Ce对UV-B辐射胁迫下大豆幼苗光合作用影响:Ⅱ对光合量子效率与羧化效率的影响  

Effect of Cerium on Photosynthesis in Soybean Seedling Under Supplementary UV-B Radiation Stress:Ⅱ Photosynthetic Quantum Yield and Carboxylation Efficiency

作　　者：梁婵娟[1] 黄晓华[2] 周青[1] 

机构地区：[1]江南大学工业生物技术教育部重点实验室,江苏无锡214036 [2]南京师范大学化学与环境科学学院,江苏南京210097

出　　处：《农业环境科学学报》2006年第3期580-583,共4页Journal of Agro-Environment Science

基　　金：国家发改委稀土专项基金(GFZ040628);国家自然科学基金(20471030)

摘　　要：用水培法研究了Ce(Ⅲ)对紫外辐射(UV-B,280￣320nm)胁迫下油菜幼苗光合量子效率与羧化效率变化对光合作用的影响。结果表明,20mg·L-1CeCl3能有效减缓紫外辐射(T1/0.15W·m-2和T2/0.45W·m-2)胁迫所导致饱和光光合速率(Ps)、饱和CO2光合速率(Pm)、表观量子效率(AQY)与羧化效率(CE)的降低,使得Ce+UV-B组各项指标虽低于CK,但明显优于UV-B组。动态曲线显示,Ce减缓了UV-B胁迫期各项指标的下降趋势,加快恢复期的上升速度,且最终达到较好的恢复效果。通过对AQY、CE与Pn的相关统计学分析发现,低剂量UV-B辐射胁迫下Ce对AQY调节对改善光合功能的作用大于CE。高剂量下则是CE的变化起主要作用。Effect of cerimn （Ce^3＋） on photosynthesis rate, photosynthetic pigments content and Hill reaction activity in soybean seedlings exposed to two levels of ultraviolet-B radiation （UV-B, 280～320 nm） was studied with hydroponics under laboratory conditions. The results showed that UV-B radiation made a decrease in light-saturated net photosynthesis rate （Ps）, Ps at saturating Ci （Pm）, apparent photosynthetic quantum yield （AQY）, as well as carboxylation efficiency （CE）. CeCl3 could improve photosynthesis action by promoting photosynthesis rate, increasing chlorophyll and carotenoid content, and stimulating the activity of Hill reaction. Consequently, the each index with Ce＋UV-B treatment was better than that with UV-B treatment. Analyzing the dynamic curves of net photosynthesis rate, AQY and CE under six treatments during stress and recovery phase, we found that the decreased rate of three indices with Ce＋UV-B treatments during stress phase was smaller, whereas the restored rate during recovery phase was higher, showing better restored extent, compared to those of UV-B treatments. All data indicated that Ce could alleviate the inhibition of UV-B on photosynthesis in plants to a certain extent. In addition, from the correlation coefficients of some regression equations between AQY, CE and net photosynthesis rate, we considered that the change of AQY had a relative obvious influence on photosynthesis action under low dosage of UV-B radiation, but the change of CE played more important role under high dosage of U V-B radiation.

关 键 词：稀土Ce UV—B辐射 大豆幼苗 表观光合量子效率 羧化效率 

分 类 号：S565.1[农业科学—作物学]