Nijo Nobuyoshi, Lundin Björn, Yoshioka Miho, Morita Noriko, Yamamoto Yasusi
Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan.
Methods Mol Biol. 2011;684:201-15. doi: 10.1007/978-1-60761-925-3_17.
When thylakoids of higher plant chloroplasts are exposed to excessive light or moderate heat stress, photosystem II reaction center-binding protein D1 is damaged. The photodamage of the D1 protein is caused by reactive oxygen species, mostly singlet oxygen, and also by endogenous cationic radicals generated by the photochemical reactions of photosystem II. Moreover, it was shown recently that the damage to the D1 protein by moderate heat stress is due to reactive oxygen species produced by lipid peroxidation near photosystem II. To maintain photosystem II activity, the oxidatively damaged D1 protein must be replaced by a newly synthesized copy, and thus degradation and removal of the photo- or heat-damaged D1 protein are essential for maintaining the viability of photosystem II. In this chapter, we describe the methods for assaying photoinhibition and heat inhibition of photosystem II in higher plant materials.
当高等植物叶绿体的类囊体暴露于强光或适度热胁迫时，光系统II反应中心结合蛋白D1会受到损伤。D1蛋白的光损伤是由活性氧（主要是单线态氧）以及光系统II光化学反应产生的内源性阳离子自由基引起的。此外，最近有研究表明，适度热胁迫对D1蛋白的损伤是由于光系统II附近脂质过氧化产生的活性氧所致。为维持光系统II的活性，必须用新合成的拷贝替换被氧化损伤的D1蛋白，因此，降解和去除光损伤或热损伤的D1蛋白对于维持光系统II的活力至关重要。在本章中，我们描述了在高等植物材料中检测光系统II光抑制和热抑制的方法。
