PDF(Pubmed)
Abstract：
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 in vivo and in vitro. Next, we generated and characterized double mutant adf4cark3-4 and OE-ADF4:cark3-4. The hypocotyl elongation assay indicated that the cark3-4 mutant seedlings were slightly longer hypocotyls when compared with the wild type plants (WT), while CARK3 overexpressing seedlings had no difference with WT. In addition, overexpression of ADF4 significantly inhibited long hypocotyls of cark3-4 mutants. Surprisingly, we found that overexpression of ADF4 markedly enhance drought resistance in soil when compared with WT. On the other hand, drought tolerance analysis showed that overexpression of CARK3 could rescue adf4 drought susceptibility. Taken together, our results suggest that CARK3 acts as a regulator in hypocotyl elongation and drought tolerance likely via regulating ADF4 phosphorylation.
摘要：
肌动蛋白解聚因子（ADF），作为肌动蛋白结合蛋白，在植物发育和生长中起着至关重要的作用，以及对非生物和生物胁迫的反应。这里,我们发现CARK3在调节下胚轴发育中起作用，并通过与ADF4的相互作用将肌动蛋白丝与干旱胁迫之间的串扰联系起来。通过使用双分子荧光互补（BiFC）和GST下拉法，我们证实了CARK3在体内和体外与ADF4相互作用。接下来,我们产生并表征了双突变体adf4cark3-4和OE-ADF4：cark3-4。下胚轴伸长试验表明，与野生型植物（WT）相比，cark3-4突变体幼苗的下胚轴稍长，而过表达CARK3的幼苗与WT没有差异。此外,ADF4的过表达显着抑制了cark3-4突变体的长下胚轴。令人惊讶的是,我们发现，与WT相比，ADF4的过表达显着增强了土壤的抗旱性。另一方面,耐旱性分析表明，CARK3的过表达可以挽救adf4的干旱敏感性。一起来看,我们的结果表明，CARK3可能通过调节ADF4磷酸化而在下胚轴伸长和耐旱性中起调节作用。
