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. 1971 Feb;47(2):212–216. doi: 10.1104/pp.47.2.212

Translocation and Metabolic Conversion of 14C-Labeled Assimilates in Detached and Attached Leaves of Phaseolus vulgaris L. in Different Phases of Leaf Expansion 1

Helmut Köcher a,2, O A Leonard a
PMCID: PMC365844  PMID: 16657598

Abstract

Leaf excision greatly affected the actual levels of 14C-assimilates in laminas and petioles of primary bean leaves (Phaseolus vulgaris L.) following a transport period. However, it did not affect the percentage of starch in the insoluble residue; starch decreased from 20% of the insoluble residue after exposure to 14CO2 to 3% after 5 hr in both attached and detached leaves. The transition from import to export of attached and detached leaves was at the same stage, i.e., when the cotyledons were 63 to 85% depleted. The composition of the 14C-assimilates in importing leaves was different from that in exporting leaves. In the former, only 5% of the soluble label was free sugar, while 74% was free sugar in the latter. The failure of importing leaves to export was not due to the labeled substances being nontransferable. Extracts from importing leaves applied to exporting leaves were exported; these extracts were high in amino acids and organic acids but low in free sugar. However, exporting leaves exposed to 14CO2 appeared to export sugars more readily than amino acids. Cotyledon excision did not delay transition of leaves from import to export. Actually, excision seemed to enhance slightly the transition of the primary leaves from import to export.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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