VqMAPKKK38 is essential for stilbene accumulation in grapevine

Yuntong Jiao,Changyue Jiang,Dan Wang,Lan Wang,Yuejin Wang

doi:10.1038/hortres.2017.58

Yuntong Jiao, Changyue Jiang + Show 3 more

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https://doi.org/10.1038/hortres.2017.58

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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 (H2O2) and calcium influx activated VqMAPKKK38 expression and stilbene biosynthesis, which suggests that VqMAPKKK38 may be involved in the calcium signaling and ROS signaling pathways.

Highlights

As sessile organisms, plants are constantly exposed to a wide range of biotic and abiotic stresses and have evolved a large number of sophisticated signal transduction mechanisms to both regulate their development and enhance their resistance to these stressors
Recent transcriptome data from four developmental stages of berry material from V. quinquangularis accession ‘Danfeng-2’ were analyzed by our colleagues (SRA; SRP067690), and VqMAPKKK38 was predicted to play a role in the regulation of stilbene accumulation
We investigated the involvement of VqMAPKKK38 in stilbene biosynthesis and signal transduction

Summary

Introduction

Plants are constantly exposed to a wide range of biotic and abiotic stresses and have evolved a large number of sophisticated signal transduction mechanisms to both regulate their development and enhance their resistance to these stressors. It has been established that MAPK cascades function in basal immunity 49 and are activated in response to various abiotic and biotic stresses.[5] we analyzed the expression profiles of VqMAPKKK38 during powdery mildew infection, as well as following salt, chilling, heat and wounding treatments.

Results

Conclusion