Molecular Characterization and Stress Induced Expression Profiling of TIFY Family Genes in Chinese Cabbage (Brassica rapa ssp. pekinensis)

The TIFY family is a novel, plant-specific group of genes and has been reported widely for their important functions related to biological processes, such as plants development, stress and hormone responses in different crop species. Till date, there is no information related to TIFY genes in any Brassica crop. Here, we reports 36 TIFY genes in Brassica rapa, an economically important crop species from Brassicaceae. In silico analyses confirmed 36 TIFY genes under four subfamilies (JAZ, TIFY, ZML and PPD) in B. rapa, where highest 21 TIFY genes are from JAZ subfamily. Afterwards, RT-PCR expression analysis revealed JAZ genes with constitutive expression patterns in floral organs and flower growth stages of B. rapa. To elucidate the stress responses of B. rapa JAZs, we analyzed low temperature-treated whole-genome microarray data set, where they showed variable transcript abundance between two contrasting inbred lines Chiifu and Kenshin. Subsequently, from qPCR validation study, nine JAZs showed differential up- regulation against cold stress in the same two lines. Specifically, a high and differential expression of JAZs against JA treatment indicates about their JA mediated growth regulatory functions. Furthermore, BrTIFY JAZs have also showed variable induction in response to salt, drought, Fusarium, ABA and SA treatments, where six genes (BrTIFY3a, 3b, 6a, 9a, 9b and 9c) showed corresponsive expression against all the stresses. Extensive annotation and expression profiling data related to TIFY genes presented here might be useful for functional characterization and exploitation of these genes in the fertility and stress resistance study of B. rapa.