AUTHOR=Wang Yi , Yu Wanting , Ran Lingfang , Chen Zhong , Wang Chuannan , Dou Yang , Qin Yuanyuan , Suo Qingwei , Li Yaohua , Zeng Jianyan , Liang Aimin , Dai Yonglu , Wu Yiping , Ouyang Xufen , Xiao Yuehua TITLE=DELLA-NAC Interactions Mediate GA Signaling to Promote Secondary Cell Wall Formation in Cotton Stem JOURNAL=Frontiers in Plant Science VOLUME=12 YEAR=2021 URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2021.655127 DOI=10.3389/fpls.2021.655127 ISSN=1664-462X ABSTRACT=

Gibberellins (GAs) promote secondary cell wall (SCW) development in plants, but the underlying molecular mechanism is still to be elucidated. Here, we employed a new system, the first internode of cotton, and the virus-induced gene silencing method to address this problem. We found that knocking down major DELLA genes via VIGS phenocopied GA treatment and significantly enhanced SCW formation in the xylem and phloem of cotton stems. Cotton DELLA proteins were found to interact with a wide range of SCW-related NAC proteins, and virus-induced gene silencing of these NAC genes inhibited SCW development with downregulated biosynthesis and deposition of lignin. The findings indicated a framework for the GA regulation of SCW formation; that is, the interactions between DELLA and NAC proteins mediated GA signaling to regulate SCW formation in cotton stems.