Genome-wide identification and characterization of the JAZ gene family and its expression patterns under various abiotic stresses in Sorghum bicolor

The jasmonate ZIM domain (JAZ) protein belongs to the TIFY ((TIFF/Y]XG) domain protein) family, which is composed of several plant-specific proteins that play important roles in plant growth, development, and defense responses. However, the mechanism of the sorghum JAZ family in response to abiotic stress remains unclear. In the present study, a total of 17 JAZ genes were identified in sorghum using a Hidden Markov Model search. In addition, real-time quantification polymerase chain reaction (RT-qPCR) was used to analyze the gene expression patterns under abiotic stress. Based on phylogenetic tree analysis, the sorghum JAZ proteins were mainly divided into nine subfamilies. A promoter analysis revealed that the SbJAZ family contains diverse types of promoter cis-acting elements, indicating that JAZ proteins function in multiple pathways upon stress stimulation in plants. According to RT-qPCR, SbJAZ gene expression is tissue-specific. Additionally, under cold, hot, polyethylene glycol, jasmonic acid, abscisic acid, and gibberellin treatments, the expression patterns of SbJAZ genes were distinctly different, indicating that the expression of SbJAZ genes may be coordinated with different stresses. Furthermore, the overexpression of SbJAZ1 in Escherichia coli was found to promote the growth of recombinant cells under abiotic stresses, such as PEG 6000, NaCl, and 40°C treatments. Altogether, our findings help us to better understand the potential molecular mechanisms of the SbJAZ family in sorghum in response to abiotic stresses.