Analysis of Stopping Mechanism of Dry Matter Accumulation in Seeds of Rape Plants.

油菜种子在成熟期停止以增加其干重。结果表明，角果壁的光合作用停止不是导致种子停止生长的原因。在这项研究中，我们主要调查了种皮同化物卸载停止是否是种子生长停止的原因。当角果壁中脱落酸(ABA)浓度暂时升高时，角果壁和种子的含水率开始下降。随后种皮和种胚中ABA含量暂时升高，停止了种胚中钙的积累。之后，胚胎和其他部位的钙被转移到种皮中并积累。胚胎停止生长，同时增加其干重。在此之前，胚囊液中的糖和氨基酸浓度迅速下降。从上述结果来看，种子干物质积累的停止似乎更有可能是通过停止种皮的同化物卸载来实现的。这可能受到ABA等因素的调节。

A seed of rape plants stops to increase its dry weight at maturing stage. We showed that a stop of photosynthesis of pod wall was not the cause of the stop of seed growth before. In this research, we investigated mainly whether a stop of assimilate unloading of seed coats was the cause of the stop of seed growth or not. When abscissic acid (ABA) concentration in pod wall went up temporarily, the decline of water content of pod wall and seeds was stared. And then ABA concentrations of seed coats and embryo went up temporarily, and calcium accumulation in embryo was stopped. After that, calcium in embryo and other parts were translocated to and accumulated in seed coats. Embryo stopped to increase its dry weight at the same time. Just before it, the concentrations of sugars and amino acids in embryo sac liquid were rapidly decreased. From the above-mentioned results, it seems more probable that the stop of dry matter accumulation in seeds should occur by the stop of assimilate unloading of seed coats. This may be regulated by ABA and so on.