EFFECT OF ANOXIA ON STRUCTURAL BIOCHEMICAL-CHANGES OF MITOCHONDRIAL PROTEINS IN ROOTS OF WHEAT AND RICE SEEDLINGS

We investigated the effect of anoxia on structural-biochemical reorgan izations of mitochondrial proteins in roots of wheat (Triticum aestivu m L.) and rye (Oryza sativa L.), the state of these proteins being jud ged from changes in open residues of aromatic chromophores-the amino a cids Phen, Try, and Tyr-in a suspension of native mitochondria. As a r esult of anaerobic influence, decline of protein content in mitochondr ia of wheat and rice seedling roots was accompanied by redistribution of its main chromophores: the content of Phen declined, while that of Tyr and Try rose. These shifts were manifested earlier and more sharpl y in wheat. For Phen and Try, the same changes-albeit with lesser ampl itude-were also observed during aeration under light. They were somewh at amplified in the dark, but were invariably weaker than under anoxia . Content of Tyr changed most strongly under conditions of anoxia, Tyr increase being weaker in the object resistant to oxygen deficiency th an in the unresistant one. Experiments with labelled Phen revealed act ivation of biochemical conversions of Phen to Tyr under the influence of anoxia. Possible correlation of the detected shifts in content of a mino acid residues with resistance of the plants to oxygen deficit is discussed in the paper.