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Title
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The phytohormone auxin is a component of the regulatory system that controls UV-mediated accumulation of flavonoids and UV-induced morphogenesis
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Author
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Abstract
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| In plants, ultraviolet (UV)-B acclimation is a complex, dynamic process that plays an essential role in preventing UV-B damage to targets such as DNA and the photosynthetic machinery. In this study we tested the hypothesis that the phytohormone auxin is a component of the regulatory system that controls both UV-mediated accumulation of flavonoids and UV-induced morphogenesis. We found that the leaf area of Arabidopsis thaliana Col-0 plants raised under a low dose of UV radiation (0.56 kJ m-2 daily dose) was, on average, decreased by 23% relative to plants raised in the absence of UV-B, and this was accompanied by a decrease (P = 0.063) in free auxin in young leaf tissues. Compared to Col-0, both the auxin influx mutant axr4-1 and the auxin biosynthesis mutant nit1-3 displayed significantly stronger morphogenic responses, i.e. relative decreases in leaf area were greater for these two mutants. UV exposure also induced accumulation of flavonoids. In Col-0, increases in the concentrations of specific kaempferol derivatives ranged from 2.1- to 19-fold. Thus, UV induces complex changes in flavonoidglycosylation patterns. Compared to Col-0, three auxin mutants displayed significantly different flavonoid profiles. Thus, based on mutant analysis, it is concluded that the phytohormone auxin plays a role in UV acclimation by regulating flavonoid concentration, flavonoidglycosylation pattern and by controlling UV-induced morphogenic responses. |
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Language
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English
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Source (journal)
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Physiologia plantarum. - Lund
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Publication
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Lund
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2012
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ISSN
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0031-9317
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DOI
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10.1111/J.1399-3054.2012.01590.X
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Volume/pages
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145
:4
(2012)
, p. 594-603
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ISI
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000306180500009
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Full text (Publisher's DOI)
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Full text (publisher's version - intranet only)
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