College of Horticulture, Northwest A&F University, Yangling 712100, Shaanxi, China; College of Horticulture and Gardening, College of Agronomy, Yangtze University, Jingzhou 434025, Hubei, China.
College of Horticulture, Northwest A&F University, Yangling 712100, Shaanxi, China.
Ecotoxicol Environ Saf. 2019 Jun 15;174:245-254. doi: 10.1016/j.ecoenv.2019.02.075. Epub 2019 Mar 1.
Salinity decreases the yield and quality of crops. Silicon (Si) has been widely reported to have beneficial effects on plant growth and development under salt stress. However, the mechanism is still poorly understood. In an attempt to identify genes or gene networks that may be orchestrated to improve salt tolerance of cucumber plants, we sequenced the transcriptomes of both control and salt-stressed cucumber leaves in the presence or absence of added Si. Seedlings of cucumber 'JinYou 1' were subjected to salt stress (75 mM NaCl) without or with addition of 0.3 mM Si. Plant growth, photosynthetic gas exchange and transcriptomic dynamics were investigated. The results showed that Si addition improved the growth and photosynthetic performance of cucumber seedlings under salt stress. The comparative transcriptome analysis revealed that Si played an important role in shaping the transcriptome of cucumber: the expressions of 1469 genes were altered in response to Si treatment in the control conditions, and these genes were mainly involved in ion transport, hormone and signal transduction, biosynthetic and metabolic processes, and stress and defense responses. Under salt stress alone, 1482 genes with putative functions associated with metabolic processes and responses to environmental stimuli have changed their expression levels. Si treatment shifted the transcriptome of salt-stressed cucumber back to that of the control, as evidenced that among the 708 and 774 genes that were up- or down-regulated under salt stress, a large majority of them (609 and 595, respectively) were reverted to the normal expression levels. These results suggest that Si may act as an elicitor to precondition cucumber plants and induce salt tolerance. The study may help us understand the mechanism for silicon-mediated salt tolerance and provide a theoretical basis for silicon application in crop production in saline soils.
盐度降低了作物的产量和质量。硅（Si）已被广泛报道在盐胁迫下对植物生长和发育有有益的影响。然而，其机制仍知之甚少。为了鉴定可能协调提高黄瓜植物耐盐性的基因或基因网络，我们在添加或不添加 Si 的情况下对对照和盐胁迫黄瓜叶片的转录组进行了测序。黄瓜‘金优 1’幼苗在没有或添加 0.3 mM Si 的情况下受到盐胁迫（75 mM NaCl）。研究了植物生长、光合气体交换和转录组动态。结果表明，Si 加有助于提高盐胁迫下黄瓜幼苗的生长和光合性能。比较转录组分析表明，Si 在塑造黄瓜转录组方面发挥了重要作用：在对照条件下，1469 个基因的表达因 Si 处理而改变，这些基因主要参与离子转运、激素和信号转导、生物合成和代谢过程以及应激和防御反应。单独在盐胁迫下，与代谢过程和对环境刺激的反应相关的 1482 个具有推定功能的基因改变了它们的表达水平。Si 处理使盐胁迫下的黄瓜转录组恢复到对照水平，这表明在盐胁迫下上调或下调的 708 个和 774 个基因中，大多数（分别为 609 个和 595 个）恢复到正常表达水平。这些结果表明，Si 可能作为一种激发子预先处理黄瓜植物并诱导耐盐性。该研究有助于我们理解硅介导的耐盐性机制，并为硅在盐渍土壤中作物生产中的应用提供理论基础。
