The Cyclophilin ROC3 Regulates ABA-Induced Stomatal Closure and the Drought Stress Response of Arabidopsis thaliana.

Huiping Liu,Donghua Chen,Biswa R Acharya,Mei Wang,Jianlin Shen,Wei Zhang,Dongxue Lu,Chao Yuan

doi:10.3389/fpls.2021.668792

Huiping Liu, Donghua Chen + Show 6 more

Open Access

https://doi.org/10.3389/fpls.2021.668792

Copy DOI

Abstract

Drought causes a major constraint on plant growth, development, and crop productivity. Drought stress enhances the synthesis and mobilization of the phytohormone abscisic acid (ABA). Enhanced cellular levels of ABA promote the production of reactive oxygen species (ROS), which in turn induce anion channel activity in guard cells that consequently leads to stomatal closure. Although Cyclophilins (CYPs) are known to participate in the biotic stress response, their involvement in guard cell ABA signaling and the drought response remains to be established. The Arabidopsis thaliana gene ROC3 encodes a CYP. Arabidopsis roc3 T-DNA mutants showed a reduced level of ABA-activated S-type anion currents, and stomatal closure than wild type (WT). Also, roc3 mutants exhibited rapid loss of water in leaf than wild type. Two complementation lines of roc3 mutants showed similar stomatal response to ABA as observed for WT. Both complementation lines also showed similar water loss as WT by leaf detached assay. Biochemical assay suggested that ROC3 positively regulates ROS accumulation by inhibiting catalase activity. In response to ABA treatment or drought stress, roc3 mutant show down regulation of a number of stress responsive genes. All findings indicate that ROC3 positively regulates ABA-induced stomatal closure and the drought response by regulating ROS homeostasis and the expression of various stress-activated genes.

Highlights

Drought stress causes a major constraint on plant growth, development, and productivity (Langridge and Reynolds, 2015)
Gene expression profiles of ROC3 showed that the gene was induced by both abscisic acid (ABA) treatment and drought stress (Figures 1A,B)
ROC3 promoter was mildly induced in the guard cells of plants treated with ABA (Figures 1C,H,I)

Summary

Introduction

Drought stress causes a major constraint on plant growth, development, and productivity (Langridge and Reynolds, 2015). Plants have the ability to adapt to drought stress by regulating stomatal closure (Agurla et al, 2018). The turgor and volume of the pair of guard cells determine the extent of the stomata’s aperture (Schroeder et al, 2001). ROC3 Regulates Stomatal Closure movement, but at the cellular level the most critical factor is the phytohormone abscisic acid (ABA) (Raghavendra et al, 2010; Kollist et al, 2014; Osakabe et al, 2014; Murata et al, 2015). The accumulation of ABA activates S-type anion channels in guard cells, resulting in an efflux of anions and a consequent decreases in guard cells’ turgor, which eventually induces stomatal closure (Li et al, 2000; Wang et al, 2001; Vahisalu et al, 2008)

Methods

Results

Conclusion