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，参照茎根关系研究了其发育槽和根系的生长和功能。研究了水稻分蘖体中碳氮的动态变化。在番茄植株形态上，营养液和空气中滴灌根系的呼吸和氮吸收速率有显著差异。在空气中生长的根表现出较大的光同化物质汇活性和较高的耐高温胁迫能力。在具有球茎和球茎两个汇的半夏中，13C同化物在这些器官之间的分配随光照条件的变化而变化。在水稻植株中，大量以13C和15N标记的碳和氮一旦被纳入非生产性分蘖，在抽穗后被重新转移到生产性分蘖。研究了豆科植物根轴根际pH梯度。在光照条件下，豇豆根际中部沿种子轴发生局部酸化。通过抑制光合作用或减少叶面积的处理，限制叶片的光合作用，导致局部酸化消失。认为根际酸化是由根部的质子外排引起的，而质子泵的活性则受日照条件的控制。

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.