《植物生理学报》 2014, 50(8): 1248-1254

根据光合作用能量代谢测定光呼吸的方法研究

汪义龙, 夏莹萍, 张洁, 吴倩, 梁建生*

扬州大学生物科学与技术学院, 江苏扬州225009

通信作者：梁建生；E-mail: jsliang@yzu.edu.cn；Tel: 0514-87979320

摘　要：

本文根据光合作用和光呼吸途径能量代谢, 通过改变外界CO₂和O₂浓度, 计算卡尔文循环固定的CO₂和光呼吸消耗的O₂。结果表明, 可以通过3种方法计算。方法1, 测定在CO₂饱和点(A)和正常CO₂ (A`)浓度下吸收的CO<sub>2</sub>, 得出光呼吸消耗的O<sub>2</sub>为: 18/19(A–A`), 卡尔文循环固定的CO₂为: 1/19(6A+13A`+19R<sub>d</sub>)。方法2, 测定在不含O<sub>2</sub>的空气中(O)和正常O<sub>2</sub> (O`)浓度下释放的O₂, 得出光呼吸消耗的O₂为: –13/5O–O`–18/5R<sub>d</sub>, 卡尔文循环固定的CO<sub>2</sub>为: 13/18(O`–O)。方法3, 测定在正常情况下吸收的CO₂ (A`)和释放的O<sub>2</sub> (O`), 得出光呼吸消耗的O₂为: 18(O`–A`), 卡尔文循环固定的CO₂为: 6O`–5A`+R_d。测定在CO₂饱和点和正常CO₂浓度下吸收的CO₂计算出水稻光呼吸释放的CO₂占光合作用固定的24%~40%。

关键词：光呼吸; 光合作用; 能量代谢; 水稻

收稿：2014-03-24   修定：2014-06-24

A Method to Calculate the Photorespiration Based on Photosynthesis Energy Metabolism

WANG Yi-Yong, XIA Ying-Ping, ZHANG Jie, WU Qian, LIANG Jian-Sheng*

College of Bioscience and Biotechnology, YangzhouUniversity, Yangzhou, Jiangsu 225009, China

Corresponding author: LIANG Jian-Sheng; E-mail: jsliang@yzu.edu.cn; Tel: 0514-87979320

Abstract:

According to energy metabolism of Calvin cycle and photorespiration, the rate of CO₂ fixed in Calvin cycle and O₂ consumed in photorespiration were calculated by changing the external CO₂ and O₂ concentrations. The results showed there were three ways for calculation. Method 1, based on the measurement of CO₂ absorption at CO₂ saturation point (A) and normal air (A`), consumption of O<sub>2</sub> in photorespiration could be calculated by 18/19(A–A`), and the CO₂ fixed in Calvin cycle would be considered as 1/19(6A+13A`+19R<sub>d</sub>). Method 2, on the grounds of O<sub>2</sub> released at CO<sub>2</sub>-free air (O) and normal air (O`) conditions, consumption of O₂ in photorespiration and fixation of CO₂ in Calvin cycle can be deduced by formula –13/5O–O`–18/5R<sub>d</sub> and 13/18(O`–O), respectively. Method 3, basing on the CO₂ fixation (A`) and O<sub>2</sub> consumption (O`) under the normal conditions, consumption of O₂ in photorespiration and fixation of CO₂ in dark reaction can be calculated as 18(O`–A`) and 6O`–5A`+R_d, respectively. According to the methods mentioned above, it was found that the ratio of CO₂ released by photorespiration to photosynthesis is 24%–40% in Oryza sativa.

Key words: photorespiration; photosynthesis; energy metabolism; rice