Under chronic stress, carotenoid-based colouration has often been shown to fade. However, the ecological and physiological mechanisms that govern colouration still remain largely unknown. Colour changes may be directly induced by the stressor (for example through reduced carotenoid intake) or due to the activation of the physiological stress response (PSR, e.g. due to increased blood corticoste...

The effects of nicotine on carotenoid biosynthesis have been investigated in a non-photosynthetic Flavobacterium strain 0147, and in two photosynthetic bacteria, Rhodopseudomonas spheroides and Rhodomicrobium vanrtielii. In Flavobacterium, nicotine inhibits the synthesis of the nOrmal main carotenoid, zeaxanthin, and causes an accumulation of lycopene at high nicotine concentration, and rubixan...

Germplasm of Solanum tuberosum and Solanum phureja exhibit a wide (over 20-fold) variation in tuber carotenoid content. The levels of carotenoids during tuber development and storage were compared in a high carotenoid-accumulating S. phureja accession (DB375\1) with two S. tuberosum cultivars (Pentland Javelin and Desiree) that accumulate lower levels of tuber carotenoid. On a dry weight basis,...

The cytosolic mevalonate (MVA) pathway in Hevea brasiliensis latex is the conventionally accepted pathway which provides isopentenyl diphosphate (IPP) for cis-polyisoprene (rubber) biosynthesis. However, the plastidic 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway may be an alternative source of IPP since its more recent discovery in plants. Quantitative RT-PCR (qRT-PCR) expression profiles ...

Integral membrane protein complexes consisting of proteins and small molecules that act as cofactors have important functions in all organisms. To form functional complexes, cofactor biosynthesis must be coordinated with the production of corresponding apoproteins. To examine this coordination, we study bacteriorhodopsin (BR), a light-induced proton pump in the halophilic archaeon Halobacterium...

Carotenoid-based colours in animals are valuable models for testing theories of sexual selection and life-history trade-offs because the pigments used in coloration are chemically tractable in the diet and in the body, where they serve multiple purposes (e.g. health enhancement, photoprotection). An important assumption underlying the hypothesized signalling value of carotenoid coloration is th...

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Detailed studies of the properties of carotenoids isolated from diphenylamine-inhibited cultures of Rhodospirillum rubrum have revealed a number of novel structures which indicate new features of carotenoid biosynthesis in the photosynthetic bacteria. The dehydrogenation of phytoene to coloured carotenoids occurs by a sequence which is different from that in higher plants in that 7,8,11,12-tetr...

In industry, the yeast Rhodotorula mucilaginosa is commonly used for the production of carotenoids. The production of carotenoids is important because they are used as natural colorants in food and some carotenoids are precursors of retinol (vitamin A). However, the identification and molecular characterization of the carotenoid pathway/s in species belonging to the genus Rhodotorula is scarce ...