BREVIPEDICELLUS Positively Regulates Salt-Stress Tolerance in Arabidopsis thaliana

Abstract

Salt stress is one of the major environmental threats to plant growth and development. However, the mechanisms of plants responding to salt stress are not fully understood. Through genetic screening, we identified and characterized a salt-sensitive mutant, ses5 (sensitive to salt 5), in Arabidopsis thaliana. Positional cloning revealed that the decreased salt-tolerance of ses5 was caused by a mutation in the transcription factor BP (BREVIPEDICELLUS). BP regulates various developmental processes in plants. However, the biological function of BP in abiotic stress-signaling and tolerance are still not clear. Compared with wild-type plants, the bp mutant exhibited a much shorter primary-root and lower survival rate under salt treatment, while the BP overexpressors were more tolerant. Further analysis showed that BP could directly bind to the promoter of XTH7 (xyloglucan endotransglucosylase/hydrolase 7) and activate its expression. Resembling the bp mutant, the disruption of XTH7 gave rise to salt sensitivity. These results uncovered novel roles of BP in positively modulating salt-stress tolerance, and illustrated a putative working mechanism.

Reconstruction and analysis of the gene regulatory network for cell wall function in <i>Arabidopsis thaliana</i> L. leaves in response to water deficit

“…The XTH7 enzyme and its activity have not been fully characterized yet. According to gene expression data, XTH7 is involved in salt resistance and ethylene-dependent apple softening (Zhang et al, 2017;Cai et al, 2023). It also participates in processes such as cell enlargement and restructuring.…”