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Overexpression of the triose phosphate translocator ( TPT ) complements the abnormal metabolism and development of plastidial glycolytic glyceraldehyde‐3‐phosphate dehydrogenase mutants
Author(s) -
FloresTornero María,
Anoman Armand D.,
RosaTéllez Sara,
Toujani Walid,
Weber Andreas P.M.,
Eisenhut Marion,
Kurz Samantha,
Alseekh Saleh,
Fernie Alisdair R.,
MuñozBertomeu Jesús,
Ros Roc
Publication year - 2017
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.13452
Subject(s) - glyceraldehyde 3 phosphate dehydrogenase , glycolysis , dehydrogenase , mutant , biochemistry , glyceraldehyde , phosphate , chemistry , metabolism , enzyme , gene
Summary The presence of two glycolytic pathways working in parallel in plastids and cytosol has complicated the understanding of this essential process in plant cells, especially the integration of the plastidial pathway into the metabolism of heterotrophic and autotrophic organs. It is assumed that this integration is achieved by transport systems, which exchange glycolytic intermediates across plastidial membranes. However, it is unknown whether plastidial and cytosolic pools of 3‐phosphoglycerate (3‐ PGA ) can equilibrate in non‐photosynthetic tissues. To resolve this question, we employed Arabidopsis mutants of the plastidial glycolytic isoforms of glyceraldehyde‐3‐phosphate dehydrogenase ( GAPC p) that express the triose phosphate translocator ( TPT ) under the control of the 35S (35S: TPT ) or the native GAPC p1 ( GAPC p1: TPT ) promoters. TPT expression under the control of both promoters complemented the vegetative developmental defects and metabolic disorders of the GAPC p double mutants ( gapcp1gapcp2 ). However, as the 35S is poorly expressed in the tapetum, full vegetative and reproductive complementation of gapcp1gapcp2 was achieved only by transforming this mutant with the GAPC p1: TPT construct. Our results indicate that the main function of GAPC p is to supply 3‐ PGA for anabolic pathways in plastids of heterotrophic cells and suggest that the plastidial glycolysis may contribute to fatty acid biosynthesis in seeds. They also suggest a 3‐ PGA deficiency in the plastids of gapcp1gapcp2 , and that 3‐ PGA pools between cytosol and plastid do not equilibrate in heterotrophic cells.