The Effect Of Exogenous Nitric On Physiology And Metabolism Of Alkaloid In Catharanthus Roseus Under Salt Stress

Indole alkaloids are the most extensive and effective anti-cancer medicines in clinical application. However, the content of indole alkaloidis in C. roseus are low, which always restrict the yield of indole alkaloids, because of complicated and expensive of chemical synthesis process of indole alkaloidis, so to study a way of how to enhance the content of indole alkaloidis in C. roseus is the most practical.Indole alkaloids are the second metabolin of C. roseus, so the yield of indole alkaloids are effected by environment. Salt stress could enhance the content of indole alkaloidis in C. roseus, but it is bad way to increase the biomass of C. roseus. NO as a signal molecule of plant, which mediated signal transmission in stress environment, salicylic acid and jasmonic acid are controlled by NO, base which, we treat C. roseus with exogenous NO under NaCl stress in order to enhance the content of indole alkaloids, and at same time, increasing the biomass of C. roseus.A sand culture experiment was conducted in greenhouse to study effects of exogenous nitric oxide donor (SNP) on growth, photo synthetic characteristics, antioxidase and alkaloids contents of C. roseus seedlings under NaCl stress. The main results obtained as follows:(1) Treated C. roseus with0.05,0.10and0.50mmol·L-1SNP in last7days under no salt stress, the biomass, photosynthetic characteristics and alkaloids contents of C. roseus seedlings had no significantly changes, but treated with1.0mmol·L-1SNP and2.0mmol·L-1SNP in last7days, the biomass, photosynthetic characteristics and alkaloids contents of C. roseus seedlings were affected significantly.(2)0.1mmol·L-1SNP was the best concentration of0.05,0.1,0.5,1.0and2.0mmol·L-1SNP on allevinating the stress of50mmol·L-1NaCl and100mmol·L-1NaCl.0.1mmol·L-1SNP increased fresh weight and dry weight significantly, enchanced the contents of proline and soluble sugar, easied osmosis stress, protected photosynthetic pigments and photosynthetic cell from salt stress,improved photosynthesis significantly; promoted antioxidase activity, and protected C. roseus cell from eliminating reactive oxygen species (ROS). But the activity of tryptophan decarboxylase (TDC) was heightest under0.5mmol·L-1SNP treatment, total indole alkaloids, Vinblastine, Catharanthine, Vincristine and Vindolin contents of the C. roseus were the highest under0.5mmol·L-1SNP treatment too.(3)0.05mmol·L-1SNP had best remission effect under150mmol·L-1NaCl stress,0.05mmol·L-1SNP treatment,which increased photosynthetic pigments content, hold the best photosynthesis, increased biomess and the antioxidase activity also at higher level, but the activity of TDC, total indole alkaloids, vinblastine, catharanthine, vincristine and vindolin contents of the C. roseus were the highest under0.1mmol·L-1SNP treatment.To sum up, the stress of50mmolL-1NaCl and100mmol-L’1NaCl could be alleviated by0.1mmol·L-1SNP very vell, biomess increased significantly;0.5mmol·L-1SNP increased total indole alkaloids, vinblastine, catharanthine, vincristine and vindolin contents very well.0.05mmol·L-1SNP alleviated150mmol·L-1NaCl stress very well and alkaloids contents highest under0.1mmol·L-1SNP treatment.