Baur A H, Yang S F, Pratt H K
Department of Vegetable Crops, University of California, Davis, California 95616.
Plant Physiol. 1971 May;47(5):696-9. doi: 10.1104/pp.47.5.696.
Tracer studies with avocado tissues indicate that methionine is converted to ethylene at stages of the climacteric rise and the climacteric peak, but not at the preclimacteric stage. The results suggest that the control of ethylene biosynthesis is at a step after methionine is synthesized. The endogenous content of methionine was found to be so low that methionine must be actively turned over for ethylene biosynthesis during the stages when the rate of ethylene production is high. Oxygen was found to be essential for this conversion, indicating that at least one of the steps in conversion of methionine to ethylene is oxygen-dependent. The ability of methionine and its keto analogue (alpha-keto-gamma-methylthiobutyric acid) to serve as ethylene precursors by apple tissues was compared. Chemical and kinetic evidence support the view that methionine is a closer precursor of ethylene than its keto analogue.
用鳄梨组织进行的示踪研究表明,在呼吸跃变上升期和呼吸跃变高峰期,蛋氨酸会转化为乙烯,但在呼吸跃变前期不会。结果表明,乙烯生物合成的控制发生在蛋氨酸合成之后的某个步骤。研究发现,蛋氨酸的内源含量非常低,以至于在乙烯产生速率较高的阶段,蛋氨酸必须被积极周转以用于乙烯生物合成。已发现氧气对于这种转化至关重要,这表明蛋氨酸转化为乙烯的步骤中至少有一个是依赖氧气的。比较了蛋氨酸及其酮类似物(α-酮-γ-甲基硫代丁酸)作为苹果组织乙烯前体的能力。化学和动力学证据支持蛋氨酸比其酮类似物更接近乙烯前体的观点。