AUTHOR=Jia Pei , Tang Ye , Hu Guang , Quan Yonggang , Chen Aimin , Zhong Naiqin , Peng Qingzhong , Wu Jiahe 

TITLE=Cotton miR319b-Targeted TCP4-Like Enhances Plant Defense Against Verticillium dahliae by Activating GhICS1 Transcription Expression

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.870882

DOI=10.3389/fpls.2022.870882

ISSN=1664-462X

ABSTRACT=<p>Teosinte branched1/Cincinnata/proliferating cell factor (TCP) transcription factors play important roles in plant growth and defense. However, the molecular mechanisms of TCPs participating in plant defense remain unclear. Here, we characterized a cotton TCP4-like fine-tuned by miR319b, which could interact with NON-EXPRESSER OF PATHOGEN-RELATED GENES 1 (NPR1) to directly activate <italic>isochorismate synthase 1</italic> (<italic>ICS1</italic>) expression, facilitating plant resistance against <italic>Verticillium dahliae</italic>. mRNA degradome data and GUS-fused assay showed that <italic>GhTCP4-like</italic> mRNA was directedly cleaved by ghr-miR319b. Knockdown of ghr-miR319b increased plant resistance to <italic>V. dahliae</italic>, whereas silencing <italic>GhTCP4-like</italic> increased plant susceptibility by the virus-induced gene silencing (VIGS) method, suggesting that <italic>GhTCP4-like</italic> is a positive regulator of plant defense. According to the electrophoretic mobility shift assay and GUS reporter analysis, GhTCP4-like could transcriptionally activate <italic>GhICS1</italic> expression, resulting in increased salicylic acid (SA) accumulation. Yeast two-hybrid and luciferase complementation image analyses demonstrated that <italic>GhTCP4-like</italic> interacts with <italic>GhNPR1</italic>, which can promote <italic>GhTCP4-like</italic> transcriptional activation in <italic>GhICS1</italic> expression according to the GUS reporter assay. Together, these results revealed that GhTCP4-like interacts with GhNPR1 to promote <italic>GhICS1</italic> expression through fine-tuning of ghr-miR319b, leading to SA accumulation, which is percepted by NPR1 to increase plant defense against <italic>V. dahliae</italic>. Therefore, GhTCP4-like participates in a positive feedback regulation loop of SA biosynthesis via NPR1, increasing plant defenses against fungal infection.</p>