Genome-wide identification of TGA transcription factors in wheat and the TaTGA13 negatively modulates stripe rust...

TGA transcription factors are critical regulators of plant disease resistance, primarily through reactive oxygen species signaling. While extensively studied in model plants, the evolutionary relationships and functional roles of TGA TFs in hexaploid wheat (Triticum aestivum), particularly concerning pathogen resistance, remain poorly characterized. This study conducted a genome-wide identification of wheat TGA genes, identifying 38 TaTGAs phylogenetically classified into four groups. Analyses revealed conserved chromosomal locations, gene structures, motifs, and promoter cis-elements linked to hormones/stress. Expression profiling under Puccinia striiformis f. sp. tritici (Pst) infection identified 12 differentially expressed TaTGAs, with TaTGA13 significantly upregulated. Functional validation using virus-induced gene silencing (VIGS) demonstrated that TaTGA13 knockdown enhanced stripe rust resistance, identifying it as a negative regulator. This role was further supported by polymorphism and haplotype analysis of genome-wide association study (GWAS) data. Yeast two-hybrid (Y2H) assay confirmed specific protein interactions for TaTGA13. Our findings provide the first comprehensive analysis of the TGA family in wheat, revealing evolutionary conservation and establishing TaTGA13 as a susceptibility factor. This work offers a novel target for breeding resistant cultivars and a foundation for mining wheat resistance genes.