Elicitation of resistance through the exploration of acibenzolar-S-methyl (ASM) against Meloidogyne incognita in tomato under salt stress condition

Abstract

Meloidogyne incognita is one of the prime restricting factors of yield in crops. Approaches to diminish the populations are consistently raised, and the application of elicitors as resistance inducers is an option for managing the disease. Thus, this study was conducted to examine the potential of acibenzolar-S-methyl (ASM), a chemical activator, as a soil drench to induce resistance against M. incognita infestation with and without salt stress. Results demonstrated that alone and under salt stress, ASM was able to reduce root-knot nematode population in tomato. The applied treatments significantly reduced the root-knot nematode reproduction, increased growth and phenolic compounds in the plants. Treatment of ASM (0.254 mM) with NaCl (100 mM), significantly reduced the root-knot index by 58.0% compared to untreated control. The same combination significantly enhanced the phenolic compounds and dry matter up to 60.6% and 59.0%, respectively, compared to inoculated control. However, the application of the highest concentration of ASM (1.019 mM) alone was the most potent in reducing the eggmasses and root-knot index by 74.4% and 68.0% respectively compared to inoculated control. Additionally, the lowest increase (23.0%) of phenol was observed in ASM (0.509 mM). NaCl alone also reduced the root-knot index by 32.0% and increased phenol accumulation by 47.5%. Moreover, lower concentration of ASM (0.254 mM) in combination with salt stress (NaCl 100 mM) showed significantly higher efficacy. The study revealed that application of ASM through stress modulation effect can activate the inherent M. incognita resistance in tomato, which could contribute substantially in sustainable management of nematode infestation.