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Seasonal responses ...
Seasonal responses of photosynthetic electron transport in Scots pine (Pinus sylvestris L.) studied by thermoluminescence
- Article/chapterEnglish2002
Publisher, publication year, extent ...
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Springer Science and Business Media LLC,2002
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printrdacarrier
Numbers
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LIBRIS-ID:oai:DiVA.org:umu-44773
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https://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-44773URI
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https://doi.org/10.1007/s00425-002-0765-xDOI
Supplementary language notes
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Language:English
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Summary in:English
Part of subdatabase
Classification
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Subject category:ref swepub-contenttype
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Subject category:art swepub-publicationtype
Notes
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The potential of photosynthesis to recover from winter stress was studied by following the thermoluminescence (TL) and chlorophyll fluorescence changes of winter pine needles during the exposure to room temperature (20 degreesC) and an irradiance of 100 mumol m(-2) s(-1). TL measurements of photosystem 11 (PSII) revealed that the S(2)Q(B)(-) charge recombinations (the B-band) were shifted to lower temperatures in winter pine needles, while the S(2)Q(A)(-) recombinations (the Q-band) remained close to 0 degreesC. This was accompanied by a drastically reduced (65%) PSII photochemical efficiency measured as F-v/F-m and a 20-fold faster rate of the fluorescence transient from F-o to F, as compared to summer pine. A strong positive correlation between the increase in the photochemical efficiency of PSII and the increase in the relative contribution of the B-band was found during the time course of the recovery process. The seasonal dynamics of TL in Scots pine needles studied under field conditions revealed that between November and April, the contribution of the Q- and B-bands to the overall TL emission was very low (less than 5%). During spring, the relative contribution of the Q- and B-bands, corresponding to charge recombination events between the acceptor and donor sides of PSII, rapidly increased, reaching maximal values in late July. A sharp decline of the B-band was observed in late summer, followed by a gradual decrease, reaching minimal values in November. Possible mechanisms of the seasonally induced changes in the redox properties Of S-2/S(3)Q(B)(-) recombinations are discussed. It is proposed that the lowered redox potential Of Q(B) in winter needles increases the population Of Q(A)(-). thus enhancing the probability for non-radiative P680(+) Q(A)(-) recombination. This is suggested to enhance the radiationless dissipation of excess light within the PSII reaction center during cold acclimation and during cold winter periods.
Subject headings and genre
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electron transport
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photosystem II
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Pinus (cold acclimation)
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recovery of photosynthesis
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thermoluminescence
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winter stress
Added entries (persons, corporate bodies, meetings, titles ...)
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Sane, P V
(author)
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Zeinalov, Y
(author)
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Simidjiev, I
(author)
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Huner, N P A
(author)
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Oquist, Gunnar,1941-Umeå universitet,Institutionen för fysiologisk botanik,Umeå Plant Science Centre (UPSC)(Swepub:umu)guoq0001
(author)
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Umeå universitetInstitutionen för fysiologisk botanik
(creator_code:org_t)
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In:Planta: Springer Science and Business Media LLC215:3, s. 457-4650032-09351432-2048
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