MsaH2A.W is identified response to salt tolerance in Miscanthus sacchariflorus

Miscanthus is a perennial forage plant with great potential for high stress tolerance and biomass yield. It has strong adaptability for growing in saline land and avoids competition with grain crops in arable lands. However, little is known about the underlying genetic basis of Miscanthus adaptation to salt stress. Two diploid species of the genus Miscanthus, Miscanthus sinensis and Miscanthus sacchariflorus, were the focus of this study. The transcriptome variations of these varieties and their hybrid were analysed using RNA‐seq technology under salt treatment. The number of differentially expressed genes in M. sinensis was much higher than that in M. sacchariflorus and their hybrid under salt stress, which indicated that M. sacchariflorus and their hybrid require less transcriptional variation. In addition, most salt‐tolerant genes in the enriched salt‐tolerant pathways were induced in the roots of M. sinensis and constitutively highly expressed in the roots of M. sacchariflorus and their hybrid under salt stress. According to this expression pattern of known salt‐tolerant genes, a histone variant gene MsaH2A.W of M. sacchariflorus was mined and consequently proved for the first time that it could enhance the salt tolerance of transgenic Arabidopsis plants. Overall, this study provides valuable genetic resources for studying the underlying genetic basis of salt stress resistance in Miscanthus. Identification of the salt tolerance gene MsaH2A.W can promote the genetic improvement and molecular breeding of salt‐resistant species. 芒属植物是多年生饲草植物, 因具有抗逆性强和生物质产量高等特点, 有着较大的开发潜力及应用价值。它在非生物胁迫环境下具有一定程度的耐受性, 可以利用盐碱地等各种边缘土地上进行种植, 避免与粮争地。然而, 芒属植物适应盐胁迫的遗传基础尚不清楚。本研究采用二倍体的芒、荻及其在杂交种为研究材料。利用RNA‐seq技术分析了盐处理下芒、荻及其杂交种的转录组变化。结果表明, 在盐胁迫下, 芒中的差异表达基因数量远高于荻及杂交种, 结果表明荻及杂交种需要较少的转录变化来应对盐胁迫。此外, 在盐胁迫下, 富集到耐盐途径中的大部分耐盐基因在芒根中诱导表达, 在荻及杂交种根中组成型高表达。根据这些已知耐盐基因的表达模式, 组蛋白变体基因MsaH2A.W被挖掘并首次证明了它能提高转基因拟南芥的耐盐性。总之, 本研究为研究芒属植物应对盐胁迫的遗传基础提供了宝贵的遗传资源, 并为耐盐品种的遗传改良和分子育种奠定了基础。 To study the underlying genetic basis of Miscanthus adaptation to salt stress, the transcriptome variations of Miscanthus sinensis, Miscanthus sacchariflorus and their hybrid were analysed using RNA‐seq technology under salt treatment. According to the expression pattern of known salt‐tolerant genes, a histone variant gene MsaH2AW of M. sacchariflorus was mined and consequently proved for the first time that it could enhance the salt tolerance of transgenic Arabidopsis. This study initially revealed the underlying genetic basis of sal