EFFECT OF PLANT GROWTH REGULATORS ON SECONDARY METABOLITES ACCUMULATION AND ANTIOXIDANT ACTIVITY OF CATHARANTHUS ROSEUS L.

Secondary metabolites not only play a vital role in plant defense but also had shown various medicinal properties which provide a scientific base for using herbs and different plants as alternative medicines that were used by ancient communities. Many of the drugs today are simple synthetic modifications of the natural compounds. The developing commercial requirements of secondary metabolites in recent years has resulted in a great interest in secondary metabolism. Different strategies have been studied with the objective of improving the production of secondary metabolites. Many studies proved the role of plant growth regulators in the accumulation and production of many of these active and therapeutic compounds. Short term experiment was carried out to investigate the response of Catharanthus roseus L. plant to the foliar spray of GA_3, IAA and 6-bezylaminopurin at (0, 30, 60, 90 ppm) concentrations during the blooming stage. Three parameters were studied, phenols content, alkaloids content and the antioxidant activity in leaves extracts of this plant. Results showed there were significant increments in all studied parameters, that was obvious at high concentrations of all plant growth regulators treatments. The significant increase in antioxidant activity percentage was in correlation with the significant increases in phenols and alkaloids content. This study is encouraging economically to produce high amounts of these secondary metabolites that had proved their antimicrobial and antitumor properties for decades.