The effect of stress hormones, UV-C, and stilbene precursors on calmodulin (CaM) and calmodulin-like gene (CML) expression in Vitis amurensis Rupr

Calmodulins (CaMs) and calmodulin-like proteins (CMLs) are important plant Ca2+ sensor proteins implicated in the regulation of plant response to a variety of biotic and abiotic environmental cues. The knowledge on the relationship of calcium sensor proteins with plant defense responses and secondary metabolite production remains limited. The present study aimed for a comprehensive analysis of CaM and CML gene expression in a highly resistant grapevine Vitis amurensis Rupr., known as a reach stilbene source, in response to stress hormones (salicylic acid or SA, methyl jasmonate or MeJA), phenolic precursors (p-coumaric acids or CAs), and ultraviolet irradiation (UV-C). Using quantitative real-time PCR (qRT-PCR), we analyzed the expression of 3 VaCaM and 54 VaCML genes in the leaves and cell cultures of V. amurensis coupled to the activation of stilbene biosynthesis in response to the treatments. MeJa highly up-regulated 4 and 8 VaCML genes in the V. amurensis leaves and the cell cultures at both concentrations tested, respectively; while SA induced 4 and 6 VaCMLs. UV-C irradiation considerably up-regulated 4 and 9 VaCML genes in the leaves and cell cultures, respectively, both 1 h and 24 h post-treatment. At the same time, the MeJa, SA, and UV treatments exerted a profound down-regulation effect on 3 VaCML genes. VaCaM showed a lower responsiveness to the treatments, with irregular VaCaM8 and VaCaM10 transcriptional changes. CA treatment mostly did not affect VaCaM or VaCML expression. The highly up-regulated CaM and CML genes are suggested as promising candidates playing important roles in stress hormone signaling, UV-C responses, and stilbene biosynthesis. Key message Using quantitative real-time PCR we analyzed the expression of 3 calmodulins (VaCaM) and 54 calmodulin-like proteins (VaCML) mRNA transcripts in grapevine Vitis amurensis leaves and cell cultures affected by inductors of the stilbene biosynthesis.

Automated summary

This study conducted a comprehensive analysis of the expression of CaM and CML genes in highly resistant grapevine Vitis amurensis in response to stress hormones, phenolic precursors, and ultraviolet irradiation. The results showed that MeJA and SA significantly regulated the expression of VaCML genes, while UV-C irradiation had a notable impact on VaCML gene expression.