暗处理对油菜子叶类囊体膜色素组成和荧光性质的影响

以蜀杂10号油菜为材料,播种7 d后分别置于自然光照条件和黑暗环境中进行暗处理,未处理油菜在d 5、d7、d 14、d 17、d 21、d 24和d 27时收集子叶,暗处理油菜于播种d 8、d 10、d 12和d 14时收集子叶.制备油菜子叶类囊体膜,分析色素含量,并进行类囊体膜丙酮抽提液窜温吸收光谱、叶绿素荧光发射和激发光谱以及蛋白质内源荧光光谱的分析.结果显示:与未处理油菜相比,暗处理引起油菜子叶类囊体膜光合色素Chl a和Chl b含量急剧减少,Chla/b比值和叶绿素/类胡萝卜素(Chl/Car)比值持续下降,类囊体膜对叶绿素的捕光能力和受激发能力降低,类囊体膜蛋白质内源荧光强度降低,以及色素蛋白复合物降解.上述结果表明,暗处理诱导油菜子叶快速进入衰老阶段,类囊体膜蛋白组成和色素的光合功能均发生了明显的变化.图10参23

Effect of Dark Treatment on Fluorescence Properties of Cytoledon Thylakoid Membranes of Brassica napus L.

Shuza-10 rapeseed (Brassica napus L.) was grown under natural and dark conditions 7 days after sowing. The cotyledons of untreated rapeseed were harvested on day 5, 7, 14, 17, 21, 24 and 27, and those of the dark treated on day 8, 10, 12, and 14. Thylakoid membranes were prepared from the rapeseed cotyledons of the two treatments, respectively. A comparative study on their pigment composition, absorption spectra at room temperature, chlorophyll emission and excitation fluorescence spectra and protein flourescence spectra was conducted. Compared with the untreated rapeseed, the cotyledon thylakoid membranes treated in dark had much less Chl (Chl a and Chl b), and a lower Chl a/b ratio and chlorophyll/carbtenoid (Chl/Car) ratio. Furthermore, the chlorophyll fluorescence spectra indicated that its capacities of harvesting light and being excited were lower after dark treatment. In addition, the protein composition of cotyledon thylakoid membranes also changed in the dark treatment, suggested by significant difference in protein influorescence. The data indicated that dark treatment induced senescence of rapeseed cotyledon. Fig 10, Ref 23