Genome-wide identification of the VOZ transcription factors in tomato (<i>Solanum lycopersicum</i>): their functions during fruit ripening and their responses to salinity stress

As a plant-specific transcription factor, vascular plant One-Zinc-finger (VOZ) is involved in the regulation of many biological processes. <i>VOZ</i> genes in tomato have not been analysed comprehensively so far. In this study, two <i>SIVOZ</i>s were identified on a genome-wide scale in tomato and analysed using various bioinformatics methods. According to Ka/Ks ratio, SlVOZ proteins are being changed by evolutionary processes to adapt to changing growth and stress conditions. Protein structure and phylogenetic analyses also indicated that transcriptional regulations of <i>SlVOZs</i> were controlled in a specific manner related to developmental stages and abiotic stress conditions. Digital expression results, in particular, showed that <i>SlVOZ</i>s are not only active during different growth status of tomato but are also involved in abiotic stress response mechanism. Nonetheless, <i>SlVOZ1</i> is expressed higher in both developmental stages and under salt stress conditions, confirmed by RT-qPCR. The co-expression maps constructed using RNA-seq data showed that <i>SlVOZ2</i> was associated with the genes involved in hormonal regulation, formation of fruit shape, secondary wall biosynthesis and in plant development. Overall, it can be concluded that <i>SlVOZ</i>s are not only important for plant growth and development but may also be part of the salt stress response mechanism.