Genome-Wide Analysis of the Aspartate Aminotransferase Family in Brassica rapa and the Role of BraASP1 in Response to Nitrogen Starvation

作者：Yan Liu, Zihan Gao, Chuang Liang, Yuting Wei, Yuge Li, Yan Zhang, Yaowei Zhang · 发表于：International Journal of Molecular Sciences · 年份：2025 · DOI：10.3390/ijms26041586 · 被引用次数：2 · 研究领域：Plant nutrient uptake and metabolism、Legume Nitrogen Fixing Symbiosis、Advanced Data Storage Technologies

Nitrogen (N) is the most important fertilizer for increasing crop production, as it is absorbed by various N transporters and metabolized by a series of enzymes. Aspartate aminotransferase (ASP) facilitates the conversion of Glu to Asp for N storage. Chinese cabbage is a typical leafy vegetable that requires a large amount of N for growth. To investigate the functions of BraASPs, 10 members of the ASP gene family in Brassica rapa (B. rapa) were identified. Phylogenetic analysis and collinearity comparisons of ASP members among B. rapa, Arabidopsis thaliana (A. thaliana), Oryza sativa (O. sativa), Brassica napus (B. napus), and Brassica oleracea (B. oleracea) were conducted to examine evolutionary associations and genome duplication events across species. Multiple cis-acting elements associated with stress responses were identified in the promoters of BraASPs, suggesting their diverse roles. Members of BraASPs were expressed in roots, stems, flowers, siliques, and leaves, with the highest expression in leaves. Their expression levels increased rapidly at 3 h under low N conditions, peaked at 6 h, and returned to low levels at 24 h. Based on transcriptomic data, BraASP1b was identified as a candidate gene in B. rapa under low N stress, localized in the nucleus and cytoplasm. Overexpression of BraASP1b in A. thaliana resulted in a higher biomass than Col-0 under low N conditions.