VqMAPKKK38 is essential for stilbene accumulation in grapevine. (18th October 2017)

• Record Type: Journal Article
• Authors: Jiao, Yuntong; Wang, Dan; Wang, Lan; Jiang, Changyue; Wang, Yuejin
• Is Part Of: Horticulture research. Volume 4(2017)
• Publication Date: 2017-10-18
• Subjects: Plant sciences -- Plant stress responses; Horticulture -- Research -- Periodicals; 635.072
• DOI: 10.1038/hortres.2017.58
• Languages: English
• ISSNs: 2052-7276

Abstract

Abstract: Vitis species, including grapevine, produce a class of secondary metabolites called stilbenes that are important for plant disease resistance and can have positive effects on human health. Mitogen-activated protein kinase (MAPK) signaling cascades not only play key roles in plant defense responses but also contribute to stilbene biosynthesis in grapevine. MAPKKKs function at the upper level of the MAPK network and initiate signaling through this pathway. In this study, a Raf-like MAPKKK gene, VqMAPKKK38, was identified and functionally characterized from the Chinese wild grapevine V. quinquangularis accession 'Danfeng-2'. We observed that VqMAPKKK38 transcript levels were elevated by powdery mildew infection, high salinity conditions and chilling stresses, as well as in response to treatments by the hormones salicylic acid (SA), methyl jasmonate (MeJA), ethylene (Eth) and abscisic acid (ABA). In addition, based on both transient overexpression and gene suppression of VqMAPKKK38 in grapevine leaves, we found that VqMAPKKK38 positively regulates stilbene synthase transcription and stilbene accumulation probably by mediating the activation of the transcription factor MYB14 . In addition, both hydrogen peroxide (H2 O2 ) and calcium influx activated VqMAPKKK38 expression and stilbene biosynthesis, which suggests that VqMAPKKK38 may be involved in the calcium signaling and ROS signaling pathways. Abstract : Plant defense: What stimulates stilbene production? A wild grapevine gene encodes the first component of a stress-triggered signaling cascade generating key defense molecules called stilbenes. Stilbenes are metabolites with important roles in plant protection, and are also believed to be beneficial to human health. Activation of the gene VqMAPKKK38 initiates a cascade of molecular signals linked to stilbene production in a Chinese relative of the cultivated grapevine. Yuejin Wang and colleagues of Northwest A&F University, Yangling, China, explored the triggers that switch on this gene. They found that VqMAPKKK38 activity was enhanced by stresses including cold, high-salt conditions, powdery mildew infection, and by hormones involved in plant defense. They also showed that stilbenes accumulate when VqMAPKKK38 is activated. These insights will support future breeding programs aimed at generating stress-resistant varieties of grapevine.