at a preset incident angle, and a transmitted light intensity data group is obtained; when the impedance mode operation is performed, a sweep frequency current is injected into the detection site, and an impedance component data group of a characteristic frequency point is collected; the intercellular ice crystal density is calculated according to the transmitted light intensity data group; the membrane lipid phase shift angle is calculated according to the impedance component data group; when the intercellular ice crystal density is greater than an activation threshold value, the ice crystal-membrane lipid synergy ratio is calculated based on the intercellular ice crystal density and the membrane lipid phase shift angle; the cold resistance synergy index is calculated according to the change rate of the intercellular ice crystal density and the membrane lipid phase shift angle; and the cold resistance grade is determined according to the cold resistance synergy index value.