Circadian rhythms of isoprene biosynthesis in grey poplar leaves

Loivamäki, Maaria and Louis, Sandrine and Cinege, Gyöngyi and Zimmer, Ina and Fischbach, Robert J. and Schnitzler, Jörg-Peter (2007) Circadian rhythms of isoprene biosynthesis in grey poplar leaves. Plant Physiology, 143 (1). pp. 540-551. ISSN 1532-2548

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Isoprene (2-methyl-1,3-butadiene) emission varies diurnally in different species. In poplar (Populus spp.), it has recently been shown that the gene encoding the synthesizing enzyme for isoprene, isoprene synthase (ISPS), displays diurnal variation in expression. Working on shoot cultures of Grey poplar (Populus x canescens) placed under a different light regime in phytochambers, we showed that these variations in PcISPS gene expression, measured by quantitative real-time polymerase chain reaction, are not only due to day-night changes, but also are linked to an internal circadian clock. Measurement of additional selected isoprenoid genes revealed that phytoene synthase (carotenoid pathway) displays similar fluctuations, whereas 1-deoxy-d-xylulose 5-phosphate reductoisomerase, possibly the first committed enzyme of the 1-deoxy-d-xylulose 5-phosphate pathway, only shows light regulation. On the protein level, it appeared that PcISPS activity and protein content became reduced under constant darkness, whereas under constant light, activity and protein content of this enzyme were kept high. In contrast, isoprene emission rates under continuous irradiation displayed circadian changes as is the case for gene expression of PcISPS. Furthermore, binding assays with Arabidopsis (Arabidopsis thaliana) late elongated hypocotyl, a transcription factor of Arabidopsis involved in circadian regulation, clearly revealed the presence of circadian-determining regulatory elements in the promoter region of PcISPS

Item Type: Article
Subjects: Q Science / természettudomány > QK Botany / növénytan > QK10 Plant physiology / növényélettan
Depositing User: János Zsámboki
Date Deposited: 01 Oct 2013 08:20
Last Modified: 02 Oct 2013 10:53

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