Conserved hierarchical gene regulatory networks for drought and cold stress response in .

Stress response in plant is regulated by a large number of genes co-operating in diverse networks that serve multiple adaptive process. To understand how gene regulatory networks (GRNs) modulating abiotic stress responses, we compare the GRNs underlying drought and cold stresses using samples collected at 4 or 6 h intervals within 48 h in Chinese bayberry (). We detected 7,583 and 8,840 differentially expressed genes (DEGs) under drought and cold stress respectively, which might be responsive to environmental stresses. Drought- and cold-responsive GRNs, which have been built according to the timing of transcription under both abiotic stresses, have a conserved trans-regulator and a common regulatory network. In both GRNs, basic helix-loop-helix family transcription factor (bHLH) serve as central nodes. transcripts exhibited continuous increase in the two abiotic stresses and acts upstream regulator of () gene. To examine the potential biological functions of , we generated a transgenic plant that constitutively overexpresses the gene. Compared to wild-type (WT) plants, overexpressing transgenic plants maintained higher APX activity and biomass accumulation under drought and cold stress. Consistently, RNAi plants had elevated susceptibility to both stresses. Taken together, these results suggested that mitigates abiotic stresses through the modulation of ROS scavenging.