BES/BZR Transcription Factor TaBZR2 Positively Regulates Drought Responses by Activation of TaGST1

Abstract

BRI1-EMS suppressor (BES)/brassinazole-resistant (BZR) family transcription factors are involved in a variety of physiological processes, but the biological functions of some BES/BZR transcription factors remain unknown; moreover, it is not clear if any of these proteins function in the regulation of plant stress responses. Here, wheat (Triticum aestivum) brassinazole-resistant 2 (TaBZR2)-overexpressing plants exhibited drought tolerant phenotypes, whereas downregulation of TaBZR2 in wheat by RNA interference resulted in elevated drought sensitivity. electrophoretic mobility shift assay and luciferase reporter analysis illustrate that TaBZR2 directly interacts with the gene promoter to activate the expression of T. aestivum glutathione s-transferase-1 (TaGST1), which functions positively in scavenging drought-induced superoxide anions (O 2 2). Moreover, TaBZR2 acts as a positive regulator in brassinosteroid (BR) signaling. Exogenous BR treatment enhanced TaBZR2-mediated O 2 2 scavenging and antioxidant enzyme gene expression. Taken together, we demonstrate that a BES/BZR family transcription factor, TaBZR2, functions positively in drought responses by activating TaGST1 and mediates the crosstalk between BR and drought signaling pathways. Our results thus provide new insights into the mechanisms underlying how BES/BZR family transcription factors contribute to drought tolerance in wheat.

Brassinosteroids: Multidimensional Regulators of Plant Growth, Development, and Stress Responses

“…TaBZR2, a BES1 and BZR1 homolog in wheat (Triticum aestivum), promotes drought responses by inducing the expression of wheat glutathione S-transferase1, which is involved in superoxide scavenging (Cui et al, 2019). Likewise, studies in tomato (Solanum lycopersicum) revealed that BRs promote drought tolerance, whereas overexpression of the BR receptor gene SlBRI1 had an opposite effect (Nie et al, 2019).…”

Overexpression of GmNFYA5 confers drought tolerance to transgenic Arabidopsis and soybean plants

“…Reports that overexpression of GmNFYA3 [31], Cdt-NFYC1 [11], RING-H2 [41] and GmTGA17 [42] conferred increased ABA sensitivity and drought tolerance in transgenic lines, were confirmed in this study ( Figure 3). Moreover, some physiological indices, especially the SWP, were not reported in previous reports [6,27,32,37]. One to six CCAAT cis-acting elements were detected in the promoters of all the marker genes used in this study (Table S2).…”

“…Drought is more widespread and damaging than salt stress [3]. Adaptation to drought involves complex regulatory networks involving control of water flux and cellular osmotic adjustment [4][5][6]. ABA regulates drought tolerance in plants by regulating stomatal aperture and modulating drought-responsive genes such as AP2/ERF and MYB family members that play important roles under drought stress [7][8][9].…”

Overexpression of GmNFYA5 confers drought tolerance to transgenic Arabidopsis and soybean plants

“…Reports that overexpression of GmNFYA3 [31], Cdt-NFYC1 [11], RING-H2 [41] and GmTGA17 [42] conferred increased ABA sensitivity and drought tolerance in transgenic lines, were confirmed in this study (Figure 3). Moreover, some physiological indices, especially the SWP, were not reported in previous reports [6,27,32,37]. Arabidopsis plants compared with WT plants under normal and drought conditions ( Figure 7E-I).…”