Phosphatidic acid inhibits SCAB1-mediated F-actin bundling in Arabidopsis

ABSTRACT

Stomatal closure-associated actin-binding protein 1 (SCAB1) regulates stomatal closure by mediating actin filament reorganization in Arabidopsis thaliana. Our previous study showed that phosphatidylinositol 3-phosphate (PI3P) binds to SCAB1 and inhibits its oligomerization, thereby inhibiting its activity on F-actin in guard cells during stomatal closure. In this study, we show that another phospholipid, phosphatidic acid (PA), also binds to SCAB1 and inhibits its actin-bundling activity but not its actin-binding activity. F-actin bundling was promoted in vivo by treating Col-0 seedlings with n-butanol, a suppressor of PA production, but this effect was absent in the scab1 mutant. These results indicate that the signaling molecule PA is involved in the modulation of SCAB1 activity in F-actin reorganization.

KEYWORDS:

• Arabidopsis thaliana
• PA
• SCAB1
• F-actin bundling

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [32070301, 31872659], the National Genetically Modified Organisms Breeding Major Projects [2016ZX08009002] and Exploration project of Center for Practical Courses in the Life Sciences of China Agricultural University [20210102, 20210103].