ISSN:
1573-9058
Keywords:
CO2 enrichment
;
leaf age
;
mungbean
;
net photosynthetic rate
;
14C photosynthates
;
sink
;
starch
;
sugars
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Carbon allocation to the source leaf, export and partitioning to the sink were studied in mungbean supplied by additional carbon from the source leaves subjected to high CO2 concentrations (600 and 900 cm3 m-3) in three metabolic and functional source-sink combinations. The plants were pruned to a source-path-sink system. With CO2 enrichment there was an appreciable increase in net photosynthetic CO2 uptake in earlier formed and physiologically younger leaves. Most of the carbon fixed as a result of enrichment was translocated out of the source leaf within one diurnal cycle. The carbon remaining in the source leaf was unchanged. Partitioning of extra carbon into starch or sugar depended upon the amount of extra carbon synthesized. The unloading of the extra carbon into sinks depended on whether it was used for growth or stored. Under increased carbon content, the leaf as a sink was able to reorganize its metabolic reactions more rapidly to maintain the required gradient for unloading than the pod acting as the sink.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1006820303233
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