Arabidopsis AtbHLH112 protein binds to the G-box and a novel motif GCG-box to regulate gene expression in response to abiotic stress

ABSTRACT: Plant basic helix-loop-helix (bHLH) proteins play essential roles in physiological and developmental processes and are also involved in abiotic stresses. However, their exact roles in abiotic stress are still not fully understood, and most of them have not been functionally characterised. In the present study, we characterised the functional role of AtbHLH112 in response to abiotic stress. A WRKY gene, AtWRKY66, can regulate the expression of the AtbHLH112 via binding to W-box motifs present in its promoter. AtbHLH112 is a nuclear-localised protein, and its nuclear localisation is increased upon exposure to NaCl, mannitol and ABA. In addition to binding to the G-box motif, AtbHLH112 is found to bind to a novel motif M-bM-^@M-^\GGGCCGGTCM-bM-^@M-^] (named the GCG-box) to regulate gene expression. Gain- and loss-of-function analyses showed that the transcript level of AtbHLH112 is positively correlated with tolerance to salt and drought. AtbHLH112 can confer stress tolerance via enhanced expression of POD and SOD genes to improve ROS scavenging ability and via upregulated expression of P5CS genes and decreased expression of P5CDH and PRODH genes to improve proline levels. Our data suggested that AtbHLH112 regulates the expression of genes via binding to the G-box and the GCG-box to improve stress-related pathways, such as ROS scavenging and proline biosynthesis. Differentially expression genes of AtbHLH112-overexpression plants and mutant (SALK_033618C) plants of Arabidopsis thaliana were measured under salt stressed and normal condition for 3 hours, respectively. Three independent experiments were performed at each treatment using different plants for each experiment.

ORGANISM(S): Arabidopsis thaliana

SUBMITTER: Yujia Liu 

PROVIDER: E-GEOD-52326 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress