Application of jasmonic acid-containing composition in improving root rot resistance of southern seven

Abstract

The invention relates to the technical field of fertilizers, in particular to application of a composition containing jasmonic acid to improvement of root rot resistance of southern rhodiola roots. The jasmonic acid-containing composition prepared by the invention has a remarkable effect on improving the root rot resistance of the southern rhododendron. Experimental results show that after the plant is treated by the compound, the resistance of the plant to fusarium oxysporum infection is obviously enhanced, the disease time is delayed, and the disease infection degree is obviously reduced. Field application further proves that the treatment can effectively improve the survival rate of the plants and reduce the susceptibility rate, has no adverse effect on the yield of the plants, and shows good agronomic applicability.

Description

Technical Field

[0001] This invention relates to the field of fertilizer technology, and in particular to the application of a composition containing jasmonic acid in enhancing the resistance of *Panax notoginseng* to root rot. Background Technology

[0002] Nanqi ( Panax vietnamensis *Panax notoginseng* (also known as Vietnamese ginseng), or *Panax ginseng* var. *giantha*, is a perennial herb belonging to the genus *Panax* in the family Araliaceae. This species was first clearly recorded in the local chronicle *Yuanyang County Annals*, and has been long recognized and utilized for its unique medicinal value. Modern pharmacological studies have shown that *Panax notoginseng* is rich in various active ingredients with broad biological activities. Existing literature has reported its multiple pharmacological effects, including anti-inflammatory, anti-cancer, hepatoprotective, immune-regulating (e.g., enhancing macrophage phagocytic function), and melanin-inhibiting effects, demonstrating high medicinal and health-promoting potential. In recent years, with the growth of market demand and the expansion of artificial cultivation, the large-scale cultivation of *Panax notoginseng* faces a series of challenges, especially the increasingly prominent problem of diseases.

[0003] In the cultivation of *Symplocos natans*, root rot has become a frequent and highly destructive soil-borne disease, severely restricting its yield and quality. This disease is mainly caused by fungi of the genus *Fusarium*, among which *Fusarium oxysporum* (…) Fusarium oxysporum *Fusarium oxysporum* is the dominant pathogen. Belonging to the genus *Fusarium* of the family Rhizophylum, class Deuteromycetes, order Phyllostachyales, family Rhizophyllaceae, it is a facultative parasitic fungus widely distributed in soil. This pathogen invades host plants through the root system, disrupting the vascular system and interfering with water and nutrient transport, leading to typical symptoms such as root rot, plant wilting, and tissue necrosis. Due to the pathogen's strong survival ability in soil and complex transmission routes, traditional chemical control methods are limited in effectiveness and easily cause environmental pollution and drug resistance problems. Therefore, there is an urgent need to develop green and sustainable disease management strategies.

[0004] Jasmonic acid ( Jasmonic AcidJasmonic acid (JA) is a class of lipid-derived signaling molecules widely found in plants, belonging to the jasmonic acid hormone family, and playing a core regulatory role in plant defense responses. JA can activate the expression of downstream defense genes, promote the biosynthesis of secondary metabolites such as flavonoids, enhance cell wall structure and chemical barrier function, and synergize with other hormone signaling pathways (such as the ethylene and salicylic acid pathways) to construct a multi-level, systematic plant immune network. In recent years, inducing plant disease resistance using exogenous jasmonic acid or its analogues has become a research hotspot in green plant protection and sustainable agriculture. This strategy not only helps reduce the use of chemical pesticides and lower environmental and agricultural product safety risks, but also provides a new way to improve crop stress resistance and quality. Therefore, developing green resistance-inducing technologies for *Panax notoginseng* root rot based on the jasmonic acid signaling pathway has significant theoretical and practical value and is an important direction for promoting the healthy development of the *Panax notoginseng* industry. Summary of the Invention

[0005] The purpose of this invention is to provide an application of a composition containing jasmonic acid in enhancing the resistance of *Gynostemma pentaphyllum* to root rot.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides the application of a composition containing jasmonic acid in enhancing the resistance of *Panax notoginseng* to root rot.

[0007] Preferably, the composition containing jasmonic acid comprises jasmonic acid at a concentration of 80-120 μM and a surfactant at a weight percentage of 0.04-0.06%.

[0008] Preferably, the surfactant is silwet L-77 or Tween-20 (Solarbio).

[0009] Preferably, the pathogen causing the root rot is Fusarium oxysporum.

[0010] The present invention provides a method for enhancing the resistance of *Panax notoginseng* to root rot by applying the composition containing jasmonic acid to *Panax notoginseng* plants; the composition containing jasmonic acid comprises jasmonic acid at a concentration of 80-120 μM and a surfactant at a weight percentage of 0.04-0.06%.

[0011] Preferably, the application method is foliar spraying or root irrigation.

[0012] Preferably, the application is a continuous treatment with a treatment cycle of 8 to 12 days, and each plant is sprayed with 8 to 12 mL evenly each time.

[0013] The present invention provides a method for promoting the synthesis of flavonoids in *Panax notoginseng*, comprising applying the composition containing jasmonic acid to *Panax notoginseng* plants; the composition containing jasmonic acid comprises jasmonic acid at a concentration of 80-120 μM and a surfactant at a weight percentage of 0.04-0.06%.

[0014] The present invention provides a formulation for preventing and treating root rot of *Gynostemma pentaphyllum*, the formulation comprising the composition containing jasmonic acid, wherein the composition containing jasmonic acid comprises jasmonic acid at a concentration of 80-120 μM and a surfactant at a weight percentage of 0.04-0.06%.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The jasmonic acid-containing composition prepared in this invention has a significant effect on enhancing the resistance of *Gynostemma pentaphyllum* (Nanqi) to root rot. Experimental results show that after treatment with this compound, the plants' resistance to *Fusarium oxysporum* infection is significantly enhanced, the onset of disease is delayed, and the degree of susceptibility is significantly reduced. Field application further confirms that this treatment can effectively improve plant survival rate, reduce disease susceptibility, and has no adverse effect on plant yield, demonstrating good agronomic applicability.

[0016] Furthermore, this composition containing jasmonic acid significantly activated the flavonoid metabolic pathway in *Gynostemma pentaphyllum*. qPCR analysis showed a significant upregulation of flavonoid synthesis-related gene expression, a marked increase in total flavonoid content, and a corresponding increase in chlorophyll content. This indicates that the treatment not only enhanced the plant's immune defense capabilities but also promoted the synthesis of secondary metabolites, contributing to improved overall physiological condition and stress resistance. This provides an effective technical solution for achieving green and sustainable disease control in *Gynostemma pentaphyllum*. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0018] Figure 1 The diagram shows the inoculation experiment on the roots of *Symplocos natans* in Comparative Example 1 and Example Group 2.

[0019] Figure 2 The total flavonoid content of the samples is shown at different concentration gradients.

[0020] Figure 3 For different concentration gradients, the flavonoid-related synthetic genes in the samples ( PvANS , PvCHI , PvCHS1 , PvCHS2The level of expression of ).

[0021] Figure 4 For different concentration gradients, the flavonoid-related synthetic genes in the samples ( PvDFR , PvF3H , PvFLS1 , PvFLS2 The level of expression of ).

[0022] Figure 5 Survival rate and disease susceptibility rate for field application examples and comparative examples.

[0023] Figure 6 The physiological characteristics of field samples were investigated (SPAD, total root weight, cut weight, stem diameter, stem length, and stem weight).

[0024] Figure 7 The physiological characteristics of field samples were investigated (root weight, leaf thickness, leaf length, leaf weight, plant height, and taproot dry weight).

[0025] Figure 8 The physiological characteristics of field samples (main root weight, total weight) were investigated.

[0026] Figure 9 Analysis of chlorophyll and total flavonoid content in *Symplocos rubra* foliage treated with jasmonic acid.

[0027] Figure 10 This study aimed to determine flavonoid-related synthetic genes in field samples. Detailed Implementation

[0028] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0029] Example 1

[0030] The main objective of this invention is to provide a jasmonic acid-containing composition that enhances the resistance of *Panax notoginseng* to root rot, thereby addressing the problems existing in the prior art. Specifically, this invention provides the following technical solution: 1. Experimental Materials The sample was a 2-year-old Nanqi plant, taken from a planting base in Yuanyang County, Honghe Hani and Yi Autonomous Prefecture, Yunnan Province (23.12°N, 102.72°E, altitude: 1691.54 m).

[0031] Methyl jasmonic acid was purchased from Solarbio (because jasmonic acid is highly volatile, methyl jasmonic acid was used in both the actual preparation and application); Silwet L-77 was purchased from Solarbio. F. o (BNCC-120618) was purchased from BNCC.

[0032] 2. Experimental Methods

[0033] 1. The samples were two-year-old *Panax notoginseng* plants, taken from a *Panax notoginseng* planting base in Yuanyang County, Honghe Hani and Yi Autonomous Prefecture, Yunnan Province (23.12° N, 102.72°E, altitude: 1691.54 m). After being brought back to the laboratory, they were transplanted into flowerpots and cultured under constant temperature, humidity, and sufficient light conditions. They were then randomly divided into 5 groups, with n≥3 in each group.

[0034] 2. The plants were treated using Examples 1-4, respectively. 10 mL of the jasmonic acid-containing composition was sprayed evenly onto each *Gynostemma pentaphyllum* plant daily for 10 days. On the 10th day, some leaves and roots were collected, washed with deionized water, and quickly placed in liquid nitrogen for preservation. This was for subsequent determination of total flavonoid content and extraction of RNA for reverse transcription into cDNA to determine the expression level of flavonoid synthesis genes. The roots of the remaining plants were inoculated with root rot pathogens, and their susceptible phenotypes were observed.

[0035] 3. At the Nanqi Planting Base in Yuanyang County, Honghe Hani and Yi Autonomous Prefecture, Yunnan Province (23.12° N, 102.72° E, altitude: 1691.54 m), two plots of the same size were randomly selected and treated with Example 1 and Comparative Example 1, respectively. The treatment was carried out once every 10 days for 160 days. During this period, the disease incidence and survival rate were recorded. After the treatment, the agronomic traits were measured by measuring with calipers, weighing with a scientific balance, and detecting chlorophyll with a SPAD instrument. Some leaves and roots were taken, washed with deionized water, and quickly placed in liquid nitrogen for preservation in preparation for subsequent determination of total flavonoid content and extraction of RNA to reverse transcribe into cDNA to determine the expression level of flavonoid synthesis genes.

[0036] 4. RNA was extracted separately using the RNAiso Plus kit (Takara, Japan). The RNA was then reverse transcribed into cDNA using the PrimeScript™ RT kit (with 8×gDNA Eraser Premix, 5×RT Premix, RNase-Free H2O, Takara, Japan). A gene for the synthesis of ginseng flavonoids was designed. PvActin, PvCHS1, PvCHS2, PvFLS1, PvFLS2, PvCHI, PvDFR, PvANS, PvF3H Primer sequences are shown in Table 1. Primer synthesis was commissioned to Sangon Biotech (Shanghai) Co., Ltd. Real-time quantitative PCR (RT-PCR) detection was performed using a CFX Connect™ instrument. The RT-PCR reaction system consisted of 20 µL: 1 µL template cDNA, 0.6 µL each of forward and reverse primers, 10 µL TBGreen (TaKara), and 7.8 µL PCR-grade pure water. The RT-PCR procedure was as follows: 95℃ pre-denaturation for 2 min; 95℃ denaturation for 5 s, 60℃ annealing for 30 s, repeated 40 times. The relative gene expression level was calculated using the 2-ΔΔCT method.

[0037] 5. Figures 1-4 This is not a field trial. Figures 5-10 For field trials.

[0038] Table 1: Primer sequences for the Nanqi qPCR gene

[0039] As shown in SEQ ID NO:1~18.

[0040] 3. Experimental Grouping

[0041] Example: Prepare JA (jasmonic acid) at a concentration of 100 μM and add 0.05% silwet L-77 surfactant.

[0042] Comparative Example 1: Pure water (CK).

[0043] Comparative Example 2: Prepare JA at a concentration of 10 μM and add 0.05% of silwet L-77 surfactant.

[0044] Comparative Example 3: JA was prepared at a concentration of 50 μM and 0.05% of silwet L-77 surfactant was added.

[0045] Comparative Example 4: JA was prepared at a concentration of 200 μM, and 0.05% of silwet L-77 surfactant was added.

[0046] The results are as follows Figures 1-10 As shown.

[0047] 1. Following the procedures of the Examples and Comparative Example 1, after treating the *Gynostemma pentaphyllum* samples continuously for 10 days, their roots were inoculated with Fo, and their phenotypes were observed. The results are as follows: Figure 1 : Control group and root inoculation of the example. The disease incidence in the example was significantly weaker than in the other comparative groups (fewer white fungal patches), indicating that the example effectively improved the resistance of *Gynostemma pentaphyllum* to *Fusarium oxysporum*.

[0048] 2. By Figure 2 As can be seen from the left figure, the total flavonoid content of the samples treated at each concentration was significantly higher than that of the other comparative examples. Subsequently, the root portions of the samples treated at the concentrations of the examples were taken and compared with the blank samples in the comparative examples for verification. Figure 2 As can be seen from the right figure, the total flavonoid content in JA root (example group) was also significantly higher than that in Comparative Example 1 (CK root).

[0049] 3. RNA was extracted from *Panax notoginseng* samples from different treatment groups, reverse transcribed into cDNA, and qPCR was used to verify genes related to flavonoid synthesis in *Panax notoginseng*. Figure 3 and Figure 4The expression levels of flavonoid-related genes in the *Panax notoginseng* samples were shown at different concentration gradients. It can be seen that the flavonoid synthesis-related genes were significantly upregulated in the example treatment, and the expression level of related genes was highest in the example group, i.e. the group with a JA concentration of 100 μM.

[0050] 4. Field trials using the implemented examples showed that, based on survival rate and disease susceptibility rate, the concentration of JA in the implemented examples improved the disease resistance of *Gynostemma pentaphyllum* in the field. Figure 5 ).

[0051] 5. Based on the morphology of field samples, applying the concentration of JA in the example did not affect the yield of *September oxyphylla*, but significantly enhanced its survival rate and disease resistance. Figures 6-8 ).

[0052] 6. In field samples treated with the concentrations described in the examples, both chlorophyll and flavonoid content were increased. Figure 9 ).

[0053] 7. Further qPCR verification revealed that the related synthetic genes also showed an upregulation trend. Figure 10 ).

[0054] In summary, the jasmonic acid-containing composition prepared by this invention has significant effects on the prevention and control of diseases of *Gynostemma pentaphyllum* and has a positive control effect on *Fusarium oxysporum*. Phenotypically, after using this invention, the growth of the pathogen was significantly inhibited, and the onset of disease in *Gynostemma pentaphyllum* was significantly later than that in the control group. By testing the expression level of disease resistance genes in *Gynostemma pentaphyllum*, the expression level of related genes in *Gynostemma pentaphyllum* was also significantly increased.

[0055] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. Use of a composition containing jasmonic acid in improving the resistance of Nanking cherry to Rhizoctonia solani.

2. Use according to claim 1, characterized in that, The composition containing jasmonic acid comprises jasmonic acid at a concentration of 80-120 μM and 0.04-0.06% surfactant by weight.

3. Use according to claim 1, characterized in that, The surfactant is silwet L-77 or Tween-20.

4. Use according to claim 1, characterized in that, The pathogenic bacteria of the root rot is Rhizoctonia solani.

5. A method of increasing resistance to root rot in a South 7 plant, comprising, The composition containing jasmonic acid is applied to Nanking cherry plants; the composition containing jasmonic acid comprises jasmonic acid at a concentration of 80-120 μM and 0.04-0.06% surfactant by weight.

6. The method of claim 5, wherein, The application mode is foliar spraying or root irrigation.

7. The method according to claim 5 or 6, characterized in that, The application is continuous treatment, the treatment cycle is 8-12 days, and 8-12 mL is sprayed per plant each time.

8. A method for promoting the synthesis of nanaflavonoids, characterized in that, The composition containing jasmonic acid is applied to Nanking cherry plants; the composition containing jasmonic acid comprises jasmonic acid at a concentration of 80-120 μM and 0.04-0.06% surfactant by weight.

9. A preparation for controlling southern seven root rot, characterized by, The preparation comprises the composition containing jasmonic acid, and the composition containing jasmonic acid comprises jasmonic acid at a concentration of 80-120 μM and 0.04-0.06% surfactant by weight.

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