The study of the effect of nickel heavy metal on some growth parameters and production of alkaloids in catharanthus roseus

Abstract

Plants, in their life cycle, are usually exposed to various kinds of environmental stress including heavy metals. One of these heavy metals is nickel which affects many physiological activities of plants. Catharanthus roseus being a rich source of alkaloids (indole alkaloids) consists of more than 130 secondary metabolites. Some of these compounds have pharmacological effects and are used as medicine. Vinblastine which is the most important alkaloid found in the leaves of Catharanthus roseus is used to heal the diseases like: testicle and breast cancers, lymphoma, neuroblastoma, Hodgkin and non-Hodgkin's lymphoma, mycosis fun- goides, histiocytosis, and Kaposi's sarcoma. It also controls mitotic activity by stopping the cells in metaphase through nonreturnable connection to tubeline. This alkaloid is the chemical analog of vincristine. In this study, the effect of 0, 2.5, 5, 10, 25, 50 mM concentrations of nickel chloride (NiCl2) on the amount of germination, growth factors, and alkaloids of Catharanthus roseus (seeds of pink variety) were investigated. Based on the findings of the study, the nickel metal decreased the percentage of germination and the growth factors in the plant. The total amount of alkaloid noticeably increased in both root and shoot as affected by NiCl2. Investigating the TLC plates/planes, an increase in the amounts of vinblastine, catharanthine, and ajmalicine alkaloids especially at higher concentrations were observed.