Transcription factors participate in response to powdery mildew infection in Paeonia lactiflora

Herbaceous peony (Paeonia lactiflora Pall) is a horticulturally important ornamental species that is widely cultivated in China. Biotic stress can strongly affect the quality and seed yield of herbaceous peony. Powdery mildew caused by the fungus Erysiphe polygoni is a serious biotic stress factor resulting in great losses to the peony cultivation industry. Although the molecular mechanisms underlying powdery mildew resistance have been studied extensively in various plant species, little is known about these mechanisms in P. lactiflora. In this study, we investigated the expression patterns of genes, using transcriptome profiling. During the expressed genes, we mainly focused on key TF genes that exhibited at least a log(2) fold change >= 5 difference in expression level. The identified TFs genes were most belonged to the Zn-clus, C2H2, and MTh TF families. Furthermore, we examined the expression patterns of transcription factor genes in susceptible and resistant herbaceous peony varieties and identified a set of transcription factor genes that are differentially expressed in leaves in response to powdery mildew infection Based on our result, the MYB TF Pl10128 plays a critical role in defense against powdery mildew in herbaceous peony, and the AP2 TF Pl52977 is a negative regulator in response to powdery mildew of resistant variety 'Ling Long Yu'. Taken together, this work will contribute the key transcription factors that might enhance plant immunity by controlling the expression of downstream defense-related gene.