Abstract
The legume crops have lower nitrogen use efficiency (dry matter productivity per the amount of absorbed nitrogen) than the cereal crops. It would be due to, in legume crops, low photosynthetic rate per unit nitrogen of the leaves and the consumption of photosynthate for protein synthesis of the seeds. However, it is not clear about the detail of metabolic mechanism that caused mentioned above physiological phenomenon in the leaves and the seeds. In this study, diurnal changes of metabolic profiling in seeds in rice and soybean were compared in order to get the basic knowledge of the difference of metabolic mechanism between the cereal and legume crops. As a result, an amino acid and organic acid of soybean seeds increased than those of rice. It was suggested that larger carbon skeletons supply to an amino acid in seeds of soybean.
