The National Forestry and Grassland Administration Engineering Research Center for Germplasm Innovation and Utilization of Warm-Season Turfgrasses, Jiangsu Key Laboratory for the Research and Utilization of Plant Resources, Institute of Botany, Jiangsu Province and Chinese Academy of Sciences (Nanjing Botanical Garden Mem. Sun Yat-Sen), Nanjing 210014, China.
Int J Mol Sci. 2024 Sep 20;25(18):10114. doi: 10.3390/ijms251810114.
Salt stress severely inhibits plant growth. Understanding the mechanism of plant salt tolerance is highly important to improving plant salt tolerance. Previous studies have shown that nonselective cyclic nucleotide-gated ion channels () play an important role in plant salt tolerance. However, current research on mainly focuses on in glycophytic plants, and research on in halophytes that exhibit special salt tolerance strategies is still scarce. This study used the halophilic plant , an excellent warm-season turfgrass, as the experimental material. Through bioinformatics analysis, 18 members of the family were identified in ; they were designated through according to their scaffold-level chromosomal positions. are divided into four groups (I-IV), with the same groups having differentiated protein-conserved domains and gene structures. are unevenly distributed on 16 scaffold-level chromosomes. Compared with other species, the in Group III exhibit obvious gene expansion, mainly due to duplication of gene segments. The collinearity between , , and suggests that are evolutionarily conserved among gramineous plants. However, the Group III are only partially collinear with and , implying that the expansion of Group III genes may have been an independent event occurring in . Protein interaction prediction revealed that ZjCNGCs, calcium-dependent protein kinase, H-ATPase, outwardly rectifying potassium channel protein, and polyubiquitin 3 interact with ZjCNGCs. Multiple stress response regulatory elements, including those involved in salt stress, are present on the promoter. The qPCR results revealed differences in the expression patterns of in different parts of the plant. Under salt stress conditions, the expression of was significantly upregulated in roots and leaves, with and showing the greatest increase in expression in the roots. These results collectively suggest that play an important role in salt tolerance and that their expansion into Group III may be a special mechanism underlying the salt tolerance of .
盐胁迫严重抑制植物生长。了解植物耐盐机制对于提高植物耐盐性至关重要。先前的研究表明，非选择性环核苷酸门控离子通道（CNGCs）在植物耐盐性中发挥重要作用。然而，目前对CNGCs 的研究主要集中在模式植物上，而对具有特殊耐盐策略的盐生植物的研究仍然很少。本研究以盐生植物狗牙根（Cynodon dactylon）为实验材料，通过生物信息学分析，在狗牙根中鉴定出 18 个 CNGC 家族成员，根据其支架水平染色体位置命名为 CnCNGCs。CNGCs 分为四个亚家族（I-IV），相同亚家族具有分化的蛋白保守结构域和基因结构。CNGCs 不均匀分布在 16 条支架水平染色体上。与其他物种相比，第 III 亚家族的 CnCNGCs 表现出明显的基因扩张，主要是由于基因片段的重复。CnCNGCs、AtCNGCs 和 OsCNGCs 之间的共线性表明 CNGC 基因在禾本科植物中是保守的。然而，第 III 亚家族的 CnCNGCs 与 AtCNGCs 和 OsCNGCs 仅部分共线性，这表明第 III 亚家族 CNGC 基因的扩张可能是在狗牙根中发生的一个独立事件。蛋白互作预测显示，ZjCNGCs 与钙依赖型蛋白激酶、H-ATP 酶、外向整流钾通道蛋白和多聚泛素 3 互作。在 ZjCNGCs 启动子上存在包括盐胁迫在内的多种胁迫响应调控元件。qPCR 结果显示，不同部位植物中 CnCNGCs 的表达模式存在差异。在盐胁迫条件下，ZjCNGCs 在根和叶中的表达显著上调，其中 表达量增加最大。这些结果表明 CnCNGCs 在盐胁迫下可能发挥重要作用，其第 III 亚家族的扩张可能是狗牙根耐盐性的一种特殊机制。
