Dipicolinic acid enhances kiwifruit resistance to Botrytis cinerea by promoting phenolics accumulation

Abstract

BACKGROUND Kiwifruit is highly susceptible to fungal pathogens, such as Botrytis cinerea, which reduce crop production and quality. In this study, dipicolinic acid (DPA), which is one of the main components of Bacillus spores, was evaluated as a new elicitor to enhance kiwifruit resistance to B. cinerea. RESULTS DPA enhances antioxidant capacity and induces the accumulation of phenolics in B. cinerea‐infected ‘Xuxiang’ kiwifruit. The contents of the main antifungal phenolics in kiwifruit, including caffeic acid, chlorogenic acid and isoferulic acid, increased after DPA treatment. DPA enhanced H2O2 levels after 0 and 1 days, which promoted catalase (CAT) and superoxide dismutase (SOD) activities, reducing long‐term H2O2 levels. DPA promoted the up‐regulation of several kiwifruit defense genes, including CERK1, MPK3, PR1‐1, PR1‐2, PR5‐1 and PR5‐2. Furthermore, DPA at 5 mM inhibited B. cinerea symptoms in kiwifruit (95.1% lesion length inhibition) more effectively than the commercial fungicides carbendazim, difenoconazole, prochloraz and thiram. CONCLUSIONS The antioxidant properties of DPA and the main antifungal phenolics of kiwifruit were examined for the first time. This study uncovers new insights regarding the potential mechanisms used by Bacillus species to induce disease resistance. © 2023 Society of Chemical Industry.

Recent Advances in Mechanisms Underlying Defense Responses of Horticultural Crops to Botrytis cinerea

“…B. cinerea-infected strawberries were found to show increased content of hexadecanoic acid, octadecanoic acid, sucrose, and β-lyxopyranose [31]. Overall, different plant species showed various accumulations of metabolites upon B. cinerea infection [32], and the change in plant metabolites is an important plant response to B. cinerea.…”