This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Web of Science (16) Citing Articles via Google Scholar Google Scholar Articles by Brunswick, P. Articles by Cresswell, C. F. Search for Related Content PubMed PubMed Citation Articles by Brunswick, P. Articles by Cresswell, C. F. Agricola Articles by Brunswick, P. Articles by Cresswell, C. F.

Metabolism and Enzymology

Nitrite Uptake into Intact Pea Chloroplasts ¹

I. Kinetics and Relationship with Nitrite Assimilation

CSIR/University of the Witwatersrand, Johannesburg, South Africa, Photosynthetic Nitrogen Metabolism Research Unit, Department of Botany, University of the Witwatersrand, Johannesburg, South Africa

The uptake of nitrite into intact pea chloroplasts was observed and its relationship with internal nitrite reduction was assessed. Net nitrite uptake exhibited saturation kinetics and an alkaline pH preference. This evidence questioned the accepted major role for neutral HNO₂ permeation and its reported influence on photosynthesis. The possible involvement of a nitrite permeation channel or transport protein is discussed. Net nitrite uptake curves were closely comparable with those for nitrite reduction within the chloroplast. Net nitrite uptake into chloroplasts was profoundly influenced by darkness, incubation temperature, and plant nitrate nutrition. Of several inorganic salts tested, sulfite was the only anion to exhibit a distinct inhibition of nitrite uptake. In contrast, nitrite uptake could be stimulated by the presence of certain cations, particularly at acidic pH values. It was concluded that nitrite uptake was closely related to stromal pH, internal nitrite accumulation, and nitrite reduction. The possible dependence of nitrite reduction on nitrite uptake rather than electron transport is discussed. External ATP and NAD(P)H did not significantly affect net nitrite uptake. This suggested that cytoplasmic ATP or reductant could not directly support nitrite uptake and, possibly, nitrite assimilation.

This article has been cited by other articles:

				M. Sugiura, M. N. Georgescu, and M. Takahashi A Nitrite Transporter Associated with Nitrite Uptake by Higher Plant Chloroplasts Plant Cell Physiol., July 1, 2007; 48(7): 1022 - 1035. [Abstract] [Full Text] [PDF]

				C. G. Bowsher, A. E. Lacey, G. T. Hanke, D. T. Clarkson, L. R. Saker, I. Stulen, and M. J. Emes The effect of Glc6P uptake and its subsequent oxidation within pea root plastids on nitrite reduction and glutamate synthesis J. Exp. Bot., March 1, 2007; 58(5): 1109 - 1118. [Abstract] [Full Text] [PDF]

				A. Galvan, J. Rexach, V. Mariscal, and E. Fernandez Nitrite transport to the chloroplast in Chlamydomonas reinhardtii: molecular evidence for a regulated process J. Exp. Bot., April 15, 2002; 53(370): 845 - 853. [Abstract] [Full Text] [PDF]

				J. Rexach, E. Fernández, and A. Galván The Chlamydomonas reinhardtii Nar1 Gene Encodes a Chloroplast Membrane Protein Involved in Nitrite Transport PLANT CELL, August 1, 2000; 12(8): 1441 - 1454. [Abstract] [Full Text]