Notice: Reference genome sequences of TM-1 and 3-79 are available!
Current Position:Home > Least Research

GbSOBIR1 confers Verticillium wilt resistance by phosphorylating the transcriptional factor GbbHLH171 in Gossypium barbadense

Update Time: 2018-05-25 09:30:47Click: times
Yi Zhou, Longqing Sun, Ghulam Mustafa Wassan, Xin He, Muhammad Shaban, Lin Zhang, Longfu Zhu* Xianlong Zhang.2018.Plant Biotechnology Journal


Receptorlike kinases (RLKs) are important components of plant innate immunity. Although recent studies have revealed that the RLK SUPPRESSOR OF BIR11 (SOBIR1) can interact with multiple receptorlike proteins (RLPs) and is required for resistance against fungal pathogens, how the signal is transduced and triggers immune responses remains enigmatic. In this study, we identified a defenserelated RLK from Gossypium barbadense (designated GbSOBIR1) and investigated its functional mechanism. Expression of the GbSOBIR1 gene is ubiquitous in cotton plants and is induced by Verticillium dahliae inoculation. Knockdown of GbSOBIR1 by virusinduced gene silencing resulted in attenuated resistance of cotton plants to V. dahliae, while heterologous overexpression of GbSOBIR1 in Arabidopsis improves resistance. We also found that the kinase region of GbSOBIR1 interacts with a basic helixloophelix (bHLH) transcription factor identified as GbbHLH171 in a yeasttwohybrid screen. GbbHLH171 could interact with and be phosphorylated by GbSOBIR1 in vitro and in vivo and contributes positively to the resistance of cotton against V. dahliae. Furthermore, we found that this phosphorylation is essential to the transcriptional activity and functional role of GbbHLH171. We also show by spectrometric analysis and Sitedirected mutagenesis that Ser413 is the GbSOBIR1mediated phosphorylation site of GbbHLH171. These results demonstrate that GbSOBIR1 interacts with GbbHLH171 and plays a critical role in cotton resistance to V. dahliae.