Havir E A, McHale N A
Connecticut Agricultural Experiment Station, P. O. Box 1106, New Haven, Connecticut 06504.
Plant Physiol. 1989 Nov;91(3):812-5. doi: 10.1104/pp.91.3.812.
Separation of catalase isozymes from leaf extracts of three diverse plant species (Nicotiana sylvestris, Zea mays, Hordeum vulgare L.) revealed a distinct isozyme with enhanced peroxidatic activity (30-, 70-, 28-fold over typical catalase, respectively) which constituted 10 to 20% of the total catalase activity. In maize this isozyme is the product of the Cat3 gene, which is expressed only in mesophyll cells (AS Tsaftaris, AM Bosabalidis, JG Scandalios [1983] Proc Natl Acad Sci USA 80: 4455-4459). A mutation in barley reducing levels of peroxisomal catalase (AC Kendall et al. [1983] Planta 159: 505-511) does not reduce the amount of the isozyme with enhanced peroxidatic activity. Similarly, this isozyme is unaffected in dark-grown barley in spite of a 75% decrease in total catalase activity. These results suggest that this catalase isozyme is under separate genetic control in barley. This may also be the case in tobacco where the catalase isozyme with enhanced peroxidatic activity is an immunologically distinct protein (EA Havir, NA McHale [1989] Plant Physiol 89: 952-957).
从三种不同植物（野生烟草、玉米、大麦）的叶片提取物中分离过氧化氢酶同工酶，发现了一种具有增强过氧化物酶活性的独特同工酶（分别比典型过氧化氢酶高30倍、70倍、28倍），其占总过氧化氢酶活性的10%至20%。在玉米中，这种同工酶是Cat3基因的产物，该基因仅在叶肉细胞中表达（AS·察法塔里斯、AM·博萨巴利迪斯、JG·斯坎达利奥斯[1983]《美国国家科学院院刊》80: 4455 - 4459）。大麦中过氧化物酶体过氧化氢酶水平降低的一个突变（AC·肯德尔等人[1983]《植物》159: 505 - 511）并没有降低具有增强过氧化物酶活性的同工酶的量。同样，尽管总过氧化氢酶活性降低了75%，这种同工酶在黑暗生长的大麦中不受影响。这些结果表明，这种过氧化氢酶同工酶在大麦中受独立的遗传控制。在烟草中可能也是如此，其中具有增强过氧化物酶活性的过氧化氢酶同工酶是一种免疫上不同的蛋白质（EA·哈维尔、NA·麦克黑尔[1989]《植物生理学》89: 952 - 957）。
