LchERF, a novel ethylene-responsive transcription factor from Lycium chinense, confers salt tolerance in transgenic tobacco.

Abstract

An ERF gene, LchERF , was cloned from L. chinense for the first time. Overexpression of LchERF conferred salt stress tolerance in transgenic tobacco lines during seed germination and vegetative growth. Ethylene-responsive transcription factors (ERFs) play important roles in tolerance to biotic and abiotic stresses by regulating the expression of stress-responsive genes. Although the ERF proteins involved in defense responses against biotic stresses have been extensively documented, the mechanisms by which ERF subfamily genes regulate plant responses to abiotic stresses are largely unknown. In this study, a novel ethylene-responsive transcription factor, named LchERF, was isolated from Lycium chinense (a salinity-resistant plant). Analysis of the LchERF-deduced protein sequence showed that it had a typical AP2/ERF domain and belonged to the B-3 subgroup of the ERF subfamily. The expression of LchERF was found to be tissue specific in L. chinense under normal conditions. Upon treatment with NaCl, polyethylene glycol (PEG) or ethephon (ET), transcript levels of LchERF rapidly increased in L. chinense. Overexpression of LchERF conferred salt stress tolerance in transgenic tobacco during seed germination and vegetative growth. Compared with control lines, LchERF-overexpressing plants showed higher chlorophyll and proline contents, and were associated with lower H2O2 content under salt stress. Overall, our results demonstrate that LchERF might play an important role in the regulation of plant responses to abiotic stresses and mediate various physiological pathways that enhance salt stress tolerance in plants.