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Assessing the Degree of C4 Photosynthesis in C3-C4 Species Using an Inhibitor of Phosphoenolpyruvate Carboxylase

Authors :
George T. Byrd
Clanton C. Black
R. Harold Brown
Source :
Plant Physiology. 97:985-989
Publication Year :
1991
Publisher :
Oxford University Press (OUP), 1991.

Abstract

An analog of phosphoenolpyruvate, 3,3-dichloro-2-dihydroxyphosphinoylmethyl-2-propenoate (DCDP), was used to inhibit phosphoenolpyruvate carboxylase and, therefore, assess the contribution of the C4 pathway to photosynthesis in detached leaves of several C3-C4 intermediate species. There was no effect of 4 millimolar DCDP on apparent photosynthesis or on inhibition of apparent photosynthesis by 210 milliliters per liter of O2 for the C3-C4 species Panicum milioides, Moricandia arvensis, and Neurachne minor or the C3 species Flaveria pringlei. However, when leaves of Flaveria linearis (C3-C4), Flaveria brownii (C4-like), and Flaveria trinervia (C4) were fed 4 millimolar DCDP, photosynthesis was reduced 32, 60, and 90%, respectively. Photosynthetic inhibition by 210 milliliter per liter of O2 was also significantly increased in 4 millimolar DCDP-fed leaves of F. linearis and F. brownii but not in F. trinervia when compared with control values. These results with DCDP clearly demarcate C3-C4 species into species including Panicum, Moricandia, and Neurachne whose reduced photorespiration occurs without any C4 photosynthetic involvement and species of Flaveria in which C4 photosynthesis contributes to CO2 assimilation.

Details

ISSN :
15322548 and 00320889
Volume :
97
Database :
OpenAIRE
Journal :
Plant Physiology
Accession number :
edsair.doi...........4c707fc37feb8d292d75f02bfb26ecf4