AUTHOR=Ren Zhongying , Liu Wei , Wang Xingxing , Chen Mingjiang , Zhao Junjie , Zhang Fei , Feng Hongjie , Liu Ji , Yang Daigang , Ma Xiongfeng , Li Wei 

TITLE=SEVEN IN ABSENTIA Ubiquitin Ligases Positively Regulate Defense Against Verticillium dahliae in Gossypium hirsutum

JOURNAL=Frontiers in Plant Science

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2021.760520

DOI=10.3389/fpls.2021.760520

ISSN=1664-462X

ABSTRACT=<p>Ubiquitination is a post-translational regulatory mechanism that controls a variety of biological processes in plants. The E3 ligases confer specificity by recognizing target proteins for ubiquitination. Here, we identified SEVEN IN ABSENTIA (SINA) ubiquitin ligases, which belong to the RING-type E3 ligase family, in upland cotton (<italic>Gossypium hirsutum</italic>). Twenty-four <italic>GhSINA</italic>s were characterized, and the expression levels of <italic>GhSINA7</italic>, <italic>GhSINA8</italic>, and <italic>GhSINA9</italic> were upregulated at 24 h after inoculation with <italic>Verticillium dahliae</italic>. <italic>In vitro</italic> ubiquitination assays indicated that the three GhSINAs possessed E3 ubiquitin ligase activities. Transient expression in <italic>Nicotiana benthamiana</italic> leaves showed that they localized to the nucleus. And yeast two-hybrid (Y2H) screening revealed that they could interact with each other. The ectopic overexpression of <italic>GhSINA7</italic>, <italic>GhSINA8</italic>, and <italic>GhSINA9</italic> independently in <italic>Arabidopsis thaliana</italic> resulted in increased tolerance to <italic>V. dahliae</italic>, while individual knockdowns of <italic>GhSINA7</italic>, <italic>GhSINA8</italic>, and <italic>GhSINA9</italic> compromised cotton resistance to the pathogen. Thus, <italic>GhSINA7</italic>, <italic>GhSINA8</italic>, and <italic>GhSINA9</italic> act as positive regulators of defense responses against <italic>V. dahliae</italic> in cotton plants.</p>