A Nck‐associated protein 1‐like protein affects drought sensitivity by its involvement in leaf epidermal development and stomatal closure in rice

Lichao Huang,Li Zhu,Dali Zeng,Guang Chen,Deyong Ren,Zhenyu Gao,Xueli Lu,Liping Dai,Guojun Dong,Lan Wang,Yaolong Yang,Long Chen,Weiwei Zou,Qian Qian,Longbiao Guo,Jiang Hu,Yuchun Rao,Guangheng Zhang,Lan Shen,Yi-Hong Gao

doi:10.1111/tpj.14288

Abstract

SummaryWater deficit is a major environmental threat affecting crop yields worldwide. In this study, a drought stress‐sensitive mutant drought sensitive 8 (ds8) was identified in rice (Oryza sativa L.). The DS8 gene was cloned using a map‐based approach. Further analysis revealed that DS8 encoded a Nck‐associated protein 1 (NAP1)‐like protein, a component of the SCAR/WAVE complex, which played a vital role in actin filament nucleation activity. The mutant exhibited changes in leaf cuticle development. Functional analysis revealed that the mutation of DS8 increased stomatal density and impaired stomatal closure activity. The distorted actin filaments in the mutant led to a defect in abscisic acid (ABA)‐mediated stomatal closure and increased ABA accumulation. All these resulted in excessive water loss in ds8 leaves. Notably, antisense transgenic lines also exhibited increased drought sensitivity, along with impaired stomatal closure and elevated ABA levels. These findings suggest that DS8 affects drought sensitivity by influencing actin filament activity.

Highlights

Adverse climatic conditions, such as drought, threaten rice growth and production
The SCAR/WAVE complex members can enhance the Arp2/3 complexmediated nucleation efficiency of actin filaments in vitro and in vivo (Welch and Mullins, 2002; Bai et al, 2015). All those results indicated that the SCAR/WAVE- Arp2/3 complex may be involved in abscisic acid (ABA)-mediated stomatal closure
Enormous effort has been devoted to elucidating the role of the SCAR/WAVE-Arp2/3 complex in the formation and development of leaf epidermal cells by involvement in actin filaments modeling over the past decades (Frank and Smith, 2002; Djakovic et al, 2006; Facette et al, 2015); few studies have focused on the function of SCAR/WAVE complex in plant responses to environmental stress, especially drought stress

Summary

SUMMARY

Water deficit is a major environmental threat affecting crop yields worldwide. In this study, a drought stress-sensitive mutant drought sensitive 8 (ds8) was identified in rice (Oryza sativa L.). Further analysis revealed that DS8 encoded a Nck-associated protein 1 (NAP1)-like protein, a component of the SCAR/WAVE complex, which played a vital role in actin filament nucleation activity. Functional analysis revealed that the mutation of DS8 increased stomatal density and impaired stomatal closure activity. The distorted actin filaments in the mutant led to a defect in abscisic acid (ABA)-mediated stomatal closure and increased ABA accumulation. All these resulted in excessive water loss in ds leaves. Antisense transgenic lines exhibited increased drought sensitivity, along with impaired stomatal closure and elevated ABA levels. These findings suggest that DS8 affects drought sensitivity by influencing actin filament activity

INTRODUCTION

RESULTS

DISCUSSION

Findings

EXPERIMENTAL PROCEDURES

CONFLICT OF INTEREST