Nitrogen Metabolism of Tamarindus indica: Changes in γ‐Methyleneglutamine and its Corresponding Acid γ‐Methyleneglutamic Acid During Seedling Growth

Abstract

AbstractChanges in γ‐methyleneglulamine, a third non‐protein amide, γ‐methyleneglutamic acid, its corresponding acid, other free aminoacids and amides, and protein and soluble‐nitrogen during the seedling growth of tamarind (Tamarindus indica L.), were studied. The changes in the prolein‐N content in different parts of the seedling, during growth parallel closely the growth pattern expressed as changes in fresh weight. γ‐Meythyleneglutamine is the principal amide during the early stages of seedling growth, but later on when its content starts declining, asparagini’ takes over its function. Thus, γ‐methyleneglutamine seems to spare the utilization of amide asparagine, during the early growth period. During later stages of seedling growth, asparagine content also shows a decline, indicating that during this period, asparagine contributes to the protein synthesis and growth. γ‐Methyleneglutamic acid was also recorded in large amounts in various parts of the seedling and its concentration was not found to be less than the amide at any stage of seedling growth. The two peaks observed for some of the key aminoacids including γ‐methyleneglulamic acid, γ‐methylglulamic acid, α‐alanine, glutamic acid, aspartic acid, glycine and serine, are interesting, in that the first corresponds to the active growth period of roots and the hypocotyl in the first eleven days, and the second with the active growth of the epicotyl.