Economy of water, carbon, and nitrogen in the developing cowpea fruit.
Economy of water, carbon, and nitrogen in the developing cowpea fruit.
复制标题
豇豆果实发育过程中水、碳和氮的经济性。
DOI：
10.1104/pp.77.1.142
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发表时间：
1985
期刊：
影响因子：
7.4
通讯作者：
D. Murray
中科院分区：
文献类型：
--
作者：
M. Peoples;J. Pate;C. Atkins;D. Murray
通过碳、氮和水的摄入和利用来定量评估豇豆 (Vigna unguiculata (L.) Walp cv Vita 3) 果实的营养经济。白天，果实未能从大气中净获得 CO(2)，尽管豆荚光合作用通过重新固定果实呼吸的 CO(2) 的一部分，确实在果实的碳经济中发挥了作用。进入果实的每 100 重量单位的碳中，有 70.4 单位最终并入种子中，10.3 单位作为不可移动的物质保留在豆荚壁中，其余 19.3 单位在果实呼吸中损失。韧皮部提供了果实97%的碳和72%的氮。氮对木质部的贡献主要发生在生长早期。果实中 96% 的氮被掺入种子中，其中约 10% 从衰老的豆荚中吸收。果实的平均蒸腾比非常低，每积累1克干物质蒸腾8毫升水。为果实发育的两个连续 11 天时期构建了碳、氮和水流模型，结果表明，通过木质部和韧皮部进入的水量比果实组织水和蒸腾损失的变化所能解释的要多得多。这种差异在果实生长的后半段更大，被解释为证据表明，通过韧皮部进入果实的水的很大一部分通过木质部循环回到母体植物。
The nutritional economy of the fruit of cowpea (Vigna unguiculata (L.) Walp cv Vita 3) was assessed quantitatively from intake and utilization of carbon, nitrogen, and water. Fruits failed to make net gains of CO(2) from the atmosphere during daytime, although pod photosynthesis did play a role in the fruit's carbon economy by refixing a proportion of the fruit's respired CO(2). Of every 100 units by weight of carbon entering the fruit, 70.4 were finally incorporated into seeds, 10.3 remained as nonmobilizable material in pod walls, and the remaining 19.3 were lost in fruit respiration. Phloem supplied 97% of the fruit's carbon and 72% of its nitrogen. The xylem contribution of nitrogen occurred mainly in early growth. Ninety-six% of the fruit's nitrogen was incorporated into seeds, approximately 10% of this mobilized from the senescing pod. The mean transpiration ratio of the fruit was very low-8 milliliters water transpired per gram dry matter accumulated. Models of carbon, nitrogen, and water flow were constructed for the two consecutive 11 day periods of fruit development, and indicated a considerably greater entry of water through xylem and phloem than could be accounted for in changes in fruit tissue water and transpiration loss. This discrepancy was greater in the second half of fruit growth and was interpreted as evidence that a significant fraction of the water entering the fruit through phloem cycled back to the parent plant via the xylem.