Abstract

The calcium sensing receptor (CAS) plays an important role in plant growth and development and resistance to abiotic stresses. In this study, a VyCAS gene was cloned from the accession 'Yanshan-1′, an extremely drought-tolerant Chinese wild Vitis yeshanensis . To gain insight into the roles of VyCAS , we overexpressed it in the V. vinifera cultivar 'Thompson Seedless' by Agrobacterium -mediated genetic transformation and obtained three transgenic grape lines. Compared with the wild type (WT), the transgenic lines were less damaged by drought, and had lower transpiration rate, stomatal conductance, malondialdehyde (MDA) content, electrolyte leakage, H 2 O 2 and O 2 − accumulations but higher leaf relative water content, photosynthetic water use efficiency, CAT, POD and SOD activities. Meanwhile, after drought, the transcript levels of some drought-related genes ( RD22, DREB2A, NAC72, SRK2A, CBL1 , and CYP707A2 ) in the transgenic lines were much higher than in the WT. Taken together, these results show that VyCAS can improve the drought tolerance of transgenic grapevine. Further experiments confirmed that Arabidopsis with a CAS mutation was more sensitive to drought than the WT. In addition, VyMYB59, a negative regulator of the promoter of VyCAS gene, was screened by the yeast one-hybrid, luciferase and GUS activity assays. This will help us to further explore the drought tolerance mechanism of VyCAS and provide a new thought for the following research.