Title

Effects of translocation and assimilate demand on photosynthesis

Document Type

Article

Publication Date

10-1-1976

Publication Source

Canadian Journal of Botany

Abstract

Net carbon dioxide uptake by a photosynthesizing primary leaf of bean plants, Phaseolus vulgaris cv. Black Valentine, was measured during treatments designed to alter export from the leaf. Removal of shoot apices lessened sink demand while removal of all source leaves except the one being observed increased sink demand. Export from the leaf under study was lessened by chilling the primary leaf petiole and node to 2 °C. No adjustments in the rate of net photosynthesis were observed during the 33-h period after any of the treatments. The results of this study are in general agreement with previous reports in the literature. After modification of sink demand or of export by experimental manipulation of plants, a period of 2 or 3 days is usually required for adjustment of net photosynthesis rate. Rapid changes in net photosynthesis rate are generally the result of concomitant changes in morphology or metabolism during the course of plant development. The results of this work, and of others in the literature, indicate an indirect mechanism possibly involving hormonal control in some instances rather than direct feedback control of photosynthesis by product inhibition.

Inclusive pages

2337-2345

ISBN/ISSN

1916-2804

Publisher

National Research Council Canada

Volume

54

Issue

20

Peer Reviewed

yes