An Alcohol Dehydrogenase Gene from Synechocystis sp. Confers Salt Tolerance in Transgenic Tobacco.

So Young Yi,Hee-Jung Sim,Won Joong Jeong,Ji Hyun Park,Sang-Kyu Kim,Jae Il Lyu,Eun Jin So,Jonghyun Kim,Seong Sub Ku,Suk Weon Kim,So Yeon Choi,Myung Suk Ahn,Jang Ryol Liu,Yong Pyo Lim,Sung Ran Min,Hyunwoo Park

doi:10.3389/fpls.2017.01965

Abstract

Synechocystis salt-responsive gene 1 (sysr1) was engineered for expression in higher plants, and gene construction was stably incorporated into tobacco plants. We investigated the role of Sysr1 [a member of the alcohol dehydrogenase (ADH) superfamily] by examining the salt tolerance of sysr1-overexpressing (sysr1-OX) tobacco plants using quantitative real-time polymerase chain reactions, gas chromatography-mass spectrometry, and bioassays. The sysr1-OX plants exhibited considerably increased ADH activity and tolerance to salt stress conditions. Additionally, the expression levels of several stress-responsive genes were upregulated. Moreover, airborne signals from salt-stressed sysr1-OX plants triggered salinity tolerance in neighboring wild-type (WT) plants. Therefore, Sysr1 enhanced the interconversion of aldehydes to alcohols, and this occurrence might affect the quality of green leaf volatiles (GLVs) in sysr1-OX plants. Actually, the Z-3-hexenol level was approximately twofold higher in sysr1-OX plants than in WT plants within 1–2 h of wounding. Furthermore, analyses of WT plants treated with vaporized GLVs indicated that Z-3-hexenol was a stronger inducer of stress-related gene expression and salt tolerance than E-2-hexenal. The results of the study suggested that increased C6 alcohol (Z-3-hexenol) induced the expression of resistance genes, thereby enhancing salt tolerance of transgenic plants. Our results revealed a role for ADH in salinity stress responses, and the results provided a genetic engineering strategy that could improve the salt tolerance of crops.

Highlights

Alcohol dehydrogenases (ADHs, alcohol: NAD+ oxidoreductase, EC 1.1.1.1) belong to the dehydrogenase enzyme superfamily, and they are widely distributed across all organism types (Chase, 1999; Jornvall et al, 2010; Strommer, 2011; Alka et al, 2013)
The ADH1 expression level is upregulated in response to the application of exogenous abscisic acid, and salinity stress induces the accumulation of alcohol dehydrogenase (ADH) mRNA in soybeans, grass peas, and Arabidopsis (Manak et al, 2002; Sobhanian et al, 2010; Chattopadhyay et al, 2011)
We hypothesized that communication between sysr1-transgenic and WT plants under high-salt conditions helps WT plants cope with subsequent exposures to salt stress

Summary

Introduction

Alcohol dehydrogenases (ADHs, alcohol: NAD+ oxidoreductase, EC 1.1.1.1) belong to the dehydrogenase enzyme superfamily, and they are widely distributed across all organism types (Chase, 1999; Jornvall et al, 2010; Strommer, 2011; Alka et al, 2013). These enzymes catalyze the interconversion between alcohols and aldehydes (Hoog et al, 2003; Thompson et al, 2007). Very little is known about the effects of ADHs on plant physiology during exposure to abiotic stress conditions

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Results

Conclusion