Expression of Cystathionine-β-Synthase (CBS) Genes in Grape under Various Abiotic Stresses and Subcellular Localization of VvCBS27

The cystathionine-β-synthase (CBS) domain is present in the proteins of all living organisms and functions as an energy sensor, regulating protein activity through the binding capacity of its adenosine ligands. The role of the CBS gene in plant growth and development, as well as tolerance to abiotic stresses, remains largely unknown, especially in grapevine. In our study, 32 members of the CBS gene family were obtained that were distributed on 15 chromosomes. The results of the structural and evolutionary tree analyses indicated that the VvCBS gene family exhibits diverse intron-exon patterns and highly conserved motifs. Furthermore, the phylogenetic classification of the VvCBS genes revealed the presence of three subfamilies. Subcellular localization analyses showed that the VvCBS genes are mainly located in the plasma membrane region. The secondary structure of the VvCBS protein mainly consists of α-helices, extended strands, β-turns, and random coils. The VvCBS gene family exhibited four co-linear gene pairs, while the numbers for Arabidopsis thaliana and rice were 21 and 7, respectively. The promoter cis-acting element analysis revealed the presence of light-responsive, hormone-responsive, stress-responsive, and growth- and development-related elements in the VvCBS family. The expression characterization demonstrated that 12 VvCBS genes exhibited high expression levels in all grape tissues. Additionally, the RT-qPCR expression analyses showed that the 32 VvCBS exhibited different responses to a variety of abiotic stresses (cold, drought, salt), suggesting that they were functionally differentiated. VvCBS27 was cloned from ‘Pinot Noir’ of grapevine with a coding sequence of 624 bp. Subcellular localization showed that VvCBS27 protein was mainly located in the cytoplasm, cell membrane, and nucleus. This study lays a foundation for elucidating the function of grape CBS protein.