Department of Biological Sciences, Union College, Schenectady, New York 12308.
Plant Physiol. 1976 Jan;57(1):74-9. doi: 10.1104/pp.57.1.74.
Leaves and storage roots of sweet potato plants (Ipomea batatas) showed the same qualitative isoperoxidase patterns and a similar distribution of distinctive isoperoxidases between the cell protoplast and cell wall free, ionically bound, and covalently bound fractions. No changes in the qualitative isoenzyme spectrum were found in relation to age, mechanical injury, or ethylene action. Thus, as in tobacco plants, the cell isoperoxidases in sweet potato did not reflect the possible differential mRNA synthesis in relation to organ, age, or injury. Transcription does not seem to be a limiting factor in injury- and ethylene-dependent peroxidase enhancement during the first 24 hr.The contribution of the wall ionically bound and protoplast fractions was highest in young and old leaves, respectively. In the protoplast and wall ionically and covalently bound fractions, 14, 6, and 5 isoenzyme bands were found; in addition, 4 bands, not detected in the protoplast, were also revealed in the covalently bound fraction. The distinctive "juvenile" and, developing with age, "mature" isoforms were mainly found in the ionically bound and protoplast fractions, respectively.The injury-enhanced and/or ethylene-enhanced peroxidase development was most pronounced in young leaves. Ethylene suppressed some injury-enhanced, had no effect on some other injury-enhanced, and greatly promoted some of the injury-unaffected or enhanced isoperoxidases. After ethylene removal, an increase in the "mature" isoforms was found in the protoplast of intact leaves.Electron microscopy of leaves revealed peroxidase in membrane-bound vesicles located mainly in the vacuole; a thin layer of reaction products was also found on the wall's outer surface. No Golgi apparatus were seen in the cells of control or ethylene-treated intact leaves. In ethylene-treated intact or injured leaves accumulations of reaction products between the plasmalemma and wall were also found. Numerous Golgi apparatus with dark stained vesicles were seen in injured, and especially in injured and ethylene-treated leaves; the vacuolar bodies seemed to occur in very great number.
甘薯植物（Ipomea batatas）的叶片和贮藏根显示出相同的同工过氧化物酶模式，并且在细胞质和细胞壁游离、离子结合和共价结合部分之间存在相似的独特同工过氧化物酶分布。在年龄、机械损伤或乙烯作用方面，同工酶谱的定性没有变化。因此，与烟草植物一样，甘薯细胞同工过氧化物酶不能反映器官、年龄或损伤的可能差异 mRNA 合成。在最初 24 小时内，转录似乎不是损伤和乙烯依赖性过氧化物酶增强的限制因素。
在年轻和年老的叶片中，细胞壁离子结合和原生质体部分的贡献最高。在原生质体和细胞壁离子结合和共价结合部分中，发现了 14、6 和 5 个同工酶带；此外，在共价结合部分还发现了 4 个在原生质体中未检测到的带。独特的“幼年”和随着年龄的增长而出现的“成熟”同工型主要存在于离子结合和原生质体部分。
损伤增强和/或乙烯增强的过氧化物酶发育在年轻叶片中最为明显。乙烯抑制了一些损伤增强的同工酶，对其他一些损伤增强的同工酶没有影响，并且极大地促进了一些损伤不受影响或增强的同工酶。乙烯去除后，完整叶片原生质体中发现“成熟”同工型增加。
叶片的电子显微镜显示过氧化物酶位于主要位于液泡的膜结合小泡中；细胞壁外表面也发现了一层薄的反应产物。在对照或乙烯处理的完整叶片的细胞中未发现高尔基体。在乙烯处理的完整或受伤叶片中，还发现了质膜和细胞壁之间的反应产物的积累。在受伤的叶片中，尤其是在受伤和乙烯处理的叶片中，观察到大量的高尔基体，带有深色染色的小泡；液泡体似乎数量非常多。
