bHLH122 is important for drought and osmotic stress resistance in Arabidopsis and in the repression of ABA catabolism
Article first published online: 21 NOV 2013
© 2013 The Authors. New Phytologist © 2013 New Phytologist Trust
Volume 201, Issue 4, pages 1192–1204, March 2014
How to Cite
Liu, W., Tai, H., Li, S., Gao, W., Zhao, M., Xie, C. and Li, W.-X. (2014), bHLH122 is important for drought and osmotic stress resistance in Arabidopsis and in the repression of ABA catabolism. New Phytologist, 201: 1192–1204. doi: 10.1111/nph.12607
- Issue published online: 3 FEB 2014
- Article first published online: 21 NOV 2013
- Manuscript Accepted: 15 OCT 2013
- Manuscript Received: 8 AUG 2013
- National High-Tech R & D Program. Grant Number: 2012AA10A306
- National Science Foundation of China. Grant Numbers: 31071139, 31370303
- China Government to the Institute of Crop Science
- Chinese Academy of Agricultural Sciences. Grant Number: 2013001
- abiotic stress;
- Arabidopsis thaliana ;
- Although proteins in the basic helix-loop-helix (bHLH) family are universal transcription factors in eukaryotes, the biological roles of most bHLH family members are not well understood in plants.
- The Arabidopsis thaliana bHLH122 transcripts were strongly induced by drought, NaCl and osmotic stresses, but not by ABA treatment. Promoter::GUS analysis showed that bHLH122 was highly expressed in vascular tissues and guard cells. Compared with wild-type (WT) plants, transgenic plants overexpressing bHLH122 displayed greater resistance to drought, NaCl and osmotic stresses. In contrast, the bhlh122 loss-of-function mutant was more sensitive to NaCl and osmotic stresses than were WT plants.
- Microarray analysis indicated that bHLH122 was important for the expression of a number of abiotic stress-responsive genes. In electrophoretic mobility shift assay and chromatin immunoprecipitation assays, bHLH122 could bind directly to the G-box/E-box cis-elements in the CYP707A3 promoter, and repress its expression. Further, up-regulation of bHLH122 substantially increased cellular ABA levels.
- These results suggest that bHLH122 functions as a positive regulator of drought, NaCl and osmotic signaling.