Overexpression of GmAKT2potassium channel enhances resistance to soybean mosaic virus

BMC Plant Biology

Research Article

Hongli He¹  Bao Liu¹  Huixia Shou²  Lian Zhou²  Qiang Han²  Ruifang Liu² 

[1] Key Laboratory of Molecular Epigenetics of Ministry of Education, Northeast Normal University, 130024, Changchun, China;State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, 310058, Hangzhou, P. R. China;

关键词: Soybean mosaic virus;    Resistance;    Potassium channel;    GmAKT2;   

DOI  :  10.1186/1471-2229-14-154

 received in 2014-02-25, accepted in 2014-05-27,  发布年份 2014

来源: Springer

【 摘 要 】

BackgroundSoybean mosaic virus (SMV) is the most prevalent viral disease in many soybean production areas. Due to a large number of SMV resistant loci and alleles, SMV strains and the rapid evolution in avirulence/effector genes, traditional breeding for SMV resistance is complex. Genetic engineering is an effective alternative method for improving SMV resistance in soybean. Potassium (K+) is the most abundant inorganic solute in plant cells, and is involved in plant responses to abiotic and biotic stresses. Studies have shown that altering the level of K+ status can reduce the spread of the viral diseases. Thus K+ transporters are putative candidates to target for soybean virus resistance.ResultsThe addition of K+ fertilizer significantly reduced SMV incidence. Analysis of K+ channel gene expression indicated that GmAKT2, the ortholog of Arabidopsis K+ weak channel encoding gene AKT2, was significantly induced by SMV inoculation in the SMV highly-resistant genotype Rsmv1, but not in the susceptible genotype Ssmv1. Transgenic soybean plants overexpressing GmAKT2 were produced and verified by Southern blot and RT-PCR analysis. Analysis of K+ concentrations on different leaves of both the transgenic and the wildtype (Williams 82) plants revealed that overexpression of GmAKT2 significantly increased K+ concentrations in young leaves of plants. In contrast, K+ concentrations in the old leaves of the GmAKT2-Oe plants were significantly lower than those in WT plants. These results indicated that GmAKT2 acted as a K+ transporter and affected the distribution of K+ in soybean plants. Starting from 14 days after inoculation (DAI) of SMV G7, severe mosaic symptoms were observed on the WT leaves. In contrast, the GmAKT2-Oe plants showed no symptom of SMV infection. At 14 and 28 DAI, the amount of SMV RNA in WT plants increased 200- and 260- fold relative to GmAKT2-Oe plants at each time point. Thus, SMV development was significantly retarded in GmAKT2-overexpressing transgenic soybean plants.ConclusionsOverexpression of GmAKT2 significantly enhanced SMV resistance in transgenic soybean. Thus, alteration of K+ transporter expression is a novel molecular approach for enhancing SMV resistance in soybean.

【 授权许可】

Unknown   
© Zhou et al.; licensee BioMed Central Ltd. 2014. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.