增强UV-B辐射和多效唑对绿豆光合作用的影响  

The Effects of Increased UV-B Radiation and Paclobutrazo on Photosynthesis in Mung Bean Seedlings

作　　者：郭林英[1] 佘小平[1] 贺军民[1] 孟朝妮[1] 曲威[1] 刘成[1] 

机构地区：[1]陕西师范大学生命科学学院,西安710062

出　　处：《光子学报》2006年第7期1071-1075,共5页Acta Photonica Sinica

基　　金：陕西省自然科学研究计划(99SM20;2003C101)资助项目

摘　　要：使用TPS-1便携式光合仪结合Farquhar和Sharkey的理论测定或计算增强UV-B辐射、多效唑(PP333)及其复合处理幼苗的相关光合指标,并同时测定核酮糖-1,5-二磷酸羧化/加氧酶(Rubisco)含量·发现UV-B辐射降低净光合速率(Pn)、气孔限制值(Ls)和气孔导度(Gs),但使胞间隙CO2浓度(Ci)增加;PP333提高Pn、Gs和Ci,却使Ls下降;与PP333处理相较,UV-B+PP333诱导Pn、Gs和Ci降低,却促进Ls增加;UV-B对Pn、叶肉细胞光合能力(Ao)、表观量子效率(AQY)、羧化效率(dPn/dCi)和Rubisco含量的降低程度大于PP333对上述指标的提高程度,亦大于PP333处理下UV-B对上述指标的抑制程度·结果表明,UV-B降低Pn的主要原因为叶肉细胞光合活性的抑制,而PP333促进Pn及PP333减轻UV-B对Pn的抑制效应主要是通过调节Gs实现的·The photosynthetic parameters of mung bean seedling in present of increased UV-B radiation, paclobutrazo （PP333） or their combined treatment were determined with TPS-1 photosynthesis system or calculated according to the theory of Farquhar and Sharkey. The content of RuBP carboxylase-oxygenase （Rubisco） was also assayed simultaneously. In the first leaf of seedling, UV-B radiation resulted in decreases in net photosynthetic rate （Pn）,stomatal limitation value （Ls） and stomatal conductance （Gs）, which were accompanied by increase in intercellular COz concentration （Ci）. PP333 elevated Pn,Gs and Ci, and reduced Ls. In comparison with PP333 treatment, UV-B＋PP333 induced reduction of Pn,Gs and Ci, but promoted Ls to rise. Pn, mesophyl photosynthetic capacity （Ao）, apparent quantum yield （AQY）, carboxylation velocity of Rubisco （dPn/dCi） and the content of Rubisco were reduced both in UV-B treatment （in comparison to control） and UV-B＋ PP333 treatment （in comparison to PP333 treatment） seedlings, and the reductive extent was greater in UV-B treatment seedling than in UV-B＋PP333 treatment seedling. And the reductive effects of UV-B radiation on Pn,Ao,AQY,dPn/dCi and Rubisco content were bigger than the promotive effects of PP333 treatment on those parameters. These results prove that UV-B radiation depresses Pn mainly by inhibiting photosynthetic activities of mesophyll cell, while the dominant reasons of PP333 promoting Pn and UV-B radiation inhibiting Pn in UV-B＋PP333 treatment seedling are the changes of Gs.

关 键 词：增强UV-B辐射 多效唑 复合处理 绿豆幼苗 光合作用 

分 类 号：Q945[生物学—植物学]