Differential accumulation of photosynthetic proteins regulates diurnal photochemical adjustments of PSII in common fig (Ficus carica L.) leaves

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• 作者：Selma Mlinarić^a ; ^{smlinaric@biologija.unios.hr} ; Jasenka Antunović Dunić^a ; ^{jasenka.antunovic@biologija.unios.hr} ; Martina Skendrović Babojelić^b ; ^{mskendrovic@agr.hr} ; Vera Cesar^a ; ^{vcesarus@yahoo.com} ; Hrvoje Lepedu&scaron ; ^c ; ^{hlepedus@yahoo.com}
• 关键词：Chl ; chlorophyll ; DTT ; dithiothreitol ; ECL ; enhanced chemoluminescence ; HRP ; horseradish peroxidase ; LHCII ; light harvesting complex II ; ML ; mature leaves ; PEA ; plant efficiency analyzer ; PPFD ; photosynthetic photon flux density ; PQ ; plastoquinone ; PSII ; photosystem II ; RC ; reaction center ; Rubisco LSU ; 1 ; 5-bisphosphate carboxylase/oxygenase large subunit ; SDS-PAGE ; sodium dodecyl sulfate polyacrylamide gel electrophoresis ; YL ; young leaves
• 刊名：Journal of Plant Physiology
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：209
• 期：Complete
• 页码：1-10
• 全文大小：1731 K
• 卷排序：209

文摘

Molecular processes involved in photosystem II adaptation of woody species to diurnal changes in light and temperature conditions are still not well understood. Regarding this, here we investigated differences between young and mature leaves of common fig (Ficus carica L.) in photosynthetic performance as well as accumulation of the main photosynthetic proteins: light harvesting complex II, D1 protein and Rubisco large subunit. Investigated leaf types revealed different adjustment mechanisms to keep effective photosynthesis. Rather stable diurnal accumulation of light harvesting complex II in mature leaves enabled efficient excitation energy utilization (negative L-band) what triggered faster D1 protein degradation at high light. However, after photoinhibition, greater accumulation of D1 during the night enabled them faster recovery. So, the most photosynthetic parameters, as the maximum quantum yield for primary photochemistry, electron transport and overall photosynthetic efficiency in mature leaves successfully restored to their initial values at 1 a.m. Reduced connectivity of light harvesting complexes II to its reaction centers (positive L-band) in young leaves increased dissipation of excess light causing less pressure to D1 and its slower degradation. Decreased electron transport in young leaves, due to reduced transfer beyond primary acceptor QA− most probably additionally induced degradation of Rubisco large subunit what consequently led to the stronger decrease of overall photosynthetic efficiency in young leaves at noon.