Study On Chlorophyll Metabolism Pathway Of Selaginella Uncinata

The ornamental Selaginella uncinata is a perennial herb of the genus Selaginella of Selaginellaceae,with the leavea presenting a special blue-green color under the damp and dark living condition,which is one of the ornamental fern varieties with the attractive appearance.The change of its leaf color has a unique landscape effect,which is ralatively rare in gardens,leading to the considerable prospects for garden application.In the past,the research of Selaginella uncinata mainly focused on genomics,anatomy,cultivation and reproduction,chemical engineering and pharmacology,while it is not clear whether the chlorophyll metabolic pathway of Selaginella uncinata influences of the coloration of it.In this study,a combination of the intraspecific comparison(between the blue and red leaves of Selaginella uncinata)and the interspecies comparison(among the blue and red leaves of Selaginella uncinata and green leaves of Selaginella kraussiana)was applied to explore the ough the echaracteristics of the metabolic pathway of chlorophyll in Selaginella uncinata by measuring the products and content of before the biosynthesis of chlorophyll,the content of chlorophyll and its derivatives and related metabolic characteristics.Through experiment,the conclusions are as follows:(1)By measuring the changing content of the intermediate products from chlorophyll metabolic flow in the blue and red leaves of selaginella uncinata and the green leaves of Selaginella kraussiana,it was determined that the three synthetic steps of protoporphyrin IX to Mg-protoporphyrin IX,protochlorophyllide to chlorophyllide a and chlorophyllide a to chlorophyll b were the key links within chlorophyll metabolic pathway of selagi'nella uncinata And magnesium chelatase(CHLH),protochlorophyllide oxidoreductase(LPOR)and chlorophyllase(CLH)were important enzymes in the chlorophyll biosynthesis and metabolism pathway of it.(2)Through the analysis of the chlorophyll metabolic pathway of selaginella uncinata,it was speculated that the chlorophyllide b produced in selaginella uncinata started the next step quickly,which were not accumulated during the transformation process.In order to better utilize the ambient light for the growth requirements,the conversion efficiency of chlorophyll a to chlorophyll b was higher than that of oppsite one in selaginella uncinata,resulting in increasing relative content of chlorophyll b,and the ratio between chlorophyll a and b was less than two.(3)The chlorophyllase and Mg-dechelatase in the three plant materials were negatively correlated with chlorophyll,indicating that they participated in chlorophyll degradation to a certain extent.The concentrations of chlorophyllide a and chlorophyllide b were not only regulated by the chlorophyllase.In addition,the relatively higher SOD activity or in hibited activities of POD and CAT might impact the accumulation of hydrogen peroxide through other ways,while affecting the production rate of Hydrogen peroxide and superoxide,and the content of chlorophyll.