产品介绍： Glutamine synthetase (GLN or GS) is one of the key enzymes involved in nitrogen metabolism of plants. It catalyses the synthesis of glutamine from glutamate and ammonia in an ATP-dependent reaction. There are two general classes of glutamine synthetase in plants: GLN1, a cytosolic form and GLN2, a chloroplastic form. GLN1 is highly abundant in the vascular elements of roots nodules, flowers and fruits, functioning in the assimilation of ammonium and the biosynthesis of glutamine for nitrogen transport. GLN2 is encoded by a single gene and is highly abundant in leaf mesophyll chloroplasts. Here GLN functions in the assimilation of ammonia produced from photorespiration and the reduction of nitrate in the chloroplasts