Concomitant Increases of the Developing Seed Phosph<i>oenol</i>pyruvate Carboxylase Ac-tivity and the Seed Protein Content of Field-Grown Wheat with Nitrogen Supply

• 作者: Naoki Yamamoto Takehiro Masumura Toshio Sugimoto
• 来源期刊: 农业科学(英文)
• 学科: 农学
• 关键词: Nitrogen Application PHOSPHOENOLPYRUVATE CARBOXYLASE SEED Storage Protein WHEAT
• 年，卷（期）: 2014,（14）
• 页码范围: 1558-1565
• 页数: 8页
• 分类号: S5

摘要

Wheat seed storage protein is of great importance for human food. To increase the contents of storage proteins effectively, nitrogen fertilizer at flowering stages is commonly applied. In our previous study, rice phosphoenolpyruvate carboxylase (PEPCase) activity in developing seeds was observed in response to nitrogen application at a flowering stage and was positively correlated to the response of the protein content in seeds of six cultivars. This observation might indicate that the seeds have a biological system for accepting nitrogen in seeds by using PEPCase. To test whether this physiological event occurs in wheat, we examined the PEPCase activity and protein content in field-grown wheat seeds under different nitrogen supply conditions. With only basal dressing, seeds showed lower PEPCase activity and protein content (both 0.90-fold) compared to seeds without basal fertilizer. With ammonium sulfate application at 8.3 and 25 g/m2 at a flowering stage, seeds showed higher PEPCase activity (1.08- and 1.17-fold, respectively) and protein content (1.15- and 1.42-fold, respectively), depending on the nitrogen level. We investigated the relationship between PEPCase activity and protein content in the seeds among four conditions. The effect of the nitrogen supply on PEPCase activity during grain-filling stages was validated by the results of a hydroponic culture experiment. Together the results demonstrate that our hypothesis seems to apply to field-grown wheat.