CN-117534781-B - Preparation method and application of nano resistance inducer for preventing and treating tobacco bacterial wilt

Abstract

The invention discloses a preparation method and application of a novel nano resistance inducer for preventing and treating tobacco bacterial wilt, which belong to the technical field of tobacco bacterial wilt prevention and treatment, and the novel nano particles prepared by condensation reaction of daphnetin and carboxymethyl chitosan under the catalysis of N, N' -dicyclohexylcarbodiimide and 4-dimethylaminopyridine have high water solubility and good prevention and treatment effect.

Inventors

• DING WEI
• YANG LIANG
• WANG YAO
• WEI ZHOULING
• LIANG YIJIA
• LI SHILI

Assignees

• 西南大学

Dates

Publication Date

20260508

Application Date

20231109

Claims (8)

1. 1. A preparation method of a nano resistance inducer for preventing and treating tobacco bacterial wilt is characterized in that under the catalysis of N, N' -dicyclohexylcarbodiimide and 4-dimethylaminopyridine, daphnetin and carboxymethyl chitosan are subjected to condensation reaction to form nano particles, methyl formate and glyoxylate are also added in the condensation process, and the mass ratio of the methyl formate to the glyoxylate to the daphnetin is (1-2): (2-3): 1.
2. 2. The method for preparing the nano resistance inducer for preventing and treating tobacco bacterial wilt according to claim 1, wherein the mass ratio of daphnetin to carboxymethyl chitosan is (0.01-1): 1.
3. 3. The method for preparing the nano resistance inducer for preventing and treating tobacco bacterial wilt according to claim 1, wherein the mass ratio of the N, N' -dicyclohexylcarbodiimide to the 4-dimethylaminopyridine is 2:1.
4. 4. The method for preparing the nano resistance inducer for preventing and treating tobacco bacterial wilt according to claim 3, which is characterized by comprising the following specific steps: (1) Dissolving carboxymethyl chitosan in water to obtain carboxymethyl chitosan solution; (2) Dissolving daphnetin into DMSO to obtain daphnetin solution; (3) Dissolving N, N' -dicyclohexylcarbodiimide and 4-dimethylaminopyridine in DMSO to obtain a mixed solution, adding the mixed solution and glyoxylic acid into carboxymethyl chitosan solution, heating at 60 ℃ for 1 h, adding daphnetin solution and methyl formate, stirring at 60 ℃ and N 2 for 4 h, adding acetone solution, standing for 6 h, taking out brown precipitate, washing with pure acetone, and freeze-drying for 24 h to obtain the nano-resistance inducer.
5. 5. The method for preparing a nano-resistance inducer for preventing and treating bacterial wilt of tobacco according to claim 4, wherein the reaction process of the step (3) is carried out under dark conditions.
6. 6. The use of the nano resistance inducer for preventing and treating tobacco bacterial wilt, which is prepared by the preparation method according to claim 5, wherein the use of the nano resistance inducer for improving plant disease resistance or agronomic traits is provided.
7. 7. The use according to claim 6, wherein the nanoelicitor is for plants in the transplanting and/or the tillering stage.
8. 8. The use according to claim 7, wherein the nanoelicitor is applied by foliar spraying.

Description

Preparation method and application of nano resistance inducer for preventing and treating tobacco bacterial wilt Technical Field The invention relates to the technical field of tobacco bacterial wilt prevention and treatment, in particular to a preparation method and application of a novel nano resistance inducer for preventing and treating tobacco bacterial wilt. Background Since the first report in China, the occurrence range and the hazard degree of the tobacco bacterial wilt are continuously spread and aggravated, and huge economic loss is brought to the tobacco industry every year, once the tobacco bacterial wilt is infected by field tobacco plants, the disease plants rapidly die due to the favorable disease conditions of high temperature and high humidity. At present, the prevention and treatment of tobacco bacterial wilt mainly adopts chemical prevention and treatment and is supplemented with other prevention and treatment methods, including disease-resistant variety screening, agronomic measure management and the like. Although the chemical control has better control effect on tobacco bacterial wilt, the pathogenic bacteria resistance is improved, the biological community diversity of tobacco field soil is reduced, and the environmental quality of the tobacco field soil is affected. In recent years, induced resistance is an effective plant disease resistance strategy, and continuous and broad-spectrum resistance of plants to pathogenic bacteria is increasingly emphasized by enhancing stress resistance and disease resistance potential of plants. The plant immunity inducer is a green pesticide capable of activating plant immune system and improving plant disease resistance, and unlike traditional bactericides, the plant immunity inducer can not directly inhibit bacteria, but can endow plants with the capability of resisting infection of external pathogenic organisms and repairing damage of diseases by inducing the defense mechanism of the plants, thereby achieving the purpose of disease prevention. Daphnetin is a common secondary metabolite of plants, bacteria and fungi, belongs to hydroxycoumarin, has been studied in the early stage and can be used as a plant resistance inducer for improving the resistance of tobacco to bacterial wilt, is a potential plant resistance inducer, but the problems of difficult extraction, difficult water dissolution, easy decomposition of visible light and the like restrict the development and the utilization of the compound, so that the improvement of the water solubility of daphnetin is an important problem for the development and the utilization of coumarin compounds on the premise of keeping the original induced disease resistance of daphnetin. Disclosure of Invention In view of the above, the invention aims to provide a novel nano-resistance inducer for preventing and treating tobacco bacterial wilt by adopting induction resistance, and simultaneously solve the problems of poor water solubility and low coupling rate of the existing resistance inducer. The invention solves the technical problems by the following technical means: A preparation method of a novel nano-resistance inducer for preventing and treating tobacco bacterial wilt comprises the step of condensing daphnetin and carboxymethyl chitosan to form nano-particles under the catalysis of N, N' -dicyclohexylcarbodiimide and 4-dimethylaminopyridine. The compound of the coupled carboxymethyl chitosan and daphnetin can improve the disease resistance of plants in a specific concentration range, and can synergistically prevent and control bacterial wilt. Further, the mass ratio of daphnetin to carboxymethyl chitosan is (0.01-1): 1. The ratio is preferably (0.05-7): 1, more preferably (0.1-7): 1. Further, the mass ratio of the N, N' -dicyclohexylcarbodiimide to the 4-dimethylaminopyridine is 2:1. In addition, methyl formate and glyoxylic acid are added in the condensation process, and the mass ratio of the methyl formate to the glyoxylic acid to the daphnetin is (1-2): 2-3): 1. Although daphnetin and carboxymethyl chitosan form nano particles through condensation reaction under the catalysis condition of N, N '-dicyclohexylcarbodiimide and 4-dimethylaminopyridine, the coupling rate of daphnetin and carboxymethyl chitosan is low, the coupling rate is about 10%, and the control efficiency is about 70%, so that methyl formate and glyoxylate are introduced under the catalysis condition of N, N' -dicyclohexylcarbodiimide and 4-dimethylaminopyridine, and the coupling effect is improved. Further, the specific steps are as follows: (1) Dissolving carboxymethyl chitosan in water to obtain carboxymethyl chitosan solution; (2) Dissolving daphnetin into DMSO to obtain daphnetin solution; (3) Dissolving N, N' -dicyclohexylcarbodiimide and 4-dimethylaminopyridine in DMSO to obtain a mixed solution, adding the mixed solution into carboxymethyl chitosan solution, heating at 60 ℃ to 1h, adding daphnetin solution, stirring at 60 ℃ t