AUTHOR=Peng Lu , He Juan , Yao Huan , Yu Qin , Zhang Qian , Li Kexuan , Huang Yaling , Chen Li , Li Xufeng , Yang Yi , Li Xiaoyi 

TITLE=CARK3-mediated ADF4 regulates hypocotyl elongation and soil drought stress in Arabidopsis

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.1065677

DOI=10.3389/fpls.2022.1065677

ISSN=1664-462X

ABSTRACT=<p>Actin depolymerization factors (ADFs), as actin-binding proteins, act a crucial role in plant development and growth, as well as in response to abiotic and biotic stresses. Here, we found that CARK3 plays a role in regulating hypocotyl development and links a cross-talk between actin filament and drought stress through interaction with ADF4. By using bimolecular fluorescence complementation (BiFC) and GST pull-down, we confirmed that CARK3 interacts with ADF4 <italic>in vivo</italic> and <italic>in vitro</italic>. Next, we generated and characterized double mutant <italic>adf4cark3-4</italic> and OE-ADF4:<italic>cark3-4</italic>. The hypocotyl elongation assay indicated that the <italic>cark3-4</italic> mutant seedlings were slightly longer hypocotyls when compared with the wild type plants (WT), while <italic>CARK3</italic> overexpressing seedlings had no difference with WT. In addition, overexpression of <italic>ADF4</italic> significantly inhibited long hypocotyls of cark3-4 mutants. Surprisingly, we found that overexpression of <italic>ADF4</italic> markedly enhance drought resistance in soil when compared with WT. On the other hand, drought tolerance analysis showed that overexpression of <italic>CARK3</italic> could rescue <italic>adf4</italic> drought susceptibility. Taken together, our results suggest that CARK3 acts as a regulator in hypocotyl elongation and drought tolerance likely <italic>via</italic> regulating ADF4 phosphorylation.</p>