发布时间 :2015-06-14  阅读次数 :1858

报告题目:Mechanisms of brassinsoteroid interacting with multiple hormonal and environmental signals

报  告 人:白明义 山东大学“齐鲁学者”特聘教授

报告时间:6月25日 9:30


联  系 人:林文慧 This e-mail address is being protected from spambots. You need JavaScript enabled to view it.


Abstract:      Plant growth and development are coordinated by many hormonal and environmental signals. The extensive studies of Brassinosteroid (BR) signaling network have uncovers the cross talk between BR and other signals through direct interactions between components of different signaling pathways. BZR1, the key transcription factor activated by BR signaling, interacts with the auxin-activated ARF6, the light-sensitive PIF4 and the GA-sensitive DELLA to form a  BZR1-ARF-PIF/DELLA module integrating BR, Auxin, GA and light to regulate seedling photomorphogenesis. But the molecular functions of this module in integrating signals to specify output remains unclear. Here we reported that the regulation of hypocotyl cell elongation by BZR1-ARF-PIF/DELLA module requires a triantagonistic HLH/bHLH cascade, PRE-IBH1-HBI1. Multiple members of PRE family of HLH factors were directly activated by BZR1, ARF6, and PIF4 to promote cell elongation through interacting antagonistically with another HLH factor, IBH1. IBH1 interacted with and inhibited the DNA-binding bHLH factor HBI1,whereas PRE1 interacts with IBH1 to prevent its inhibition of HBI1. The PRE-IBH1-HBI1 cascade coupling BZR1-ARF-PIF/DELLA module integrates BR, GA, auxin, temperature and light to regulate plant growth. To systematically investigate the function of PRE-IBH1-HBI1 cascade, we generated a genome-wide expression map and two-hybrid interactome network of PRE1, IBH1 and HBI1, and uncovered the significant effect of PRE-IBH1-HBI1 module on the biotic and abiotic stress response. Combination of transcriptome, interactome, and phenome data enhances our understanding of the functions of the triantagonistic PRE-IBH1-HBI1 module on the integration of hormonal and environmental signals to control plant growth and development.