Plant and Cell Physiology Advance Access originally published online on March 15, 2006
Plant and Cell Physiology 2006 47(5):644-652; doi:10.1093/pcp/pcj033
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Effects of Carbohydrate Accumulation on Photosynthesis Differ between Sink and Source Leaves of Phaseolus vulgaris L.
Department of Biology, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, 560-0043 Japan
* Corresponding author: E-mail, araya{at}bio.sci.osaka-u.ac.jp; Fax, 81-6-6850-5808.
Accumulation of non-structural carbohydrate in leaves represses photosynthesis. However, the extent of repression should be different between sink leaves (sugar consumers) and source leaves (sugar exporters). We investigated the effects of carbohydrate accumulation on photosynthesis in the primary leaves of bean (Phaseolus vulgaris L.) during leaf expansion. To increase the carbohydrate content of the leaves, we supplied 20 mM sucrose solution to the roots for 5 d (sugar treatment). Plants supplied only with water and nutrients were used as controls. The carbohydrate contents, which are the sum of glucose, sucrose and starch, of the sugar-treated leaves were 1.5–3 times of those of the control leaves at all developmental stages. In the young sink leaves, the photosynthetic rate at saturating light and at an ambient CO2 concentration (A360) did not differ between the sugar-treated and control leaves. The A360 of sugar-treated source leaves gradually decreased relative to the control source leaves with leaf expansion. The initial slope of the A–Ci (CO2 concentration in the intercellular space) curve, and the Rubisco (ribulose-1,5-bisphosphate carboxylase/oxygenase) content per leaf area showed trends similar to that of A360. Differences in Amax between the treatments were slightly smaller than those in A360. These results indicate that the effect of carbohydrate accumulation on photosynthesis is significant in the source leaves, but not in the young sink leaves, and that the decrease in Rubisco content was the main cause of the carbohydrate repression of photosynthesis.
(Received December 12, 2005; Accepted March 8, 2006)
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  M. Sagaram and J. K. Burns Leaf Chlorophyll Fluorescence Parameters and Huanglongbing J. Amer. Soc. Hort. Sci., March 1, 2009; 134(2): 194 - 201. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. D. Coleman, A. L. Samuels, R. D. Guy, and S. D. Mansfield Perturbed Lignification Impacts Tree Growth in Hybrid Poplar--A Function of Sink Strength, Vascular Integrity, and Photosynthetic Assimilation Plant Physiology, November 1, 2008; 148(3): 1229 - 1237. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Schiavon, E. A.H. Pilon-Smits, M. Wirtz, R. Hell, and M. Malagoli Interactions between Chromium and Sulfur Metabolism in Brassica juncea J. Environ. Qual., June 23, 2008; 37(4): 1536 - 1545. [Abstract] [Full Text] [PDF]
|
|