基于代谢组学揭示海藻糖促进长春花拮抗低温胁迫机制

Based on Metabonomics Reveals the Mechanism of Trehalose Promoting Catharanthus roseus against Low Temperature Stress

长春碱和长春质碱具有高效抗癌活性,而长春花是其重要来源植物。随着人们对抗癌药物原材料需求的增加,长春花(Catharanthus roseus)种植范围逐渐由南向北延伸。随着纬度增加,气温的降低成为长春花种植、繁育过程中重要的胁迫条件。海藻糖作为一种信号分子能有效地调节植物应对低温胁迫,而海藻糖促进长春花拮抗低温胁迫的代谢机制仍亟待研究与解决。本实验研究发现:低温胁迫后外源施加海藻糖,叶绿素含量与抗氧化酶活性呈现先升高后降低趋势;MDA含量显著降低,初步验证海藻糖可以提高长春花对低温的耐受性。GC-MS及PLS-DA分析从59种初生代谢产物中发现23种化合物具有显著差异。糖类化合物(如甘露糖)以及一些抗逆物质(如尸胺、硅烷)低温处理后明显积累,而外源添加海藻糖后其含量显著下降。有机酸类化合物像丙酸、苹果酸、没食子酸等却表现出相反的趋势。说明海藻糖通过调控一些糖类、有机酸和抗逆性等初生代谢物来减少低温带来的伤害。通过real-time PCR对长春花酚类和生物碱代谢途径关键酶基因的表达量以及UPLC-MS测定长春花6种生物碱的变化情况皆可证明长春花次生代谢产物在植物响应低温胁迫过程中也参与其中。

Vinblastine and vinblastine have highly effective anti-cancer activity, and Catharanthus roseus is an important source of plants. With the increasing demand for raw materials for anti-cancer drugs, the cultivation range of Catharanthus roseus gradually extends from south to north. As the latitude increases, the decrease of temperature becomes an important stress condition in the process of periwinkle planting and breeding. As a signal molecule, trehalose can effectively regulate plants to respond to low temperature stress, and the metabolic mechanism of trehalose in promoting Catharanthus roseus to antagonize low temperature stress still needs to be studied and resolved urgently. This experimental study found that the chlorophyll content and antioxi-dant enzyme activity showed a trend of first increasing and then decreasing after the exogenous application of trehalose after low temperature stress;the MDA content was significantly re-duced, which preliminarily verified that trehalose can improve the tolerance of Catharanthus roseus to low temperature. GC-MS and PLA-SD analysis revealed significant differences in 23 compounds from 59 primary metabolites. Carbohydrate compounds (such as mannose) and some anti-stress substances (such as cadaverine, silane) accumulate significantly after low tem-perature treatment, while the content of trehalose decreases significantly after exogenous addi-tion of trehalose. Organic acid compounds like propionic acid, malic acid, gallic acid, etc. show the opposite trend. It shows that trehalose reduces the damage caused by low temperature by regulating some primary metabolites such as sugars, organic acids and stress resistance. The expression of key enzyme genes in the phenol and alkaloid metabolism pathways of Catharanthus roseus by real-time PCR and the changes of the six alkaloids of Catharanthus roseus by UPLC-MS can prove that the secondary metabolites of Catharanthus roseus respond to low temperature stress in plants.