The Water-Water Cycle in Algae
The Water-Water Cycle in Algae
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DOI：
10.1007/978-94-007-1038-2_9
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
C. Miyake;K. Asada
中科院分区：
文献类型：
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作者：
C. Miyake;K. Asada
在干旱、低温、高温和高光强等环境胁迫下，当光子能量超过光合作用时，蓝藻和藻类囊体的PS I处的O2被光还原为O2。产生的活性氧被清除酶解毒，这些清除酶包括超氧化物歧化酶、抗坏血酸过氧化物酶、铁还蛋白、单脱氢抗坏血酸自由基还原酶、脱氢抗坏血酸还原酶和谷胱甘肽还原酶。在这些氧的氧化还原反应中，PSⅡ中的HP光氧化产生的电子流向类囊体膜的PS I中的O2，再流向HP，这被称为水-水循环。本文综述了藻类中水-水循环的运作，并总结了活性氧清除酶的特点。与高等植物叶绿体不同，HP2的藻类清除系统有四种类型。阐述了藻类水-水循环的生理功能。
Photoreduction ofO2 to O2 at PS I ofthylakoids in Cyanobacteria and algae is stimulated when photon energy is in excess ofphotosynthesis by environmental stress such as drought, chilling, high temperature and high light intensity. Active oxygen so produced is detoxified by the scavenging enzymes including superoxide dismutase, ascorbate peroxidase, ferredoxin, monodehydroascorbate radical reductase, dehydroascorbate reductase and glutathione reductase. In these redox reactions ofoxygen, the electrons generated by the photooxidation ofHP in PS II flow to O2 in PS I ofthylakoid membranes to Hp, which is referred to as the water-water cycle. Here, the operation ofthe water-water cycle in algae is reviewed and the characteristics ofthe scavenging enzymes ofactive oxygen are summarized. In contrast to higher plant chloroplasts, the algal scavenging system ofHP2 comes in four types. The physiological functions ofthe water-water cycle in algae arc described.