期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1983
卷号：80
期号：5
页码：1290-1294
DOI：10.1073/pnas.80.5.1290
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Reactions of the photorespiratory pathway of C3 plants are found in three subcellular organelles. Transport processes are, therefore, particularly important for maintaining the uninterrupted flow of carbon through this pathway. We describe here the isolation and characterization of a photorespiratory mutant of Arabidopsis thaliana defective in chloroplast dicarboxylate transport. Genetic analysis indicates the defect is due to a simple, recessive, nuclear mutation. Glutamine and inorganic phosphate transport are unaffected by the mutation. Thus, in contrast to previous reports for pea and spinach, glutamine uptake by Arabidopsis chloroplasts is mediated by a transporter distinct from the dicarboxylate transporter. Both the inviability and the disruption of amino-group metabolism of the mutant under photorespiratory conditions suggest that the primary function of the dicarboxylate transporter in vivo is the transfer of 2-oxoglutarate and glutamate across the chloroplast envelope in conjunction with photorespiratory nitrogen metabolism. The role commonly ascribed to this transporter, conducting malate-aspartate exchanges for the indirect export of reducing equivalents from the chloroplast, appears to be a minor one.
关键词：photorespiration ; malate shuttle ; glutamine transport
