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

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.