To study non-structural carbohydrate character-istics and nutrient utilization strategies of Pinus yunnanen-sis under continuous drought conditions,2-year-old seed-lings were planted in pots with appropriate water,lig...To study non-structural carbohydrate character-istics and nutrient utilization strategies of Pinus yunnanen-sis under continuous drought conditions,2-year-old seed-lings were planted in pots with appropriate water,light and moderate and severe drought treatments[(80±5),(65±5),(50±5),and(35±5)%of field water-holding capacity].Non-structural carbohydrates,carbon(C),nitrogen(N),and phosphorus(P)concentrations were measured in each plant component.The results show that:(1)With increasing drought,non-structural carbohydrates gradually increased in leaves,stems,and coarse roots,while gradually decreased in fine roots;(2)C concentrations of all were relatively stable under different stress levels.Phosphorous utilization of each component increased under light and moderate drought conditions,while N and P utilization efficiency of each plant component decreased under severe drought.Growth was mainly restricted by N,first decreasing and then increasing with increased drought;(3)There was a correlation between the levels of non-structural carbohydrates and C,N,and P in each component.Changes in N concentration affected the interconversion between soluble sugar and starch,which play a regulatory role in the fluctuation of the concentration of non-structural carbohydrates;and,(4)Plasticity analysis showed that P.yunnanensis seedlings responded to drought mainly by altering starch concentration,the ratio of soluble sugar to starch in leaves and stems,and further by alter-ing N and P utilization efficiencies.Overall,these results suggest that the physiological activities of all organs of P.yunnanensis seedlings are restricted under drought and that trade-offs exist between different physiological indicators and organs.Our findings are helpful in understanding non-structural carbohydrate and nutrient adaptation mechanisms under drought in P.yunnanensis seedlings.展开更多
Four new taxane diterpenoids were isolated from the bark of Taxus yunnanensis.Their structures were elucidated as the new skeleton with 5/7/6/4 membered rings by spectral analysis and 2D NMR shift correlation experime...Four new taxane diterpenoids were isolated from the bark of Taxus yunnanensis.Their structures were elucidated as the new skeleton with 5/7/6/4 membered rings by spectral analysis and 2D NMR shift correlation experiments.展开更多
Two new sterols. 3 beta,7 alpha, 16 beta-trihydroxy-stigmast-5,22-diene 1,3 beta,7 alpha,16 beta-trihydroxy-stigmast-5-ene 2. were isolated together with two known ergosterols, ergosta-5,24(28)-diene-3 beta.7 alpha-di...Two new sterols. 3 beta,7 alpha, 16 beta-trihydroxy-stigmast-5,22-diene 1,3 beta,7 alpha,16 beta-trihydroxy-stigmast-5-ene 2. were isolated together with two known ergosterols, ergosta-5,24(28)-diene-3 beta.7 alpha-diol, ergosta-5,24(28)-diene-3 beta,7 beta,16 beta-triol from the bark of Amoora yunnanensis (H. L. Li) C. Y. Wu. Their structures were deduced on the basis of spectral data.展开更多
基金This study was supported by the National Natural Science Foundation of China(31960306).
文摘To study non-structural carbohydrate character-istics and nutrient utilization strategies of Pinus yunnanen-sis under continuous drought conditions,2-year-old seed-lings were planted in pots with appropriate water,light and moderate and severe drought treatments[(80±5),(65±5),(50±5),and(35±5)%of field water-holding capacity].Non-structural carbohydrates,carbon(C),nitrogen(N),and phosphorus(P)concentrations were measured in each plant component.The results show that:(1)With increasing drought,non-structural carbohydrates gradually increased in leaves,stems,and coarse roots,while gradually decreased in fine roots;(2)C concentrations of all were relatively stable under different stress levels.Phosphorous utilization of each component increased under light and moderate drought conditions,while N and P utilization efficiency of each plant component decreased under severe drought.Growth was mainly restricted by N,first decreasing and then increasing with increased drought;(3)There was a correlation between the levels of non-structural carbohydrates and C,N,and P in each component.Changes in N concentration affected the interconversion between soluble sugar and starch,which play a regulatory role in the fluctuation of the concentration of non-structural carbohydrates;and,(4)Plasticity analysis showed that P.yunnanensis seedlings responded to drought mainly by altering starch concentration,the ratio of soluble sugar to starch in leaves and stems,and further by alter-ing N and P utilization efficiencies.Overall,these results suggest that the physiological activities of all organs of P.yunnanensis seedlings are restricted under drought and that trade-offs exist between different physiological indicators and organs.Our findings are helpful in understanding non-structural carbohydrate and nutrient adaptation mechanisms under drought in P.yunnanensis seedlings.
文摘Four new taxane diterpenoids were isolated from the bark of Taxus yunnanensis.Their structures were elucidated as the new skeleton with 5/7/6/4 membered rings by spectral analysis and 2D NMR shift correlation experiments.
文摘Two new sterols. 3 beta,7 alpha, 16 beta-trihydroxy-stigmast-5,22-diene 1,3 beta,7 alpha,16 beta-trihydroxy-stigmast-5-ene 2. were isolated together with two known ergosterols, ergosta-5,24(28)-diene-3 beta.7 alpha-diol, ergosta-5,24(28)-diene-3 beta,7 beta,16 beta-triol from the bark of Amoora yunnanensis (H. L. Li) C. Y. Wu. Their structures were deduced on the basis of spectral data.
