《植物生理学报》 2015, 51(9): 1425-1432

低氮对产油尖状栅藻荧光特性及色素蛋白复合物的影响

罗舒怀, 张莹, 吴琼芳, 彭倩倩, 李爱芬^*, 张成武

暨南大学生态学系, 广州510632

通信作者：李爱芬；E-mail: tiger@jnu.edu.cn；Tel: 020-85224366

摘　要：

以产油绿藻尖状栅藻(Scenedesmus acuminatus)为实验材料, 采用77 K低温荧光、SDS-PAGE圆盘电泳、iTRAQ蛋白定量等方法, 研究其在低氮胁迫产油条件下, 藻细胞的低温荧光特性及光合色素蛋白复合物的变化。结果表明, 在77 K低温条件下尖状栅藻有3个荧光发射峰, 分别位于685、695和715 nm处。利用圆盘电泳从藻细胞类囊体膜上分离到6个条带, 从上至下依次为CPIa、CPI、CPa1、CPa2、LHCP和FP (游离色素), 与对照组(18 mmol•L^-1 NaNO₃)相比, 低氮(3.6 mmol•L^-1 NaNO₃)培养的藻细胞光能耗散增强, 分离的类囊体膜色素蛋白复合物代表PSII的条带CPa1和CPa2模糊, D1蛋白及捕光色素蛋白表达下调。综上低氮限制条件下产油尖状栅藻的PSII核心复合物降解, 制约藻细胞吸收和转化光能, 进而影响光合效率。

关键词：尖状栅藻; 低氮胁迫; 色素蛋白复合物; 荧光特性

收稿：2015-07-22   修定：2015-08-19

资助：国家自然科学基金(41176105)和中央高校基本科研业务费专项资金(21614101)。

Effects of N-Depleted on Fluorescence Characteristic and Pigment-Protein Complexes of an Oleaginous Scenedesmus acuminatus

LUO Shu-Huai, ZHANG Ying, WU Qiong-Fang, PENG Qian-Qian, LI Ai-Fen^*, ZHANG Cheng-Wu

Department of Ecology, Jinan University, Guangzhou 510632, China

Corresponding author: LI Ai-Fen; E-mail: tiger@jnu.edu.cn; Tel: 020-85224366

Abstract:

In this study, the photosynthetic apparatus of S. acuminatus was analyzed by purifying the thylakoids and isolating the different pigment-protein complexes upon solubilization. In addition, the effects of N-depleted on photosynthetic apparatus were investigated using SDS-PAGE, 77 K fluorescence and isobaric tags for relative and absolute quantification (iTRAQ). The results showed that, six pigment complexes bands including CPIa, CPI, CPa1, CPa2, LHCP, and FP were isolated from the thylakoid membrane of S. acuminatus. Under N-depleted conditions, the bands CPa1, CPa2 which represented PSII became very vague, meanwhile D1 protein and light-harvesting proteins were down-regulated. The 77 K fluorescence spectra of PSI and PSII were located at 685, 695 and 715 nm. The results from the biochemical and spectroscopic characterization showed that, during the culture period, effects of N-depleted on PSII was greater than PSI, while algal cells decreased light utilization and increased dissipation. So we concluded that, there was difference between microaglal and high plant on photosynthetic traits, otherwise the damage of PSII complexes of S. acuminatus in N-depleted conditions does restrict photosynthetic efficiency.

Key words: Scenedesmus acuminatus; N-depleted; pigment-protein complexes; fluorescence characteristic