Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q8NEX9 (reductase)
 26,410 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In this work we analysed, at the transcript level, the response of Arabidopsis anthocyanin regulatory genes of the MYB (PAP1 and PAP2), bHLH (TT8, EGL3 and GL3) and WD40 (TTG1) families to white light in seedlings and to different light qualities in rosette leaves. Our experiments showed strong light induction of the MYB genes PAP1 and PAP2. In particular, the kinetics of PAP1 expression preceded those of PAP2 and all of the structural genes (CHS, DFR, F3H, LDOX), consistent with the hypothesis that it has a key role in light induction of anthocyanin biosynthesis. All bHLH genes analysed showed light induction, and in seedlings their expression preceded that of the late structural genes, suggesting their possible role in light regulation of these structural genes. TTG1 expression is essentially constitutive in both systems. Experiments with transgenic lines over-expressing the MYB factors show that PAP1, but not PAP2, strongly stimulates expression of the anthocyanin structural gene encoding dihydroflavonol reductase, but neither factor affected expression of the early flavonoid biosynthesis gene encoding chalcone synthase. Consistent with these findings, PAP1, but not PAP2, stimulated light induction of anthocyanin biosynthesis in seedlings. We conclude that specific members of the MYB and bHLH families play important roles in regulating anthocyanin biosynthesis in response to different light qualities in Arabidopsis.
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PMID:Expression analysis of anthocyanin regulatory genes in response to different light qualities in Arabidopsis thaliana. 1776 4

TTG1 (Transparent Testa Glabra 1), a WD-40 repeat protein, is involved in regulation of flavonoid/anthocyanin biosynthesis, seed coat (mucilage) development/pigmentation and trichome formation in leaves. Here, we characterized the TTG1 gene of Matthiola incana wild type (e locus), showing 85.3% similarity to TTG1 of A. thaliana on the nucleotide level and 96.2% on the protein level. A white-flowered and glabrous mutant, line 17, of M. incana exhibits one nucleotide change, leading to an amino acid substitution directly in the WD motif (W158R). Correspondingly, the DFR (dihydroflavonol 4-reductase) gene, in which the expression is known to be dependent on TTG1, is not expressed in Matthiola mutant lines 17 (and 19). Comparison of the GC content of the Matthiola TTG1 (54.1%) and Arabidopsis TTG1 (46.1%) genes revealed a strong difference, mostly obtained by neutral substitutions (C to T transitions). To examine whether this is an ecologically influenced trend, a fragment of TTG1 was characterized from another Matthiola species (M. tricuspidata) and from Malcolmia flexuosa subsp. naxensis from the eastern Mediterranean, near a beach with sandy and salty soils. Both Matthiola species have a higher GC content in the TTG1 gene than Arabidopsis and the closer-related Malcolmia, indicating that the GC content is rather an evolutionary than an ecological signal. A similar WD-40 repeat protein gene (containing no intron in the 3' untranslated region) with high similarity to the Arabidopsis TTG1-like (AtAN11) gene was found in Matthiola.
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PMID:Transparent Testa Glabra 1 (TTG1) and TTG1-like genes in Matthiola incana R. Br. and related Brassicaceae and mutation in the WD-40 motif. 1922 27

The bHLH transcription factors EGL3 (ENHANCER OF GLABRA3) and its close homologue GL3 (GLABRA3) are important regulators of the anthocyanin pathway in Arabidopsis thaliana, and together with TTG1 (a WD40 repeat protein) and MYB transcription factors regulate specific genes in the pathway. In response to nitrogen depletion, the MYB genes PAP1/PAP2 (production of anthocyanin pigment 1/2) and GL3 are strongly induced, and anthocyanin synthesis is activated in seedlings and rosette stage plants. In this study we show that anthocyanins accumulate in both wild type and egl3, but not in gl3 loss-of-function mutants when depleted of nitrogen. Several structural genes of flavonoid metabolism including CHS (chalcone synthase), FLS1 (flavonol synthase 1) and ANS (anthocyanidin synthase) were induced in response to nitrogen depletion in wild type as well as in the egl3 and gl3 mutants. Strikingly, in the gl3 mutant DFR (dihydroflavonol-4-reductase) transcript level was only 2% of the levels in wild type or egl3 mutant. Hence, low expression of DFR appears to be the bottleneck preventing anthocyanin synthesis in the gl3 mutant. The specific effect on DFR, but not ANS is compatible with involvement of the MYBL2 inhibitor.
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PMID:The endogenous GL3, but not EGL3, gene is necessary for anthocyanin accumulation as induced by nitrogen depletion in Arabidopsis rosette stage leaves. 1962 Dec 39