Virus-induced silencing of genes encoding LEA protein in Tibetan hulless barley (Hordeum vulgare ssp. vulgare) and their relationship to drought tolerance
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Expression of the late embryogenesis abundant (LEA) gene is usually associated with plant response to dehydration. In this study, a drought-tolerant genotype was screened from 48 accessions of Tibetan hulless barley (Hordeum vulgare ssp. vulgare). By using virus-induced gene silencing, the influence of two LEA genes (HVA1 and Dhn6) on drought tolerance of Tibetan hulless barley was investigated. Results of quantitative real-time PCR indicated that the relative expression levels of HVA1 and Dhn6 in silenced plants were significantly reduced compared with control plants. Both HVA1-silenced and Dhn6-silenced plants showed a consequently lower survival rate than control plants under drought stress. However, only HVA1-silenced plants exhibited a significantly higher water loss rate (WLR). These results suggested that HVA1 and Dhn6 might participate in adaptive responses to water deficit in different ways. Vegetative growth of HVA1-silenced plants was significantly retarded even under optimal growth conditions, and their biomass accumulation was also much lower than that of the controls. These results indicate that HVA1 might play a role in vegetative growth of Tibetan hulless barley.
KeywordsHVA1 Dhn6 Virus-induced gene silencing (VIGS) Barley stripe mosaic virus (BSMV) Water loss rate (WLR)
We thank Chengdu Institute of Biology, Chinese Academy of Sciences for the Senior Research Fellowship award. Prof. Daowen Wang of Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, are kindly acknowledged for providing BSMV vectors. We sincerely acknowledge Dr. Bin Li for technical expertise and advice on BSMV inoculation, and Dr. Gang Qian for thoughtful discussion during the preparation of this manuscript. We also wish to thank the two anonymous reviewers for helpful comments that improved the manuscript. This work was supported by Major transgenic program (2008ZX08002-002), Ministry of Agriculture, P. R. China and Special Basic Research Funds of the Ministry of Science and Technology of China (No. 2006FY110700).
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