Lieberman M, Kunishi A T
Pioneering Research Laboratory, Market Quality Research Division, Agricultural Research Service, United States Department of Agriculture, Beltsville, Maryland 20705.
Plant Physiol. 1971 Apr;47(4):576-80. doi: 10.1104/pp.47.4.576.
Stimulation of ethylene production by cauliflower (Brassica oleracea var. botrytis L.) tissue in buffer solution containing 4-S-methyl-2-keto-butyric acid is not due to activation of the natural in vivo system. Increased ethylene production derives from an extra-cellular ethylene-forming system, catalyzed by peroxidase and other factors, which leak from the cauliflower tissue and cause the degradation of 4-S-methyl-2-keto-butyric acid. This exogenous ethylene-forming system is similar to the ethylene-forming horseradish peroxidase system which utilizes methional or 4-S-methyl-2-keto-butyric acid as substrate. We conclude that 4-S-methyl-2-keto-butyric acid is probably not an intermediate in the biosynthetic pathway between methionine and ethylene.
在含有4-S-甲基-2-酮丁酸的缓冲溶液中，花椰菜（Brassica oleracea var. botrytis L.）组织对乙烯生成的刺激并非源于体内天然系统的激活。乙烯生成的增加源自一种细胞外乙烯形成系统，该系统由过氧化物酶和其他从花椰菜组织中渗漏出来的因子催化，导致4-S-甲基-2-酮丁酸的降解。这种外源乙烯形成系统类似于以甲硫醛或4-S-甲基-2-酮丁酸为底物的辣根过氧化物酶乙烯形成系统。我们得出结论，4-S-甲基-2-酮丁酸可能不是甲硫氨酸和乙烯生物合成途径中的中间体。
