Sui Dezong, Wang Baosong
Jiangsu Academy of Forestry, Nanjing, 211153 Jiangsu, China.
Int J Genomics. 2020 Jul 27;2020:6870157. doi: 10.1155/2020/6870157. eCollection 2020.
Salinity stress is one of the most devastating abiotic stresses limiting plant growth and productivity. As a moderately salt-tolerant crop, shrub willow ( spp.) is widely distributed over the world and can provide multiple bioenergy product and environmental benefits. To delve into the salt tolerance mechanism and screen out salt-tolerant genes, two shrub willow cultivars (a salt-sensitive genotype JW9-6 and a salt-tolerant genotype JW2372) at three time points (0, 2, and 12 h) after NaCl treatments were used for RNA sequencing. A comparative analysis between genotypes and time points showed 1,706 differentially expressed genes (DEGs), of which 1,029 and 431 DEGs were only found in the JW9-6 and JW2372, respectively. Gene Ontology (GO) and MapMan annotations suggested that many DEGs were involved in various defense-related biological pathways, including cell wall integrity, hormone signaling, antioxidant system, heat shock proteins, and transcription factors. Compared to JW9-6, JW2372 contained more DEGs involved in the maintenance of the cell wall integrity, ABA, and ethylene signal transduction pathways. In addition, more DEGs encoding heat shock proteins were found in JW2372. Instead, transcription factors including ERF, MYB, NAC, and WRKY were found to be more differentially expressed in JW9-6 under salinity stress. Furthermore, expressions of nine randomly selected DEGs were verified by qRT-PCR analysis. This study contributes in new perspicacity into underlying the salt tolerance mechanism of a shrub willow at the transcriptome level and also provides numerous salt-tolerant genes for further genetic engineering and breeding purposes in the future.
盐胁迫是限制植物生长和生产力的最具破坏性的非生物胁迫之一。作为一种中度耐盐作物，灌木柳（Salix spp.）在世界范围内广泛分布，可提供多种生物能源产品并带来环境效益。为深入探究耐盐机制并筛选出耐盐基因，在NaCl处理后的三个时间点（0、2和12小时）对两个灌木柳品种（一个盐敏感基因型JW9-6和一个耐盐基因型JW2372）进行了RNA测序。基因型和时间点之间的比较分析显示有1706个差异表达基因（DEG），其中分别仅在JW9-6和JW2372中发现了1029个和431个DEG。基因本体论（GO）和MapMan注释表明，许多DEG参与了各种与防御相关的生物学途径，包括细胞壁完整性、激素信号传导、抗氧化系统、热休克蛋白和转录因子。与JW9-6相比，JW2372包含更多参与细胞壁完整性、脱落酸和乙烯信号转导途径维持的DEG。此外在JW2372中发现了更多编码热休克蛋白的DEG。相反，在盐胁迫下，包括ERF、MYB、NAC和WRKY在内的转录因子在JW9-6中差异表达更为明显。此外，通过qRT-PCR分析验证了九个随机选择的DEG的表达。本研究在转录组水平上对灌木柳的耐盐机制有了新的洞察，也为未来进一步的基因工程和育种目的提供了众多耐盐基因。
