Water stress-induced flag leaf senescence may be accelerated by rehydration
Tomasz Hura , Katarzyna Hura , Agnieszka Ostrowska , Joanna Gadzinowska , Anna Fiust
AbstractThe aim of the study was to determine molecular, biochemical and physiological responses of non-fully recovered DH line of triticale exposed to water stress during generative stage. The study involved two DH lines of winter triticale that produce different number of shoots with ears during rehydration. We analyzed the content of proteins associated with the photosynthetic apparatus and plant senescence. We also determined the content of hydrogen peroxide and assimilation pigments and assessed stomatal conductance and activity of the photosynthetic apparatus. Water stress-initiated senescence did not slow down during rehydration in the not fully recovered DH line. This line showed an increase in pheophorbide a oxygenase (PaO), a protein associated with chlorophyll degradation, and a decrease in the proteins related to its synthesis (chlorophyll synthase - ChS, protochlorophilide oxidoreductase - POR). Pheophorbide a oxygenase is a marker of accelerated cell death as it catalyzes opening of the porphyrin ring in the chlorophyll degradation pathway. The level of hydrogen peroxide remained high during rehydration with the photosynthetic apparatus being one of its sources. Lower content of Rieske protein reduced the quantum yield of electron transport (ϕRo) from the primary acceptors QA/QB to the final acceptors in PSI. Intensification of metabolic processes during rehydration resulted in overloading the electron transport chain in PSII and transfer of electrons from the primary acceptors to oxygen molecule. Overproduction of hydrogen peroxide accelerated senescence during rehydration and significantly reduced plant yield.
|Journal series||Journal of Plant Physiology, ISSN 0176-1617, e-ISSN 1618-1328, (N/A 100 pkt)|
|Publication size in sheets||0.5|
|Keywords in English||Chlorophyll synthase, Pheophorbide a oxygenase, Protochlorophilide oxidoreductase, Rehydration, Rieske protein, Water stress|
|ASJC Classification||; ;|
|Publication indicators||: 2018 = 1.174; : 2018 = 2.825 (2) - 2018=3.236 (5)|
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