Institute of Plant Biology, Biological Research Center, Szeged, Hungary.
Cellular Imaging Laboratory, Biological Research Center, Szeged, Hungary.
Photochem Photobiol. 2014 Jan;90(1):129-36. doi: 10.1111/php.12148. Epub 2013 Sep 4.
Singlet oxygen ((1) O2 ) is of special interest in plant stress physiology. Studies focused on internal, chlorophyll-mediated production are often complemented with the use of artificial (1) O2 photosensitizers. Here, we report a comparative study on the effects of Rose Bengal (RB), Methylene Violet (MVI), Neutral Red (NR) and Indigo Carmine (IC). These were infiltrated into tobacco leaves at concentrations generating the same fluxes of (1) O2 in solution. Following green light-induced (1) O2 production from these dyes, leaf photosynthesis was characterized by Photosystem (PS) II and PSI electron transport and oxidative damage was monitored as degradation of D1, a PSII core protein. Cellular localizations were identified on the basis of the dyes' fluorescence using confocal laser scanning microscopy. We found that RB and NR were both localized in chloroplasts but the latter had very little effect, probably due to its pH-dependent photosensitizing. Both RB and intracellular, nonplastid MVI decreased PSII electron transport, but the effect of RB was stronger than that of MVI and only RB was capable of damaging the D1 protein. Intercellularly localized IC had no significant effect. Our results also suggest caution when using RB as photosensitizer because it affects PSII electron transport.
单线态氧（(1)O2）在植物应激生理学中具有特殊的意义。集中研究内部、叶绿素介导的产生的研究通常辅以使用人工（1）O2 光敏剂。在这里，我们报告了对孟加拉玫瑰红（RB）、甲烯蓝（MVI）、中性红（NR）和靛胭脂（IC）的影响的比较研究。这些染料以在溶液中产生相同的（1）O2 通量的浓度被渗透到烟草叶片中。在这些染料的绿光诱导（1）O2 产生之后，通过 PSII 和 PSI 电子传递来描述叶片光合作用，并监测氧化损伤作为 PSII 核心蛋白 D1 的降解。根据染料的荧光，使用共聚焦激光扫描显微镜来鉴定细胞定位。我们发现 RB 和 NR 都定位于叶绿体中，但后者影响很小，可能是由于其 pH 依赖性光敏性。RB 和细胞内、非质体 MVI 都降低了 PSII 电子传递，但 RB 的作用比 MVI 更强，只有 RB 能够破坏 D1 蛋白。细胞间定位的 IC 没有显著影响。我们的结果还表明，在使用 RB 作为光敏剂时要谨慎，因为它会影响 PSII 电子传递。
