Study On The Key Enzymes In Nitrogen Assimilation And Metabolism In Soybean (Glycine Max(L.)Merrill)

This research was conducted at Northeast Agricultrual University from 2004 to 2005. Six varieties, Heinong35, Dongnong42, Dongnong46, Kenfeng9, G.gracilis and G.soja were tested by means of pots and plots experiments to study the key enzymes in protein synthesis and the difference among different genotypes, and to analyse the characteristics of the accumulation and distribution of nitrogen.The results showed that:Dynamics of GS activities in the leaves, and the stems except Dongnong46 and G.soya which showed a single-peak curve and the peaks appeared at R₁ and R₂, came to be a double-peak curve, the peaks appeared at R₂ and R₅. Dynamics of GS activities had a single-peak curve in the roots of tested varieties, while it came to be a double-peak curve in the roots of G.soja. The changing pattern of GS activities in the nodudles was single-peak curve. Dynamics of GS activities in the pod sheds of G.soja declined gradually and the tenndency was low-high-low. The GS activities in the organs except nodules of G.soja were obviously lower than other varieties. The gradation of GS activities in different organs was leaf>nodule>stem>root>pod shed.Dynamics of NADH-GOGAT activities in the leaves of G.gracilis and G.soja was drop-rise-drop, the peaks appeared at R₂. Other varieties had a single-peak curve. NADH-GOGAT activities reached the highest at R₅ for high oil varieties and at R₄ for the high protein varieties. The changing pattern of NADH-GOGAT activities in stems was a single-peak curve. The changing pattern of NADH-GOGAT activities in roots of the tested varieties except Heinong35 and Dongnong42 were similar to that in stems and showed as a single-peak curve. The dynamics of NADH-GOGAT activities in the nodules of Dongnong46 was double-peak curve and other varieties had a single-peak curve. The dynamics of NADH-GOGAT activities in pod sheds decreased gradually with development. The maximum of NADH-GOGAT activities appeared at different stage, the peaks of G.gracilis and G.soja were earlier than that in other cultivars. The NADH-GOGAT activities in G.soja were higher than that in other varieties after R₅ except in nodules. The gradation of GOGAT activities in different organs was leaf> nodules> stem> root> pod shed.Variance analysis showed that difference of protein and oil was significantly. The GS activities in leaves, roots and pod sheds at R₅ were positively related to seed protein.The NADH-GOGAT activities in leaves and roots before R₁, and in pod sheds after R₅ were positively or significant positively related to the protein content in seeds.