Genome-Wide Identification of TIFY Genes and Their Response to Various Pathogen Infections in Cucumber (Cucumis sativus L.)

Abstract

TIFY proteins are plant-specific transcription factors, which play important role in multiple biological processes in plants. Here, seventeen TIFY genes in cucumber (Cucumis sativus L.) were identified and could be divided into ZML (4 genes), JAZ (10 genes), TIFY (2 genes), and PPD (1 gene) subfamilies. TIFY family has various protein lengths (80aa-324aa) and gene exon numbers (2-11). In this study, phylogenetic tree, Ka/Ks ratio, and collinearity analysis provide more clues for the origin and evolution of the cucumber TIFY family. The prediction of protein interaction and cis-acting element reveal the function of TIFY family genes. RNA-seq data showed that all the TIFY genes respond to powdery mildew and downy mildew. qRT-PCR analysis showed that the expression of JAZ subfamily genes was significantly changed when plants were infected by four common cucumber diseases (powdery mildew, downy mildew, gummy stem blight, and gray mold). In particular, CsJAZ1 and CsJAZ2 were regulated by four pathogens, indicating that these two genes might play important roles in plant immunity. In addition, the relative expression of CsJAZ8 was up-regulated, while the relative expression of CsJAZ9 was down-regulated in disease resistance response. This study provides further understanding for the cucumber TIFY family genes and reveals that JAZ genes play important roles in cucumber hormone transmission and plant defense.