Department of Botany, M.S. University of Baroda, Baroda-2, India.
Plant Physiol. 1974 Oct;54(4):539-43. doi: 10.1104/pp.54.4.539.
Cotton plants (Gossypium hirsutum. Linn. var. Sankar 4) were grown at normal and toxic levels of substrate manganese, and the altered metabolism of manganese toxic plants was studied. The tissues of plants exposed to toxic levels of manganese had higher activities of peroxidase and polyphenol oxidase, and the activities of catalase, ascorbic acid oxidase, glutathione oxidase and cytochrome c oxidase were lowered. In addition, the high manganese tissue had lower contents of ATP and glutathione but higher amounts of ascorbic acid. The respiration of the partially expanded leaves and the growing tips of toxic plants were depressed when compared to that of the normal tissues. The metabolic changes of manganese toxicity of cotton are placed in the following order: accumulation of manganese in the leaf tissue; a rise in respiration; stimulation of polyphenol oxidase; the appearance of initial toxicity symptoms; the evolution of ethylene and stimulation of peroxidase; the presence of severe toxicity symptoms; the depression of terminal oxidases and respiration; abscission of the growing tip and proliferation of the stem tissue. The early stimulation of polyphenol oxidase may be used to detect potential manganese toxicity.
棉花植株（Gossypium hirsutum. Linn. var. Sankar 4）在正常和有毒水平的基质锰中生长，并研究了锰毒性植物改变的代谢。暴露于有毒水平锰的植物组织具有更高的过氧化物酶和多酚氧化酶活性，而过氧化氢酶、抗坏血酸氧化酶、谷胱甘肽氧化酶和细胞色素 c 氧化酶的活性降低。此外，高锰组织中的 ATP 和谷胱甘肽含量较低，抗坏血酸含量较高。与正常组织相比，有毒植物的部分展开叶片和生长尖端的呼吸受到抑制。棉花锰毒性的代谢变化按以下顺序排列：叶片组织中锰的积累；呼吸作用上升；多酚氧化酶的刺激；出现初始毒性症状；乙烯的出现和过氧化物酶的刺激；出现严重毒性症状；末端氧化酶和呼吸作用的抑制；生长尖端的脱落和茎组织的增殖。多酚氧化酶的早期刺激可用于检测潜在的锰毒性。
