Suppression of OsVPE3 Enhances Salt Tolerance by Attenuating Vacuole Rupture during Programmed Cell Death and Affects Stomata Development in Rice.

Wenyun Lu,Minjuan Deng,Hongwu Bian,Yinong Yang,Mingqiang Wang,Muyuan Zhu,Fu Guo,Ning Han,Zhanghui Zeng

doi:10.1186/s12284-016-0138-x

Wenyun Lu, Minjuan Deng + Show 7 more

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https://doi.org/10.1186/s12284-016-0138-x

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Abstract

BackgroundVacuolar processing enzymes (VPEs) are cysteine proteinases that act as crucial mediators of programmed cell death (PCD) in plants. In rice, however, the role of VPEs in abiotic stress-induced PCD remains largely unknown. In this study, we generated OsVPE3 overexpression and suppression transgenic lines to elucidate the function of this gene in rice.ResultsSurvival rate and chlorophyll retention analyses showed that suppression of OsVPE3 clearly enhanced salt stress tolerance in transgenic rice compared with wild type. Furthermore, fragmentation of genomic DNA was inhibited in plants with down-regulated OsVPE3. Vital staining studies indicated that vacuole rupture occurred prior to plasma membrane collapse during salt-induced PCD. Notably, overexpression of OsVPE3 promoted vacuole rupture, whereas suppression of OsVPE3 attenuated or delayed the disintegration of vacuolar membranes. Moreover, we found that suppression of OsVPE3 caused decreased leaf width and guard cell length in rice.ConclusionsTaken together, these results indicated that suppression of OsVPE3 enhances salt tolerance by attenuating vacuole rupture during PCD. Therefore, we concluded that OsVPE3 plays a crucial role in vacuole-mediated PCD and in stomatal development in rice.Electronic supplementary materialThe online version of this article (doi:10.1186/s12284-016-0138-x) contains supplementary material, which is available to authorized users.

Highlights

Vacuolar processing enzymes (VPEs) are cysteine proteinases that act as crucial mediators of programmed cell death (PCD) in plants
To determine the function of OsVPE3 in rice under salt stress, we generated transgenic lines to either overexpress and suppress OsVPE3, and we found that OsVPE3 regulates the collapse of vacuolar membranes during PCD
To determine the subcellular localization of OsVPE3, the full-length cDNA was fused to green fluorescent protein (GFP) under control of the 35S promoter

Summary

Introduction

Vacuolar processing enzymes (VPEs) are cysteine proteinases that act as crucial mediators of programmed cell death (PCD) in plants. The role of VPEs in abiotic stress-induced PCD remains largely unknown. Rice (Oryza sativa L.) is one of the most important cereal crops for more than half of the world’s population. The world will need to produce 25% more rice by 2030 to meet the challenges of feeding increasing populations. Programmed cell death (PCD) is a highly conserved and genetically controlled process in multicellular organisms. PCD is involved in maintaining cellular homeostasis, development and senescence(Azeez et al 2007; Williams and Dickman 2008), and this process is triggered by a variety of abiotic and biotic stresses (Huh et al 2002; Lam 2004; Gechev et al 2006). Vacuoles are storage organelles that function as reservoirs for both hydrolytic enzymes

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