Apple ZAT11 , a C2H2 ‐type zinc finger protein, enhances resistance to Penicillium expansum by affecting jasmonic acid biosynthesis in apple

Blue mold, caused by Penicillium expansum, is a prevalent postharvest disease of apple and significantly limits apple quality. Apple have key genes underlying their biological stress responses and corresponding functions that remain largely unexplored. Here, we identified MdZAT11, a Cys2/His2 (C2H2)-type zinc finger protein, as a crucial positive regulator of apple resistance to P. expansum infection. Utilizing transcription factor-centered yeast one-hybrid (TF-centered Y1H) and RNA sequencing analyses, we discovered 1059 potential target genes of MdZAT11, with Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment indicating significant enrichment in stress-responsive pathways, particularly jasmonic acid (JA) biosynthesis. Further investigation revealed that MdZAT11 enhances the expression of JA biosynthesis genes (MdAOS, MdAOC, MdLOX6, and MdLOX3.1) by directly binding to their promoters, as demonstrated by electrophoretic mobility shift assays (EMSA), dual-luciferase reporter (DLR) assays, and RT-qPCR analysis, thereby augmenting JA biosynthesis. Taken together, our findings advance understanding of the transcriptional regulation of defense against P. expansum in apple and identify MdZAT11 as a candidate gene worth further investigation for disease resistance in this species.