The effect of the gp gene on fruit development in Pisum sativum L.
II. Photosynthetic implications
Article first published online: 28 APR 2006
Volume 110, Issue 2, pages 271–277, October 1988
How to Cite
PRICE, D. N. and HEDLEY, C. L. (1988), The effect of the gp gene on fruit development in Pisum sativum L. New Phytologist, 110: 271–277. doi: 10.1111/j.1469-8137.1988.tb00262.x
- Issue published online: 28 APR 2006
- Article first published online: 28 APR 2006
- (Received 29 January 1988; accepted 25 April 1988)
Photosynthetic activity in the yellow pods of gp.gp lines has been compared with that in normal Gp.Gp pods. As expected from a previous structural study, the occurrence of aberrant plastids in the mesocarp resulted in reduced activity in the gp.gp lines.
Illuminated green fruits, 5–16 d post-anthesis showed net uptake of CO2, from the atmosphere. Positive carbon gain was extended until d 28 in deseeded pods. Conversely, in yellow (gp.gp) fruits no net uptake of CO2, from the atmosphere was observed at any stage, even in deseeded pods, but carbon losses in the light were restricted compared with those in the dark, indicating some photosynthetic activity.
Analysis of the photosynthetic machinery within the yellow pods showed considerable differences in the effect of the gp gene on the mesocarp and endocarp layers. Compared with those of green pods, concentrations of RuBP carboxylase in the mesocarp were depressed, and the Hill reaction activity of isolated chloroplasts was virtually undetectable. However, in the parenchyma layer of the endocarp, RuBP carboxylase reached higher concentrations than in Gp.Gp pods, and Hill reaction rates were comparable. There was little difference between the lines in their PEP carboxylase concentrations in either tissue.