铜胁迫与外源乙烯相互作用对长春花幼苗生长和生理代谢的影响

The Effects of Copper Stress and the Involved Role of Ethylene on the Growth and Physiological Metabolism of Catharanthus roseus

摘要: 铜是植物生长发育所必需的营养元素。本文以药用植物长春花(Catharanthus roseus)为材料，从长春花在铜胁迫的逆境条件下培养入手，并且辅助以外源乙烯调控，研究其对长春花初生代谢、Cu的富集和转运以及次生代谢等方面的协同效应。当铜胁迫浓度较低时叶绿素含量减少导致光合作用减弱；根部对Cu有着较强的富集能力，并且Cu在长春花植株体内由成熟组织向幼嫩组织转运率较高，在此基础上加入外源乙烯利后，降低了植株各组织部位对铜的富集能力，降低了铜胁迫对长春花植株的胁迫伤害，促进了铜由成熟叶片向幼嫩组织的转运率。这些结果表明，铜胁迫对长春花初生和次生代谢具有显著的抑制作用，外源添加乙烯不但可以缓解铜胁迫引起的生长抑制和生理伤害，同时对长春花叶片中生物碱的合成积累具有协同促进效应。

Abstract: Copper is the essential nutrient for the growth and development of plants. Here, a medical plant Catharanthus roseus was subjected to different concentrations of copper plus with exogenous ethylene, investigating their cooperative effects on plant growth, primary metabolism, accumula-tion and transportation of Cu, as well as secondary metabolisms. Our results showed that the treatment with low level of Cu decreased chlorophyll content and photosynthetic rate. In addition, large amounts of Cu was accumulated in roots and brought about obvious hurt on root growth. In this case, the plant was able to actively transfer Cu from mature tissues to young ones. When ex-ogenous ethylene was applied, the accumulation of Cu in detected tissues was decreased, partly reducing the physiological hurt of copper stress on plant and largely promoting the Cu transport rate from mature leaves to young tissues. It was concluded that the copper stress exerted an ob-viously adverse effect on plant primary and secondary metabolism. An increased exogenous ethy-lene supply could not only alleviate the inhibitory effect of copper stress on plant growth, but en-hance vinblastine accumulation in plants.