Overexpression of StERECTA enhances drought tolerance in Arabidopsis thaliana.

Drought is a major abiotic stresses that severely hinder plant growth and agricultural productivity. The receptor-like kinase gene, ERECTA, has been proved to play important role in promoting the response to abiotic stress in crops. However, the specific molecular mechanisms underlying the drought resistance mediated by ERECTA in potato (Solanum tuberosum L.) are not well understood. In this study, sequence analysis confirmed that the StERECTA gene contains eight leucine-rich repeat (LRR) domains and an S_TKc domain, and these domains were highly conserved in Solanaceae family. Under drought stress, Arabidopsis thaliana strains overexpressing StERECTA showed increased biomass, proline (PRO) content, and antioxidant enzyme activities compared to the wild-type strains while the mutant ERECTA strain (er105) exhibited opposite phenotype. Additionally, StERECTA overexpression upregulated the expression of drought response marker genes (LEA3, DREB2A and P5CS1), improved levels of ABA and auxin, reduced stomatal density and relative expression level of stomatal development related genes (SPCH, FAMA and MUTE). Furthermore, Co-immunoprecipitation (Co-IP) assays demonstrated that StERECTA physically interacted with the YODA protein. In conclusion, our study provides new insights into the role and regulatory mechanism of StERECTA in response to drought stress. These findings may serve as a basis for genetic improvement of potato to enhance their tolerance to abiotic stress.