OsSGL, a Novel DUF1645 Domain-Containing Protein, Confers Enhanced Drought Tolerance in Transgenic Rice and Arabidopsis.

Yanchun Cui,Mingjuan Li,Guoyun Xu,Xinjie Xia,Fucheng Lin,Huina Zhou,Xuming Yin,Manling Wang,Lifang Huang,Guoqiang Zhao

doi:10.3389/fpls.2016.02001

Abstract

Drought is a major environmental factor that limits plant growth and crop productivity. Genetic engineering is an effective approach to improve drought tolerance in various crops, including rice (Oryza sativa). Functional characterization of relevant genes is a prerequisite when identifying candidates for such improvements. We investigated OsSGL (Oryza sativa Stress tolerance and Grain Length), a novel DUF1645 domain-containing protein from rice. OsSGL was up-regulated by multiple stresses and localized to the nucleus. Transgenic plants over-expressing or hetero-expressing OsSGL conferred significantly improved drought tolerance in transgenic rice and Arabidopsis thaliana, respectively. The overexpressing plants accumulated higher levels of proline and soluble sugars but lower malondialdehyde (MDA) contents under osmotic stress. Our RNA-sequencing data demonstrated that several stress-responsive genes were significantly altered in transgenic rice plants. We unexpectedly observed that those overexpressing rice plants also had extensive root systems, perhaps due to the altered transcript levels of auxin- and cytokinin-associated genes. These results suggest that the mechanism by which OsSGL confers enhanced drought tolerance is due to the modulated expression of stress-responsive genes, higher accumulations of osmolytes, and enlarged root systems.

Highlights

Rice (Oryza sativa) is the most important food sources for more than half of the world’s population
Bioinformatics analysis showed that OsSGL has a conserved domain of DUF1645 (Pfam PF07816) from amino acid residues 69-2271
To investigate the possible evolutionary relationships between OsSGL and other DUF1645 proteins, we constructed a phylogenetic tree via the Neighbor-Joining method, using full-length amino acid sequences (Figure 1)

Summary

Introduction

Rice (Oryza sativa) is the most important food sources for more than half of the world’s population. Water is already a scarce resource in many parts of the world, and increasingly frequent drought events present enormous challenges for sustainable rice production (Zhang, 2007). Drought is a major environmental factor that adversely affects plant growth and development, limiting agricultural productivity. Many genes encoding functional proteins, OsSGL Enhances Drought Tolerance transcription factors, and proteins involved in signaling pathways have been identified as abiotic stress-responsive genes (Shinozaki and Yamaguchi-Shinozaki, 2007; Masclaux-Daubresse et al, 2010; Turan et al, 2012). Tolerant plants have been engineered through heterologous expression of genes that encode functional or regulatory proteins (Golldack et al, 2011; Kim M. et al, 2013; Lu et al, 2013; Li et al, 2014)

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Results

Conclusion