title: [Effects of exogenous CaCl2 on the functions of flue-cured tobacco seedlings leaf photosystem II under drought stress].
abstract: Taking chlorophyll a fluorescence transient OJIP as the probe, this paper studied the effects of foliar spraying 10 mmol x L(-1) of CaCl2 on the functions of photosystem II (PS II) in tobacco seedling leaves under drought stress. Drought stress decreased the conversion efficiency of PS II primary light energy (F(v)/F(m)) and electron transport rate (ETR), and inhibited the primal process of photosynthesis, resulting in an obvious photoinhibition. After the spraying of CaCl2, the decrement of quantum yield for electron transport (phiE(o)) under drought stress was obviously lower, and the increment of electron transport efficiency of per reaction center (ET(o)/RC) was obviously higher, compared with those after the spraying of water. Foliar spraying CaCl2 increased the amount of PS II -captured light energy used for photosynthesis electron transport, the efficiency of surplus active reaction center, as well as the energy transport in electron transport chain, making the PS II remain relatively high activity under drought stress, and accordingly, the drought resistance of the tobacco seedlings was improved.
authors.affiliation: College of Life Science, Northeast Forest University, Harbin 150040, China. xtwfwf@126.com
authors.forename: Hui-Hui
authors.initials: HH
authors.lastname: Zhang
authors.forename: Xiu-Li
authors.initials: XL
authors.lastname: Zhang
authors.forename: Nan
authors.initials: N
authors.lastname: Xu
authors.forename: Guo-Qiang
authors.initials: GQ
authors.lastname: He
authors.forename: Wei-Wei
authors.initials: WW
authors.lastname: Jin
authors.forename: Bing-Bing
authors.initials: BB
authors.lastname: Yue
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.forename: Guang-Yu
authors.initials: GY
authors.lastname: Sun
mesh_terms: D002122:Calcium Chloride / Q000494:pharmacology*; D055864:Droughts; D010788:Photosynthesis / Q000502:physiology; D045332:Photosystem II Protein Complex / Q000378:metabolism*; D018515:Plant Leaves / Q000502:physiology; D036226:Seedlings / Q000502:physiology*; D013312:Stress, Physiological; D014026:Nicotiana / Q000502:physiology*
chemical_list: D045332:Photosystem II Protein Complex; D002122:Calcium Chloride