Chitosan Oligosaccharide Fluorinated Derivative Control Root-Knot Nematode (Meloidogyne incognita) Disease Based on the Multi-Efficacy Strategy

Abstract

Plant root-knot nematode disease is a great agricultural problem and commercially available nematicides have the disadvantages of high toxicity and limited usage; thus, it is urgent to develop new nematicides derived from nature substances. In this study, a novel fluorinated derivative was synthesized by modifying chitosan oligosaccharide (COS) using the strategy of multiple functions. The derivatives were characterized by FTIR, NMR, elemental analysis, and TG/DTG. The activity assays show that the derivatives can effectively kill the second instar larvae of Meloidogyne incognita in vitro, among them, chitosan-thiadiazole-trifluorobutene (COSSZFB) perform high eggs hatching inhibitory activity. The derivatives can regulate plant growth (photosynthetic pigment), improve immunity (chitinase and β-1,3-glucanase), and show low cytotoxicity and phytotoxicity. According to the multi-functional activity, the derivatives exhibit a good control effect on plant root-knot nematode disease in vivo. The results demonstrate that the COS derivatives (especially fluorinated derivative) perform multiple activities and show the potential to be further evaluated as nematicides.

Efficacy of a Chitin-Based Water-Soluble Derivative in Inducing Purpureocillium lilacinum against Nematode Disease (Meloidogyne incognita)

“…Additionally, chitin is considered a good soil organic amendment that has been widely studied in agriculture due to the fact that it can stimulate the growth of chitinolytic microorganisms and increase their biological control activity to enhance plant protection [7][8][9]. Chitin and its derivatives have been proven to be effective in controlling plant pathogens, including fungi, bacteria, viruses, and nematodes [10][11][12][13]. Chitin is applied to the soil to control nematodes by producing nematicidal substances such as ammonia or regulating the soil microbial community environment.…”

Induced Resistance by Ascorbate Oxidation Involves Potentiating of the Phenylpropanoid Pathway and Improved Rice Tolerance to Parasitic Nematodes

“…Next to that, our image-based data show that low nematode infection in AO/DHA-sprayed plants is correlated with increases in Fv/Fm and ChlIdx. Similarly, Fan et al (2020) showed that COS derivatives chitosan-thiadiazole-trifluorobutene (COSSZFB) activate induced resistance against M. incognita in cucumber and simultaneously improved plant growth through accumulation of photosynthetic pigments. Fv/Fm values are known to decrease along with the increasing effect of stresses ( Rolfe and Scholes, 2010 ; Gorbe and Calatayud, 2012 ).…”

Antiviral and Antinematodal potentials of chitosan: Review

“…The availability of chemical nematicides commercially have environmental limitations and high toxic for humans. Hence, it was necessary to ind new nematicides derived from natural substances or to develop new strategies for managing PPNs [41].…”

“…The nematicidal activity of chitosan and its derivatives hasn'tbeen studied enough. However, there are certain investigations con irmed the activity of chitosan against plant parasitic nematodes [41,[44][45][46][47].…”