The sucrose non-fermenting 1-related kinase 2 gene SAPK9 improves drought tolerance and grain yield in rice by modulating cellular osmotic potential, stomatal closure and stress-responsive gene expression

BMC Plant Biology

Research Article

Avishek Dey¹  Milan Kumar Samanta¹  Mrinal K. Maiti²  Srimonta Gayen³ 

[1] Advanced Laboratory for Plant Genetic Engineering, Advanced Technology Development Centre, Indian Institute of Technology Kharagpur, 721302, Kharagpur, India;Advanced Laboratory for Plant Genetic Engineering, Advanced Technology Development Centre, Indian Institute of Technology Kharagpur, 721302, Kharagpur, India;Department of Biotechnology, Indian Institute of Technology Kharagpur, 721302, Kharagpur, India;Advanced Laboratory for Plant Genetic Engineering, Advanced Technology Development Centre, Indian Institute of Technology Kharagpur, 721302, Kharagpur, India;Present address: Department of Human Genetics, University of Michigan, 48109, Ann Arbor, MI, USA;

关键词: Abscisic acid (ABA);    Drought tolerance;    Gene silencing;    Grain yield;    Overexpression;    Osmotic potential;    Rice crop;    SAPK9;    Stomatal closure;    Stress-responsive gene;    Sucrose non-fermenting 1-related kinase 2 (SnRK2);   

DOI  :  10.1186/s12870-016-0845-x

 received in 2016-03-16, accepted in 2016-07-05,  发布年份 2016

来源: Springer

【 摘 要 】

BackgroundFamily members of sucrose non-fermenting 1-related kinase 2 (SnRK2), being plant-specific serine/threonine protein kinases, constitute the central core of abscisic acid (ABA)-dependent and ABA-independent signaling pathways, and are key regulators of abiotic stress adaptation in plants. We report here the functional characterization of SAPK9 gene, one of the 10 SnRK2s of rice, through developing gain-of-function and loss-of-function phenotypes by transgenesis.ResultsThe gene expression profiling revealed that the abundance of single gene-derived SAPK9 transcript was significantly higher in drought-tolerant rice genotypes than the drought-sensitive ones, and its expression was comparatively greater in reproductive stage than the vegetative stage. The highest expression of SAPK9 gene in drought-tolerant Oryza rufipogon prompted us to clone and characterise the CDS of this allele in details. The SAPK9 transcript expression was found to be highest in leaf and upregulated during drought stress and ABA treatment. In silico homology modelling of SAPK9 with Arabidopsis OST1 protein showed the bilobal kinase fold structure of SAPK9, which upon bacterial expression was able to phosphorylate itself, histone III and OsbZIP23 as substrates in vitro. Transgenic overexpression (OE) of SAPK9 CDS from O. rufipogon in a drought-sensitive indica rice genotype exhibited significantly improved drought tolerance in comparison to transgenic silencing (RNAi) lines and non-transgenic (NT) plants. In contrast to RNAi and NT plants, the enhanced drought tolerance of OE lines was concurrently supported by the upgraded physiological indices with respect to water retention capacity, soluble sugar and proline content, stomatal closure, membrane stability, and cellular detoxification. Upregulated transcript expressions of six ABA-dependent stress-responsive genes and increased sensitivity to exogenous ABA of OE lines indicate that the SAPK9 is a positive regulator of ABA-mediated stress signaling pathways in rice. The yield-related traits of OE lines were augmented significantly, which resulted from the highest percentage of fertile pollens in OE lines when compared with RNAi and NT plants.ConclusionThe present study establishes the functional role of SAPK9 as transactivating kinase and potential transcriptional activator in drought stress adaptation of rice plant. The SAPK9 gene has potential usefulness in transgenic breeding for improving drought tolerance and grain yield in crop plants.

【 授权许可】

CC BY   
© The Author(s). 2016