title: Detection of singlet oxygen and superoxide with fluorescent sensors in leaves under stress by photoinhibition or UV radiation.
abstract: In order to understand the physiological functions of reactive oxygen species (ROS) generated in leaves, their direct measurement in vivo is of special importance. Here we report experiments with two dansyl-based ROS sensors, the singlet oxygen specific DanePy and HO-1889NH, which is reactive to both singlet oxygen and superoxide radicals. Here we report in vivo detection of (1)O(2) and O(2)(-*) by fluorescence quenching of two dansyl-based ROS sensors, the (1)O(2) specific DanePy and HO-1889NH, which was reactive with both (1)O(2) and O(2)(-*). The ROS sensors were administered to spinach leaves through a pinhole, and then the leaves were exposed to either excess photosynthetically active radiation or UV (280-360 nm) radiation. Microlocalization of the sensors' fluorescence and its ROS-induced quenching was followed with confocal laser scanning microscopy and with fluorescence imaging. These sensors were specifically localized in chloroplasts. Quenching analysis indicated that the leaves exposed to strong light produced (1)O(2), but hardly any O(2)(-*). On the other hand, the dominant ROS in UV-irradiated leaves was O(2)(-*), while (1)O(2) was minor.
authors.affiliation: Institute of Plant Biology, Biological Research Center, H-6701 Szeged, P.O. Box 521, Hungary. ehideg@nucleus.szbk.u-szeged.hu
authors.forename: Eva
authors.initials: E
authors.lastname: Hideg
authors.forename: Csengele
authors.initials: C
authors.lastname: Barta
authors.forename: Tamás
authors.initials: T
authors.lastname: Kálai
authors.forename: Imre
authors.initials: I
authors.lastname: Vass
authors.forename: Kálmán
authors.initials: K
authors.lastname: Hideg
authors.forename: Kozi
authors.initials: K
authors.lastname: Asada
mesh_terms: D002736:Chloroplasts / Q000378:metabolism / Q000528:radiation effects; D005453:Fluorescence; D008027:Light; D018613:Microscopy, Confocal; D010788:Photosynthesis / Q000528:radiation effects; D018515:Plant Leaves / Q000378:metabolism* / Q000528:radiation effects; D017382:Reactive Oxygen Species / Q000378:metabolism* / Q000528:radiation effects; D012680:Sensitivity and Specificity; D026082:Singlet Oxygen / Q000378:metabolism* / Q000528:radiation effects; D013057:Spectrum Analysis / Q000379:methods; D018724:Spinacia oleracea / Q000378:metabolism / Q000528:radiation effects; D013481:Superoxides / Q000378:metabolism* / Q000528:radiation effects; D014466:Ultraviolet Rays
chemical_list: D017382:Reactive Oxygen Species; D013481:Superoxides; D026082:Singlet Oxygen