کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2057438 1075884 2008 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
A pronounced light-induced zeaxanthin formation accompanied by an unusually slight increase in non-photochemical quenching: A study with barley leaves treated with methyl viologen at moderate light
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک علوم زراعت و اصلاح نباتات
پیش نمایش صفحه اول مقاله
A pronounced light-induced zeaxanthin formation accompanied by an unusually slight increase in non-photochemical quenching: A study with barley leaves treated with methyl viologen at moderate light
چکیده انگلیسی

SummaryLight-induced deepoxidation of violaxanthin to antheraxanthin and zeaxanthin in plants is associated with the induction of pronounced xanthophyll-dependent non-photochemical quenching (NPQ). To date, a misbalance between a high amount of zeaxanthin in thylakoid membranes and low NPQ has been explained by an absence of lumen acidification (e.g. when NPQ is measured in the dark after high light stress). In this study, we report that this misbalance can also be observed under moderate light. We found this result (deepoxidation state, DEPS, above 55% and NPQ∼0.9) in barley leaves treated with 10 μM methyl viologen (MV) under white light (100 μmol photons m−2 s−1, photosynthetically active radiation (PAR), growth irradiance). The addition of MV at this moderate light did not accelerate electron transport in thylakoid membranes, and induced only slight oxidative stress (no lipid peroxidation, almost unchanged maximum yield of photosystem II photochemistry, a decrease in activity of ascorbate peroxidase, and an increase in that of glutathion reductase). We suggest that, in leaves treated under the conditions used here, the lumen acidification induced by light-limited electron transport in thylakoid membranes was high enough to activate violaxanthin deepoxidase, but not sufficiently high to form the expected number of zeaxanthin-dependent quenching centers in photosystem II antennae.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Plant Physiology - Volume 165, Issue 15, 9 October 2008, Pages 1563–1571
نویسندگان
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