Redox transients of P680 associated with the incremental chlorophyll-a fluorescence yield rises elicited by a series of saturating flashes in diuron-treated Photosystem II core complex of Thermosynechococcus vulcanus

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61988987%3A17310%2F19%3AA2001YBO" target="_blank" >RIV/61988987:17310/19:A2001YBO - isvavai.cz</a>

Výsledek na webu

<a href="https://onlinelibrary.wiley.com/doi/10.1111/ppl.12945" target="_blank" >https://onlinelibrary.wiley.com/doi/10.1111/ppl.12945</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1111/ppl.12945" target="_blank" >10.1111/ppl.12945</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Redox transients of P680 associated with the incremental chlorophyll-a fluorescence yield rises elicited by a series of saturating flashes in diuron-treated Photosystem II core complex of Thermosynechococcus vulcanus

Popis výsledku v původním jazyce

Recent chlorophyll-a fluorescence yield measurements, using single-turnover saturating flashes (STSFs), have revealed the involvement of a rate-limiting step in the reactions following the charge separation induced by the first flash. As also shown here, in diuron-inhibited PSII core complexes isolated from Thermosynechococcus vulcanus the fluorescence maximum could only be reached by a train of STSFs. In order to elucidate the origin of the fluorescence yield increments in STSF series, we performed transient absorption measurements at 819nm, reflecting the photooxidation and re-reduction kinetics of the primary electron donor P680. Upon single flash excitation of the dark-adapted sample, the decay kinetics could be described with lifetimes of 17ns (approximate to 50%) and 167ns (approximate to 30%), and a longer-lived component (approximate to 20%). This kinetics are attributed to re-reduction of P680(center dot+) by the donor side of PSII. In contrast, upon second-flash (with t between 5s and 100ms) or repetitive excitation, the 819nm absorption changes decayed with lifetimes of about 2ns (approximate to 60%) and 10ns (approximate to 30%), attributed to recombination of the primary radical pair P680(center dot+)Pheo(center dot-), and a small longer-lived component (approximate to 10%). These data confirm that only the first STSF is capable of generating stable charge separation-leading to the reduction of Q(A); and thus, the fluorescence yield increments elicited by the consecutive flashes must have a different physical origin. Our double-flash experiments indicate that the rate-limiting steps, detected by chlorophyll-a fluorescence, are not correlated with the turnover of P680.

Název v anglickém jazyce

Redox transients of P680 associated with the incremental chlorophyll-a fluorescence yield rises elicited by a series of saturating flashes in diuron-treated Photosystem II core complex of Thermosynechococcus vulcanus

Popis výsledku anglicky

Recent chlorophyll-a fluorescence yield measurements, using single-turnover saturating flashes (STSFs), have revealed the involvement of a rate-limiting step in the reactions following the charge separation induced by the first flash. As also shown here, in diuron-inhibited PSII core complexes isolated from Thermosynechococcus vulcanus the fluorescence maximum could only be reached by a train of STSFs. In order to elucidate the origin of the fluorescence yield increments in STSF series, we performed transient absorption measurements at 819nm, reflecting the photooxidation and re-reduction kinetics of the primary electron donor P680. Upon single flash excitation of the dark-adapted sample, the decay kinetics could be described with lifetimes of 17ns (approximate to 50%) and 167ns (approximate to 30%), and a longer-lived component (approximate to 20%). This kinetics are attributed to re-reduction of P680(center dot+) by the donor side of PSII. In contrast, upon second-flash (with t between 5s and 100ms) or repetitive excitation, the 819nm absorption changes decayed with lifetimes of about 2ns (approximate to 60%) and 10ns (approximate to 30%), attributed to recombination of the primary radical pair P680(center dot+)Pheo(center dot-), and a small longer-lived component (approximate to 10%). These data confirm that only the first STSF is capable of generating stable charge separation-leading to the reduction of Q(A); and thus, the fluorescence yield increments elicited by the consecutive flashes must have a different physical origin. Our double-flash experiments indicate that the rate-limiting steps, detected by chlorophyll-a fluorescence, are not correlated with the turnover of P680.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10610 - Biophysics

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2019

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Physiologia Plantarum

ISSN

0031-9317

e-ISSN

1399-3054

Svazek periodika

166

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

11

Strana od-do

22-32

Kód UT WoS článku

000466108300004

EID výsledku v databázi Scopus

2-s2.0-85064712279