The Pathway of Ammonium Primary Assimilation in Kidney Bean

Authors: Tinatin SADUNİSHVİLİ, Nino GVARLİANİ, Nodar NUTSUBİDZE

Abstract: The changes in the activities of glutamine synthetase (GS). glutamate synthase (GOGAT) and glutamate dehydrogenase (GDH) . as well as the amounts of free amino acids and kinetics of the incorporation of {^15}N into them during assimilation of {^15}NH _4 ) _2SO _4 against a background of methionine sulfoximine (MSO) have been investigated. The inhibition of GS by MSO in Ieaves Ieads to ammonia accumulation. and decreasing in the amounts of glutamine and glutamic acid and increasing in the incorporation of {^15}N into them. In roots the inhibition of GS is not accompanied by a decrease in {^15}N content in glutamete. The analysis of the data obtained enables us to conclude that the pathway of ammonia primary assimilation in Ieaves is via GS and GOGAT, while in roos. GDH also plays and important role in this process.

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