Molecular Physiological and Ecological studies on the Plant Hormonal Regulation in Rice Production.

研究了植物激素的生理生态作用模式及其在水稻全生命周期包括营养生长和生殖生长，特别是籽粒灌浆过程中的调控作用。我们还以大豆植物为实验材料。这些不仅在日本，而且在世界上都是重要的主食植物。在水稻生命周期中，2叶期2叶在光照条件下的乙烯产量明显高于3叶期3叶和其他叶期2叶，2叶在含糖量（淀粉和蔗糖）大的条件下表现出不同于其他叶的特殊产乙烯特性。不同叶期的大部分叶鞘、花期和成熟生长期的柱和成熟穗对乙烯的产生也有光促进作用（约8000勒克斯）。这是我们新发现的结果之一。在光照条件下，雄性不育和雌性不育的水稻品系开花后空穗的乙烯产量都低于正常穗。结果表明，水稻成熟穗（尤其是乳熟期）的糖积累与乙烯产量密切相关。结果表明，在穗形成阶段和从营养向生殖过渡阶段，整株植株中应含有适当浓度的内源赤霉素，以确定轴数和粒数。油菜素内酯是一种新的植物激素，对水稻的成熟粒率和低温条件下的成熟具有激活作用。内源脱落酸含量也与大豆成熟密切相关。

We studied on the physiological and ecological mode of action of plant hormones and their regulatory action in plant growth and development of rice life cycle including vegetative and reproductive growth, especially grain filling. We also used soybean plant as the experimental materials. These are important staple food plants not only in Japan, but also in the world.1. In rice life cycle, 2nd leaf blade in 2nd leaf stage greatly produced ethylene under light condition deferent from 3rd leaf in 3rd leaf stage including other leaf stage, 2nd leaf expressed special character different from other leaf in ethylene production with big amount of sugar contents (Starch and sucrose). Most leaf sheath in various leaf stage, colum in flowering and ripening growth stage, and maturing panicle also had light (round 8,000 lux) promotion effects for ethylene production. This was one of our new finding results.2. Empty panicle after flowering in male sterile and female sterile mutants rice lines had not so much ethylene production deferent from normal panicles under the light condition. We found that it was closed relation ship between the sugars accumulation and the remarkable ethylene production in matured rice panicles (especially in milk-ripe growth stage).3. It was strongly indicated that the appropriate concentrations of endogenous gibberellin should be present in whole plant at panicle initiation stage at the transit stage from vegetative to reproductive for determination of rachis and grain numbers. Brassinolide, one of new plant hormones, activated percent of maturation grain rate and the ripening under low temperature condition in rice. Endogenous abscisic acid content had also closed relationship with soybean maturation.