title: Dissipation of excess excitation energy of the needle leaves in Pinus trees during cold winters.
abstract: Photooxidative damage to the needle leaves of evergreen trees results from the absorption of excess excitation energy. Efficient dissipation of this energy is essential to prevent photodamage. In this study, we determined the fluorescence transients, absorption spectra, chlorophyll contents, chlorophyll a/b ratios, and relative membrane permeabilities of needle leaves of Pinus koraiensis, Pinus tabulaeformis, and Pinus armandi in both cold winter and summer. We observed a dramatic decrease in the maximum fluorescence (Fm) and substantial absorption of light energy in winter leaves of all three species. The Fmdecline was not correlated with a decrease in light absorption or with changes in chlorophyll content and chlorophyll a/b ratio. The results suggested that the winter leaves dissipated a large amount of excess energy as heat. Because the cold winter leaves had lost normal physiological function, the heat dissipation depended solely on changes in the photosystem II supercomplex rather than the xanthophyll cycle. These findings imply that more attention should be paid to heat dissipation via changes in the photosystem complex structure during the growing season.
authors.affiliation: College of Biological Sciences and Technology, Shenyang Agricultural University, Shenyang, 110866, China.|College of Agronomy, Shenyang Agricultural University, Shenyang, 110866, China.
authors.forename: A O
authors.initials: AO
authors.lastname: Zhang
authors.affiliation: College of Biological Sciences and Technology, Shenyang Agricultural University, Shenyang, 110866, China.|Liaoning Province Research Center of Plant Genetic Engineering Technology, Shenyang, 110866, China.
authors.forename: Zhen-Hai
authors.initials: ZH
authors.lastname: Cui
authors.affiliation: College of Biological Sciences and Technology, Shenyang Agricultural University, Shenyang, 110866, China.
authors.forename: Jia-Lin
authors.initials: JL
authors.lastname: Yu
authors.affiliation: College of Biological Sciences and Technology, Shenyang Agricultural University, Shenyang, 110866, China.
authors.forename: Zi-Ling
authors.initials: ZL
authors.lastname: Hu
authors.affiliation: College of Biological Sciences and Technology, Shenyang Agricultural University, Shenyang, 110866, China.|College of Agronomy, Shenyang Agricultural University, Shenyang, 110866, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Ding
authors.affiliation: College of Biological Sciences and Technology, Shenyang Agricultural University, Shenyang, 110866, China. daming_ren@hotmail.com.
authors.forename: Da-Ming
authors.initials: DM
authors.lastname: Ren
authors.affiliation: College of Biological Sciences and Technology, Shenyang Agricultural University, Shenyang, 110866, China. ljzhang@syau.edu.cn.|College of Agronomy, Shenyang Agricultural University, Shenyang, 110866, China. ljzhang@syau.edu.cn.|Liaoning Province Research Center of Plant Genetic Engineering Technology, Shenyang, 110866, China. ljzhang@syau.edu.cn.
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Zhang
mesh_terms: D002463:Cell Membrane Permeability; D002734:Chlorophyll / Q000378:metabolism; D003080:Cold Temperature; D005453:Fluorescence; D006358:Hot Temperature; D045332:Photosystem II Protein Complex / Q000378:metabolism; D028223:Pinus / Q000378:metabolism / Q000502:physiology*; D018515:Plant Leaves / Q000378:metabolism / Q000502:physiology; D012621:Seasons
chemical_list: D045332:Photosystem II Protein Complex; D002734:Chlorophyll
keywords: Absorption spectrum; Chlorophyll fluorescence; Photoinhibition; Photosystem complex; Pinus armandi; Pinus koraiensis; Pinus tabulaeformis; Xanthophyll cycle