Genome-wide identification of phospholipase D gene family in wheat reveals miRNA-regulated module underlying FHB resistance

Phospholipase D (PLD)-mediated lipid signalling is a crucial component of plant defence responses. However, the PLD gene family remains poorly characterised in hexaploid wheat ( Triticum aestivum L.), particularly regarding its role in resistance to Fusarium head blight (FHB), a devastating fungal disease. This study identified 178 non-redundant PLD genes in the wheat genome and comprehensively analysed their phylogenetic relationships, conserved domains, chromosomal distribution, promoter cis-elements, and expression profiles under Fusarium graminearum infection. These PLDs were classified into C2-dependent, PX–PH, and uncharacterised types. Promoter analysis revealed stress- and hormone-responsive cis-elements, while expression profiling demonstrated genotype-dependent induction patterns, with several PLDs strongly upregulated in the resistant genotype. We experimentally validated that tae-miR160 targets specific TaPLD transcripts, revealing a post-transcriptional regulatory layer. Furthermore, polymorphic SSR markers were developed from PLD loci for potential use in marker-assisted breeding. This study provides the first evidence of a miRNA–PLD regulatory network in wheat defence and highlights PLDs as critical mediators of FHB resistance.