Department of Botany, University of California, Davis, California 95616.
Plant Physiol. 1971 Feb;47(2):212-6. doi: 10.1104/pp.47.2.212.
Leaf excision greatly affected the actual levels of (14)C-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 (14)CO(2) 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 (14)C-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 (14)CO(2) 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.
叶切除极大地影响了主菜豆叶（Phaseolus vulgaris L.）在运输期后叶肉和叶柄中（14）C 同化产物的实际水平。然而，它并不影响不溶性残渣中的淀粉百分比；在附着和分离的叶子中，暴露于（14）CO2 5 小时后，不溶性残渣中的淀粉从 20%下降到 3%。附着和分离叶片从导入到导出的转变处于同一阶段，即当子叶消耗 63%到 85%时。导入叶中（14）C 同化产物的组成与导出叶中的不同。在前者中，可溶性标记物中只有 5%是游离糖，而在后者中，74%是游离糖。导入叶不能导出不是因为标记物质不可转移。将导入叶的提取物施用于导出叶，这些提取物富含氨基酸和有机酸，但游离糖含量低。然而，暴露于（14）CO2 的导出叶似乎比氨基酸更容易导出糖。子叶切除并没有延迟叶片从导入到导出的转变。实际上，切除似乎略微促进了主叶从导入到导出的转变。
