An Arabidopsis Zinc Finger Protein Increases Abiotic Stress Tolerance by Regulating Sodium and Potassium Homeostasis, Reactive Oxygen Species Scavenging and Osmotic Potential.

Dandan Zang,Wenhui Zhang,Xinxin Shi,Yucheng Wang,Hongyan Li,Yiming Zhang,Hongyun Xu

doi:10.3389/fpls.2016.01272

Abstract

Plant zinc finger proteins (ZFPs) comprise a large protein family and they are mainly involved in abiotic stress tolerance. Although Arabidopsis RING/FYVE/PHD ZFP At5g62460 (AtRZFP) is found to bind to zinc, whether it is involved in abiotic stress tolerance is still unknown. In the present study, we characterized the roles of AtRZFP in response to abiotic stresses. The expression of AtRZFP was induced significantly by salt and osmotic stress. AtRZFP positively mediates tolerance to salt and osmotic stress. Additionally, compared with wild-type Arabidopsis plants, plants overexpressing AtRZFP showed reduced reactive oxygen species (ROSs) accumulation, enhanced superoxide dismutase and peroxidase activity, increased soluble sugars and proline contents, reduced K+ loss, decreased Na+ accumulation, stomatal aperture and the water loss rate. Conversely, AtRZFP knockout plants displayed the opposite physiological changes when exposed to salt or osmotic stress conditions. These data suggested that AtRZFP enhances salt and osmotic tolerance through a series of physiological processes, including enhanced ROSs scavenging, maintaining Na+ and K+ homeostasis, controlling the stomatal aperture to reduce the water loss rate, and accumulating soluble sugars and proline to adjust the osmotic potential.

Highlights

Zinc-finger proteins (ZFPs) are known to play various important roles in diverse organisms (Luo et al, 2012a), and their expression responds to various abiotic stresses (Sun et al, 2010)
Cheuk and Houde (2016) investigated 53 Q-type C2H2 zinc finger protein (TaZFPs) from Triticum aestivum, and showed that these TaZFPs are mainly responsive to high light (44/53), H2O2 (37/53), drought (37/53), and flooding (31/53); 16 genes were responsive to all stresses tested
These results showed that the expression of AtRZFP responded to salt and osmotic stress, suggesting that AtRZFP plays a role the abiotic stress response

Summary

Introduction

Zinc-finger proteins (ZFPs) are known to play various important roles in diverse organisms (Luo et al, 2012a), and their expression responds to various abiotic stresses (Sun et al, 2010). Cheuk and Houde (2016) investigated 53 Q-type C2H2 zinc finger protein (TaZFPs) from Triticum aestivum, and showed that these TaZFPs are mainly responsive to high light (44/53), H2O2 (37/53), drought (37/53), and flooding (31/53); 16 genes were responsive to all stresses tested This result indicated that these TaZFPs play important roles in abiotic stress resistance. Genes involved in antioxidation are regulated significantly by ZFPs, which leads to elevated antioxidant enzyme activities and reduced ROS accumulation; enhancing abiotic stress tolerance (Davletova et al, 2005; Sun et al, 2010; Zhang et al, 2014; Baek et al, 2015; Fan et al, 2015). OsDOG and ZFP185 play negative roles in abiotic stress tolerance (Liu et al, 2011; Zhang Y. et al, 2016)

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Results

Conclusion