Dynamics and regulation of partitioning and utilization of photoassimilates in crop plants.

以番茄、水稻、半夏和豆科作物为研究对象，从地上部与根系的关系出发，探讨了植物库和根的发育与功能。研究了水稻分蘖碳氮动态。在滴灌条件下，营养液和大气中生长的番茄根系在形态、呼吸和氮素吸收速率上存在显著差异。在空气中生长的根系具有较大的光合同化物库活性和较高的耐高温能力。在具有球茎和珠芽两个库的半夏中，~（13）C同化物在这两个器官之间的分配随光照条件的变化而变化。在水稻中，大量的13 C和15 N标记的碳和氮一旦进入非生产性分蘖中，在抽穗后重新转移到生产性分蘖中。研究了豆科植物种子根轴沿着根际pH梯度。豇豆根际中部沿着种子轴在光照条件下局部酸化。光合作用抑制剂处理或减小叶面积处理限制了叶片的光合作用，导致局部酸化消失。推测根际酸化是由于根系质子流出所致，质子泵活性受地上部光照条件控制。

The growth and function of developing sinks and roots of tomato, rice, Pinellia ternata and legume crops were investigated with reference to shoot-root relationship. The dynamics of carbon and nitrogen in rice tillers were also investigated. In tomato plants morphology, respiration and nitrogen uptake rate were characteristically different between the roots grown in nutrient solution and atmospheric air with drip irrigation. The roots grown in air showed large sink activity of photoassimilates and higher stress tolerance to high temperature. In Pinellia which has two sinks, corms and bulbils, partitioning of 13C assimilates between these organs was changed reciprocally with the light conditions. In rice plants considerable amount of carbon and nitrogen labeled with 13C and 15N once incorporated in non-productive tillers were retranslocated to productive tillers after heading. The pH gradient of rhizosphere was investigated along seminal root axis of legumes. In cowpea mid portion of rhizospehere along seminal axis was locally acidified under the shoot light conditions. The restriction of photosynthesis of leaves with treatments of photosynthesis inhibitor or reduce leaf area resulted in disappearance of local acidification. It was assumed that rhizosphere acidification was due to the proton efflux from root, and the activity of proton pump was controlled by shoot light conditions.