The Conringia planisiliqua Alfin-like2 gene enhances drought and salt tolerance in Arabidopsis thaliana

Alfin-like (AL) gene plays a role in regulation of plant abiotic stress. Here we aimed to find a AL gene from the drought and salt stress tolerant plant Conringia planisiliqua. The approximately 187 bp long core fragments and the RACE method were used to obtain a full-length cDNA of approximately 1120 bp with an open reading frame of 735 bp. This cDNA encodes a protein composed of 245 amino acids with a calculated molecular mass of 27.691 kD. Real-time quantitative PCR analysis showed that expression of CpAL2 was induced strongly under 20% PEG6000 drought and 200 mM (NaCl) salt stress. Three independent overexpression lines were obtained and used for functional analysis. The survival rate of CpAL2-overexpressing A. thaliana plant was 2.5 times of wild-type A. thaliana under the soil drought stress. Under drought stress 1/2MS (- 0.5 MPa) plate, the overexpression lines grown on PEG plate exhibit a significantly greater root length compared with the control plants. The survival rate of CpAL2-overexpressing A. thaliana plant was approximately 1.4 times of wild-type A. thaliana under 200 mM center dot NaCl salt stress. Under 150 mM salt stress 1/2MS plate, the root growth of CpAL2-overexpressing A. thaliana plant was increased by 1.75-2.12 folds of wild-type A. thaliana. Overexpression of CpAL2 gene significantly enhanced salt tolerance and drought resistance in transgenic Arabidopsis. Our data indicated that CpAL2 plays an important role in the regulation of stress-responses, and is useful in Arabidopsis with improving tolerance to salt and drought stresses.