OBJECTIVETo reveal the effects of UV-B radiation on the growth of medical plant Mentha piperita, simulate an enhanced UV-B radiation and evaluate intensity of radiation on the photosynthesis of M. piperita.

METHODThree different levels of UV-B radiation were set in the experiment which included: natural light control (0 W x m(-2)), light UV-B radiation stress (0.15 W x m(-2)) and heavy UV-B radiation stress (0.35 W x m(-2)). The chloroplast ultrastructure, photosynthesis indexes and chlorophyll fluorescence parameters of the M. piperita were observed under the three treatments.

RESULTAlthough the chloroplast ultrastructure was destroyed to some degree under the light UV-B radiation stress, F(v)/(F)m, F(v)/F(o), qP, phiPS II and ETR could resume to the comparative level of natural light control. At the same time, qN increased firstly and decreased thereafter. But under the high strength UV-B radiation stress, the photosynthetic structures were badly destroyed, which could not recover through protecting mechanism by itself.

CONCLUSIONIt was showed that M. piperita was able to protect photosynthetic structures by increasing respiration and dissipation when photosynthetic capacity reduced under light UV-B radiation stress. It is demonstrated that M. piperita has high adaptation to light UV-B radiation stress, which is kind of promising medical plant for area with higher UV-B radiation.

Chlorophyll ; metabolism ; Chloroplasts ; metabolism ; radiation effects ; ultrastructure ; Mentha piperita ; metabolism ; radiation effects ; ultrastructure ; Photosynthesis ; radiation effects ; Ultraviolet Rays

OBJECTIVETo reveal the response of content berberine in root of Coptis chinensis to different intensity of UV-B radiation, and provide the theory basis for promoting the content of berberine.

METHODFour groups of UV-B radiation were set in the experiment which included: natural light control (0 W x m(-2)), UL (0.05 W x m(-2)), UM (0.10 W x m(-2)), UH (0.20 W x m(-2)). The special photosynthesis character, PPP pathway in the primary metabolism and lyrosinase activity, the changes of berberine in the root of C. chinensis were measured under different UV-B radiation.

RESULTPhotosynthetic pigment, qN, Fo, ETR, activity of glucose-6-phosphate dehydrogenase and the content of berberine in the root of C. chinensis, all of these parameters were lower than other groups under the UH radiation. However, under the UM radiation, C. chinensis protected itself from the light UV-B radiation by promoting the power of photosynthesis and PPP pathway in order to produce more NADPH and secondary metabolites.

CONCLUSIONC. chinensis increases its photosynthetic ability and PPP pathway which can furnish more precursor of secondary metabolites and NADPH that are needed in the secondary metabolism. Furthermore, the content of berberine increases correspondingly. The research provide the example for increasing the content of berberine in C. chinensis cultivation.

Berberine ; analysis ; Coptis ; chemistry ; drug effects ; metabolism ; Glucosephosphate Dehydrogenase ; metabolism ; NADP ; metabolism ; Photosynthesis ; radiation effects ; Ultraviolet Rays

OBJECTIVEUnder various drought conditions and nitrogen application, the content of vindoline, catharanthine, vincristine and vinblastine in the leaf of Catharanthus roseus were illustrated to improve the content of alkaloid theoretically.

METHODSix groups were set in the experiment, which included: CK (natural control), CN (natural control + nitrogen), LK (low drought), LN (low drought + nitrogen), HK (high drought), HN (high drought + nitrogen) to discuss the change characteristics of total nitrogen, the activity of alkaline POD and TDC, the content of four alkaloids under the different conditions were measured.

RESULTUnder LK condition, the activity of POD, TDC were enhanced. In the early stage of stress (0-21 d), vindoline, catharanthine, vincristine and vinblastine accumulated, and reduced in the later stage (28-35 d). For all groups, adding exogenous nitrogen could improve the total content of nitrogen, vindoline and vinblastine, meanwhile the activity of POD and TDC were enhanced as well. The LN, HN treatments were beneficial to accumulating catharanthine and vinblastine.

CONCLUSIONDrought stress or additional nitrogen have an influence on both of the activities of POD and TDC, and the four alkaloids were affected as well. Thereinto, the LN condition was the most effective treatment for accumulating the four alkaloids (vindoline, catharanthine, vincristine and vinblastine), which were regulated by improve nitrogen content and enzymatic activity.

Catharanthus ; metabolism ; Nitrogen ; metabolism ; Peroxidase ; metabolism ; Stress, Physiological ; Vinblastine ; analogs & derivatives ; metabolism ; Vinca Alkaloids ; metabolism ; Vincristine ; metabolism ; Water ; metabolism