Differential Expression Patterns Within the Grapevine Stilbene Synthase Gene Family Revealed Through Their Regulatory Regions

The analyses of the grapevine (Vitis vinifera L.) genome have revealed an unusually large and closely related stilbene synthase (VvSTS) gene family. Interestingly, despite the high sequence similarity among those genes, several studies have observed clear differences between their expression patterns. Here, we studied the transcriptional responses to different elicitors of several VvSTSs in cellular suspension cultures. Primarily, we performed the in silico analysis of the VvSTS regulatory sequences and found the presence of several putative cis-regulatory elements. Then, we evaluated the effect of three treatments—naphtalene acetic acid, methyl jasmonate (MeJA), and ethylene—over the gene expression and found that the genes follow expression patterns probably specific to their sequences. According to this, we focused our study on their regulatory regions and adopted a novel and efficient transient expression assay to determine the activity of these promoters. The results demonstrated that variation in gene expression could be assessed through the analysis of VvSTS regulatory sequences under the effect of different stimuli such as MeJA and cyclodextrins. Furthermore, taking advantage of the lower sequence identity at the promoter level, this strategy accomplished a more accurate alternative to differentiate the members of a large multi-gene family such as STS.