Comparative proteomics provide insights on the basis of resistance to Aspergillus flavus infection and aflatoxin production in peanut (Arachis hypogea L.)

Aspergillus flavus is an opportunistic fungal pathogen that produces carcinogenic aflatoxin, a serious constraint for food safety and human health. In this study, to better understand the molecular mechanism/s of peanut resistance to A. flavus growth and aflatoxin accumulation, comparative proteomic analysis was performed in two contrasting peanut genotypes, variety JL 24 (susceptible) and its near-isogenic resistant transgenic derivative expressing an alfalfa defensin gene. Several resistance proteins associated with secondary metabolic pathways were strongly induced in the resistant genotypes including phenylalanine ammonia lyase, cinnamic acid-4-hydroxylase, chalcone synthase, resveratrol synthase, flavanone-3-hydroxylase, lipoxygenase, diacylglycerol-glycerol-3-phosphate-3-phosphatidyltransferase, beta-ketoacyl-ACP-reductase, monoacylglycerol acyltransferase, and diacylglycerol acyltransferase, indicating their roles in resistance. Besides, several putative susceptibility-associated proteins were revealed providing knowledge on potential candidate target genes for precise breeding interventions for aflatoxin mitigation. This is the first study to demonstrate comparative proteomics analysis in Aspergillus-peanut interaction using contrasting near-isogenic lines to elucidate the underlying molecular mechanisms of resistance.

Automated summary

This study conducted a comparative proteomic analysis in two contrasting peanut genotypes to understand the molecular mechanisms of resistance to Aspergillus flavus and aflatoxin accumulation. The results showed that several resistance proteins associated with secondary metabolic pathways were induced in the resistant genotypes, while putative susceptibility-associated proteins were also identified. This study provides valuable insights for potential breeding interventions to mitigate aflatoxin contamination.