Seasonal changes in protein, amino acid and elemental composition of perennial nodules of beach pea

Abstract

Changes in proteins, amino acids and elements were studied in the perennial nodules of beach pea during winter, summer and fall. Accumulation of total protein content in the nodules increased from mid-summer to early winter and then decreased. Among the total amino acids studied, arginine, cystathionine, ethanolamine, histidine, hydroxyproline, ornithine and proline were found to increase in winter nodules. γ-aminobutyric acid was found to be significantly higher in fall and summer, whereas sarcosine was higher in summer and winter. Large amounts of K followed by Ca were found in almost all nodule tissues. Phosphorus, A l, Si and Cu showed significant variation among different nodule tissues within winter and summer. In the nodular tissue, significantly larger amounts of Na, K and Mg were found in the winter and S in the summer. In both winter and summer, no significant difference could be observed in the distribution of Cl, Mo, Ca, Mn, Fe and Zn among nodule tissues. Irrespective of nodule tissues, the complete nodule showed the following seasonal changes: high K, Ca and Zn in winter; high Cl and Al in summer; high S and Si in fall; high Mn in both winter and summer; high Cu in both winter and fall; high Na, Mg and Fe in both summer and fall; no significant changes in the amounts of P and Mo. Key words: Beach pea, Lathyrus maritimus L., protein, amino acid, element, cold stress