کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10795713 | 1052592 | 2014 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Disentangling two non-photochemical quenching processes in Cyclotella meneghiniana by spectrally-resolved picosecond fluorescence at 77Â K
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کلمات کلیدی
photoinhibitory quenchingTCSPCDASChlFWHMFCPDDXDTXNPQFm′ - Fm 'Fv/Fm - Fv / FmExcitation energy transfer - انتقال انرژی هیجان انگیزLHC - برخورد دهنده بزرگ هادرون Non-photochemical quenching - خنک سازی غیر فتوشیمیاییEET - خوردنDiatoxanthin - دیاتوکسانتینDiadinoxanthin - دیادینوکسانتینEnergy-dependent quenching - رطوبت وابسته به انرژیChlorophyll - سبزینه یا کلروفیلPhotosystem - سیستم عکسTime-correlated single photon counting - شمارش تک فوتون وابسته به زمانfull-width at half-maximum - عرض کامل در نیمه حداکثرFucoxanthin - فوکوکسانینreaction center - مرکز واکنشoptical density - چگالی نوری
موضوعات مرتبط
علوم زیستی و بیوفناوری
علوم کشاورزی و بیولوژیک
دانش گیاه شناسی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Diatoms, which are primary producers in the oceans, can rapidly switch on/off efficient photoprotection to respond to fast light-intensity changes in moving waters. The corresponding thermal dissipation of excess-absorbed-light energy can be observed as non-photochemical quenching (NPQ) of chlorophyll a fluorescence. Fluorescence-induction measurements on Cyclotella meneghiniana diatoms show two NPQ processes: qE1 relaxes rapidly in the dark while qE2 remains present upon switching to darkness and is related to the presence of the xanthophyll-cycle pigment diatoxanthin (Dtx). We performed picosecond fluorescence measurements on cells locked in different (quenching) states, revealing the following sequence of events during full development of NPQ. At first, trimers of light-harvesting complexes (fucoxanthin-chlorophyll a/c proteins), or FCPa, become quenched, while being part of photosystem II (PSII), due to the induced pH gradient across the thylakoid membrane. This is followed by (partial) detachment of FCPa from PSII after which quenching persists. The pH gradient also causes the formation of Dtx which leads to further quenching of isolated PSII cores and some aggregated FCPa. In subsequent darkness, the pH gradient disappears but Dtx remains present and quenching partly pertains. Only in the presence of some light the system completely recovers to the unquenched state.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochimica et Biophysica Acta (BBA) - Bioenergetics - Volume 1837, Issue 6, June 2014, Pages 899-907
Journal: Biochimica et Biophysica Acta (BBA) - Bioenergetics - Volume 1837, Issue 6, June 2014, Pages 899-907
نویسندگان
Volha U. Chukhutsina, Claudia Büchel, Herbert van Amerongen,