The grapevine R2R3-type MYB transcription factor VdMYB1 positively regulates defense responses by activating the stilbene synthase gene 2 (VdSTS2)

Abstract

BackgroundResveratrol is a naturally occurring plant stilbene that exhibits a wide range of valuable biological and pharmacological properties. Although the beneficial effects of trans-resveratrol to human health and plant protection against fungal pathogens and abiotic stresses are well-established, yet little is known about the molecular mechanisms regulating stilbene biosynthesis in plant defense progress.ResultsHere, we cloned and identified the Chinese wild grape (Vitis davidii) R2R3-MYB transcription factor VdMYB1, which activates defense responses against invading pathogen. VdMYB1 transcripts were significantly upregulated after inoculation with the grapevine powdery mildew fungus Erysiphe necator (Schw.) Burr. Transient expression analysis using onion epidermal cells and Arabidopsis thaliana protoplasts showed that VdMYB1 was localized in the nucleus. Yeast one-hybrid assays revealed that VdMYB1 acts as a transcriptional activator. Grapevine leaves transiently overexpressing VdMYB1 showed a lower number of fungal conidiophores compared with wild-type leaves. Overexpression of VdMYB1 in grapevine leaves did not alter the expression of genes in salicylic acid- and jasmonate-dependent pathways, but affected the expression of stilbene synthase (STS) genes, key regulators of flavonoid metabolism. Results of electrophoretic mobility shift assays and in vivo transcriptional activation assays showed that VdMYB1 binds to the MYB binding site (MYBBS) in the STS2 gene promoter, thus activating STS2 transcription. In heterologous expression assays using tobacco leaves, VdMYB1 activated STS2 gene expression and increased the accumulation of resveratrol.ConclusionsOur study showed that VdMYB1 activates STS2 gene expression to positively regulate defense responses, and increases the content of resveratrol in leaves.Electronic supplementary materialThe online version of this article (10.1186/s12870-019-1993-6) contains supplementary material, which is available to authorized users.

Transcription Factors in Plant Stress Responses: Challenges and Potential for Sugarcane Improvement

“…CaPHL8, a novel MYB TF, was proven to be effective for increasing pepper plants immunity against Ralstonia solanacerum infection [129]. VdMYB1, a member of R2R3-MYB TF, was observed as a positive activator of the defense response by activating the expression of stilbene synthase gene2 (VdSTS2) against infection stress caused by Erysiphe necator fungus of grapevine [130]. Overall, MYB TFs play a crucial role in enhancing the tolerance of plants against all type of stresses via biotic stresses and abiotic stresses.…”

Fasciclin-like arabinogalactan gene family in Nicotiana benthamiana: genome-wide identification, classification and expression in response to pathogens

“…Several abundant predicted cis-acting elements are known to mediate plant immunity. For example, VdMYB1 binds to the MBS in the VdSTS2 gene promoter, thus activating VdSTS2 transcription and positively regulating defense responses [36]. Machi3-1 and TaRIM1 also bind MBS cis-acting elements to increase host resistance [37,38].…”

Fasciclin-like arabinogalactan gene family in Nicotiana benthamiana: genome-wide identification, classification and expression in response to pathogens

“…Several abundant predicted cis-acting elements are known to mediate plant immunity. For example, VdMYB1 binds to the MBS in the VdSTS2 gene promoter, thus activating VdSTS2 transcription and positively regulating defense responses [36]. Machi3-1 and TaRIM1 also bind MBS cisacting elements to increase host resistance [37,38].…”