title: Influences of nano-TiO2 on the chloroplast aging of spinach under light.
abstract: The effects of nano-TiO2 (rutile) on the chloroplast aging of spinach under light were studied. The results showed that when the chloroplasts were illuminated for 1, 5, and 10 min with 500 micromol/cm2/min light intensity, respectively, the evolution oxygen rate was rapidly increased; when the chloroplasts were treated for 20, 30, and 40 min with 500 micromol/cm2/min light intensity, respectively, the evolution oxygen rate was gradually decreased. While spinach was treated with 0.25% nano-TiO2, the rate of evolution oxygen of chloroplasts in different illumination times (1, 5, 10, 20, 30, and 40 min) was higher than that of control, and when the illumination time was over 10 min, the reduction of the evolution oxygen rate was lower than that of control. It suggested that nano-TiO2 treatment could protect chloroplasts from aging for long-time illumination. The mechanism researches indicated that nano-TiO2 treatment could significantly increase the activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD), decrease accumulation of reactive oxygen free radicals and the level of malondialdehyde (MDA), and maintain stability of membrane structure of chloroplast under light.
authors.affiliation: College of Life Sciences, Suzhou University, Suzhou-215006, People's Republic of China.
authors.forename: Fashui
authors.initials: F
authors.lastname: Hong
authors.forename: Fan
authors.initials: F
authors.lastname: Yang
authors.forename: Chao
authors.initials: C
authors.lastname: Liu
authors.forename: Qing
authors.initials: Q
authors.lastname: Gao
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Wan
authors.forename: Fugen
authors.initials: F
authors.lastname: Gu
authors.forename: Cheng
authors.initials: C
authors.lastname: Wu
authors.forename: Zhenni
authors.initials: Z
authors.lastname: Ma
authors.forename: Juan
authors.initials: J
authors.lastname: Zhou
authors.forename: Ping
authors.initials: P
authors.lastname: Yang
mesh_terms: D002374:Catalase / Q000378:metabolism; D002736:Chloroplasts / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects*; D007425:Intracellular Membranes / Q000187:drug effects; D008027:Light; D010539:Permeability / Q000187:drug effects; D010544:Peroxidases / Q000378:metabolism; D010788:Photosynthesis / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects / Q000502:physiology; D018724:Spinacia oleracea; D013268:Stimulation, Chemical; D013482:Superoxide Dismutase / Q000378:metabolism; D014025:Titanium / Q000494:pharmacology*
chemical_list: D017382:Reactive Oxygen Species; C009495:titanium dioxide; D014025:Titanium; D010544:Peroxidases; D002374:Catalase; D013482:Superoxide Dismutase