Yoshioka et al. Nontechnical Summary Yoshioka, H., R. G. Gregerson, D. A. Samac, K. C. M. Hoevens, G. Trepp, J. S. Gantt, and C. P. Vance. Aspartate amino transferase in alfalfa nodules. Molecular Plant-Microbe Interact.
Mineral nutrients are critical for plant growth and reproduction.
One of the most important mineral nutrients is nitrogen, which is used to form amino acids, proteins, enzymes, and other plant components. Plants in the bean family, such as alfalfa, are able to form a symbiotic relationship with a soil bacterium that allows them to use nitrogen gas from the atmosphere, in a process called nitrogen fixation, to form amino acids. This process occurs in an organ called a root nodule. Plants lacking this ability rely on nitrogen in the form of nitrate or ammonia that is usually found in only limited amounts in soil and must be added as fertilizer for crop production. The enzyme aspartate aminotransferase plays a critical role in capturing symbiotically fixed nitrogen through synthesis of the amino acid aspartate.