A specific allele of MYB14 in grapevine correlates with high stilbene inducibility triggered by Al3+ and UV-C radiation

Abstract

Key messageThe structural differences of MYB14 promoter in two grapevine genotypes affect the expression of MYB14 and stilbene synthesis in response to Al3+ and UV-C radiation.AbstractGrapevines provide an important fruit crop worldwide, but production is often limited by pathogen infection. Stilbenes, a class of secondary metabolite, represent phytoalexins that contribute to defence against pathogens in many plants, including grapevine. It is known that the transcription factors MYB14 and MYB15 are required for the activation of the promoters of resveratrol synthase to regulate stilbene biosynthesis. In the current study, we observed that stilbene levels were more highly induced by Al3+ and UV-C radiation treatments in the cultivar Vitis labrusca ‘Concord’ than in the cultivar V. vinifera ‘Cabernet Sauvignon’. We investigated whether genetic/structural variations in the MYB14 and MYB15 promoters between these two representative genotypes are responsible for the differences in stilbene accumulation. Significant differences in the structure and activity of the promoter of MYB14, but not MYB15 were identified between the two genotypes, following heterologous expression in Nicotiana benthamiana system and treatments with Al3+ and UV-C. Hydrogen peroxide (H2O2) was detected in Concord soon after the stress treatments, but after diphenyleneiodonium chloride pre-treatment, the expressing level of VlMYB14, the promoter activity of VlMYB14 and the accumulation of stilbenes was significantly reduced. A model is presented where the induction of MYB14 contributes to stilbene accumulation in Concord following Al3+ and UV-C treatments involving reactive oxygen species (ROS) production as an early signal.Electronic supplementary materialThe online version of this article (10.1007/s00299-018-2347-9) contains supplementary material, which is available to authorized users.

Changes in the chlorophyll content of grape leaves could provide a physiological index for responses and adaptation to UV‐C radiation

“…MDA can be used as a stress indicator, since it is a signal molecule associated with rapid cellular responses during early defense responses (Bai et al 2019). We measured changes in MDA levels and, as shown in Fig.…”

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

“…In grapevine, STS enzymes mediate the biosynthesis of stilbenes and exhibit broad-spectrum resistance to various pathogens [19]. To explore the molecular mechanisms of V. davidii cv.…”

“…Recent research has indicated that ROS not only function as toxic compounds that lead HR, but also act important early signal molecules [30]. Duan et al, proposed that ROS are necessary for the induction of stilbene synthase, and resulted in production of proanthocyanidin [19]. Jiao et al, reported that the accumulation of trans-resveratrol, trans-piceid and cis-piceid markedly increased after treatment with H 2 O 2 [31].…”

Transcriptomic and Metabolomic Basis of Short- and Long-Term Post-Harvest UV-C Application in Regulating Grape Berry Quality Development

“…Pre-harvest UV-C treatment can increase the expression levels of FaCHS1 , FaCHI , FaFHT , FaDFR , FaFLS , and FaFGT to promote the accumulation of polyphenols in strawberry fruit [ 42 ]. Stilbene biosynthesis could be promoted by MYB14 under UV-C [ 43 ]. UV-B can affect low molecular weight polyphenol (LMWP) accumulation by promoting DNA methylation to regulate the acclimation mechanisms of plants [ 36 ].…”