Abiotic Stress/Whole Plant Bio
CS-4-3 - To Grow or Survive: Plants Modulate Brassinosteroid-Regulated Transcription Factor BES1 During Drought to Mediate Growth-Stress Tradeoffs
Sunday, July 15
1:43 PM - 2:03 PM
Understanding how plants balance growth and stress responses is essential to optimize crop yield in an ever-changing environment. Brassinosteroids (BRs) regulate plant growth and stress responses, including that of drought. BRs signal to control the activities of the BES1/BZR1 family transcription factors, which in turn mediate the expression of more than 5,000 BR-responsive genes. However, the network through which BES1 regulates the large number of target genes and the factors that modulate BES1 during stress are only beginning to be understood. Our recent work has shown that several mechanisms converge on BES1 to restrain growth when stress is encountered. First, BES1 is degraded by selective autophagy during stress, which is mediated by autophagy receptor DSK2 and SINAT E3 Ubiquitin ligases (Nolan et al., 2017 Developmental Cell). Additionally, drought induced transcription factor RD26 inhibits the activity of BES1 on target gene promoters during drought conditions (Ye et al., 2017 Nature Communications). In contrast, under growth promoting conditions, BES1 cooperates with a large network of transcription factors including WRKY46/54/70 to inhibit drought responses, thereby enabling optimal growth (Chen et al., 2017 Plant Cell). To more fully characterize the BR-regulatory network, we used omics approaches to identify more than 500 BR-related Transcription Factors (BR-TFs) involved in both BR-regulated growth and drought responses. We built a comprehensive BR gene regulatory network using 11,760 microarray datasets and prioritized BR-TFs for phenomics studies, which identified hundreds of BR-TF mutants that display altered BR responses. Genetic and genomic analysis of these BR-TFs is being used to reveal how BR-TFs regulate specific aspects of growth and stress response programs. Taken together, BES1 is emerging as a critical hub for Brassinosteroid-drought crosstalk, allowing plants to efficiently balance growth and stress responses. This work is supported by NIH (1R01GM120316-01A1), NSF (IOS-1257631) and the Plant Sciences Institute at Iowa State University.
Sriram Chockalingam – Georgia Institute of Technology; Zaki Jubery – Iowa State University; Jiani Chen – Iowa State University; Mengran Yang – Huazhong Agricultural University; Zhouli Xie – Iowa State University; Ping Wang – Iowa State University; Adedotun Akintayo – Iowa State University; Dior Kelley – Iowa State University; Mingcai Zhang – China Agricultural University; Soumik Sarkar – Iowa State University; Xuelu Wang – Huazhong Agricultural University; Dan Nettleton – Iowa State University; Maneesha Aluru – Georgia Institute of Technology; Baskar Ganapathysubramanian – Iowa State University; Zhaohu Li – China Agricultural University; Srinivas Aluru – Georgia Institute of Technology; Patrick Schnable – Iowa State University; Diane Bassham – Iowa State University; Justin Walley – Iowa State University; Yanhai Yin – Iowa State University