title: Comparative study on the changes in photosynthetic activity of the homoiochlorophyllous desiccation-tolerant Haberlea rhodopensis and desiccation-sensitive spinach leaves during desiccation and rehydration.
abstract: The functional peculiarities and responses of the photosynthetic system in the flowering homoiochlorophyllous desiccation-tolerant (HDT) Haberlea rhodopensis and the non-desiccation-tolerant spinach were compared during desiccation and rehydration. Increasing rate of water loss clearly modifies the kinetic parameters of fluorescence induction, thermoluminescence emission, far-red induced P700 oxidation and oxygen evolution in the leaves of both species. The values of these parameters returned nearly to the control level after 24 h rehydration only of the leaves of HDT plant. PS II was converted in a non-functional state in desiccated spinach in accordance with the changes in membrane permeability, malondialdehyde, proline and H(2)O(2) contents. Moreover, our data showed a strong reduction of the total number of PS II centers in Haberlea without any changes in the energetics of the charge recombination. We consider this observation, together with the previously reported unusually high temperature of B-band (S(2)Q(B)-) emission of Haberlea to reflect some specific adaptive characteristics of the photosynthetic system. As far as we know this is the first time when such adaptive characteristics and mechanism of the photosynthetic system of a flowering HDT higher plant is described. These features of Haberlea can explain the fast recovery of its photosynthesis after desiccation, which enable this HDT plant to rapidly take advantage of frequent changes in water availability.
authors.affiliation: Acad. M. Popov Institute of Plant Physiology, Bulgarian Academy of Sciences, Sofia, Bulgaria. katya@obzor.bio21.bas.bg
authors.forename: Katya
authors.initials: K
authors.lastname: Georgieva
authors.forename: Liliana
authors.initials: L
authors.lastname: Maslenkova
authors.forename: Violeta
authors.initials: V
authors.lastname: Peeva
authors.forename: Yuliana
authors.initials: Y
authors.lastname: Markovska
authors.forename: Detelin
authors.initials: D
authors.lastname: Stefanov
authors.forename: Zoltan
authors.initials: Z
authors.lastname: Tuba
mesh_terms: D002734:Chlorophyll / Q000378:metabolism; D003890:Desiccation; D004573:Electrolytes / Q000378:metabolism; D004579:Electron Transport; D006861:Hydrogen Peroxide / Q000378:metabolism; D019684:Magnoliopsida / Q000378:metabolism*; D008315:Malondialdehyde / Q000378:metabolism; D018384:Oxidative Stress; D010100:Oxygen / Q000378:metabolism; D010788:Photosynthesis / Q000502:physiology*; D045331:Photosystem I Protein Complex / Q000378:metabolism; D045332:Photosystem II Protein Complex / Q000378:metabolism; D018515:Plant Leaves / Q000378:metabolism*; D011392:Proline / Q000378:metabolism; D018724:Spinacia oleracea / Q000378:metabolism*; D014867:Water / Q000378:metabolism*
chemical_list: D004573:Electrolytes; D045331:Photosystem I Protein Complex; D045332:Photosystem II Protein Complex; D014867:Water; D002734:Chlorophyll; D008315:Malondialdehyde; D011392:Proline; D006861:Hydrogen Peroxide; D010100:Oxygen