Tolerance of Arabidopsis thaliana plants overexpressing grapevine VaSTS1 or VaSTS7 genes to cold, heat, drought, salinity, and ultraviolet irradiation

Stilbene synthases (STS) are plant enzymes that are responsible for the biosynthesis of stilbenes, which are plant phenolic compounds with valuable biological properties. Stilbenes also play important roles in plant tolerance to biotic and abiotic stresses. Therefore, plants that overexpress STS genes can be more resistant to various stresses. This paper investigated the effects of STS gene overexpression in Arabidopsis thaliana (L.) Heynh. Columbia-0 plants on stilbene content and tolerance to the following abiotic stresses: low and high temperatures, salinity, drought, and ultraviolet irradiation (UV-B and UV-C). We used VaSTS1 and VaSTS7 genes from grapevine (Vitis amurensis Rupr.) expressed under the double cauliflower mosaic virus 35S (CaMV35S) promoter. This study firstly demonstrated that overexpression of the VaSTS1 and VaSTS7 genes in A. thaliana plants considerably increased plant tolerance to UV-B and UV-C, while the tolerance to the low and high temperatures, salinity, and drought was not affected. We showed that the highest trans-piceid and trans-resveratrol total content was in ST1 A. thaliana plants that overexpressed the VaSTS1 gene in the range 8.28 - 22.66 µg g-1(f.m.). ST7 plants that overexpressed the VaSTS7 gene showed only trans-resveratrol at 0.02 - 0.08 µg g-1(f.m). Stilbene content and UV tolerance in transgenic A. thaliana plants correlated with STS transgene expression. STS expression, UV tolerance, and stilbene content was higher in VaSTS1 transgenic plants compared with that in VaSTS7 transgenic plants.