Effects of nitrogen fertilizer on protein synthesis, accumulation, and physicochemical properties in common buckwheat

• DOI: 10.1016/j.cj.2023.01.002
• Publication Date: 2023-02-02T11:29:47Z
• Authors: Chenxi Wan; Licheng Gao; Jiale Wang; Xinhui Lei; Jincai Tao; Baili Feng; Jinfeng Gao
• Keywords: 0301 basic medicine; Common buckwheat; 03 medical and health sciences; S; Agriculture (General); Grain quality; Storage protein; Agriculture; Nitrogen metabolism; Nitrogen fertilizer; S1-972

Nitrogen (N) fertilization affects grain quality in common buckwheat (Fagopyrum esculentum Moench). But the effects of N fertilizer on various buckwheat protein parameters are not fully understood. This study aimed to investigate the synthesis, accumulation, and quality of buckwheat protein under four N application rates in the Loess Plateau, China. Optimal N application (180 kg N ha−1) improved yield, agronomic traits, and N transport and increased protein yield and protein component accumulation. Prolamin and glutelin accumulation first increased and then decreased with increasing N application. The relationships between the contents of protein components and the amount of applied N generally followed quadratic functions. Nitrate reductase and glutamine synthetase activities first increased and then decreased with increasing N levels. Optimal N fertilizer increased the waterholding capacity and thermal stability of buckwheat protein and reduced its emulsification capacity, but negligibly changed its oil-absorption capacity. Hydrophobic amino acids and glutelin content were the main factors affecting protein quality.