Application of cis-3-hexenol propionate in prevention and control of tea garden pests and / or improvement of tea quality

Abstract

The invention belongs to the technical field of pest control, and particularly relates to application of cis-3-hexenol propionate in control of tea garden pests and / or improvement of tea quality. As a natural plant volatile organic compound, the cis-3-hexenol propionate disclosed by the invention can obviously induce expression of key genes in a tea tree phenylpropane pathway and a flavonoid pathway. Biological experiment results show that the selection rate of tea trees applied with cis-3-hexenol propionate by tea garden pests is reduced by 50%, the aphid yield is reduced by 25%, and the death rate is increased by 2.3 times. The results prove that the cis-3-hexenol propionate treatment can effectively enhance the resistance of the tea trees to the pests in the tea garden, and also can promote the accumulation of total phenols and flavonoid substances in the tea leaves to improve the quality of the tea leaves.

Description

Technical Field

[0001] This invention belongs to the field of pest control technology, specifically relating to the application of cis-3-hexenol propionate in controlling pests in tea gardens and / or improving tea quality. Background Technology

[0002] Tea has a long history of cultivation and is a highly nutritious health product. Tea contains a variety of active ingredients, such as tea polyphenols, which have antioxidant, anti-inflammatory, and anti-aging effects; tea pigments and polysaccharides, which have anti-tumor and blood sugar and lipid-regulating effects; and caffeine, which has invigorating, digestive-promoting, and cardiovascular-improving effects. In recent years, with rapid socio-economic development, people's demand for tea has gradually shifted from quantity to quality. Cultivating and producing high-quality tea has become the primary goal of tea gardens. To improve tea yield and quality and ensure safe tea production, accurate prediction and green, safe control of tea garden pests and diseases are essential.

[0003] Tea gardens in my country are home to a diverse array of pests, totaling 808 species belonging to 2 classes, 14 orders, and 209 families. Currently documented tea garden pests mainly include leaf-eating pests and piercing-sucking pests. Leaf-eating pests primarily damage tea leaves by feeding on the larvae, causing notches and holes in the leaves. Piercing-sucking pests pierce and suck the leaves, affecting the growth of the tea trees and the quality of the tea leaves. Leaf-eating pests are predominantly Lepidoptera, mainly belonging to the families Limacodidae, Geometridae, and Lymantidae; piercing-sucking pests are concentrated in the order Hemiptera, with the small green leafhopper being a major example. Empoasca onukii Black spiny whitefly Aleurocanthus spiniferus Green-spotted bug Lygocoris lucorum Tea aphids Toxoptera aurantii horned wax scale Ceroplastes ceriferus Tea aphid nymphs and adults prefer to suck sap from the back and tips of tender tea buds using a piercing-sucking method. Tea aphid outbreaks cause tender buds and leaves to wither and growth to stagnate, significantly impacting tea yield and quality. In particular, the large amounts of honeydew excreted by tea aphids can introduce diseases such as sooty mold, further affecting tea tree growth and tea farmers' income. Tea aphids reproduce rapidly and have a high reproductive capacity; under suitable conditions, a generation can be completed in only 5-7 days, and a single wingless female aphid can produce 35-45 offspring in its lifetime.

[0004] In the long-term interaction with herbivorous insects, plants employ various defense strategies to resist pest damage, thus forming sophisticated and effective insect-resistant mechanisms. Plant defense responses mainly include constitutive defense and inducible defense. The former includes inherent physical or chemical barriers on the plant that hinder insect feeding, such as physical structures like waxes, spines, and trichomes on the plant surface, as well as constitutively expressed insect-resistant substances. The latter refers to the activation of hormone-mediated signal transduction pathways after plant damage, leading to the expression of downstream related defense genes and the accumulation of secondary insect-resistant substances, thereby exhibiting induced resistance to pests. Plant inducible defense can be further divided into direct defense and indirect defense. The former refers to secondary metabolites produced by plants after damage that have repellent, antifeedant, or toxic effects on pests, thus adversely affecting the normal growth, development, and reproduction of insects. The latter refers to pest-inducing volatiles (HIPVs) produced by plants after damage that attract the natural enemies of pests, thereby enhancing the plant's control over pests. In addition, HIVVs also play an important role in interplant communication. Volatile substances released by damaged plants can induce defensive responses in surrounding unaffected plants, enhancing their resistance to pests. HIV-induced plant defense responses have become a cutting-edge topic in plant chemical ecology and biological pest control in recent decades. Although the phenomenon of HIV-induced defense responses in neighboring plants is widespread in nature, the molecular mechanisms underlying early signaling events in plant perception and recognition of HIV-induced defenses are poorly understood, and the downstream regulatory networks inducing plant resistance after HIV perception and recognition are rarely reported, limiting the potential application of HIV-induced defenses in green pest control.

[0005] Tea aphids are a major pest of tea trees, severely impacting tea quality and yield. Currently, tea aphid control primarily employs techniques including chemical, physical, and biological control. Due to the adverse health effects of chemical pesticides, low-toxicity plant-derived pesticides are currently used for tea aphid control, but their effectiveness is unsatisfactory. Therefore, there is an urgent need to develop safe and convenient new control measures. Summary of the Invention

[0006] The purpose of this invention is to provide an application of cis-3-hexenol propionate in the control of pests in tea gardens and / or the improvement of tea quality, thereby solving the problems existing in the prior art.

[0007] The technical solution adopted in this invention is: This invention provides the application of cis-3-hexenol propionate in controlling pests in tea gardens and / or improving tea quality.

[0008] Preferably, the tea garden pests include at least one of tea aphids, black spiny whiteflies, and leafhoppers.

[0009] Preferably, the tea aphid is the tea bifida.

[0010] Preferably, improving tea quality means at least one of the following: 1) Increase the total phenolic content in tea; 2) Increase the content of flavonoids in tea.

[0011] Preferably, the administration method of the cis-3-hexenol propionate is as follows: Place cis-3-hexenol propionate 5cm to 30cm away from the tea plant to achieve application through air diffusion.

[0012] Preferably, the application time of cis-3-hexenol propionate is 3h to 12h.

[0013] Preferably, the application time of cis-3-hexenol propionate is 6 hours.

[0014] Preferably, the dosage of cis-3-hexenol propionate is 10 μL to 30 μL per tea plant.

[0015] The present invention also provides a composition for controlling tea aphids and / or improving tea quality, the composition comprising the aforementioned cis-3-hexenol propionate.

[0016] Preferably, the dosage form of the composition includes any one of the following: 1) Aerosol; 2) Sustained-release agents; 3) Smoke agent; 4) Liquid formulations for drip irrigation and spraying.

[0017] Compared with the prior art, the beneficial effects of the present invention are: This invention provides the application of cis-3-hexenol propionate in controlling tea garden pests and / or improving tea quality. The cis-3-hexenol propionate described in this invention, as a natural plant volatile organic compound, can significantly induce the phenylpropane pathway in tea plants. PAL , C4H , 4CL and CHS With the flavonoid pathway CHI , F3'5'H and FLS The compound was used to treat tea plants, which showed a 50% decrease in the selectivity of tea plants treated with it, a 25% decrease in aphid production, and a 2.3-fold increase in mortality. These results confirm that cis-3-hexenol propionate treatment effectively enhances the resistance of tea plants to tea plantation pests, while also promoting the accumulation of total phenols and flavonoids in tea leaves, thus improving tea quality. Attached Figure Description

[0018] Figure 1 Effects of HP application at different times on the expression of phenylpropane pathway genes in tea plants. A: PAL B: C4H C: 4CL D: CHS .

[0019] Figure 2 Effects of HP application at different times on gene expression in the flavonoid pathway of tea. A: CHI B: F3H C: F3'5'H D: FLS .

[0020] Figure 3 Effects of HP application at different times on the accumulation of total phenols and flavonoids in tea. A: Total phenols in tea; B: Flavonoids.

[0021] Figure 4 Effects of HP application on tea aphid selective behavior, mortality rate, and reproductive capacity at different times. A: Tea aphid selective behavior; B: Tea aphid mortality rate; C: Tea aphid reproductive capacity. Detailed Implementation

[0022] The present invention will be further illustrated below with specific embodiments, but these embodiments do not limit the scope of the invention. Modifications or substitutions to the details and form of the technical solutions of the present invention may be made without departing from the spirit and scope of the invention, but all such modifications or substitutions fall within the protection scope of the present invention.

[0023] The inventive concept of this invention is as follows: Tea yield and quality are severely affected by pests and diseases. Although chemical pesticides have good control effects on pests and diseases, their application on tea trees is strictly controlled due to concerns about human health. Currently, pest control on tea trees typically employs non-chemical methods such as ecological, physical, and biological control. While these non-chemical methods avoid biosafety issues, their drawbacks, such as cumbersome operation and high cost, necessitate new, efficient, and convenient control methods. Although reports are increasing regarding the volatiles released by plants after being damaged by pests inducing plant defense responses, these are currently only in the indoor testing phase, with very few successful field examples. Possible reasons limiting the application of HIVs include: firstly, many HIVs are aldehydes, alcohols, and olefins, which are unstable in the air, limiting their widespread use; secondly, the mechanism by which HIVs induce plant insect resistance is unclear, also limiting their development.

[0024] cis-3-hexenol propionate is a naturally occurring volatile compound released by Solanaceae plants such as tomatoes, tobacco, and peppers after being damaged by pests like thrips and whiteflies. It can induce increased insect resistance in surrounding unaffected plants, but its ability to induce resistance in tea trees and its potential to control the tea aphid require further investigation. In our previous study, we applied cis-3-hexenol propionate to tea trees and found that the phenylpropane pathway genes in tea trees were significantly upregulated, and the secondary insect-resistant substances total phenols and flavonoids synthesized by these target genes also accumulated significantly. Simultaneously, we attempted to apply cis-3-hexenol propionate to tea trees to target the important tea aphid. Toxoptera aurantii For example, the feeding selectivity of tea aphids on tea leaves treated with HP and those not treated with HP was tested; further, the mortality rate and reproductive capacity of tea aphids feeding on the two different tea trees were determined over 7 days.

[0025] Indoor experiments revealed that adult tea aphids preferred to feed on control tea leaves (without HP treatment), and their numbers were twice those on HP-treated tea leaves, indicating that HP-treated tea leaves had a repellent effect on tea aphids. Simultaneously, the mortality rate of adult aphids on HP-treated tea leaves was twice that of those on untreated tea leaves, and the number of nymphs on HP-treated tea leaves decreased by nearly 30% compared to the control. This demonstrates that HP application significantly reduces the population growth potential of tea aphids and has a good control effect. It is worth noting that HP application increased the total phenolic and flavonoid content of tea plants. These antioxidants are important indicators of tea quality, suggesting that applying HP to tea plants not only increases their insect resistance but also improves tea quality.

[0026] To address the shortcomings of current highly effective and safe pest control technologies for tea trees, this invention innovatively applies the ecologically safe and stable volatile compound HP to tea trees, elucidating its inducing effect on tea tree insect resistance and its molecular mechanism. Simultaneously, it measures its repellent effect on the important tea aphid (a piercing-sucking pest) and its inhibitory effect on aphid populations. This discovery not only alleviates the deficiencies in tea tree pest control technologies but also improves tea quality, providing a new measure and option for the safe and sustainable control and production of tea tree pests.

[0027] To enable those skilled in the art to better understand and implement the technical solutions of this invention, the invention will be further described below with reference to specific embodiments. Unless otherwise specified, all reagents used in this invention are commercially available, and all methods used are conventional techniques in the art.

[0028] The list of abbreviations for this invention is shown in Table 1.

[0029] Table 1. List of abbreviations for this invention The CAS number of HP described in this invention is: 33467-74-2.

[0030] Example 1 The application of cis-3-hexenol propionate in controlling tea garden pests and / or improving tea quality is as follows: 1. The main technical concept of this invention includes: 1) The effect of HP application on the expression of phenylpropane pathway genes in tea plants was measured. 2) After HP was applied to tea trees, the total phenolic and flavonoid contents of insect-resistant substances in tea trees were measured; 3) The effects of HP application on tea aphids, nymph production, and mortality were determined in the laboratory.

[0031] 2. The main experimental design is as follows: The tea aphid used in this invention Toxoptera aurantii The tea was harvested from the tea garden of Huazhong Agricultural University and then inoculated onto tea seedlings transplanted in pots. The seedlings were placed in a temperature- and light-controlled greenhouse with conditions of 26℃, 16L:8D, and 70% relative humidity.

[0032] 1) Expression of phenylpropane pathway genes in tea plants.

[0033] Tea seedlings at the same growth stage were randomly divided into 4 groups: 1 control group and 3 treatment groups. The 3 treatment groups were: HP exposure for 3h, HP exposure for 6h and HP exposure for 12h.

[0034] Control group: Tea seedlings were placed in clean air.

[0035] Treatment group: Tea seedlings were placed 10 cm away from a 10 μL HP odor source and exposed to HP for 3 h, 6 h and 12 h by air diffusion.

[0036] Each group consisted of 4 tea seedlings. After treatment, 100 mg of tea leaf samples were collected and immediately stored in liquid nitrogen at -80°C. Tea seedlings not treated with HP served as the control group. Then, phenylpropanoid pathway genes were determined using an RNA assay kit. PAL , C4H , 4CL , CHS and flavonoid pathway genes CHI , F3H , F3'5'H and FLS The relative expression level.

[0037] 2) Accumulation of total phenols and flavonoids, insect-resistant substances in tea trees.

[0038] Tea seedlings were grouped and treated as described above. Samples were collected at each time point and immediately stored in liquid nitrogen at -80℃. Tea seedlings not treated with HP were used as a control. Then, following the instructions for the total phenols and flavonoids kit, the contents of total phenols and flavonoids (insect-resistant substances) in tea plants at different time points under different treatments were determined.

[0039] 3) The repellent effect of HP on tea aphids in tea trees.

[0040] This experiment used the in vitro leaf method in petri dishes. The experiment consisted of two groups: an HP exposure group and a control group.

[0041] HP exposure group: Tea seedlings were exposed to 10 μL of HP for 6 h.

[0042] Control group: Tea seedlings were placed in clean air.

[0043] After treatment, leaves were taken from tea seedlings, and leaf discs with a diameter of 1 cm were made using a perforator. Two leaf discs from each treatment were placed in a cross shape in a 15 cm diameter petri dish. A healthy adult aphid was then introduced into the center of four leaves using a soft brush. The aphid selection was assessed two hours later. If the adult aphid was not on the tea leaf, the data was discarded. All leaves and adult aphids were used only once. This experiment was repeated 60 times.

[0044] 4) Determination of the number of nymphs produced by adult tea aphids and the mortality rate.

[0045] This experiment was divided into two groups: an HP exposure group and a control group, with 5 plants in each group.

[0046] HP exposure group: Tea seedlings were placed 10 cm away from a 10 μL HP odor source, and the seedlings were exposed to HP for 6 hours through air diffusion before inoculation. Toxoptera aurantii .

[0047] Control group: vaccinated Toxoptera aurantii The tea seedlings were then cultivated normally.

[0048] After treatment, six leaves were selected from each seedling, and one adult tea aphid was attached to each leaf and secured with a microphid trap. Seven days later, the number of nymphs and the survival status of adults in each microphid trap were investigated. The number of newly produced nymphs and the number of dead adults were recorded in both the HP-exposed group and the control group.

[0049] The tea aphid used in this invention is the tea bifida (Aphidius chapensis). Toxoptera aurantii ).

[0050] 3. Experimental results.

[0051] 1) Genes of the phenylpropane pathway and flavonoid pathway in tea plants were significantly upregulated.

[0052] See results Figure 1 and Figure 2 Compared with the control group, HP exposure significantly upregulated the expression levels of related genes in the phenylpropane pathway and most key genes in the flavonoid pathway of tea plants.

[0053] In the phenylpropane pathway PAL , C4H , 4CL and CHS The expression level of [a substance] was significantly increased; [a substance] in the flavonoid pathway CHI , F3' 5'H and FLS The expression level of was significantly increased, only F3H The difference was not statistically significant.

[0054] 2) The total phenols and flavonoids, which are insect-resistant substances, accumulate significantly in tea trees.

[0055] See results Figure 3 Compared with the control, HP exposure significantly promoted the accumulation of total phenols and flavonoids in tea.

[0056] 3) Determination of adult tea aphid selection behavior, nymph production, and mortality rate.

[0057] See results Figure 4 Compared with the control, HP exposure significantly reduced the selective preference of tea aphids, significantly decreased aphid reproductive capacity, and significantly increased mortality.

[0058] In summary, through biological experiments including the expression of target genes in the phenylpropanoid pathway of tea trees, the accumulation of secondary insect-resistant substances such as total phenols and flavonoids, and the selection preferences, reproductive capacity, and survival rate of adult tea aphids, it was determined that *HP* induces a significant accumulation of insect-resistant substances such as total phenols and flavonoids in tea trees. Further findings revealed that adult tea aphids avoid feeding on tea trees treated with *HP*; the mortality rate of adult aphids on *HP*-treated tea trees was significantly higher than the control, while the aphid population was significantly lower. This indicates that the application of *HP* has a significant inhibitory effect on the tea aphid population and has broad application prospects for improving the quality and efficiency of tea cultivation.

[0059] This invention, based on indoor potted plant experiments, confirms the effectiveness of HP against the tea aphid (…). Toxoptera aurantii It exhibits significant control effects. Furthermore, preliminary results of this invention show that HP also demonstrates good control potential against black spiny whiteflies, leafhoppers, and tea tree pathogens. The control effects on these targets require further comprehensive verification and evaluation through further outdoor trials. The results of this invention provide important evidence for promoting HP from indoor application to outdoor tea garden practice.

[0060] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0061] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. Application of cis-3-hexenol propionate in the control of pests in tea gardens and / or the improvement of tea quality.

2. The application as described in claim 1, characterized in that, The tea garden pests include at least one of the following: tea aphid, black spiny whitefly, and leafhopper.

3. The application as described in claim 2, characterized in that, The tea aphid is the tea bifida.

4. The application as described in claim 1, characterized in that, Improving tea quality refers to at least one of the following: 1) Increase the total phenolic content in tea; 2) Increase the content of flavonoids in tea.

5. The application as described in claim 1, characterized in that, The administration method of the cis-3-hexenol propionate is as follows: Place cis-3-hexenol propionate 5cm to 30cm away from the tea plant to achieve application through air diffusion.

6. The application as described in claim 5, characterized in that, The application time for cis-3-hexenol propionate is 3h to 12h.

7. The application as described in claim 6, characterized in that, The application time for cis-3-hexenol propionate is 6 hours.

8. The application as described in claim 5, characterized in that, The dosage of cis-3-hexenol propionate is 10 μL to 30 μL per tea plant.

9. A composition for controlling tea aphids and / or improving tea quality, characterized in that, The composition comprises the cis-3-hexenol propionate of claim 1.

10. The composition according to claim 9, characterized in that, The dosage form of the composition includes any one of the following: 1) Aerosol; 2) Sustained-release agents; 3) Smoke agent; 4) Liquid formulations for drip irrigation and spraying.

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