Exogenous melatonin confers salt stress tolerance to Chlamydomonas reinhardtii (Volvocales, Chlorophyceae) by improving redox homeostasis
Exogenous melatonin confers salt stress tolerance to Chlamydomonas reinhardtii (Volvocales, Chlorophyceae) by improving redox homeostasis
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DOI：
10.2216/17-141.1
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发表时间：
2018-09
期刊：
影响因子：
1.6
通讯作者：
Yujing Zhang;Wenying Gao;Yawei Lv;Qingqing Bai;Yingjuan Wang
中科院分区：
文献类型：
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作者：
Yujing Zhang;Wenying Gao;Yawei Lv;Qingqing Bai;Yingjuan Wang
摘要：褪黑素(MT；N-乙酰-5-甲氧基色胺)是色氨酸的天然衍生物，是包括动植物在内的几乎所有生物体都能合成的中枢生物分子。作为一种抗氧化剂，MT参与了许多与保护植物免受非生物胁迫相关的细胞反应。然而，关于MT在微藻中的作用的研究很少。本论文主要研究了外源MT与盐胁迫的关系，评价了100 mM盐胁迫下真核生物莱茵衣藻的生长、细胞形态、丙二醛(MDA)含量、抗氧化酶活性和MT浓度。0.1和1.0μM的MT对衣藻生长有促进作用，10和10 0μM的MT对衣藻生长有负面影响。1μM的MT在不利的盐环境中保持了完整的细胞形态和细胞聚集。MT浓度为0.1、1和10μ时，抗氧化剂超氧化物歧化酶、过氧化氢酶和过氧化物酶活性升高，丙二醛含量降低。综上所述，外源MT可能通过提高相对酶活性和维持平衡的氧化还原状态来提高莱茵哈迪尔乳杆菌的耐盐性，从而使其能够正常生长。适当浓度的外源MT能促进莱茵梭菌在盐环境中的生长，提高抗氧化系统相关酶的活性，从而保护细胞。这些结果为MT在一个模型绿藻中的功能提供了深入的了解。
Abstract: Melatonin (MT; N-acetyl-5-methoxy-tryptamine), a natural derivative of tryptophan, is a central biomolecule synthesised by almost all organisms, including animals and plants. As an antioxidant, MT is involved in many cell responses associated with the protection of plants against abiotic stress. However, there are few studies on the function of MT in microalgae. Our work focused on the relationship between exogenous MT and salt stress in the single-celled eukaryote Chlamydomonas reinhardtii, evaluating for growth, cell morphology, malondialdehyde (MDA) content (the peroxidation product of the cell membrane), activity of antioxidant enzymes and MT concentration under 100 mM NaCl treatment. Growth of Chlamydomonas was promoted at MT concentrations of 0.1 and 1.0 μM, but at 10 and 100 μM, MT was associated with negative effects on growth. MT at 1 μM maintained intact cell morphology and cellular aggregation in an unfavourable salt environment. MT concentrations of 0.1, 1 and 10 μM MT led to increased activity of the antioxidants superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) but reduced MDA. In conclusion, by increasing relative enzyme activity and maintaining a balanced redox state, exogenous MT may improve salt tolerance of C. reinhardtii to allow normal growth. A suitable concentration of exogenous MT improved the growth of C. reinhardtii in a salt environment and increased the activity of antioxidant system–related enzymes to protect cells. These results provide insight into the function of MT in a model green alga.