Respiration and Phosphorylation of Mitochondria from Normal and Crown-Gall Tissue Cultures of Tomato.

Knowledge of the initiation mechanism of the crown-gall disease incited by Agrobacterium tuimefaciens (Smith & Town.) and the subsequent growth of the abnormal tissue is fundamental to understanding diseased growth (2, 18, 24). The nutritional requirements for normal and gall tissues have been intensively studied (25), and the necessity for proper balance of amino acids and growth substances in the gall formation has been emphasized (2, 23). Braun (3) has suggested that conversion of a normal cell into a crown-gall cell is accompanied by the permanent activation of a series of growth-substance-synthesizing systems, which are precisely regulated in all normal cells. Similarly, Klein (17) has proposed stepwise activation of metabolic systems, such as respiration as well as protein and nucleic acid syntheses, during the period of transformation of a normal cell into a tumor cell. Biochemical analyses are needed to clarify further the metabolic characteristics of the diseased growth. Experiments are especially interesting with isolated enzymes or enzyme systems from normal and diseased tissues. Recent results with plant tissue cultures in studies of cell cytology and physiology (16), and pathology (12, 36) have made attractive the use of such cultures for biochemical analyses. Earlier respiratory studies of normal and crowngall tissues were concerned largely with tissue slices or suspensions of intact cells from tissue cultures at various stages of growth. In general, reduced respiratory levels were observed with crown-gall tissue (24). The results, however, were not always consistent; they were dependent upon the basis for expressing the respiratory activity (2). The purpose of the present paper is to report the