The BR signaling pathway regulates primary root development and drought stress response by suppressing the expression of PLT1 and PLT2 in Arabidopsis thaliana

Abstract

IntroductionWith the warming global climate, drought stress has become an important abiotic stress factor limiting plant growth and crop yield. As the most rapidly drought-sensing organs of plants, roots undergo a series of changes to enhance their ability to absorb water, but the molecular mechanism is unclear.Results and methodsIn this study, we found that PLT1 and PLT2, two important transcription factors of root development in Arabidopsis thaliana, are involved in the plant response to drought and are inhibited by BR signaling. PLT1- and PLT2-overexpressing plants showed greater drought tolerance than wild-type plants. Furthermore, we found that BZR1 could bind to the promoter of PLT1 and inhibit its transcriptional activity in vitro and in vivo. PLT1 and PLT2 were regulated by BR signaling in root development and PLT2 could partially rescue the drought sensitivity of bes1-D. In addition, RNA-seq data analysis showed that BR-regulated root genes and PLT1/2 target genes were also regulated by drought; for example, CIPK3, RCI2A, PCaP1, PIP1;5, ERF61 were downregulated by drought and PLT1/2 but upregulated by BR treatment; AAP4, WRKY60, and AT5G19970 were downregulated by PLT1/2 but upregulated by drought and BR treatment; and RGL2 was upregulated by drought and PLT1/2 but downregulated by BR treatment.DiscussionOur findings not only reveal the mechanism by which BR signaling coordinates root growth and drought tolerance by suppressing the expression of PLT1 and PLT2 but also elucidates the relationship between drought and root development. The current study thus provides an important theoretical basis for the improvement of crop yield under drought conditions.

SlSERK3B Promotes Tomato Seedling Growth and Development by Regulating Photosynthetic Capacity

“…In our study, EBR treatment significantly increased the expression of the BR receptor gene BRI1, the co-receptor gene SERK3A and its homolog SERK3B, and the transcription factor BZR1. The BR signaling pathway regulated primary root development and drought stress response by suppressing the expression of PLT1 and PLT2 in A. thaliana [26]. This further suggests that key genes in the BR signaling pathway may be involved in the promotion of plant growth and development.…”

ZmC2H2‐149 negatively regulates drought tolerance by repressing ZmHSD1 in maize

“…Exogenous brassinolide (BL) treatment induced OsHSD1 expression, suggesting that it may have a specific role in epidermal formation and maintaining lipid balance by mediating sterol signalling (Zhang, Cheng, et al, 2016). BRs are plant steroids that regulate numerous developmental processes, such as cell division, morphogenesis, elongation, and stress responses, including drought stress (Jan et al, 2018;Marková et al, 2023;Tang et al, 2023;Yusuf et al, 2022;Zhao et al, 2023). ZmC2H2-149 may be involved in the BR pathway response to drought stress through ZmHSD1.…”

Exogenous 24-Epibrassinolide Enhanced Drought Tolerance and Promoted BRASSINOSTEROID-INSENSITIVE2 Expression of Quinoa

“…The reduction in root morphology parameters was due to the inhibition of cell division and expansion under drought stress, resulting in the inhibition of growth and biomass accumulation. EBR application could alleviate the decrease in the root morphology parameters; it may be due to EBR treatment up-regulating the expression level of genes that promote root development [ 6 , 7 ].…”

“…BRs are a class of natural steroid hormones that regulate plant growth and development and promote growth and enhance plant resistance to biotic and abiotic stresses [ 5 , 6 , 7 ]. The contribution of exogenous BR treatments to drought tolerance has been studied in many plants.…”