期刊
JOURNAL OF EXPERIMENTAL BOTANY
卷 68, 期 14, 页码 3915-3924出版社
OXFORD UNIV PRESS
DOI: 10.1093/jxb/erx188
关键词
CCM; chloroplast bicarbonate permeability; chloroplast CO2 permeability; MIMS; photosynthesis
资金
- University of Illinois as part of the Bill and Melinda Gates Foundation-funded Realizing Increased Photosynthetic Efficiency (RIPE) consortium
- Australian Research Council's Centre of Excellence for Translational Photosynthesis
To support photosynthetic CO2 fixation by Rubisco, the chloroplast must be fed with inorganic carbon in the form of CO2 or bicarbonate. However, the mechanisms allowing the rapid passage of this gas and this charged molecule through the bounding membranes of the chloroplast envelope are not yet completely elucidated. We describe here a method allowing us to measure the permeability of these two molecules through the chloroplast envelope using a membrane inlet mass spectrometer and O-18-labelled inorganic carbon. We established that the internal stromal carbonic anhydrase activity is not limiting for this technique, and precisely measured the chloroplast surface area and permeability values for CO2 and bicarbonate. This was performed on chloroplasts from several plant species, with values ranging from 2.3 x 10(-4) m s(-1) to 8 x 10(-4) m s(-1) permeability for CO2 and 1 x 10(-8) m s(-1) for bicarbonate. We were able to apply our method to chloroplasts from an Arabidopsis aquaporin mutant, and this showed that CO2 permeability was reduced 50% in the mutant compared with the wild-type reference.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据