Wang Lingxia, Pan Dezhuo, Lv Xiaojie, Cheng Chi-Lien, Li Jian, Liang Wenyu, Xing Jianhong, Chen Wei
School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
School of Life Sciences, Ningxia University, Yinchuan, 750021, China.
Plant Cell Environ. 2016 Nov;39(11):2486-2497. doi: 10.1111/pce.12804. Epub 2016 Sep 7.
The halophilic mangrove species Kandelia candel is an excellent model for understanding why halophytes thrive in high salinity. Preliminary transcriptomic analyses revealed that genes involved in diverse functions, such as in phenylpropanoid and amino acid metabolisms, and those in DNA replication and damage repair were highly responsive to salt stress. Proteomic analyses revealed that the proteins involved in light reaction of photosynthesis, amino acid and carbohydrate metabolisms, secondary metabolite biosynthesis and posttranslational modification showed increased levels in response to salt stress. The metabolisms of phenylpropanoids and amino acids under salt stress were systematically examined based on the preliminary omics analyses. The activities of phenylpropanoid biosynthetic enzymes and the contents of phenols, flavonoids, anthocyanins and lignins were significantly increased under salt stress. In the free amino acid pool, glutamate was the most abundant. Together with γ-aminobutyric acid, glutamate levels further increased, while proline levels remained unchanged in response to salt stress. These findings point to the potential importance of phenylpropanoids and free amino acids in salt tolerance of K. candel that have been observed, but not systemically investigated at the levels of gene expression, enzyme activity and metabolite accumulation in glycophytes and non-tree halophytes.
嗜盐红树植物秋茄是理解盐生植物为何能在高盐环境中茁壮成长的优秀模式植物。初步转录组分析表明，参与多种功能的基因，如苯丙烷类和氨基酸代谢相关基因，以及DNA复制和损伤修复相关基因，对盐胁迫高度敏感。蛋白质组分析显示，参与光合作用光反应、氨基酸和碳水化合物代谢、次生代谢物生物合成及翻译后修饰的蛋白质在盐胁迫下水平升高。基于初步的组学分析，系统研究了盐胁迫下苯丙烷类和氨基酸的代谢情况。盐胁迫下，苯丙烷类生物合成酶的活性以及酚类、黄酮类、花青素和木质素的含量显著增加。在游离氨基酸池中，谷氨酸含量最为丰富。盐胁迫下，谷氨酸与γ-氨基丁酸一起进一步增加，而脯氨酸水平保持不变。这些发现表明，苯丙烷类和游离氨基酸在秋茄耐盐性中具有潜在重要性，此前在甜土植物和非树木盐生植物的基因表达、酶活性和代谢物积累水平上虽有观察，但未进行系统研究。
