Wang Yujiao, Zhang Jin, Qiu Zhenfei, Zeng Bingshan, Zhang Yong, Wang Xiaoping, Chen Jun, Zhong Chonglu, Deng Rufang, Fan Chunjie
State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of State Forestry and Grassland Administration on Tropical Forestry, Research Institute of Tropical Forestry, Chinese Academy of Forestry, Guangzhou, China.
State Key Laboratory of Subtropical Silviculture, School of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, Zhejiang, China.
PeerJ. 2021 Sep 22;9:e12133. doi: 10.7717/peerj.12133. eCollection 2021.
High soil salinity seriously affects plant growth and development. Excessive salt ions mainly cause damage by inducing osmotic stress, ion toxicity, and oxidation stress. is a highly salt-tolerant plant, commonly grown as wind belts in coastal areas with sandy soils. However, little is known about its physiology and the molecular mechanism of its response to salt stress.
Eight-week-old seedlings grown from rooted cuttings were exposed to salt stress for varying durations (0, 1, 6, 24, and 168 h under 200 mM NaCl) and their ion contents, cellular structure, and transcriptomes were analyzed. Potassium concentration decreased slowly between 1 h and 24 h after initiation of salt treatment, while the content of potassium was significantly lower after 168 h of salt treatment. Root epidermal cells were shed and a more compact layer of cells formed as the treatment duration increased. Salt stress led to deformation of cells and damage to mitochondria in the epidermis and endodermis, whereas stele cells suffered less damage. Transcriptome analysis identified 10,378 differentially expressed genes (DEGs), with more genes showing differential expression after 24 h and 168 h of exposure than after shorter durations of exposure to salinity. Signal transduction and ion transport genes such as and were enriched among DEGs in the early stages (1 h or 6 h) of salt stress, while expression of genes involved in programmed cell death was significantly upregulated at 168 h, corresponding to changes in ion contents and cell structure of roots. Oxidative stress and detoxification genes were also expressed differentially and were enriched among DEGs at different stages.
These results not only elucidate the mechanism and the molecular pathway governing salt tolerance, but also serve as a basis for identifying gene function related to salt stress in .
高土壤盐分严重影响植物的生长发育。过量的盐离子主要通过诱导渗透胁迫、离子毒性和氧化胁迫造成损害。[植物名称]是一种高度耐盐的植物，通常作为防风带种植在沿海沙质土壤地区。然而，人们对其生理学以及对盐胁迫响应的分子机制知之甚少。
将从生根插条培育的8周龄[植物名称]幼苗暴露于不同时长的盐胁迫下（在200 mM NaCl条件下分别处理0、1、6、24和168小时），并分析其离子含量、细胞结构和转录组。盐处理开始后1小时至24小时之间，钾浓度缓慢下降，而盐处理168小时后钾含量显著降低。随着处理时间的增加，根表皮细胞脱落，形成了一层更紧密的细胞层。盐胁迫导致表皮和内皮层细胞变形以及线粒体损伤，而中柱细胞受损较轻。转录组分析鉴定出10378个差异表达基因（DEG），暴露于盐胁迫24小时和168小时后比暴露时间较短时显示出更多差异表达的基因。在盐胁迫早期（1小时或6小时），诸如[基因名称1]和[基因名称2]等信号转导和离子转运基因在DEG中富集，而在168小时时，参与程序性细胞死亡的基因表达显著上调，这与根的离子含量和细胞结构变化相对应。氧化应激和解毒基因也有差异表达，并在不同阶段的DEG中富集。
这些结果不仅阐明了[植物名称]耐盐性的机制和分子途径，也为鉴定与[植物名称]盐胁迫相关的基因功能奠定了基础。
