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Sample records for r2r3 myb genes

  1. The onion (Allium cepa L. R2R3-MYB gene MYB1 regulates anthocyanin biosynthesis

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    Kathy Schwinn

    2016-12-01

    Full Text Available Bulb colour is an important consumer trait for onion (Allium cepa L., Allioideae, Asparagales. The bulbs accumulate a range of flavonoid compounds, including anthocyanins (red, flavonols (pale yellow and chalcones (bright yellow. Flavonoid regulation is poorly characterised in onion and in other plants belonging to the Asparagales, despite being a major plant order containing many important crop and ornamental species. R2R3-MYB transcription factors associated with the regulation of distinct branches of the flavonoid pathway were isolated from onion. These belonged to sub-groups (SGs that commonly activate anthocyanin (SG6, MYB1 or flavonol (SG7, MYB29 production, or repress phenylpropanoid/flavonoid synthesis (SG4, MYB4, MYB5. MYB1 was demonstrated to be a positive regulator of anthocyanin biosynthesis by the induction of anthocyanin production in onion tissue when transiently overexpressd and by reduction of pigmentation when transiently repressed via RNAi. Furthermore, ectopic red pigmentation was observed in garlic (A. sativum L. plants stably transformed with a construct for co-overexpression of MYB1 and a bHLH partner. MYB1 also was able to complement the acyanic petal phenotype of a defined R2R3-MYB anthocyanin mutant in Antirrhinum majus of the asterid clade of eudicots. The availability of sequence information for flavonoid-related MYBs from onion enabled phylogenetic groupings to be determined across monocotyledonous and dicotyledonous species, including the identification of characteristic amino acid motifs. This analysis suggests that divergent evolution of the R2R3-MYB family has occurred between Poaceae/Orchidaceae and Allioideae species. The DNA sequences identified will be valuable for future analysis of classical flavonoid genetic loci in Allium crops and will assist the breeding of these important crop species.

  2. The Onion (Allium cepa L.) R2R3-MYB Gene MYB1 Regulates Anthocyanin Biosynthesis

    Science.gov (United States)

    Schwinn, Kathy E.; Ngo, Hanh; Kenel, Fernand; Brummell, David A.; Albert, Nick W.; McCallum, John A.; Pither-Joyce, Meeghan; Crowhurst, Ross N.; Eady, Colin; Davies, Kevin M.

    2016-01-01

    Bulb color is an important consumer trait for onion (Allium cepa L., Allioideae, Asparagales). The bulbs accumulate a range of flavonoid compounds, including anthocyanins (red), flavonols (pale yellow), and chalcones (bright yellow). Flavonoid regulation is poorly characterized in onion and in other plants belonging to the Asparagales, despite being a major plant order containing many important crop and ornamental species. R2R3-MYB transcription factors associated with the regulation of distinct branches of the flavonoid pathway were isolated from onion. These belonged to sub-groups (SGs) that commonly activate anthocyanin (SG6, MYB1) or flavonol (SG7, MYB29) production, or repress phenylpropanoid/flavonoid synthesis (SG4, MYB4, MYB5). MYB1 was demonstrated to be a positive regulator of anthocyanin biosynthesis by the induction of anthocyanin production in onion tissue when transiently overexpressed and by reduction of pigmentation when transiently repressed via RNAi. Furthermore, ectopic red pigmentation was observed in garlic (Allium sativum L.) plants stably transformed with a construct for co-overexpression of MYB1 and a bHLH partner. MYB1 also was able to complement the acyanic petal phenotype of a defined R2R3-MYB anthocyanin mutant in Antirrhinum majus of the asterid clade of eudicots. The availability of sequence information for flavonoid-related MYBs from onion enabled phylogenetic groupings to be determined across monocotyledonous and dicotyledonous species, including the identification of characteristic amino acid motifs. This analysis suggests that divergent evolution of the R2R3-MYB family has occurred between Poaceae/Orchidaceae and Allioideae species. The DNA sequences identified will be valuable for future analysis of classical flavonoid genetic loci in Allium crops and will assist the breeding of these important crop species. PMID:28018399

  3. The Onion (Allium cepa L.) R2R3-MYB Gene MYB1 Regulates Anthocyanin Biosynthesis.

    Science.gov (United States)

    Schwinn, Kathy E; Ngo, Hanh; Kenel, Fernand; Brummell, David A; Albert, Nick W; McCallum, John A; Pither-Joyce, Meeghan; Crowhurst, Ross N; Eady, Colin; Davies, Kevin M

    2016-01-01

    Bulb color is an important consumer trait for onion ( Allium cepa L., Allioideae, Asparagales). The bulbs accumulate a range of flavonoid compounds, including anthocyanins (red), flavonols (pale yellow), and chalcones (bright yellow). Flavonoid regulation is poorly characterized in onion and in other plants belonging to the Asparagales, despite being a major plant order containing many important crop and ornamental species. R2R3-MYB transcription factors associated with the regulation of distinct branches of the flavonoid pathway were isolated from onion. These belonged to sub-groups (SGs) that commonly activate anthocyanin (SG6, MYB1) or flavonol (SG7, MYB29) production, or repress phenylpropanoid/flavonoid synthesis (SG4, MYB4, MYB5). MYB1 was demonstrated to be a positive regulator of anthocyanin biosynthesis by the induction of anthocyanin production in onion tissue when transiently overexpressed and by reduction of pigmentation when transiently repressed via RNAi. Furthermore, ectopic red pigmentation was observed in garlic ( Allium sativum L.) plants stably transformed with a construct for co-overexpression of MYB1 and a bHLH partner. MYB1 also was able to complement the acyanic petal phenotype of a defined R2R3-MYB anthocyanin mutant in Antirrhinum maju s of the asterid clade of eudicots. The availability of sequence information for flavonoid-related MYBs from onion enabled phylogenetic groupings to be determined across monocotyledonous and dicotyledonous species, including the identification of characteristic amino acid motifs. This analysis suggests that divergent evolution of the R2R3-MYB family has occurred between Poaceae/Orchidaceae and Allioideae species. The DNA sequences identified will be valuable for future analysis of classical flavonoid genetic loci in Allium crops and will assist the breeding of these important crop species.

  4. Genome-Wide Identification of R2R3-MYB Genes and Expression Analyses During Abiotic Stress in Gossypium raimondii

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    He, Qiuling; Jones, Don C.; Li, Wei; Xie, Fuliang; Ma, Jun; Sun, Runrun; Wang, Qinglian; Zhu, Shuijin; Zhang, Baohong

    2016-01-01

    The R2R3-MYB is one of the largest families of transcription factors, which have been implicated in multiple biological processes. There is great diversity in the number of R2R3-MYB genes in different plants. However, there is no report on genome-wide characterization of this gene family in cotton. In the present study, a total of 205 putative R2R3-MYB genes were identified in cotton D genome (Gossypium raimondii), that are much larger than that found in other cash crops with fully sequenced genomes. These GrMYBs were classified into 13 groups with the R2R3-MYB genes from Arabidopsis and rice. The amino acid motifs and phylogenetic tree were predicted and analyzed. The sequences of GrMYBs were distributed across 13 chromosomes at various densities. The results showed that the expansion of the G. Raimondii R2R3-MYB family was mainly attributable to whole genome duplication and segmental duplication. Moreover, the expression pattern of 52 selected GrMYBs and 46 GaMYBs were tested in roots and leaves under different abiotic stress conditions. The results revealed that the MYB genes in cotton were differentially expressed under salt and drought stress treatment. Our results will be useful for determining the precise role of the MYB genes during stress responses with crop improvement. PMID:27009386

  5. Expression of the sweetpotato R2R3-type IbMYB1a gene induces anthocyanin accumulation in Arabidopsis.

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    Chu, Hyosub; Jeong, Jae Cheol; Kim, Wook-Jin; Chung, Dong Min; Jeon, Hyo Kon; Ahn, Young Ock; Kim, Sun Ha; Lee, Haeng-Soon; Kwak, Sang-Soo; Kim, Cha Young

    2013-06-01

    R2R3-type MYB transcription factors (TFs) play important roles in transcriptional regulation of anthocyanins. The R2R3-type IbMYB1 is known to be a key regulator of anthocyanin biosynthesis in the storage roots of sweetpotato. We previously showed that transient expression of IbMYB1a led to anthocyanin pigmentation in tobacco leaves. In this article, we generated transgenic Arabidopsis plants expressing the IbMYB1a gene under the control of CaMV 35S promoter, and the sweetpotato SPO and SWPA2 promoters. Overexpression of IbMYBa in transgenic Arabidopsis produced strong anthocyanin pigmentation in seedlings and generated a deep purple color in leaves, stems and seeds. Reverse transcription-polymerase chain reaction analysis showed that IbMYB1a expression induced upregulation of several structural genes in the anthocyanin biosynthetic pathway, including 4CL, CHI, F3'H, DFR, AGT, AAT and GST. Furthermore, overexpression of IbMYB1a led to enhanced expression of the AtTT8 (bHLH) and PAP1/AtMYB75 genes. high-performance liquid chromatography analysis revealed that IbMYB1a expression led to the production of cyanidin as a major core molecule of anthocyanidins in Arabidopsis, as occurs in the purple leaves of sweetpotato (cv. Sinzami). This result shows that the IbMYB1a TF is sufficient to induce anthocyanin accumulation in seedlings, leaves, stems and seeds of Arabidopsis plants. Copyright © Physiologia Plantarum 2012.

  6. Three R2R3 MYB transcription factor genes from Capsicum annuum ...

    African Journals Online (AJOL)

    Jane

    2011-08-08

    Aug 8, 2011 ... between plants and microbes, and in male fertility of some species .... (Gerbera hybrid, CAD87010), AmROSEA1 (Antirrhinum majus,ABB83826), ..... MYB26 results in male sterility due to non-dehiscent anthers. Plant J.

  7. Conifer R2R3-MYB transcription factors: sequence analyses and gene expression in wood-forming tissues of white spruce (Picea glauca

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    Grima-Pettenati Jacqueline

    2007-03-01

    Full Text Available Abstract Background Several members of the R2R3-MYB family of transcription factors act as regulators of lignin and phenylpropanoid metabolism during wood formation in angiosperm and gymnosperm plants. The angiosperm Arabidopsis has over one hundred R2R3-MYBs genes; however, only a few members of this family have been discovered in gymnosperms. Results We isolated and characterised full-length cDNAs encoding R2R3-MYB genes from the gymnosperms white spruce, Picea glauca (13 sequences, and loblolly pine, Pinus taeda L. (five sequences. Sequence similarities and phylogenetic analyses placed the spruce and pine sequences in diverse subgroups of the large R2R3-MYB family, although several of the sequences clustered closely together. We searched the highly variable C-terminal region of diverse plant MYBs for conserved amino acid sequences and identified 20 motifs in the spruce MYBs, nine of which have not previously been reported and three of which are specific to conifers. The number and length of the introns in spruce MYB genes varied significantly, but their positions were well conserved relative to angiosperm MYB genes. Quantitative RTPCR of MYB genes transcript abundance in root and stem tissues revealed diverse expression patterns; three MYB genes were preferentially expressed in secondary xylem, whereas others were preferentially expressed in phloem or were ubiquitous. The MYB genes expressed in xylem, and three others, were up-regulated in the compression wood of leaning trees within 76 hours of induction. Conclusion Our survey of 18 conifer R2R3-MYB genes clearly showed a gene family structure similar to that of Arabidopsis. Three of the sequences are likely to play a role in lignin metabolism and/or wood formation in gymnosperm trees, including a close homolog of the loblolly pine PtMYB4, shown to regulate lignin biosynthesis in transgenic tobacco.

  8. A R2R3-MYB Gene LfMYB113 is Responsible for Autumn Leaf Coloration in Formosan sweet gum (Liquidambar formosana Hance).

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    Wen, Chi-Hsiang; Chu, Fang-Hua

    2017-03-01

    The regulation of autumn leaf coloration in deciduous trees has long been an enigma. Due to the fact that different coloration phenotypes may be considered when planting, more understanding of the regulation mechanism is needed. In this study, a R2R3-MYB transcription factor gene LfMYB113 was identified from a subtropical deciduous tree species Formosan sweet gum (Liquidambar formosana Hance). The expression patterns of LfMYB113 in four selected phenotypes were different and were positively correlated with leaf anthocyanin content. In a 35S::LfMYB113 transgenic Nicotiana tabacum plant, both the early and late genes in the anthocyanin biosynthetic pathway were shown to be up-regulated. It was also shown that LfMYB113 can activate the promoter sequence of LfDFR1 and LfDFR2. Transient overexpression of LfMYB113 in Nicotiana benthamiana showed strong anthocyanin accumulation and pre-senescence; the latter was confirmed by up-regulation of senescence-associated genes. In addition, the activation of proLfSGR::YFP by LfMYB113 in transient experiments indicated that LfMYB113 may have a role in regulation of Chl degradation. To our knowledge, this is the first time a R2R3-MYB transcription factor has been functionally identified as one of the key regulators of autumn leaf coloration and autumn leaf senescence. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  9. An R2R3-MYB gene, LeAN2, positively regulated the thermo-tolerance in transgenic tomato.

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    Meng, Xia; Wang, Jie-Ru; Wang, Guo-Dong; Liang, Xiao-Qing; Li, Xiao-Dong; Meng, Qing-Wei

    2015-03-01

    LeAN2 is an anthocyanin-associated R2R3-MYB transcription factor, but little is known about its function in imparting thermo-tolerance to higher plants. To examine the function of LeAN2 in the regulation of heat stress in tomato, LeAN2 was isolated and transgenic tomato plants were obtained. Overexpression of LeAN2 under the control of the CaMV35S promoter in tomato induced the up-regulation of several structural genes in the anthocyanin biosynthetic pathway as well as anthocyanin accumulation in transgenic tomato plants. Transgenic tomato plants showed enhanced tolerance to heat stress by maintaining higher fresh weight (FW), net photosynthetic rate (Pn) and maximal photochemical efficiency of photosystem II (PSII) (Fv/Fm) compared with wild-type (WT) plants. Furthermore, transgenic plants showed higher non-enzymatic antioxidant activity, lower levels of reactive oxygen species (ROS), and higher contents of D1 protein than that in WT plants under heat stress. These results indicate that LeAN2 had an important function in heat stress resistance. Copyright © 2014 Elsevier GmbH. All rights reserved.

  10. Activation of anthocyanin biosynthesis by expression of the radish R2R3-MYB transcription factor gene RsMYB1.

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    Lim, Sun-Hyung; Song, Ji-Hye; Kim, Da-Hye; Kim, Jae Kwang; Lee, Jong-Yeol; Kim, Young-Mi; Ha, Sun-Hwa

    2016-03-01

    RsMYB1, a MYB TF of red radish origin, was characterized as a positive regulator to transcriptionally activate the anthocyanin biosynthetic machinery by itself in Arabidopsis and tobacco plants. Anthocyanins, providing the bright red-orange to blue-violet colors, are flavonoid-derived pigments with strong antioxidant activity that have benefits for human health. We isolated RsMYB1, which encodes an R2R3-MYB transcription factor (TF), from red radish plants (Raphanus sativus L.) that accumulate high levels of anthocyanins. RsMYB1 shows higher expression in red radish than in common white radish, in both leaves and roots, at different growth stages. Consistent with RsMYB1 function as an anthocyanin-promoting TF, red radishes showed higher expression of all six anthocyanin biosynthetic and two anthocyanin regulatory genes. Transient expression of RsMYB1 in tobacco showed that RsMYB1 is a positive regulator of anthocyanin production with better efficiency than the basic helix-loop-helix (bHLH) TF gene B-Peru. Also, the synergistic effect of RsMYB1 with B-Peru was larger than the effect of the MYB TF gene mPAP1D with B-peru. Arabidopsis plants stably expressing RsMYB1 produced red pigmentation throughout the plant, accompanied by up-regulation of the six structural and two regulatory genes for anthocyanin production. This broad transcriptional activation of anthocyanin biosynthetic machinery in Arabidopsis included up-regulation of TRANSPARENT TESTA8, which encodes a bHLH TF. These results suggest that overexpression of RsMYB1 promotes anthocyanin production by triggering the expression of endogenous bHLH genes as potential binding partners for RsMYB1. In addition, RsMYB1-overexpressing Arabidopsis plants had a higher antioxidant capacity than did non-transgenic control plants. Taken together, RsMYB1 is an actively positive regulator for anthocyanins biosynthesis in radish plants and it might be one of the best targets for anthocyanin production by single gene

  11. A systems biology approach identifies a R2R3 MYB gene subfamily with distinct and overlapping functions in regulation of aliphatic glucosinolates.

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    Ida Elken Sønderby

    Full Text Available BACKGROUND: Glucosinolates are natural metabolites in the order Brassicales that defend plants against both herbivores and pathogens and can attract specialized insects. Knowledge about the genes controlling glucosinolate regulation is limited. Here, we identify three R2R3 MYB transcription factors regulating aliphatic glucosinolate biosynthesis in Arabidopsis by combining several systems biology tools. METHODOLOGY/PRINCIPAL FINDINGS: MYB28 was identified as a candidate regulator of aliphatic glucosinolates based on its co-localization within a genomic region controlling variation both in aliphatic glucosinolate content (metabolite QTL and in transcript level for genes involved in the biosynthesis of aliphatic glucosinolates (expression QTL, as well as its co-expression with genes in aliphatic glucosinolate biosynthesis. A phylogenetic analysis with the R2R3 motif of MYB28 showed that it and two homologues, MYB29 and MYB76, were members of an Arabidopsis-specific clade that included three characterized regulators of indole glucosinolates. Over-expression of the individual MYB genes showed that they all had the capacity to increase the production of aliphatic glucosinolates in leaves and seeds and induce gene expression of aliphatic biosynthetic genes within leaves. Analysis of leaves and seeds of single knockout mutants showed that mutants of MYB29 and MYB76 have reductions in only short-chained aliphatic glucosinolates whereas a mutant in MYB28 has reductions in both short- and long-chained aliphatic glucosinolates. Furthermore, analysis of a double knockout in MYB28 and MYB29 identified an emergent property of the system since the absence of aliphatic glucosinolates in these plants could not be predicted by the chemotype of the single knockouts. CONCLUSIONS/SIGNIFICANCE: It seems that these cruciferous-specific MYB regulatory genes have evolved both overlapping and specific regulatory capacities. This provides a unique system within which to

  12. Ectopic Expression of the Coleus R2R3 MYB-Type Proanthocyanidin Regulator Gene SsMYB3 Alters the Flower Color in Transgenic Tobacco.

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    Qinlong Zhu

    Full Text Available Proanthocyanidins (PAs play an important role in plant disease defense and have beneficial effects on human health. We isolated and characterized a novel R2R3 MYB-type PA-regulator SsMYB3 from a well-known ornamental plant, coleus (Solenostemon scutellarioides, to study the molecular regulation of PAs and to engineer PAs biosynthesis. The expression level of SsMYB3 was correlated with condensed tannins contents in various coleus tissues and was induced by wounding and light. A complementation test in the Arabidopsis tt2 mutant showed that SsMYB3 could restore the PA-deficient seed coat phenotype and activated expression of the PA-specific gene ANR and two related genes, DFR and ANS. In yeast two-hybrid assays, SsMYB3 interacted with the Arabidopsis AtTT8 and AtTTG1 to reform the ternary transcriptional complex, and also interacted with two tobacco bHLH proteins (NtAn1a and NtJAF13-1 and a WD40 protein, NtAn11-1. Ectopic overexpression of SsMYB3 in transgenic tobacco led to almost-white flowers by greatly reducing anthocyanin levels and enhancing accumulation of condensed tannins. This overexpression of SsMYB3 upregulated the key PA genes (NtLAR and NtANR and late anthocyanin structural genes (NtDFR and NtANS, but downregulated the expression of the final anthocyanin gene NtUFGT. The formative SsMYB3-complex represses anthocyanin accumulation by directly suppressing the expression of the final anthocyanin structural gene NtUFGT, through competitive inhibition or destabilization of the endogenous NtAn2-complex formation. These results suggested that SsMYB3 may form a transcription activation complex to regulate PA biosynthesis in the Arabidopsis tt2 mutant and transgenic tobacco. Our findings suggest that SsMYB3 is involved in the regulation of PA biosynthesis in coleus and has the potential as a molecular tool for manipulating biosynthesis of PAs in fruits and other crops using metabolic engineering.

  13. Analysis of the grape MYB R2R3 subfamily reveals expanded wine quality-related clades and conserved gene structure organization across Vitis and Arabidopsis genomes

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    Matus, José Tomás; Aquea, Felipe; Arce-Johnson, Patricio

    2008-01-01

    Background The MYB superfamily constitutes the most abundant group of transcription factors described in plants. Members control processes such as epidermal cell differentiation, stomatal aperture, flavonoid synthesis, cold and drought tolerance and pathogen resistance. No genome-wide characterization of this family has been conducted in a woody species such as grapevine. In addition, previous analysis of the recently released grape genome sequence suggested expansion events of several gene families involved in wine quality. Results We describe and classify 108 members of the grape R2R3 MYB gene subfamily in terms of their genomic gene structures and similarity to their putative Arabidopsis thaliana orthologues. Seven gene models were derived and analyzed in terms of gene expression and their DNA binding domain structures. Despite low overall sequence homology in the C-terminus of all proteins, even in those with similar functions across Arabidopsis and Vitis, highly conserved motif sequences and exon lengths were found. The grape epidermal cell fate clade is expanded when compared with the Arabidopsis and rice MYB subfamilies. Two anthocyanin MYBA related clusters were identified in chromosomes 2 and 14, one of which includes the previously described grape colour locus. Tannin related loci were also detected with eight candidate homologues in chromosomes 4, 9 and 11. Conclusion This genome wide transcription factor analysis in Vitis suggests that clade-specific grape R2R3 MYB genes are expanded while other MYB genes could be well conserved compared to Arabidopsis. MYB gene abundance, homology and orientation within particular loci also suggests that expanded MYB clades conferring quality attributes of grapes and wines, such as colour and astringency, could possess redundant, overlapping and cooperative functions. PMID:18647406

  14. Analysis of the grape MYB R2R3 subfamily reveals expanded wine quality-related clades and conserved gene structure organization across Vitis and Arabidopsis genomes

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    Arce-Johnson Patricio

    2008-07-01

    Full Text Available Abstract Background The MYB superfamily constitutes the most abundant group of transcription factors described in plants. Members control processes such as epidermal cell differentiation, stomatal aperture, flavonoid synthesis, cold and drought tolerance and pathogen resistance. No genome-wide characterization of this family has been conducted in a woody species such as grapevine. In addition, previous analysis of the recently released grape genome sequence suggested expansion events of several gene families involved in wine quality. Results We describe and classify 108 members of the grape R2R3 MYB gene subfamily in terms of their genomic gene structures and similarity to their putative Arabidopsis thaliana orthologues. Seven gene models were derived and analyzed in terms of gene expression and their DNA binding domain structures. Despite low overall sequence homology in the C-terminus of all proteins, even in those with similar functions across Arabidopsis and Vitis, highly conserved motif sequences and exon lengths were found. The grape epidermal cell fate clade is expanded when compared with the Arabidopsis and rice MYB subfamilies. Two anthocyanin MYBA related clusters were identified in chromosomes 2 and 14, one of which includes the previously described grape colour locus. Tannin related loci were also detected with eight candidate homologues in chromosomes 4, 9 and 11. Conclusion This genome wide transcription factor analysis in Vitis suggests that clade-specific grape R2R3 MYB genes are expanded while other MYB genes could be well conserved compared to Arabidopsis. MYB gene abundance, homology and orientation within particular loci also suggests that expanded MYB clades conferring quality attributes of grapes and wines, such as colour and astringency, could possess redundant, overlapping and cooperative functions.

  15. Genome-wide identification, functional prediction, and evolutionary analysis of the R2R3-MYB superfamily in Brassica napus.

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    Hajiebrahimi, Ali; Owji, Hajar; Hemmati, Shiva

    2017-10-01

    R2R3-MYB transcription factors (TFs) have been shown to play important roles in plants, including in development and in various stress conditions. Phylogenetic analysis showed the presence of 249 R2R3-MYB TFs in Brassica napus, called BnaR2R3-MYB TFs, clustered into 38 clades. BnaR2R3-MYB TFs were distributed on 19 chromosomes of B. napus. Sixteen gene clusters were identified. BnaR2R3-MYB TFs were characterized by motif prediction, gene structure analysis, and gene ontology. Evolutionary analysis revealed that BnaR2R3-MYB TFs are mainly formed as a result of whole-genome duplication. Orthologs and paralogs of BnaR2R3-MYB TFs were identified in B. napus, B. rapa, B. oleracea, and Arabidopsis thaliana using synteny-based methods. Purifying selection was pervasive within R2R3-MYB TFs. K n /K s values lower than 0.3 indicated that BnaR2R3-MYB TFs are being functionally converged. The role of gene conversion in the formation of BnaR2R3-MYB TFs was significant. Cis-regulatory elements in the upstream regions of BnaR2R3-MYB genes, miRNA targeting BnaR2R3MYB TFs, and post translational modifications were identified. Digital expression data revealed that BnaR2R3-MYB genes were highly expressed in the roots and under high salinity treatment after 24 h. BnaMYB21, BnaMYB141, and BnaMYB148 have been suggested for improving salt-tolerant B. napus. BnaR2R3-MYB genes were mostly up regulated on the 14th day post inoculation with Leptosphaeria biglobosa and L. maculan. BnaMYB150 is a candidate for increased tolerance to Leptospheria in B. napus.

  16. Ectopic Expression of the Grape Hyacinth (Muscari armeniacum R2R3-MYB Transcription Factor Gene, MaAN2, Induces Anthocyanin Accumulation in Tobacco

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    Kaili Chen

    2017-06-01

    Full Text Available Anthocyanins are responsible for the different colors of ornamental plants. Grape hyacinth (Muscari armeniacum, a monocot plant with bulbous flowers, is popular for its fascinating blue color. In the present study, we functionally characterized an R2R3-MYB transcription factor gene MaAN2 from M. armeniacum. Our results indicated that MaAN2 participates in controlling anthocyanin biosynthesis. Sequence alignment and phylogenetic analysis suggested that MaAN2 belonged to the R2R3-MYB family AN2 subgroup. The anthocyanin accumulation of grape hyacinth flowers was positively correlated with the expression of MaAN2. And the transcriptional expression of MaAN2 was also consistent with that of M. armeniacum dihydroflavonol 4-reductase (MaDFR and M. armeniacum anthocyanidin synthase (MaANS in flowers. A dual luciferase transient expression assay indicated that when MaAN2 was co-inflitrated with Arabidopsis thaliana TRANSPARENT TESTA8 (AtTT8, it strongly activated the promoters of MaDFR and MaANS, but not the promoters of M. armeniacum chalcone synthase (MaCHS, M. armeniacum chalcone isomerase (MaCHI, and M. armeniacum flavanone 3-hydroxylase (MaF3H. Bimolecular fluorescence complementation assay confirmed that MaAN2 interacted with AtTT8 in vivo. The ectopic expression of MaAN2 in Nicotiana tabacum resulted in obvious red coloration of the leaves and much redder flowers. Almost all anthocyanin biosynthetic genes were remarkably upregulated in the leaves and flowers of the transgenic tobacco, and NtAn1a and NtAn1b (two basic helix–loop–helix anthocyanin regulatory genes were highly expressed in the transformed leaves, compared to the empty vector transformants. Collectively, our results suggest that MaAN2 plays a role in anthocyanin biosynthesis.

  17. A R2R3-MYB transcription factor gene in common wheat (namely TaMYBsm1) involved in enhancement of drought tolerance in transgenic Arabidopsis.

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    Li, Meng-Jun; Qiao, Yu; Li, Ya-Qing; Shi, Zhan-Liang; Zhang, Nan; Bi, Cai-Li; Guo, Jin-Kao

    2016-11-01

    We isolated the TaMYBsm1 genes, encoding R2R3-type MYB proteins in common wheat, aimed to uncover the possible molecular mechanisms related to drought response. The TaMYBsm1 genes, TaMYBsm1-A, TaMYBsm1-B and TaMYBsm1-D, were isolated and analyzed from the common wheat cultivar Shimai 15. Their expression patterns under PEG 6000 and mannitol were monitored by semi-quantitative RT-PCR and β-glucuronidase (Gus) assay. The function of TaMYBsm1-D under drought stress in transgenic Arabidopsis plants was investigated, and the germination rate, water loss rate, as well as the proline and malondialdehyde (MDA) content were compared with that in wild type (WT) plants. The expression of three downstream genes (DREB2A, P5CS1 and RD29A) in TaMYBsm1-D transgenic plants was analyzed. The R2R3-MYB domains of the MYBsm1 proteins were highly conserved in plants. In addition, the TaMYBsm1 proteins were targeted to the nucleus and contained transcriptional activation domains (TADs). Gus assay and semi-quantitative RT-PCR analysis demonstrated that the TaMYBsm1 genes were up-regulated when the wheat was treated by PEG and mannitol. Compared with WT plants, the germination rates were much higher, but the water loss rates were much lower in TaMYBsm1-D overexpression plants. TaMYBsm1-D transgenic plants showed distinct higher proline contents but a lower MDA content than the WT plants. The three downstream genes were highly expressed in TaMYBsm1-D transgenic plants. We concluded from these results that TaMYBsm1 genes play an important role in plant drought stress tolerance through up-regulation of DREB2A, P5CS1 and RD29A. The increase of proline content and decrease of MDA content may also be involved in the drought response.

  18. Genome-wide identification and characterization of R2R3MYB family in Rosaceae.

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    González, Máximo; Carrasco, Basilio; Salazar, Erika

    2016-09-01

    Transcription factors R2R3MYB family have been associated with the control of secondary metabolites, development of structures, cold tolerance and response to biotic and abiotic stress, among others. In recent years, genomes of Rosaceae botanical family are available. Although this information has been used to study the karyotype evolution of these species from an ancestral genome, there are no studies that treat the evolution and diversity of gene families present in these species or in the botanical family. Here we present the first comparative study of the R2R3MYB subfamily of transcription factors in three species of Rosaceae family (Malus domestica, Prunus persica and Fragaria vesca). We described 186, 98 and 86 non-redundant gene models for apple, peach and strawberry, respectively. In this research, we analyzed the intron-exon structure and genomic distribution of R2R3MYB families mentioned above. The phylogenetic comparisons revealed putative functions of some R2R3MYB transcription factors. This analysis found 44 functional subgroups, seven of which were unique for Rosaceae. In addition, our results showed a highly collinearity among some genes revealing the existence of conserved gene models between the three species studied. Although some gene models in these species have been validated under several approaches, more research in the Rosaceae family is necessary to determine gene expression patterns in specific tissues and development stages to facilitate understanding of the regulatory and biochemical mechanism in this botanical family.

  19. Multiple R2R3-MYB transcription factors involved in the regulation of anthocyanin accumulation in peach flower

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    Hui Zhou

    2016-10-01

    Full Text Available Anthocyanin accumulation is responsible for flower coloration in peach. Here, we report the identification and functional characterization of eight flavonoid-related R2R3-MYB transcription factors, designated PpMYB10.2, PpMYB9, PpMYBPA1, Peace, PpMYB17, PpMYB18, PpMYB19 and PpMYB20, respectively, in peach flower transcriptome. PpMYB10.2 and PpMYB9 are able to activate transcription of anthocyanin biosynthetic genes, whilst PpMYBPA1 and Peace have a strong activation on the promoters of proanthocyanin (PA biosynthetic genes. PpMYB17-20 show a strong repressive effect on transcription of flavonoid pathway genes such as DFR. These results indicate that anthocyanin accumulation in peach flower is coordinately regulated by a set of R2R3-MYB genes. In addition, PpMYB9 and PpMYB10.2 are closely related but separated into two groups, designated MYB9 and MYB10, respectively. PpMYB9 shows a strong activation on the PpUGT78A2 promoter, but with no effect on the promoter of PpUGT78B (commonly called PpUFGT in previous studies. In contrast, PpMYB10.2 is able to activate the PpUFGT promoter, but not for the PpUGT78A2 promoter. Unlike the MYB10 gene that is universally present in plants, the MYB9 gene is lost in most dicot species. Therefore, the PpMYB9 gene represents a novel group of anthocyanin-related MYB activators, which may have diverged in function from the MYB10 genes. Our study will aid in understanding the complex mechanism regulating floral pigmentation in peach and functional divergence of the R2R3-MYB gene family in plants.

  20. An R2R3-MYB transcription factor, OjMYB1, functions in anthocyanin biosynthesis in Oenanthe javanica.

    Science.gov (United States)

    Feng, Kai; Xu, Zhi-Sheng; Que, Feng; Liu, Jie-Xia; Wang, Feng; Xiong, Ai-Sheng

    2018-02-01

    This study showed that an R2R3-MYB transcription factor, OjMYB1, is involved in anthocyanin biosynthesis and accumulation in Oenanthe javanica. Anthocyanins can be used as safe natural food colorants, obtained from many plants. R2R3-MYB transcription factors (TFs) play important roles in anthocyanins biosynthesis during plant development. Oenanthe javanica is a popular vegetable with high nutritional values and numerous medical functions. O. javanica has purple petioles that are mainly due to anthocyanins accumulation. In the present study, the gene encoding an R2R3-MYB TF, OjMYB1, was isolated from purple O. javanica. Sequencing results showed that OjMYB1 contained a 912-bp open reading frame encoding 303 amino acids. Sequence alignments revealed that OjMYB1 contained bHLH-interaction motif ([DE]Lx2[RK]x3Lx6Lx3R) and ANDV motif ([A/G]NDV). Phylogenetic analysis indicated that the OjMYB1 classified into the anthocyanins biosynthesis clade. Subcellular localization assay showed that OjMYB1 was a nuclear protein in vivo. The heterologous expression of OjMYB1 in Arabidopsis could enhance the anthocyanins content and up-regulate the expression levels of the structural genes-related anthocyanins biosynthesis. Yeast two-hybrid assay indicated that OjMYB1 could interact with AtTT8 and AtEGL3 proteins. Enzymatic analysis revealed that overexpression of OjMYB1 gene up-regulated the enzyme activity of 3-O-glycosyltransferase encoded by AtUGT78D2 in transgenic Arabidopsis. Our results provided a comprehensive understanding of the structure and function of OjMYB1 TF in O. javanica.

  1. A R2R3-MYB transcription factor from Epimedium sagittatum regulates the flavonoid biosynthetic pathway.

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    Wenjun Huang

    Full Text Available Herba epimedii (Epimedium, a traditional Chinese medicine, has been widely used as a kidney tonic and antirheumatic medicine for thousands of years. The bioactive components in herba epimedii are mainly prenylated flavonol glycosides, end-products of the flavonoid pathway. Epimedium species are also used as garden plants due to the colorful flowers and leaves. Many R2R3-MYB transcription factors (TFs have been identified to regulate the flavonoid and anthocyanin biosynthetic pathways. However, little is known about the R2R3-MYB TFs involved in regulation of the flavonoid pathway in Epimedium. Here, we reported the isolation and functional characterization of the first R2R3-MYB TF (EsMYBA1 from Epimedium sagittatum (Sieb. Et Zucc. Maxim. Conserved domains and phylogenetic analysis showed that EsMYBA1 belonged to the subgroup 6 clade (anthocyanin-related MYB clade of R2R3-MYB family, which includes Arabidopsis AtPAP1, apple MdMYB10 and legume MtLAP1. EsMYBA1 was preferentially expressed in leaves, especially in red leaves that contain higher content of anthocyanin. Alternative splicing of EsMYBA1 resulted in three transcripts and two of them encoded a MYB-related protein. Yeast two-hybrid and transient luciferase expression assay showed that EsMYBA1 can interact with several bHLH regulators of the flavonoid pathway and activate the promoters of dihydroflavonol 4-reductase (DFR and anthocyanidin synthase (ANS. In both transgenic tobacco and Arabidopsis, overexpression of EsMYBA1 induced strong anthocyanin accumulation in reproductive and/or vegetative tissues via up-regulation of the main flavonoid-related genes. Furthermore, transient expression of EsMYBA1 in E. sagittatum leaves by Agrobacterium infiltration also induced anthocyanin accumulation in the wounded area. This first functional characterization of R2R3-MYB TFs in Epimedium species will promote further studies of the flavonoid biosynthesis and regulation in medicinal plants.

  2. A R2R3-MYB transcription factor from Epimedium sagittatum regulates the flavonoid biosynthetic pathway.

    Science.gov (United States)

    Huang, Wenjun; Sun, Wei; Lv, Haiyan; Luo, Ming; Zeng, Shaohua; Pattanaik, Sitakanta; Yuan, Ling; Wang, Ying

    2013-01-01

    Herba epimedii (Epimedium), a traditional Chinese medicine, has been widely used as a kidney tonic and antirheumatic medicine for thousands of years. The bioactive components in herba epimedii are mainly prenylated flavonol glycosides, end-products of the flavonoid pathway. Epimedium species are also used as garden plants due to the colorful flowers and leaves. Many R2R3-MYB transcription factors (TFs) have been identified to regulate the flavonoid and anthocyanin biosynthetic pathways. However, little is known about the R2R3-MYB TFs involved in regulation of the flavonoid pathway in Epimedium. Here, we reported the isolation and functional characterization of the first R2R3-MYB TF (EsMYBA1) from Epimedium sagittatum (Sieb. Et Zucc.) Maxim. Conserved domains and phylogenetic analysis showed that EsMYBA1 belonged to the subgroup 6 clade (anthocyanin-related MYB clade) of R2R3-MYB family, which includes Arabidopsis AtPAP1, apple MdMYB10 and legume MtLAP1. EsMYBA1 was preferentially expressed in leaves, especially in red leaves that contain higher content of anthocyanin. Alternative splicing of EsMYBA1 resulted in three transcripts and two of them encoded a MYB-related protein. Yeast two-hybrid and transient luciferase expression assay showed that EsMYBA1 can interact with several bHLH regulators of the flavonoid pathway and activate the promoters of dihydroflavonol 4-reductase (DFR) and anthocyanidin synthase (ANS). In both transgenic tobacco and Arabidopsis, overexpression of EsMYBA1 induced strong anthocyanin accumulation in reproductive and/or vegetative tissues via up-regulation of the main flavonoid-related genes. Furthermore, transient expression of EsMYBA1 in E. sagittatum leaves by Agrobacterium infiltration also induced anthocyanin accumulation in the wounded area. This first functional characterization of R2R3-MYB TFs in Epimedium species will promote further studies of the flavonoid biosynthesis and regulation in medicinal plants.

  3. An R2R3 MYB transcription factor associated with regulation of the anthocyanin biosynthetic pathway in Rosaceae (on linr)

    OpenAIRE

    Wang, Kui-Lin; Bolitho, Karen; Grafton, Karryn; Kortstee, A.J.; Karunairetnam, Sakuntala; McGhie, T.K.; Espley, R.V.; Hellens, R.P.; Allan, A.C.

    2010-01-01

    Background - The control of plant anthocyanin accumulation is via transcriptional regulation of the genes encoding the biosynthetic enzymes. A key activator appears to be an R2R3 MYB transcription factor. In apple fruit, skin anthocyanin levels are controlled by a gene called MYBA or MYB1, while the gene determining fruit flesh and foliage anthocyanin has been termed MYB10. In order to further understand tissue-specific anthocyanin regulation we have isolated orthologous MYB genes from all th...

  4. An R2R3 MYB transcription factor associated with regulation of the anthocyanin biosynthetic pathway in Rosaceae (on linr)

    NARCIS (Netherlands)

    Wang, Kui-Lin; Bolitho, Karen; Grafton, Karryn; Kortstee, A.J.; Karunairetnam, Sakuntala; McGhie, T.K.; Espley, R.V.; Hellens, R.P.; Allan, A.C.

    2010-01-01

    Background - The control of plant anthocyanin accumulation is via transcriptional regulation of the genes encoding the biosynthetic enzymes. A key activator appears to be an R2R3 MYB transcription factor. In apple fruit, skin anthocyanin levels are controlled by a gene called MYBA or MYB1, while the

  5. Identification of a R2R3-MYB gene regulating anthocyanin biosynthesis and relationships between its variation and flower color difference in lotus (Nelumbo Adans.

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    Shan-Shan Sun

    2016-09-01

    Full Text Available The lotus (Nelumbonaceae: Nelumbo Adans. is a highly desired ornamental plant, comprising only two extant species, the sacred lotus (N. nucifera Gaerten. with red flowers and the American lotus (N. lutea Willd. with yellow flowers. Flower color is the most obvious difference of two species. To better understand the mechanism of flower color differentiation, the content of anthocyanins and the expression levels of four key structural genes (e.g., DFR, ANS, UFGT and GST were analyzed in two species. Our results revealed that anthocyanins were detected in red flowers, not yellow flowers. Expression analysis showed that no transcripts of GST gene and low expression level of three UFGT genes were detected in yellow flowers. In addition, three regulatory genes (NnMYB5, NnbHLH1 and NnTTG1 were isolated from red flowers and showed a high similarity to corresponding regulatory genes of other species. Sequence analysis of MYB5, bHLH1 and TTG1 in two species revealed striking differences in coding region and promoter region of MYB5 gene. Population analysis identified three MYB5 variants in Nelumbo: a functional allele existed in red flowers and two inactive forms existed in yellow flowers. This result revealed that there was an association between allelic variation in MYB5 gene and flower color difference. Yeast two-hybrid experiments showed that NnMYB5 interacts with NnbHLH1, NlbHLH1 and NnTTG1, and NnTTG1 also interacts with NnbHLH1 and NlbHLH1. The over-expression of NnMYB5 led to anthocyanin accumulation in immature seeds and flower stalks and up-regulation of expression of TT19 in Arabidopsis. Therefore, NnMYB5 is a transcription activator of anthocyanin synthesis. This study helps to elucidate the function of NnMYB5 and will contribute to clarify the mechanism of flower coloration and genetic engineering of flower color in lotus.

  6. Interactions between the R2R3-MYB transcription factor, AtMYB61, and target DNA binding sites.

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    Michael B Prouse

    Full Text Available Despite the prominent roles played by R2R3-MYB transcription factors in the regulation of plant gene expression, little is known about the details of how these proteins interact with their DNA targets. For example, while Arabidopsis thaliana R2R3-MYB protein AtMYB61 is known to alter transcript abundance of a specific set of target genes, little is known about the specific DNA sequences to which AtMYB61 binds. To address this gap in knowledge, DNA sequences bound by AtMYB61 were identified using cyclic amplification and selection of targets (CASTing. The DNA targets identified using this approach corresponded to AC elements, sequences enriched in adenosine and cytosine nucleotides. The preferred target sequence that bound with the greatest affinity to AtMYB61 recombinant protein was ACCTAC, the AC-I element. Mutational analyses based on the AC-I element showed that ACC nucleotides in the AC-I element served as the core recognition motif, critical for AtMYB61 binding. Molecular modelling predicted interactions between AtMYB61 amino acid residues and corresponding nucleotides in the DNA targets. The affinity between AtMYB61 and specific target DNA sequences did not correlate with AtMYB61-driven transcriptional activation with each of the target sequences. CASTing-selected motifs were found in the regulatory regions of genes previously shown to be regulated by AtMYB61. Taken together, these findings are consistent with the hypothesis that AtMYB61 regulates transcription from specific cis-acting AC elements in vivo. The results shed light on the specifics of DNA binding by an important family of plant-specific transcriptional regulators.

  7. Functional Characterization of a Novel R2R3-MYB Transcription Factor Modulating the Flavonoid Biosynthetic Pathway from Epimedium sagittatum

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    Wenjun Huang

    2017-07-01

    Full Text Available Epimedium species have been widely used both as traditional Chinese medicinal plants and ornamental perennials. Both flavonols, acting as the major bioactive components (BCs and anthocyanins, predominantly contributing to the color diversity of Epimedium flowers belong to different classes of flavonoids. It is well-acknowledged that flavonoid biosynthetic pathway is predominantly regulated by R2R3-MYB transcription factor (TF as well as bHLH TF and WD40 protein at the transcriptional level. MYB TFs specifically regulating anthocyanin or flavonol biosynthetic pathway have been already isolated and functionally characterized from Epimedium sagittatum, but a R2R3-MYB TF involved in regulating both these two pathways has not been functionally characterized to date in Epimedium plants. In this study, we report the functional characterization of EsMYB9, a R2R3-MYB TF previously isolated from E. sagittatum. The previous study indicated that EsMYB9 belongs to a small subfamily of R2R3-MYB TFs containing grape VvMYB5a and VvMYB5b TFs, which regulate flavonoid biosynthetic pathway. The present studies show that overexpression of EsMYB9 in tobacco leads to increased transcript levels of flavonoid pathway genes and increased contents of anthocyanins and flavonols. Yeast two-hybrid assay indicates that the C-terminal region of EsMYB9 contributes to the autoactivation activity, and EsMYB9 interacts with EsTT8 or AtTT8 bHLH regulator. Transient reporter assay shows that EsMYB9 slightly activates the expression of EsCHS (chalcone synthase promoter in transiently transformed leaves of Nicotiana benthamiana, but the addition of AtTT8 or EsTT8 bHLH regulator strongly enhances the transcriptional activation of EsMYB9 against five promoters of the flavonoid pathway genes except EsFLS (flavonol synthase. In addition, co-transformation of EsMYB9 and EsTT8 in transiently transfected tobacco leaves strongly induces the expressions of flavonoid biosynthetic genes. The

  8. Anthocyanin biosynthesis in pears is regulated by a R2R3-MYB transcription factor PyMYB10.

    Science.gov (United States)

    Feng, Shouqian; Wang, Yanling; Yang, Song; Xu, Yuting; Chen, Xuesen

    2010-06-01

    Skin color is an important factor in pear breeding programs. The degree of red coloration is determined by the content and composition of anthocyanins. In plants, many MYB transcriptional factors are involved in regulating anthocyanin biosynthesis. In this study, a R2R3-MYB transcription factor gene, PyMYB10, was isolated from Asian pear (Pyrus pyrifolia) cv. 'Aoguan'. Sequence analysis suggested that the PyMYB10 gene was an ortholog of MdMYB10 gene, which regulates anthocyanin biosynthesis in red fleshed apple (Malus x domestica) cv. 'Red Field'. PyMYB10 was identified at the genomic level and had three exons, with its upstream sequence containing core sequences of cis-acting regulatory elements involved in light responsiveness. Fruit bagging showed that light could induce expression of PyMYB10 and anthocyanin biosynthesis. Quantitative real-time PCR revealed that PyMYB10 was predominantly expressed in pear skins, buds, and young leaves, and the level of transcription in buds was higher than in skin and young leaves. In ripening fruits, the transcription of PyMYB10 in the skin was positively correlated with genes in the anthocyanin pathway and with anthocyanin biosynthesis. In addition, the transcription of PyMYB10 and genes of anthocyanin biosynthesis were more abundant in red-skinned pear cultivars compared to blushed cultivars. Transgenic Arabidopsis plants overexpressing PyMYB10 exhibited ectopic pigmentation in immature seeds. The study suggested that PyMYB10 plays a role in regulating anthocyanin biosynthesis and the overexpression of PyMYB10 was sufficient to induce anthocyanin accumulation.

  9. An R2R3-type MYB transcription factor, GmMYB29, regulates isoflavone biosynthesis in soybean.

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    Shanshan Chu

    2017-05-01

    Full Text Available Isoflavones comprise a group of secondary metabolites produced almost exclusively by plants in the legume family, including soybean [Glycine max (L. Merr.]. They play vital roles in plant defense and have many beneficial effects on human health. Isoflavone content is a complex quantitative trait controlled by multiple genes, and the genetic mechanisms underlying isoflavone biosynthesis remain largely unknown. Via a genome-wide association study (GWAS, we identified 28 single nucleotide polymorphisms (SNPs that are significantly associated with isoflavone concentrations in soybean. One of these 28 SNPs was located in the 5'-untranslated region (5'-UTR of an R2R3-type MYB transcription factor, GmMYB29, and this gene was thus selected as a candidate gene for further analyses. A subcellular localization study confirmed that GmMYB29 was located in the nucleus. Transient reporter gene assays demonstrated that GmMYB29 activated the IFS2 (isoflavone synthase 2 and CHS8 (chalcone synthase 8 gene promoters. Overexpression and RNAi-mediated silencing of GmMYB29 in soybean hairy roots resulted in increased and decreased isoflavone content, respectively. Moreover, a candidate-gene association analysis revealed that 11 natural GmMYB29 polymorphisms were significantly associated with isoflavone contents, and regulation of GmMYB29 expression could partially contribute to the observed phenotypic variation. Taken together, these results provide important genetic insights into the molecular mechanisms underlying isoflavone biosynthesis in soybean.

  10. The Eucalyptus grandis R2R3-MYB transcription factor family: evidence for woody growth-related evolution and function.

    Science.gov (United States)

    Soler, Marçal; Camargo, Eduardo Leal Oliveira; Carocha, Victor; Cassan-Wang, Hua; San Clemente, Hélène; Savelli, Bruno; Hefer, Charles A; Paiva, Jorge A Pinto; Myburg, Alexander A; Grima-Pettenati, Jacqueline

    2015-06-01

    The R2R3-MYB family, one of the largest transcription factor families in higher plants, controls a wide variety of plant-specific processes including, notably, phenylpropanoid metabolism and secondary cell wall formation. We performed a genome-wide analysis of this superfamily in Eucalyptus, one of the most planted hardwood trees world-wide. A total of 141 predicted R2R3-MYB sequences identified in the Eucalyptus grandis genome sequence were subjected to comparative phylogenetic analyses with Arabidopsis thaliana, Oryza sativa, Populus trichocarpa and Vitis vinifera. We analysed features such as gene structure, conserved motifs and genome location. Transcript abundance patterns were assessed by RNAseq and validated by high-throughput quantitative PCR. We found some R2R3-MYB subgroups with expanded membership in E. grandis, V. vinifera and P. trichocarpa, and others preferentially found in woody species, suggesting diversification of specific functions in woody plants. By contrast, subgroups containing key genes regulating lignin biosynthesis and secondary cell wall formation are more conserved across all of the species analysed. In Eucalyptus, R2R3-MYB tandem gene duplications seem to disproportionately affect woody-preferential and woody-expanded subgroups. Interestingly, some of the genes belonging to woody-preferential subgroups show higher expression in the cambial region, suggesting a putative role in the regulation of secondary growth. © 2014 The Authors New Phytologist © 2014 New Phytologist Trust.

  11. Ectopic Overexpression of a Novel R2R3-MYB, NtMYB2 from Chinese Narcissus Represses Anthocyanin Biosynthesis in Tobacco

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    Muhammad Anwar

    2018-03-01

    Full Text Available R2R3 MYB transcription factors play key functions in the regulation of secondary metabolites. In the present study, a R2R3 MYB transcriptional factor NtMYB2 was identified from Chinese narcissus (Narcissus tazetta L. var. Chinensis Roem and functionally characterized. NtMYB2 belongs to subgroup 4 of the R2R3 MYB transcription factor family that are related to repressor MYBs involved in the regulation of anthocyanin and flavonoids. Transient expression confirmed that NtMYB2 strongly reduced the red pigmentation induced by MYB- anthocyanin activators in agro-infiltrated tobacco leaves. Ectopic expression of NtMYB2 in tobacco significantly reduced the pigmentation and altered the floral phenotypes in transgenic tobacco flowers. Gene expression analysis suggested that NtMYB2 repressed the transcript levels of structural genes involved in anthocyanin biosynthesis pathway, especially the UFGT gene. NtMYB2 gene is expressed in all examined narcissus tissues; the levels of transcription in petals and corona is higher than other tissues and the transcription level at the bud stage was highest. These results show that NtMYB2 is involved in the regulation of anthocyanin biosynthesis pathway and may act as a repressor by down regulating the transcripts of key enzyme genes in Chinese narcissus.

  12. Ectopic Overexpression of a Novel R2R3-MYB, NtMYB2 from Chinese Narcissus Represses Anthocyanin Biosynthesis in Tobacco.

    Science.gov (United States)

    Anwar, Muhammad; Wang, Guiqing; Wu, Jiacheng; Waheed, Saquib; Allan, Andrew C; Zeng, Lihui

    2018-03-28

    R2R3 MYB transcription factors play key functions in the regulation of secondary metabolites. In the present study, a R2R3 MYB transcriptional factor NtMYB2 was identified from Chinese narcissus ( Narcissus tazetta L. var. Chinensis Roem) and functionally characterized. NtMYB2 belongs to subgroup 4 of the R2R3 MYB transcription factor family that are related to repressor MYBs involved in the regulation of anthocyanin and flavonoids. Transient expression confirmed that NtMYB2 strongly reduced the red pigmentation induced by MYB- anthocyanin activators in agro-infiltrated tobacco leaves. Ectopic expression of NtMYB2 in tobacco significantly reduced the pigmentation and altered the floral phenotypes in transgenic tobacco flowers. Gene expression analysis suggested that NtMYB2 repressed the transcript levels of structural genes involved in anthocyanin biosynthesis pathway, especially the UFGT gene. NtMYB2 gene is expressed in all examined narcissus tissues; the levels of transcription in petals and corona is higher than other tissues and the transcription level at the bud stage was highest. These results show that NtMYB2 is involved in the regulation of anthocyanin biosynthesis pathway and may act as a repressor by down regulating the transcripts of key enzyme genes in Chinese narcissus.

  13. An R2R3 MYB transcription factor associated with regulation of the anthocyanin biosynthetic pathway in Rosaceae.

    Science.gov (United States)

    Lin-Wang, Kui; Bolitho, Karen; Grafton, Karryn; Kortstee, Anne; Karunairetnam, Sakuntala; McGhie, Tony K; Espley, Richard V; Hellens, Roger P; Allan, Andrew C

    2010-03-21

    The control of plant anthocyanin accumulation is via transcriptional regulation of the genes encoding the biosynthetic enzymes. A key activator appears to be an R2R3 MYB transcription factor. In apple fruit, skin anthocyanin levels are controlled by a gene called MYBA or MYB1, while the gene determining fruit flesh and foliage anthocyanin has been termed MYB10. In order to further understand tissue-specific anthocyanin regulation we have isolated orthologous MYB genes from all the commercially important rosaceous species. We use gene specific primers to show that the three MYB activators of apple anthocyanin (MYB10/MYB1/MYBA) are likely alleles of each other. MYB transcription factors, with high sequence identity to the apple gene were isolated from across the rosaceous family (e.g. apples, pears, plums, cherries, peaches, raspberries, rose, strawberry). Key identifying amino acid residues were found in both the DNA-binding and C-terminal domains of these MYBs. The expression of these MYB10 genes correlates with fruit and flower anthocyanin levels. Their function was tested in tobacco and strawberry. In tobacco, these MYBs were shown to induce the anthocyanin pathway when co-expressed with bHLHs, while over-expression of strawberry and apple genes in the crop of origin elevates anthocyanins. This family-wide study of rosaceous R2R3 MYBs provides insight into the evolution of this plant trait. It has implications for the development of new coloured fruit and flowers, as well as aiding the understanding of temporal-spatial colour change.

  14. An R2R3 MYB transcription factor associated with regulation of the anthocyanin biosynthetic pathway in Rosaceae

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    McGhie Tony K

    2010-03-01

    Full Text Available Abstract Background The control of plant anthocyanin accumulation is via transcriptional regulation of the genes encoding the biosynthetic enzymes. A key activator appears to be an R2R3 MYB transcription factor. In apple fruit, skin anthocyanin levels are controlled by a gene called MYBA or MYB1, while the gene determining fruit flesh and foliage anthocyanin has been termed MYB10. In order to further understand tissue-specific anthocyanin regulation we have isolated orthologous MYB genes from all the commercially important rosaceous species. Results We use gene specific primers to show that the three MYB activators of apple anthocyanin (MYB10/MYB1/MYBA are likely alleles of each other. MYB transcription factors, with high sequence identity to the apple gene were isolated from across the rosaceous family (e.g. apples, pears, plums, cherries, peaches, raspberries, rose, strawberry. Key identifying amino acid residues were found in both the DNA-binding and C-terminal domains of these MYBs. The expression of these MYB10 genes correlates with fruit and flower anthocyanin levels. Their function was tested in tobacco and strawberry. In tobacco, these MYBs were shown to induce the anthocyanin pathway when co-expressed with bHLHs, while over-expression of strawberry and apple genes in the crop of origin elevates anthocyanins. Conclusions This family-wide study of rosaceous R2R3 MYBs provides insight into the evolution of this plant trait. It has implications for the development of new coloured fruit and flowers, as well as aiding the understanding of temporal-spatial colour change.

  15. Functional Characterization of Cotton GaMYB62L, a Novel R2R3 TF in Transgenic Arabidopsis.

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    Hamama Islam Butt

    Full Text Available Drought stress can trigger the production of ABA in plants, in response to adverse conditions, which induces the transcript of stress-related marker genes. The R2R3 MYB TFs are implicated in regulation of various plants developmental, metabolic and multiple environmental stress responses. Here, a R2R3-MYB cloned gene, GaMYB62L, was transformed in Arabidopsis and was functionally characterized. The GaMYB62L protein contains two SANT domains with a conserved R2R3 imperfect repeats. The GaMYB62L cDNA is 1,017 bp with a CDS of 879, encodes a 292-residue polypeptide with MW of 38.78 kD and a pI value of 8.91. Overexpressed GaMYB62L transgenic Arabidopsis have increased proline and chlorophyll content, superior seed germination rate under salt and osmotic stress, less water loss rate with reduced stomatal apertures, high drought avoidance as compared to WT on water deprivation and also significant plant survival rates at low temperature. In addition, overexpressed GaMYB62L lines were more sensitive to ABA mediated germination and root elongation assay. Moreover, ABA induced GaMYB62L overexpression, enhanced the expression of ABA stress related marker genes like RD22, COR15A, ADH1, and RD29A. Together, overexpression of GaMYB62L suggested having developed better drought, salt and cold tolerance in transgenic Arabidopsis and thus presented it as a prospective candidate gene to achieve better abiotic stress tolerance in cotton crop.

  16. The R2R3-MYB-like regulatory factor EOBI, acting downstream of EOBII, regulates scent production by activating ODO1 and structural scent-related genes in petunia.

    Science.gov (United States)

    Spitzer-Rimon, Ben; Farhi, Moran; Albo, Boaz; Cna'ani, Alon; Ben Zvi, Michal Moyal; Masci, Tania; Edelbaum, Orit; Yu, Yixun; Shklarman, Elena; Ovadis, Marianna; Vainstein, Alexander

    2012-12-01

    Flower scent is a highly dynamic trait, under developmental, spatial, and diurnal regulation. The mechanism governing scent production is only beginning to be unraveled. In petunia (Petunia hybrida), EMISSION OF BENZENOIDS II (EOBII) controls transcription of both the shikimate pathway-regulating MYB factor ODORANT1 (ODO1) and phenylpropanoid scent-related structural genes. A promoter-activation screen identified an R2R3-MYB-like regulatory factor of phenylpropanoid volatile biosynthesis acting downstream of EOBII, designated EOBI. EOBI silencing led to downregulation of ODO1 and numerous structural scent-related genes from both the shikimate and phenylpropanoid pathways. The ability of EOBI to directly activate ODO1, as revealed by electrophoretic mobility shift assay and yeast one-hybrid analysis, place EOBI upstream of ODO1 in regulating substrate availability for volatile biosynthesis. Interestingly, ODO1-silenced transgenic petunia flowers accumulated higher EOBI transcript levels than controls, suggesting a complex feedback loop between these regulatory factors. The accumulation pattern of EOBI transcript relative to EOBII and ODO1, and the effect of up/downregulation of EOBII on transcript levels of EOBI and ODO1, further support these factors' hierarchical relationships. The dependence of scent production on EOBI expression and its direct interaction with both regulatory and structural genes provide evidence for EOBI's wide-ranging involvement in the production of floral volatiles.

  17. An R2R3-MYB transcription factor regulates carotenoid pigmentation in Mimulus lewisii flowers.

    Science.gov (United States)

    Sagawa, Janelle M; Stanley, Lauren E; LaFountain, Amy M; Frank, Harry A; Liu, Chang; Yuan, Yao-Wu

    2016-02-01

    Carotenoids are yellow, orange, and red pigments that contribute to the beautiful colors and nutritive value of many flowers and fruits. The structural genes in the highly conserved carotenoid biosynthetic pathway have been well characterized in multiple plant systems, but little is known about the transcription factors that control the expression of these structural genes. By analyzing a chemically induced mutant of Mimulus lewisii through bulk segregant analysis and transgenic experiments, we have identified an R2R3-MYB, Reduced Carotenoid Pigmentation 1 (RCP1), as the first transcription factor that positively regulates carotenoid biosynthesis during flower development. Loss-of-function mutations in RCP1 lead to down-regulation of all carotenoid biosynthetic genes and reduced carotenoid content in M. lewisii flowers, a phenotype recapitulated by RNA interference in the wild-type background. Overexpression of this gene in the rcp1 mutant background restores carotenoid production and, unexpectedly, results in simultaneous decrease of anthocyanin production in some transgenic lines by down-regulating the expression of an activator of anthocyanin biosynthesis. Identification of transcriptional regulators of carotenoid biosynthesis provides the 'toolbox' genes for understanding the molecular basis of flower color diversification in nature and for potential enhancement of carotenoid production in crop plants via genetic engineering. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  18. Combinatorial analysis of lupulin gland transcription factors from R2R3Myb, bHLH and WDR families indicates a complex regulation of chs_H1 genes essential for prenylflavonoid biosynthesis in hop (Humulus Lupulus L.

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    Matoušek Jaroslav

    2012-02-01

    chs_H1 gene that depends on variable activation by combinations of R2R3Myb, bHLH and WDR TF homologues and inhibition by a Myb repressor.

  19. Multiple Copies of a Simple MYB-Binding Site Confers Trans-regulation by Specific Flavonoid-Related R2R3 MYBs in Diverse Species

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    Cyril Brendolise

    2017-10-01

    Full Text Available In apple, the MYB transcription factor MYB10 controls the accumulation of anthocyanins. MYB10 is able to auto-activate its expression by binding its own promoter at a specific motif, the R1 motif. In some apple accessions a natural mutation, termed R6, has more copies of this motif within the MYB10 promoter resulting in stronger auto-activation and elevated anthocyanins. Here we show that other anthocyanin-related MYBs selected from apple, pear, strawberry, petunia, kiwifruit and Arabidopsis are able to activate promoters containing the R6 motif. To examine the specificity of this motif, members of the R2R3 MYB family were screened against a promoter harboring the R6 mutation. Only MYBs from subgroups 5 and 6 activate expression by binding the R6 motif, with these MYBs sharing conserved residues in their R2R3 DNA binding domains. Insertion of the apple R6 motif into orthologous promoters of MYB10 in pear (PcMYB10 and Arabidopsis (AtMY75 elevated anthocyanin levels. Introduction of the R6 motif into the promoter region of an anthocyanin biosynthetic enzyme F3′5′H of kiwifruit imparts regulation by MYB10. This results in elevated levels of delphinidin in both tobacco and kiwifruit. Finally, an R6 motif inserted into the promoter the vitamin C biosynthesis gene GDP-L-Gal phosphorylase increases vitamin C content in a MYB10-dependent manner. This motif therefore provides a tool to re-engineer novel MYB-regulated responses in plants.

  20. Coordinated regulation of anthocyanin biosynthesis in Chinese bayberry (Myrica rubra) fruit by a R2R3 MYB transcription factor.

    Science.gov (United States)

    Niu, Shan-Shan; Xu, Chang-Jie; Zhang, Wang-Shu; Zhang, Bo; Li, Xian; Lin-Wang, Kui; Ferguson, Ian B; Allan, Andrew C; Chen, Kun-Song

    2010-03-01

    Chinese bayberry (Myrica rubra) is a fruit crop with cultivars producing fruit ranging from white (Shuijing, SJ) to red (Dongkui, DK) and dark red-purple (Biqi, BQ), as a result of different levels of anthocyanin accumulation. Genes encoding the anthocyanin biosynthesis enzymes chalcone synthase, chalcone isomerase, flavanone 3-hydroxylase (F3H), flavonoid 3'-hydroxylase (F3'H), dihydroflavonol 4-reductase (DFR), anthocyanidin synthase (ANS) and UDPglucose: flavonoid 3-O-glucosyltransferase (UFGT), as well as MrMYB1, a R2R3 MYB transcription factor homologous to known activators of anthocyanin biosynthesis, were isolated from ripe fruit of BQ. Differences in mRNA abundance of MrF3H, MrF3'H, MrDFR1, MrANS and MrUFGT were highly correlated with differential accumulation of anthocyanins between cultivars, suggesting coordinated regulation by transcription factors. The transcript level of MrMYB1 was strongly associated with the anthocyanin content in ripe fruit of the three cultivars, as well as different anthocyanin containing tissues of BQ fruit. Fruit bagging strongly inhibited anthocyanin accumulation in fruit as well as the expression of all anthocyanin biosynthetic genes and MrMYB1. Overexpression of MrMYB1 stimulated both anthocyanin accumulation and activated an Arabidopsis-DFR promoter in tobacco (Nicotiana tabacum). MrMYB1d, an allele with a 1 bp deletion at nucleotide 30 of coding sequence, was observed in SJ and DK fruit, suggesting that a nonsense mutation of the MYB1 protein may be responsible for no or low expression of MYB1 in the white and red fruit. These results show that coordinated expression of multiple biosynthetic genes is involved in anthocyanin accumulation in Chinese bayberry fruit, and this is regulated by MrMYB1.

  1. Analysis of the DNA-Binding Activities of the Arabidopsis R2R3-MYB Transcription Factor Family by One-Hybrid Experiments in Yeast.

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    Zsolt Kelemen

    Full Text Available The control of growth and development of all living organisms is a complex and dynamic process that requires the harmonious expression of numerous genes. Gene expression is mainly controlled by the activity of sequence-specific DNA binding proteins called transcription factors (TFs. Amongst the various classes of eukaryotic TFs, the MYB superfamily is one of the largest and most diverse, and it has considerably expanded in the plant kingdom. R2R3-MYBs have been extensively studied over the last 15 years. However, DNA-binding specificity has been characterized for only a small subset of these proteins. Therefore, one of the remaining challenges is the exhaustive characterization of the DNA-binding specificity of all R2R3-MYB proteins. In this study, we have developed a library of Arabidopsis thaliana R2R3-MYB open reading frames, whose DNA-binding activities were assayed in vivo (yeast one-hybrid experiments with a pool of selected cis-regulatory elements. Altogether 1904 interactions were assayed leading to the discovery of specific patterns of interactions between the various R2R3-MYB subgroups and their DNA target sequences and to the identification of key features that govern these interactions. The present work provides a comprehensive in vivo analysis of R2R3-MYB binding activities that should help in predicting new DNA motifs and identifying new putative target genes for each member of this very large family of TFs. In a broader perspective, the generated data will help to better understand how TF interact with their target DNA sequences.

  2. Arabidopsis R2R3-MYB transcription factor AtMYB60 functions as a transcriptional repressor of anthocyanin biosynthesis in lettuce (Lactuca sativa).

    Science.gov (United States)

    Park, Jong-Sug; Kim, Jung-Bong; Cho, Kang-Jin; Cheon, Choong-Ill; Sung, Mi-Kyung; Choung, Myoung-Gun; Roh, Kyung-Hee

    2008-06-01

    The MYB transcription factors play important roles in the regulation of many secondary metabolites at the transcriptional level. We evaluated the possible roles of the Arabidopsis R2R3-MYB transcription factors in flavonoid biosynthesis because they are induced by UV-B irradiation but their associated phenotypes are largely unexplored. We isolated their genes by RACE-PCR, and performed transgenic approach and metabolite analyses in lettuce (Lactuca sativa). We found that one member of this protein family, AtMYB60, inhibits anthocyanin biosynthesis in the lettuce plant. Wild-type lettuce normally accumulates anthocyanin, predominantly cyanidin and traces of delphinidin, and develops a red pigmentation. However, the production and accumulation of anthocyanin pigments in AtMYB60-overexpressing lettuce was inhibited. Using RT-PCR analysis, we also identified the complete absence or reduction of dihydroflavonol 4-reductase (DFR) transcripts in AtMYB60- overexpressing lettuce (AtMYB60-117 and AtMYB60-112 lines). The correlation between the overexpression of AtMYB60 and the inhibition of anthocyanin accumulation suggests that the transcription factorAtMYB60 controls anthocyanin biosynthesis in the lettuce leaf. Clarification of the roles of the AtMYB60 transcription factor will facilitate further studies and provide genetic tools to better understand the regulation in plants of the genes controlled by the MYB-type transcription factors. Furthermore, the characterization of AtMYB60 has implications for the development of new varieties of lettuce and other commercially important plants with metabolic engineering approaches.

  3. Genome-wide organization and expression profiling of the R2R3-MYB transcription factor family in pineapple (Ananas comosus).

    Science.gov (United States)

    Liu, Chaoyang; Xie, Tao; Chen, Chenjie; Luan, Aiping; Long, Jianmei; Li, Chuhao; Ding, Yaqi; He, Yehua

    2017-07-01

    The MYB proteins comprise one of the largest families of plant transcription factors, which are involved in various plant physiological and biochemical processes. Pineapple (Ananas comosus) is one of three most important tropical fruits worldwide. The completion of pineapple genome sequencing provides a great opportunity to investigate the organization and evolutionary traits of pineapple MYB genes at the genome-wide level. In the present study, a total of 94 pineapple R2R3-MYB genes were identified and further phylogenetically classified into 26 subfamilies, as supported by the conserved gene structures and motif composition. Collinearity analysis indicated that the segmental duplication events played a crucial role in the expansion of pineapple MYB gene family. Further comparative phylogenetic analysis suggested that there have been functional divergences of MYB gene family during plant evolution. RNA-seq data from different tissues and developmental stages revealed distinct temporal and spatial expression profiles of the AcMYB genes. Further quantitative expression analysis showed the specific expression patterns of the selected putative stress-related AcMYB genes in response to distinct abiotic stress and hormonal treatments. The comprehensive expression analysis of the pineapple MYB genes, especially the tissue-preferential and stress-responsive genes, could provide valuable clues for further function characterization. In this work, we systematically identified AcMYB genes by analyzing the pineapple genome sequence using a set of bioinformatics approaches. Our findings provide a global insight into the organization, phylogeny and expression patterns of the pineapple R2R3-MYB genes, and hence contribute to the greater understanding of their biological roles in pineapple.

  4. A chimeric repressor of petunia PH4 R2R3-MYB family transcription factor generates margined flowers in torenia.

    Science.gov (United States)

    Kasajima, Ichiro; Sasaki, Katsutomo

    2016-05-03

    The development of new phenotypes is key to the commercial development of the main floricultural species and cultivars. Important new phenotypes include features such as multiple-flowers, color variations, increased flower size, new petal shapes, variegation and distinctive petal margin colourations. Although their commercial use is not yet common, the transgenic technologies provide a potentially rapid means of generating interesting new phenotypes. In this report, we construct 5 vectors which we expected to change the color of the flower anthocyanins, from purple to blue, regulating vacuolar pH. When these constructs were transformed into purple torenia, we unexpectedly recovered some genotypes having slightly margined petals. These transgenic lines expressed a chimeric repressor of the petunia PhPH4 gene under the control of Cauliflower mosaic virus 35 S RNA promoter. PhPH4 is an R2R3-type MYB transcription factor. The transgenic lines lacked pigmentation in the petal margin cells both on the adaxial and abaxial surfaces. Expressions of Flavanone 3-hydroxylase (F3H), Flavonoid 3'-hydroxylase (F3'H) and Flavonoid 3'5'-hydroxylase (F3'5'H) genes were reduced in the margins of these transgenic lines, suggesting an inhibitory effect of PhPH4 repressor on anthocyanin synthesis.

  5. Spearmint R2R3-MYB transcription factor MsMYB negatively regulates monoterpene production and suppresses the expression of geranyl diphosphate synthase large subunit (MsGPPS.LSU).

    Science.gov (United States)

    Reddy, Vaishnavi Amarr; Wang, Qian; Dhar, Niha; Kumar, Nadimuthu; Venkatesh, Prasanna Nori; Rajan, Chakravarthy; Panicker, Deepa; Sridhar, Vishweshwaran; Mao, Hui-Zhu; Sarojam, Rajani

    2017-09-01

    Many aromatic plants, such as spearmint, produce valuable essential oils in specialized structures called peltate glandular trichomes (PGTs). Understanding the regulatory mechanisms behind the production of these important secondary metabolites will help design new approaches to engineer them. Here, we identified a PGT-specific R2R3-MYB gene, MsMYB, from comparative RNA-Seq data of spearmint and functionally characterized it. Analysis of MsMYB-RNAi transgenic lines showed increased levels of monoterpenes, and MsMYB-overexpressing lines exhibited decreased levels of monoterpenes. These results suggest that MsMYB is a novel negative regulator of monoterpene biosynthesis. Ectopic expression of MsMYB, in sweet basil and tobacco, perturbed sesquiterpene- and diterpene-derived metabolite production. In addition, we found that MsMYB binds to cis-elements of MsGPPS.LSU and suppresses its expression. Phylogenetic analysis placed MsMYB in subgroup 7 of R2R3-MYBs whose members govern phenylpropanoid pathway and are regulated by miR858. Analysis of transgenic lines showed that MsMYB is more specific to terpene biosynthesis as it did not affect metabolites derived from phenylpropanoid pathway. Further, our results indicate that MsMYB is probably not regulated by miR858, like other members of subgroup 7. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  6. A R2R3-MYB transcription factor regulates the flavonol biosynthetic pathway in a traditional Chinese medicinal plant, Epimedium sagittatum

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    Wenjun Huang

    2016-07-01

    Full Text Available Flavonols as plant secondary metabolites with vital roles in plant development and defense against UV light, have been demonstrated to be the main bioactive components in the genus Epimedium plants, several species of which are used as materials for Herba Epimedii, an important traditional Chinese medicine. The flavonol biosynthetic pathway genes had been already isolated from E. sagittatum, but a R2R3-MYB transcription factor regulating the flavonol synthesis has not been functionally characterized so far in Epimedium plants. In this study, we isolated and characterized the R2R3-MYB transcription factor EsMYBF1 involved in regulation of the flavonol biosynthetic pathway from E. sagittatum. Sequence analysis indicated that EsMYBF1 belongs to the subgroup 7 of R2R3-MYB family which contains the flavonol-specific MYB regulators identified to date. Transient reporter assay showed that EsMYBF1 strongly activated the promoters of EsF3H (flavanone 3-hydroxylase and EsFLS (flavonol synthase, but not the promoters of EsDFRs (dihydroflavonol 4-reductase and EsANS (anthocyanidin synthase in transiently transformed Nicotiana benthamiana leaves. Both yeast two-hybrid assay and transient reporter assay validated EsMYBF1 to be independent of EsTT8, or AtTT8 bHLH regulators of the flavonoid pathway as cofactors. Ectopic expression of EsMYBF1 in transgenic tobacco resulted in the increased flavonol content and the decreased anthocyanin content in flowers. Correspondingly, the structural genes involved in flavonol synthesis were upregulated in the EsMYBF1 overexpression lines, including NtCHS (chalcone synthase, NtCHI (chalcone isomerase, NtF3H and NtFLS, whereas the late biosynthetic genes of the anthocyanin pathway (NtDFR and NtANS were remarkably downregulated, compared to the controls. These results suggest that EsMYBF1 is a flavonol-specific R2R3-MYB regulator, and involved in regulation of the biosynthesis of the flavonol-derived bioactive components in E

  7. dsRNA silencing of an R2R3-MYB transcription factor affects flower cell shape in a Dendrobium hybrid.

    Science.gov (United States)

    Lau, Su-Ee; Schwarzacher, Trude; Othman, Rofina Yasmin; Harikrishna, Jennifer Ann

    2015-08-11

    The R2R3-MYB genes regulate pigmentation and morphogenesis of flowers, including flower and cell shape, and therefore have importance in the development of new varieties of orchids. However, new variety development is limited by the long breeding time required in orchids. In this study, we identified a cDNA, DhMYB1, that is expressed during flower development in a hybrid orchid, Dendrobium hybrida (Dendrobium bobby messina X Dendrobium chao phraya) then used the direct application of dsRNA to observe the effect of gene silencing on flower phenotype and floral epidermal cell shape. Flower bud development in the Dendrobium hybrid was characterised into seven stages and the time of meiosis was determined as between stages 3 to 5 when the bud is approximately half of the mature size. Scanning electron microscopy characterisation of adaxial epidermal cells of the flower perianth, showed that the petals and sepals each are divided into two distinct domains based on cell shape and size, while the labellum comprises seven domains. Thirty-two partial cDNA fragments representing R2R3-MYB gene sequences were isolated from D. hybrida. Phylogenetic analysis revealed that nine of the translated sequences were clustered with MYB sequences that are known to be involved in cell shape development and from these, DhMYB1 was selected for full length cDNA cloning and functional study. Direct application of a 430 bp dsRNA from the 3' region of DhMYB1 to emerging orchid flower buds reduced expression of DhMYB1 RNA compared with untreated control. Scanning electron microscopy of adaxial epidermal cells within domain one of the labellum of flowers treated with DhMYB1 dsRNA showed flattened epidermal cells whilst those of control flowers were conical. DhMYB1 is expressed throughout flower bud development and is involved in the development of the conical cell shape of the epidermal cells of the Dendrobium hybrida flower labellum. The direct application of dsRNA changed the phenotype of

  8. The Phenylpropanoid Pathway Is Controlled at Different Branches by a Set of R2R3-MYB C2 Repressors in Grapevine1

    Science.gov (United States)

    Cavallini, Erika; Matus, José Tomás; Finezzo, Laura; Zenoni, Sara; Loyola, Rodrigo; Guzzo, Flavia; Schlechter, Rudolf; Ageorges, Agnès; Arce-Johnson, Patricio

    2015-01-01

    Because of the vast range of functions that phenylpropanoids possess, their synthesis requires precise spatiotemporal coordination throughout plant development and in response to the environment. The accumulation of these secondary metabolites is transcriptionally controlled by positive and negative regulators from the MYB and basic helix-loop-helix protein families. We characterized four grapevine (Vitis vinifera) R2R3-MYB proteins from the C2 repressor motif clade, all of which harbor the ethylene response factor-associated amphiphilic repression domain but differ in the presence of an additional TLLLFR repression motif found in the strong flavonoid repressor Arabidopsis (Arabidopsis thaliana) AtMYBL2. Constitutive expression of VvMYB4a and VvMYB4b in petunia (Petunia hybrida) repressed general phenylpropanoid biosynthetic genes and selectively reduced the amount of small-weight phenolic compounds. Conversely, transgenic petunia lines expressing VvMYBC2-L1 and VvMYBC2-L3 showed a severe reduction in petal anthocyanins and seed proanthocyanidins together with a higher pH of crude petal extracts. The distinct function of these regulators was further confirmed by transient expression in tobacco (Nicotiana benthamiana) leaves and grapevine plantlets. Finally, VvMYBC2-L3 was ectopically expressed in grapevine hairy roots, showing a reduction in proanthocyanidin content together with the down-regulation of structural and regulatory genes of the flavonoid pathway as revealed by a transcriptomic analysis. The physiological role of these repressors was inferred by combining the results of the functional analyses and their expression patterns in grapevine during development and in response to ultraviolet B radiation. Our results indicate that VvMYB4a and VvMYB4b may play a key role in negatively regulating the synthesis of small-weight phenolic compounds, whereas VvMYBC2-L1 and VvMYBC2-L3 may additionally fine tune flavonoid levels, balancing the inductive effects of

  9. Metabolic and molecular analyses of white mutant Vaccinium berries show down-regulation of MYBPA1-type R2R3 MYB regulatory factor.

    Science.gov (United States)

    Primetta, Anja K; Karppinen, Katja; Riihinen, Kaisu R; Jaakola, Laura

    2015-09-01

    MYBPA1-type R2R3 MYB transcription factor shows down-regulation in white mutant berries of Vaccinium uliginosum deficient in anthocyanins but not proanthocyanidins suggesting a role in the regulation of anthocyanin biosynthesis. Berries of the genus Vaccinium are among the best natural sources of flavonoids. In this study, the expression of structural and regulatory flavonoid biosynthetic genes and the accumulation of flavonoids in white mutant and blue-colored wild-type bog bilberry (V. uliginosum) fruits were measured at different stages of berry development. In contrast to high contents of anthocyanins in ripe blue-colored berries, only traces were detected by HPLC-ESI-MS in ripe white mutant berries. However, similar profile and high levels of flavonol glycosides and proanthocyanidins were quantified in both ripe white and ripe wild-type berries. Analysis with qRT-PCR showed strong down-regulation of structural genes chalcone synthase (VuCHS), dihydroflavonol 4-reductase (VuDFR) and anthocyanidin synthase (VuANS) as well as MYBPA1-type transcription factor VuMYBPA1 in white berries during ripening compared to wild-type berries. The profiles of transcript accumulation of chalcone isomerase (VuCHI), anthocyanidin reductase (VuANR), leucoanthocyanidin reductase (VuLAR) and flavonoid 3'5' hydroxylase (VuF3'5'H) were more similar between the white and the wild-type berries during fruit development, while expression of UDP-glucose: flavonoid 3-O-glucosyltransferase (VuUFGT) showed similar trend but fourfold lower level in white mutant. VuMYBPA1, the R2R3 MYB family member, is a homologue of VmMYB2 of V. myrtillus and VcMYBPA1 of V. corymbosum and belongs to MYBPA1-type MYB family which members are shown in some species to be related with proanthocyanidin biosynthesis in fruits. Our results combined with earlier data of the role of VmMYB2 in white mutant berries of V. myrtillus suggest that the regulation of anthocyanin biosynthesis in Vaccinium species could differ

  10. AtMyb7, a subgroup 4 R2R3 Myb, negatively regulates ABA-induced inhibition of seed germination by blocking the expression of the bZIP transcription factor ABI5

    KAUST Repository

    Kim, Junhyeok; Hyun, Wooyoung; Nguyen, Hoai Nguyen; Jeong, Chanyoung; Xiong, Liming; Hong, Sukwhan; Lee, Hojoung

    2014-01-01

    Various Myb proteins have been shown to play crucial roles in plants, including primary and secondary metabolism, determination of cell fate and identity, regulation of development and involvement in responses to biotic and abiotic stresses. The 126 R2R3 Myb proteins (with two Myb repeats) have been found in Arabidopsis; however, the functions of most of these proteins remain to be fully elucidated. In the present study, we characterized the function of AtMyb7 using molecular biological and genetic analyses. We used qRT-PCR to determine the levels of stress-response gene transcripts in wild-type and atmyb7 plants. We showed that ArabidopsisAtMyb7 plays a critical role in seed germination. Under abscisic acid (ABA) and high-salt stress conditions, atmyb7 plants showed a lower germination rate than did wild-type plants. Furthermore, AtMyb7 promoter:GUS seeds exhibited different expression patterns in response to variations in the seed imbibition period. AtMyb7 negatively controls the expression of the gene encoding bZIP transcription factor, ABI5, which is a key transcription factor in ABA signalling and serves as a crucial regulator of germination inhibition in Arabidopsis. © 2014 John Wiley & Sons Ltd.

  11. AtMyb7, a subgroup 4 R2R3 Myb, negatively regulates ABA-induced inhibition of seed germination by blocking the expression of the bZIP transcription factor ABI5

    KAUST Repository

    Kim, Junhyeok

    2014-08-27

    Various Myb proteins have been shown to play crucial roles in plants, including primary and secondary metabolism, determination of cell fate and identity, regulation of development and involvement in responses to biotic and abiotic stresses. The 126 R2R3 Myb proteins (with two Myb repeats) have been found in Arabidopsis; however, the functions of most of these proteins remain to be fully elucidated. In the present study, we characterized the function of AtMyb7 using molecular biological and genetic analyses. We used qRT-PCR to determine the levels of stress-response gene transcripts in wild-type and atmyb7 plants. We showed that ArabidopsisAtMyb7 plays a critical role in seed germination. Under abscisic acid (ABA) and high-salt stress conditions, atmyb7 plants showed a lower germination rate than did wild-type plants. Furthermore, AtMyb7 promoter:GUS seeds exhibited different expression patterns in response to variations in the seed imbibition period. AtMyb7 negatively controls the expression of the gene encoding bZIP transcription factor, ABI5, which is a key transcription factor in ABA signalling and serves as a crucial regulator of germination inhibition in Arabidopsis. © 2014 John Wiley & Sons Ltd.

  12. A R2R3-MYB transcription factor that is specifically expressed in cotton (Gossypium hirsutum) fibers affects secondary cell wall biosynthesis and deposition in transgenic Arabidopsis.

    Science.gov (United States)

    Sun, Xiang; Gong, Si-Ying; Nie, Xiao-Ying; Li, Yang; Li, Wen; Huang, Geng-Qing; Li, Xue-Bao

    2015-07-01

    Secondary cell wall (SCW) is an important industrial raw material for pulping, papermaking, construction, lumbering, textiles and potentially for biofuel production. The process of SCW thickening of cotton fibers lays down the cellulose that will constitute the bulk (up to 96%) of the fiber at maturity. In this study, a gene encoding a MYB-domain protein was identified in cotton (Gossypium hirsutum) and designated as GhMYBL1. Quantitative real-time polymerase chain reaction (RT-PCR) analysis revealed that GhMYBL1 was specifically expressed in cotton fibers at the stage of secondary wall deposition. Further analysis indicated that this protein is a R2R3-MYB transcription factor, and is targeted to the cell nucleus. Overexpression of GhMYBL1 in Arabidopsis affected the formation of SCW in the stem xylem of the transgenic plants. The enhanced SCW thickening also occurred in the interfascicular fibers, xylary fibers and vessels of the GhMYBL1-overexpression transgenic plants. The expression of secondary wall-associated genes, such as CesA4, CesA7, CesA8, PAL1, F5H and 4CL1, were upregulated, and consequently, cellulose and lignin biosynthesis were enhanced in the GhMYBL1 transgenic plants. These data suggested that GhMYBL1 may participate in modulating the process of secondary wall biosynthesis and deposition of cotton fibers. © 2014 Scandinavian Plant Physiology Society.

  13. A Wheat R2R3-type MYB Transcription Factor TaODORANT1 Positively Regulates Drought and Salt Stress Responses in Transgenic Tobacco Plants

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    Qiuhui Wei

    2017-08-01

    Full Text Available MYB transcription factors play important roles in plant responses to biotic and abiotic stress. In this study, TaODORANT1, a R2R3-MYB gene, was cloned from wheat (Triticum aestivum L.. TaODORANT1 was localized in the nucleus and functioned as a transcriptional activator. TaODORANT1 was up-regulated in wheat under PEG6000, NaCl, ABA, and H2O2 treatments. TaODORANT1-overexpressing transgenic tobacco plants exhibited higher relative water content and lower water loss rate under drought stress, as well as lower Na+ accumulation in leaves under salt stress. The transgenic plants showed higher CAT activity but lower ion leakage, H2O2 and malondialdehyde contents under drought and salt stresses. Besides, the transgenic plants also exhibited higher SOD activity under drought stress. Our results also revealed that TaODORANT1 overexpression up-regulated the expression of several ROS- and stress-related genes in response to both drought and salt stresses, thus enhancing transgenic tobacco plants tolerance. Our studies demonstrate that TaODORANT1 positively regulates plant tolerance to drought and salt stresses.

  14. Comparative transcriptome analysis of oil palm flowers reveals an EAR-motif-containing R2R3-MYB that modulates phenylpropene biosynthesis.

    Science.gov (United States)

    Li, Ran; Reddy, Vaishnavi Amarr; Jin, Jingjing; Rajan, Chakaravarthy; Wang, Qian; Yue, Genhua; Lim, Chin Huat; Chua, Nam-Hai; Ye, Jian; Sarojam, Rajani

    2017-11-23

    Oil palm is the most productive oil crop and the efficiency of pollination has a direct impact on the yield of oil. Pollination by wind can occur but maximal pollination is mediated by the weevil E. kamerunicus. These weevils complete their life cycle by feeding on male flowers. Attraction of weevils to oil palm flowers is due to the emission of methylchavicol by both male and female flowers. In search for male flowers, the weevils visit female flowers by accident due to methylchavicol fragrance and deposit pollen. Given the importance of methylchavicol emission on pollination, we performed comparative transcriptome analysis of oil palm flowers and leaves to identify candidate genes involved in methylchavicol production in flowers. RNA sequencing (RNA-Seq) of male open flowers, female open flowers and leaves was performed using Illumina HiSeq 2000 platform. Analysis of the transcriptome data revealed that the transcripts of methylchavicol biosynthesis genes were strongly up-regulated whereas transcripts encoding genes involved in lignin production such as, caffeic acid O-methyltransferase (COMT) and Ferulate-5-hydroxylase (F5H) were found to be suppressed in oil palm flowers. Among the transcripts encoding transcription factors, an EAR-motif-containing R2R3-MYB transcription factor (EgMYB4) was found to be enriched in oil palm flowers. We determined that EgMYB4 can suppress the expression of a monolignol pathway gene, EgCOMT, in vivo by binding to the AC elements present in the promoter region. EgMYB4 was further functionally characterized in sweet basil which also produces phenylpropenes like oil palm. Transgenic sweet basil plants showed significant reduction in lignin content but produced more phenylpropenes. Our results suggest that EgMYB4 possibly restrains lignin biosynthesis in oil palm flowers thus allowing enhanced carbon flux into the phenylpropene pathway. This study augments our understanding of the diverse roles that EAR-motif-containing MYBs play to

  15. Members of an R2R3-MYB transcription factor family in Petunia are developmentally and environmentally regulated to control complex floral and vegetative pigmentation patterning.

    Science.gov (United States)

    Albert, Nick W; Lewis, David H; Zhang, Huaibi; Schwinn, Kathy E; Jameson, Paula E; Davies, Kevin M

    2011-03-01

    We present an investigation of anthocyanin regulation over the entire petunia plant, determining the mechanisms governing complex floral pigmentation patterning and environmentally induced vegetative anthocyanin synthesis. DEEP PURPLE (DPL) and PURPLE HAZE (PHZ) encode members of the R2R3-MYB transcription factor family that regulate anthocyanin synthesis in petunia, and control anthocyanin production in vegetative tissues and contribute to floral pigmentation. In addition to these two MYB factors, the basic helix-loop-helix (bHLH) factor ANTHOCYANIN1 (AN1) and WD-repeat protein AN11, are also essential for vegetative pigmentation. The induction of anthocyanins in vegetative tissues by high light was tightly correlated to the induction of transcripts for PHZ and AN1. Interestingly, transcripts for PhMYB27, a putative R2R3-MYB active repressor, were highly expressed during non-inductive shade conditions and repressed during high light. The competitive inhibitor PhMYBx (R3-MYB) was expressed under high light, which may provide feedback repression. In floral tissues DPL regulates vein-associated anthocyanin pigmentation in the flower tube, while PHZ determines light-induced anthocyanin accumulation on exposed petal surfaces (bud-blush). A model is presented suggesting how complex floral and vegetative pigmentation patterns are derived in petunia in terms of MYB, bHLH and WDR co-regulators. © 2011 The Authors. The Plant Journal © 2011 Blackwell Publishing Ltd.

  16. Overexpression of PtrMYB119, a R2R3-MYB transcription factor from Populus trichocarpa, promotes anthocyanin production in hybrid poplar.

    Science.gov (United States)

    Cho, Jin-Seong; Nguyen, Van Phap; Jeon, Hyung-Woo; Kim, Min-Ha; Eom, Seok Hyun; Lim, You Jin; Kim, Won-Chan; Park, Eung-Jun; Choi, Young-Im; Ko, Jae-Heung

    2016-09-01

    Anthocyanins are a group of colorful and bioactive natural pigments with important physiological and ecological functions in plants. We found an MYB transcription factor (PtrMYB119) from Populus trichocarpa that positively regulates anthocyanin production when expressed under the control of the CaMV 35S promoter in transgenic Arabidopsis Amino acid sequence analysis revealed that PtrMYB119 is highly homologous to Arabidopsis PAP1 (PRODUCTION OF ANTHOCYANIN PIGMENT1), a well-known transcriptional activator of anthocyanin biosynthesis. Independently produced transgenic poplars overexpressing PtrMYB119 or PtrMYB120 (a paralogous gene to PtrMYB119) (i.e., 35S::PtrMYB119 and 35S::PtrMYB120, respectively) showed elevated accumulation of anthocyanins in the whole plants, including leaf, stem and even root tissues. Using a reverse-phase high-performance liquid chromatography, we confirmed that the majority of the accumulated anthocyanin in our transgenic poplar is cyanidin-3-O-glucoside. Gene expression analyses revealed that most of the genes involved in the anthocyanin biosynthetic pathway were highly upregulated in 35S::PtrMYB119 poplars compared with the nontransformed control poplar. Among these genes, expression of PtrCHS1 (Chalcone Synthase1) and PtrANS2 (Anthocyanin Synthase2), which catalyze the initial and last steps of anthocyanin biosynthesis, respectively, was upregulated by up to 350-fold. Subsequent transient activation assays confirmed that PtrMYB119 activated the transcription of both PtrCHS1 and PtrANS2 Interestingly, expression of MYB182, a repressor of both anthocyanin and proanthocyanidin (PA) biosynthesis, was largely suppressed in 35S::PtrMYB119 poplars, while expression of MYB134, an activator of PA biosynthesis, was not changed significantly. More interestingly, high-level accumulation of anthocyanins in 35S::PtrMYB119 poplars did not have an adverse effect on plant growth. Taken together, our results demonstrate that PtrMYB119 and PtrMYB120

  17. TaMYB13-1, a R2R3 MYB transcription factor, regulates the fructan synthetic pathway and contributes to enhanced fructan accumulation in bread wheat

    Science.gov (United States)

    Kooiker, Maarten; Drenth, Janneke; Glassop, Donna; McIntyre, C. Lynne; Xue, Gang-Ping

    2013-01-01

    Fructans are the major component of temporary carbon reserve in the stem of temperate cereals, which is used for grain filling. Three families of fructosyltransferases are directly involved in fructan synthesis in the vacuole of Triticum aestivum. The regulatory network of the fructan synthetic pathway is largely unknown. Recently, a sucrose-upregulated wheat MYB transcription factor (TaMYB13-1) was shown to be capable of activating the promoter activities of sucrose:sucrose 1-fructosyltransferase (1-SST) and sucrose:fructan 6-fructosyltransferase (6-SFT) in transient transactivation assays. This work investigated TaMYB13-1 target genes and their influence on fructan synthesis in transgenic wheat. TaMYB13-1 overexpression resulted in upregulation of all three families of fructosyltransferases including fructan:fructan 1-fructosyltransferase (1-FFT). A γ-vacuolar processing enzyme (γ-VPE1), potentially involved in processing the maturation of fructosyltransferases in the vacuole, was also upregulated by TaMYB13-1 overexpression. Multiple TaMYB13 DNA-binding motifs were identified in the Ta1-FFT1 and Taγ-VPE1 promoters and were bound strongly by TaMYB13-1. The expression profiles of these target genes and TaMYB13-1 were highly correlated in recombinant inbred lines and during stem development as well as the transgenic and non-transgenic wheat dataset, further supporting a direct regulation of these genes by TaMYB13-1. TaMYB13-1 overexpression in wheat led to enhanced fructan accumulation in the leaves and stems and also increased spike weight and grain weight per spike in transgenic plants under water-limited conditions. These data suggest that TaMYB13-1 plays an important role in coordinated upregulation of genes necessary for fructan synthesis and can be used as a molecular tool to improve the high fructan trait. PMID:23873993

  18. A dominant negative mutant of an Arabidopsis R2R3 Myb (AtMyb90) blocks flower pigment production in tobacco

    Science.gov (United States)

    A spontaneous mutation converted a hyper-pigmented (anthocyanins), CaMV-35S-pro::AtMYB90 containing, transgenic tobacco line into one displaying wild-type pigmentation in all tissues except for flower petals, which, counter-intuitively, showed anthocyanin levels dramatically below wild-type in the p...

  19. The R2R3-MYB–Like Regulatory Factor EOBI, Acting Downstream of EOBII, Regulates Scent Production by Activating ODO1 and Structural Scent-Related Genes in Petunia[C][W

    Science.gov (United States)

    Spitzer-Rimon, Ben; Farhi, Moran; Albo, Boaz; Cna’ani, Alon; Ben Zvi, Michal Moyal; Masci, Tania; Edelbaum, Orit; Yu, Yixun; Shklarman, Elena; Ovadis, Marianna; Vainstein, Alexander

    2012-01-01

    Flower scent is a highly dynamic trait, under developmental, spatial, and diurnal regulation. The mechanism governing scent production is only beginning to be unraveled. In petunia (Petunia hybrida), EMISSION OF BENZENOIDS II (EOBII) controls transcription of both the shikimate pathway-regulating MYB factor ODORANT1 (ODO1) and phenylpropanoid scent-related structural genes. A promoter-activation screen identified an R2R3-MYB–like regulatory factor of phenylpropanoid volatile biosynthesis acting downstream of EOBII, designated EOBI. EOBI silencing led to downregulation of ODO1 and numerous structural scent-related genes from both the shikimate and phenylpropanoid pathways. The ability of EOBI to directly activate ODO1, as revealed by electrophoretic mobility shift assay and yeast one-hybrid analysis, place EOBI upstream of ODO1 in regulating substrate availability for volatile biosynthesis. Interestingly, ODO1-silenced transgenic petunia flowers accumulated higher EOBI transcript levels than controls, suggesting a complex feedback loop between these regulatory factors. The accumulation pattern of EOBI transcript relative to EOBII and ODO1, and the effect of up/downregulation of EOBII on transcript levels of EOBI and ODO1, further support these factors' hierarchical relationships. The dependence of scent production on EOBI expression and its direct interaction with both regulatory and structural genes provide evidence for EOBI’s wide-ranging involvement in the production of floral volatiles. PMID:23275577

  20. PH4 of petunia is an R2R3-MYB protein that activates vacuolar acidification through interactions with Basic-Helix-Loop-Helix transcription factors of the anthocyanin pathway.

    NARCIS (Netherlands)

    Quattrocchio, F.M.; Verweij, C.W.; Spelt, C.E.; Mol, J.N.M.; Koes, R.E.

    2007-01-01

    The Petunia hybrids genes ANTHOCYANIN1 (AN1) and AN2 encode transcription factors with a basic-helix-loop-helix (BHLH) and a MYB domain, respectively, that are required for anthocyanin synthesis and acidification of the vacuole in petal cells. Mutation of PH4 results in a bluer flower color,

  1. PH4 of petunia is an R2R3-MYB protein that activates vacuolar acidification through interactions with Basic-Helix-Loop transcription factors of the anthocyanin pathway.

    NARCIS (Netherlands)

    Quattrocchio, F.M.; Verweij, C.W.; Kroon, A.R.; Spelt, C.E.; Mol, J.N.M.; Koes, R.E.

    2006-01-01

    The Petunia hybrids genes ANTHOCYANIN1 (AN1) and AN2 encode transcription factors with a basic-helix-loop-helix (BHLH) and a MYB domain, respectively, that are required for anthocyanin synthesis and acidification of the vacuole in petal cells. Mutation of PH4 results in a bluer flower color,

  2. Genomic Survey and Expression Profiling of the MYB Gene Family in Watermelon

    Directory of Open Access Journals (Sweden)

    Qing XU

    2018-01-01

    Full Text Available Myeloblastosis (MYB proteins constitute one of the largest transcription factor (TF families in plants. They are functionally diverse in regulating plant development, metabolism, and multiple stress responses. However, the function of watermelon MYB proteins remains elusive to date. Here, a genome-wide identification of watermelon MYB TFs was performed by bioinformatics analysis. A total of 162 MYB genes were identified from watermelon (ClaMYB. A comprehensive overview of the ClaMYB genes was undertaken, including the gene structures, chromosomal distribution, gene duplication, conserved protein motif, and phylogenetic relationship. According to the analyses, the watermelon MYB genes were categorized into three groups (R1R2R3-MYB, R2R3-MYB, and MYB-related. Amino acid alignments for all MYB motifs of ClaMYBs demonstrated high conservation. Investigation of their chromosomal localization revealed that these ClaMYB genes distributed across the 11 watermelon chromosomes. Gene duplication analyses showed that tandem duplication events contributed predominantly to the expansion of the MYB gene family in the watermelon genome. Phylogenetic comparison of the ClaMYB proteins with Arabidopsis MYB proteins revealed that watermelon MYB proteins underwent a more diverse evolution after divergence from Arabidopsis. Some watermelon MYBs were found to cluster into the functional clades of Arabidopsis MYB proteins. Expression analysis under different stress conditions identified a group of watermelon MYB proteins implicated in the plant stress responses. The comprehensive investigation of watermelon MYB genes in this study provides a useful reference for future cloning and functional analysis of watermelon MYB proteins. Keywords: watermelon, MYB transcription factor, abiotic stress, phylogenetic analysis

  3. Genome-wide analysis of the MYB gene family in physic nut (Jatropha curcas L.).

    Science.gov (United States)

    Zhou, Changpin; Chen, Yanbo; Wu, Zhenying; Lu, Wenjia; Han, Jinli; Wu, Pingzhi; Chen, Yaping; Li, Meiru; Jiang, Huawu; Wu, Guojiang

    2015-11-01

    The MYB proteins comprise one of the largest transcription factor families in plants, and play key roles in regulatory networks controlling development, metabolism, and stress responses. A total of 125 MYB genes (JcMYB) have been identified in the physic nut (Jatropha curcas L.) genome, including 120 2R-type MYB, 4 3R-MYB, and 1 4R-MYB genes. Based on exon-intron arrangement of MYBs from both lower (Physcomitrella patens) and higher (physic nut, Arabidopsis, and rice) plants, we can classify plant MYB genes into ten groups (MI-X), except for MIX genes which are nonexistent in higher plants. We also observed that MVIII genes may be one of the most ancient MYB types which consist of both R2R3- and 3R-MYB genes. Most MYB genes (76.8% in physic nut) belong to the MI group which can be divided into 34 subgroups. The JcMYB genes were nonrandomly distributed on its 11 linkage groups (LGs). The expansion of MYB genes across several subgroups was observed and resulted from genome triplication of ancient dicotyledons and from both ancient and recent tandem duplication events in the physic nut genome. The expression patterns of several MYB duplicates in the physic nut showed differences in four tissues (root, stem, leaf, and seed), and 34 MYB genes responded to at least one abiotic stressor (drought, salinity, phosphate starvation, and nitrogen starvation) in leaves and/or roots based on the data analysis of digital gene expression tags. Overexpression of the JcMYB001 gene in Arabidopsis increased its sensitivity to drought and salinity stresses. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Arabidopsis MYB68 in development and responses to environmental cues

    DEFF Research Database (Denmark)

    Feng, Caiping; Andreasson, E.; Maslak, A.

    2004-01-01

    The Arabidopsis MYB68 gene encodes a MYB family protein with N-terminal R2R3 DNA-binding domains. Analyses of MYB68 expression by RNA blot and a transposant gene-trap MYB68::GUS reporter indicated that MYB68 is expressed specifically in root pericycle cells. Root cultures of the myb68 mutant......, caused by the gene trap insertion in the first MYB68 exon, produced increased biomass and lignin levels compared to wild type. Under high temperature regimes, MYB68::GUS activity was elevated in roots, while vegetative growth of myb68 mutants was reduced compared to wild type. These data suggest that MYB...

  5. The FOUR LIPS and MYB88 transcription factor genes are widely expressed in Arabidopsis thaliana during development.

    Science.gov (United States)

    Lei, Qin; Lee, EunKyoung; Keerthisinghe, Sandra; Lai, Lien; Li, Meng; Lucas, Jessica R; Wen, Xiaohong; Ren, Xiaolin; Sack, Fred D

    2015-09-01

    The FOUR LIPS (FLP) and MYB88 transcription factors, which are closely related in structure and function, control the development of stomata, as well as entry into megasporogenesis in Arabidopsis thaliana. However, other locations where these transcription factors are expressed are poorly described. Documenting additional locations where these genes are expressed might define new functions for these genes. Expression patterns were examined throughout vegetative and reproductive development. The expression from two transcriptional-reporter fusions were visualized with either β-glucuronidase (GUS) or green fluorescence protein (GFP). Both flp and myb88 genes were expressed in many, previously unreported locations, consistent with the possibility of additional functions for FLP and MYB88. Moreover, expression domains especially of FLP display sharp cutoffs or boundaries. In addition to stomatal and reproductive development, FLP and MYB88, which are R2R3 MYB transcription factor genes, are expressed in many locations in cells, tissues, and organs. © 2015 Botanical Society of America.

  6. Identification and Characterization of the Diverse Stress-Responsive R2R3-RMYB Transcription Factor from Hibiscus sabdariffa L.

    Science.gov (United States)

    Mohamed, Bahaeldeen Babikar; Aftab, Beenish; Sarwar, Muhammad Bilal; Ahmad, Zarnab; Hassan, Sameera; Husnain, Tayyab

    2017-01-01

    Various regulatory proteins play a fundamental role to manage the healthy plant growth under stress conditions. Differential display reverse transcriptase PCR and random amplification of cDNA ends (RACE) was used to explore the osmotic stress-responsive transcripts. We identified and characterized the salt stress-responsive R2R3 type RMYB transcription factor from Hibiscus sabdariffa which has an open reading frame of 690 bp, encoding 229 long chain amino acids. In silico analysis confirmed the conserved R2 and R3 domain as well as an NLS-1 localization site. The deduced amino acids of RMYB shared 83, 81, 80, 79, 72, 71, and 66% homology with Arabidopsis thaliana, Glycine max, Oryza sativa, Zea maize, Malus domestica, Populus tremula × Populus alba, and Medicago sativa specific MYB family, respectively. We observed the gene upregulation in stem, leaf, and root tissue in response to abiotic stress. Furthermore, RMYB gene was cloned into plant expression vector under CaMV35S promoter and transformed to Gossypium hirsutum: a local cotton cultivar. Overexpression of RMYB was observed in transgenic plants under abiotic stresses which further suggests its regulatory role in response to stressful conditions. The RMYB transcription factor-overexpressing in transgenic cotton plants may be used as potential agent for the development of stress tolerant crop cultivars. PMID:29181384

  7. The sweet potato IbMYB1 gene as a potential visible marker for sweet potato intragenic vector system.

    Science.gov (United States)

    Kim, Cha Young; Ahn, Young Ock; Kim, Sun Ha; Kim, Yun-Hee; Lee, Haeng-Soon; Catanach, Andrew S; Jacobs, Jeanne M E; Conner, Anthony J; Kwak, Sang-Soo

    2010-07-01

    MYB transcription factors play important roles in transcriptional regulation of many secondary metabolites including anthocyanins. We cloned the R2R3-MYB type IbMYB1 complementary DNAs from the purple-fleshed sweet potato (Ipomoea batatas L. cv Sinzami) and investigated the expression patterns of IbMYB1 gene with IbMYB1a and IbMYB1b splice variants in leaf and root tissues of various sweet potato cultivars by reverse transcription-polymerase chain reaction. The transcripts of IbMYB1 were predominantly expressed in the purple-fleshed storage roots and they were also detectable in the leaf tissues accumulating anthocyanin pigments. In addition, transcript levels of IbMYB1 gene were up-regulated by treatment with methyl jasmonate or salicylic acid in leaf and root tissues of cv. White Star. To set up the intragenic vector system in sweet potato, we first evaluated the utilization of the IbMYB1 gene as a visible selectable marker. The IbMYB1a was transiently expressed in tobacco leaves under the control of a constitutive cauliflower mosaic virus 35S promoter, a root-specific and sucrose-inducible sporamin promoter, and an oxidative stress-inducible sweet potato anionic peroxidase2 promoter. We also showed that overexpression of IbMYB1a induced massive anthocyanin pigmentation in tobacco leaves and up-regulated the transcript levels of the structural genes in anthocyanin biosynthetic pathway. Furthermore, high-performance liquid chromatography analysis revealed that the expression of IbMYB1a led to production of cyanidin as a major core molecule of anthocyanidins in tobacco leaves. These results suggest that the IbMYB1 gene can be applicable to a visible marker for sweet potato transformation with intragenic vectors, as well as the production of anthocyanin as important nutritive value in other plant species.

  8. Genome-wide classification and expression analysis of MYB transcription factor families in rice and Arabidopsis

    Science.gov (United States)

    2012-01-01

    Background The MYB gene family comprises one of the richest groups of transcription factors in plants. Plant MYB proteins are characterized by a highly conserved MYB DNA-binding domain. MYB proteins are classified into four major groups namely, 1R-MYB, 2R-MYB, 3R-MYB and 4R-MYB based on the number and position of MYB repeats. MYB transcription factors are involved in plant development, secondary metabolism, hormone signal transduction, disease resistance and abiotic stress tolerance. A comparative analysis of MYB family genes in rice and Arabidopsis will help reveal the evolution and function of MYB genes in plants. Results A genome-wide analysis identified at least 155 and 197 MYB genes in rice and Arabidopsis, respectively. Gene structure analysis revealed that MYB family genes possess relatively more number of introns in the middle as compared with C- and N-terminal regions of the predicted genes. Intronless MYB-genes are highly conserved both in rice and Arabidopsis. MYB genes encoding R2R3 repeat MYB proteins retained conserved gene structure with three exons and two introns, whereas genes encoding R1R2R3 repeat containing proteins consist of six exons and five introns. The splicing pattern is similar among R1R2R3 MYB genes in Arabidopsis. In contrast, variation in splicing pattern was observed among R1R2R3 MYB members of rice. Consensus motif analysis of 1kb upstream region (5′ to translation initiation codon) of MYB gene ORFs led to the identification of conserved and over-represented cis-motifs in both rice and Arabidopsis. Real-time quantitative RT-PCR analysis showed that several members of MYBs are up-regulated by various abiotic stresses both in rice and Arabidopsis. Conclusion A comprehensive genome-wide analysis of chromosomal distribution, tandem repeats and phylogenetic relationship of MYB family genes in rice and Arabidopsis suggested their evolution via duplication. Genome-wide comparative analysis of MYB genes and their expression analysis

  9. VIGS approach reveals the modulation of anthocyanin biosynthetic genes by CaMYB in Chili pepper leaves

    Directory of Open Access Journals (Sweden)

    zhen ezhang

    2015-07-01

    Full Text Available The purple coloration of pepper leaves arises from the accumulation of anthocyanin. Three regulatory and 12 structural genes have been characterized for their involvement in the anthocyanin biosynthesis. Examination of the abundance of these genes in leaves showed that the majority of them differed between anthocyanin pigmented line Z1 and non-pigmented line A3. Silencing of the R2R3-MYB transcription factor CaMYB in pepper leaves of Z1 resulted in the loss of anthocyanin accumulation. Moreover, the expression of multiple genes was altered in the silenced leaves. The expression of MYC was significantly lower in CaMYB-silenced leaves, whereas WD40 showed the opposite pattern. Most structural genes including CHS, CHI, F3H, F3’5’H, DFR, ANS, UFGT, ANP and GST were repressed in CaMYB-silenced foliage with the exception of PAL, C4H and 4CL. These results indicated that MYB plays an important role in the regulation of anthocyanin biosynthetic related genes. Besides CaMYB silenced leaves rendered more sporulation of Phytophthora capsici Leonian indicating that CaMYB might be involved in the defense response to pathogens.

  10. The MYB182 protein down-regulates proanthocyanidin and anthocyanin biosynthesis in poplar by repressing both structural and regulatory flavonoid genes.

    Science.gov (United States)

    Yoshida, Kazuko; Ma, Dawei; Constabel, C Peter

    2015-03-01

    Trees in the genus Populus (poplar) contain phenolic secondary metabolites including the proanthocyanidins (PAs), which help to adapt these widespread trees to diverse environments. The transcriptional activation of PA biosynthesis in response to herbivory and ultraviolet light stress has been documented in poplar leaves, and a regulator of this process, the R2R3-MYB transcription factor MYB134, has been identified. MYB134-overexpressing transgenic plants show a strong high-PA phenotype. Analysis of these transgenic plants suggested the involvement of additional MYB transcription factors, including repressor-like MYB factors. Here, MYB182, a subgroup 4 MYB factor, was found to act as a negative regulator of the flavonoid pathway. Overexpression of MYB182 in hairy root culture and whole poplar plants led to reduced PA and anthocyanin levels as well as a reduction in the expression of key flavonoid genes. Similarly, a reduced accumulation of transcripts of a MYB PA activator and a basic helix-loop-helix cofactor was observed in MYB182-overexpressing hairy roots. Transient promoter activation assays in poplar cell culture demonstrated that MYB182 can disrupt transcriptional activation by MYB134 and that the basic helix-loop-helix-binding motif of MYB182 was essential for repression. Microarray analysis of transgenic plants demonstrated that down-regulated targets of MYB182 also include shikimate pathway genes. This work shows that MYB182 plays an important role in the fine-tuning of MYB134-mediated flavonoid metabolism. © 2015 American Society of Plant Biologists. All Rights Reserved.

  11. Identification and expression analyses of MYB and WRKY transcription factor genes in Papaver somniferum L.

    Science.gov (United States)

    Kakeshpour, Tayebeh; Nayebi, Shadi; Rashidi Monfared, Sajad; Moieni, Ahmad; Karimzadeh, Ghasem

    2015-10-01

    Papaver somniferum L. is an herbaceous, annual and diploid plant that is important from pharmacological and strategic point of view. The cDNA clones of two putative MYB and WRKY genes were isolated (GeneBank accession numbers KP411870 and KP203854, respectively) from this plant, via the nested-PCR method, and characterized. The MYB transcription factor (TF) comprises 342 amino acids, and exhibits the structural features of the R2R3MYB protein family. The WRKY TF, a 326 amino acid-long polypeptide, falls structurally into the group II of WRKY protein family. Quantitative real-time PCR (qRT-PCR) analyses indicate the presence of these TFs in all organs of P. somniferum L. and Papaver bracteatum L. Highest expression levels of these two TFs were observed in the leaf tissues of P. somniferum L. while in P. bracteatum L. the espression levels were highest in the root tissues. Promoter analysis of the 10 co-expressed gene clustered involved in noscapine biosynthesis pathway in P. somniferum L. suggested that not only these 10 genes are co-expressed, but also share common regulatory motifs and TFs including MYB and WRKY TFs, and that may explain their common regulation.

  12. An R2R3-MYB Transcription Factor Regulates Eugenol Production in Ripe Strawberry Fruit Receptacles

    NARCIS (Netherlands)

    Medina-Puche, L.; Molina-Hidalgo, F.J.; Boersma, M.; Schuurink, R.C.; López-Vidriero, I.; Solano, R.; Franco-Zorrilla, J.M.; Caballero, J.L.; Blanco-Portales, R.; Muñoz-Blanco, J.

    2015-01-01

    Eugenol is a volatile phenylpropanoid that contributes to flower and ripe fruit scent. In ripe strawberry (Fragaria x ananassa) fruit receptacles, eugenol is biosynthesized by eugenol synthase (FaEGS2). However, the transcriptional regulation of this process is still unknown. We have identified and

  13. CsMYB5a and CsMYB5e from Camellia sinensis differentially regulate anthocyanin and proanthocyanidin biosynthesis.

    Science.gov (United States)

    Jiang, Xiaolan; Huang, Keyi; Zheng, Guangshun; Hou, Hua; Wang, Peiqiang; Jiang, Han; Zhao, Xuecheng; Li, Mingzhuo; Zhang, Shuxiang; Liu, Yajun; Gao, Liping; Zhao, Lei; Xia, Tao

    2018-05-01

    Tea is one of the most widely consumed nonalcoholic beverages worldwide. Polyphenols are nutritional compounds present in the leaves of tea plants. Although numerous genes are functionally characterized to encode enzymes that catalyze the formation of diverse polyphenolic metabolites, transcriptional regulation of those different pathways such as late steps of the proanthcoyanidin (PA) pathway remains unclear. In this study, using different tea transcriptome databases, we screened at least 140 R2R3-MYB transcription factors (TFs) and grouped them according to the basic function domains of the R2R3 MYB TF superfamily. Among 140 R2R3 TFs, CsMYB5a and CsMYB5e were chosen for analysis because they may be involved in PA biosynthesis regulation. CsMYB5a-overexpressing tobacco plants exhibited downregulated anthocyanin accumulation but a high polymeric PA content in the flowers. Overexpression of CsMYB5e in tobacco plants did not change the anthocyanin content but increased the dimethylaminocinnamaldehyde-stained PA content. RNA-seq and qRT-PCR analyses revealed that genes related to PA and anthocyanin biosynthesis pathways were markedly upregulated in both CsMYB5a- and CsMYB5e-overexpressing flowers. Three UGTs and four GSTs were identified as involved in PA and anthocyanin glycosylation and transportation in transgenic plants. These results provide new insights into the regulation of PA and anthocyanin biosynthesis in Camellia sinensis. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. An apple MYB transcription factor, MdMYB3, is involved in regulation of anthocyanin biosynthesis and flower development.

    Science.gov (United States)

    Vimolmangkang, Sornkanok; Han, Yuepeng; Wei, Guochao; Korban, Schuyler S

    2013-11-07

    Red coloration of fruit is an important trait in apple, and it is mainly attributed to the accumulation of anthocyanins, a class of plant flavonoid metabolites. Anthocyanin biosynthesis is genetically determined by structural and regulatory genes. Plant tissue pigmentation patterns are mainly controlled by expression profiles of regulatory genes. Among these regulatory genes are MYB transcription factors (TFs), wherein the class of two-repeats (R2R3) is deemed the largest, and these are associated with the anthocyanin biosynthesis pathway. Although three MdMYB genes, almost identical in nucleotide sequences, have been identified in apple, it is likely that there are other R2R3 MYB TFs that are present in the apple genome that are also involved in the regulation of coloration of red color pigmentation of the skin of apple fruits. In this study, a novel R2R3 MYB gene has been isolated and characterized in apple. This MYB gene is closely related to the Arabidopsis thaliana AtMYB3, and has been designated as MdMYB3. This TF belongs to the subgroup 4 R2R3 family of plant MYB transcription factors. This apple MdMYB3 gene is mapped onto linkage group 15 of the integrated apple genetic map. Transcripts of MdMYB3 are detected in all analyzed tissues including leaves, flowers, and fruits. However, transcripts of MdMYB3 are higher in excocarp of red-skinned apple cultivars than that in yellowish-green skinned apple cultivars. When this gene is ectopically expressed in Nicotiana tabacum cv. Petite Havana SR1, flowers of transgenic tobacco lines carrying MdMYB3 have exhibited increased pigmentation and accumulate higher levels of anthocyanins and flavonols than wild-type flowers. Overexpression of MdMYB3 has resulted in transcriptional activation of several flavonoid pathway genes, including CHS, CHI, UFGT, and FLS. Moreover, peduncles of flowers and styles of pistils of transgenic plants overexpressing MdMYB3 are longer than those of wild-type plants, thus suggesting that this

  15. Combinatorial analysis of lupulin gland transcription factors from R2R3Myb, bHLH and WDR families indicates a complex regulation of chs_H1 genes essential for prenylflavonoid biosynthesis in hop (Humulus lupulus L.)

    Czech Academy of Sciences Publication Activity Database

    Matoušek, Jaroslav; Kocábek, Tomáš; Patzak, J.; Füssy, Zoltán; Procházková, Jitka; Heyerick, A.

    2012-01-01

    Roč. 12, č. 27 (2012), s. 1471-2229 ISSN 1471-2229 R&D Projects: GA ČR GA521/08/0740; GA MZe QH81052 Institutional research plan: CEZ:AV0Z50510513 Keywords : transcription factor * protein complexes * transient expression assay Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.354, year: 2012

  16. Identification of transcription factors ZmMYB111and ZmMYB148 involved in phenylpropanoid metabolism

    Directory of Open Access Journals (Sweden)

    Junjie eZhang

    2016-02-01

    Full Text Available Maize is the leading crop worldwide in terms of both planting area and total yields, but environmental stresses cause significant losses in productivity. Phenylpropanoid compounds play an important role in plant stress resistance; however, the mechanism of their synthesis is not fully understood, especially in regard to the expression and regulation of key genes. Phenylalanine ammonia-lyase (PAL is the first key enzyme involved in phenylpropanoid metabolism, and it has a significant effect on the synthesis of important phenylpropanoid compounds. According to the results of sequence alignments and functional prediction, we selected two conserved R2R3-MYB transcription factors as candidate genes for the regulation of phenylpropanoid metabolism. The two candidate R2R3-MYB genes, which we named ZmMYB111and ZmMYB148, were cloned, and then their structural characteristics and phylogenetic placement were predicted and analyzed. In addition, a series of evaluations were performed, including expression profiles, subcellular localization, transcription activation, protein-DNA interaction, and transient expression in maize endosperm. Our results indicated that both ZmMYB111 and ZmMYB148 are indeed R2R3-MYB transcription factors and that they may play a regulatory role in PAL gene expression.

  17. A MYB transcription factor, DcMYB6, is involved in regulating anthocyanin biosynthesis in purple carrot taproots

    OpenAIRE

    Xu, Zhi-Sheng; Feng, Kai; Que, Feng; Wang, Feng; Xiong, Ai-Sheng

    2017-01-01

    Carrots are widely grown and enjoyed around the world. Purple carrots accumulate rich anthocyanins in the taproots, while orange, yellow, and red carrots accumulate rich carotenoids in the taproots. Our previous studies indicated that variation in the activity of regulatory genes may be responsible for variations in anthocyanin production among various carrot cultivars. In this study, an R2R3-type MYB gene, designated as DcMYB6, was isolated from a purple carrot cultivar. In a phylogenetic an...

  18. Genome-Wide Identification, Evolution and Functional Divergence of MYB Transcription Factors in Chinese White Pear (Pyrus bretschneideri).

    Science.gov (United States)

    Li, Xiaolong; Xue, Cheng; Li, Jiaming; Qiao, Xin; Li, Leiting; Yu, Li'ang; Huang, Yuhua; Wu, Jun

    2016-04-01

    The MYB superfamily is large and functionally diverse in plants. To date, MYB family genes have not yet been identified in Chinese white pear (Pyrus bretschneideri), and their functions remain unclear. In this study, we identified 231 genes as candidate MYB genes and divided them into four subfamilies. The R2R3-MYB (PbrMYB) family shared an R2R3 domain with 104 amino acid residues, including five conserved tryptophan residues. The Pbr MYB family was divided into 37 functional subgroups including 33 subgroups which contained both MYB genes of Rosaceae plants and AtMYB genes, and four subgroups which included only Rosaceae MYB genes or AtMYB genes. PbrMYB genes with similar functions clustered into the same subgroup, indicating functional conservation. We also found that whole-genome duplication (WGD) and dispersed duplications played critical roles in the expansion of the MYB family. The 87 Pbr MYB duplicated gene pairs dated back to the two WGD events. Purifying selection was the primary force driving Pbr MYB gene evolution. The 15 gene pairs presented 1-7 codon sites under positive selection. A total of 147 expressed genes were identified from RNA-sequencing data of fruit, and six Pbr MYB members in subgroup C1 were identified as important candidate genes in the regulation of lignin synthesis by quantitative real-time PCR analysis. Further correlation analysis revealed that six PbrMYBs were significantly correlated with five structural gene families (F5H, HCT, CCR, POD and C3'H) in the lignin pathway. The phylogenetic, evolution and expression analyses of the MYB gene family in Chinese white pear establish a solid foundation for future comprehensive functional analysis of Pbr MYB genes. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  19. Two MYB-related transcription factors play opposite roles in sugar signaling in Arabidopsis.

    Science.gov (United States)

    Chen, Yi-Shih; Chao, Yi-Chi; Tseng, Tzu-Wei; Huang, Chun-Kai; Lo, Pei-Ching; Lu, Chung-An

    2017-02-01

    Sugar regulation of gene expression has profound effects at all stages of the plant life cycle. Although regulation at the transcriptional level is one of the most prominent mechanisms by which gene expression is regulated, only a few transcription factors have been identified and demonstrated to be involved in the regulation of sugar-regulated gene expression. OsMYBS1, an R1/2-type MYB transcription factor, has been demonstrated to be involved in sugar- and hormone-regulated α-amylase gene expression in rice. Arabidopsis contains two OsMYBS1 homologs. In the present study, we investigate MYBS1 and MYBS2 in sugar signaling in Arabidopsis. Our results indicate that MYBS1 and MYBS2 play opposite roles in regulating glucose and ABA signaling in Arabidopsis during seed germination and early seedling development. MYB proteins have been classified into four subfamilies: R2R3-MYB, R1/2-MYB, 3R-MYB, and 4R-MYB. An R1/2-type MYB transcription factor, OsMYBS1, has been demonstrated to be involved in sugar- and hormone-regulated α-amylase genes expression in rice. In this study, two genes homologous to OsMYBS1, MYBS1 and MYBS2, were investigated in Arabidopsis. Subcellular localization analysis showed that MYBS1 and MYBS2 were localized in the nucleus. Rice embryo transient expression assays indicated that both MYBS1 and MYBS2 could recognize the sugar response element, TA-box, in the promoter and induced promoter activity. mybs1 mutant exhibited hypersensitivity to glucose, whereas mybs2 seedlings were hyposensitive to it. MYBS1 and MYBS2 are involved in the control of glucose-responsive gene expression, as the mybs1 mutant displayed increased expression of a hexokinase gene (HXK1), chlorophyll a/b-binding protein gene (CAB1), ADP-glucose pyrophosphorylase gene (APL3), and chalcone synthase gene (CHS), whereas the mybs2 mutant exhibited decreased expression of these genes. mybs1 also showed an enhanced response to abscisic acid (ABA) in the seed germination and seedling

  20. Overexpression of the IbMYB1 gene in an orange-fleshed sweet potato cultivar produces a dual-pigmented transgenic sweet potato with improved antioxidant activity.

    Science.gov (United States)

    Park, Sung-Chul; Kim, Yun-Hee; Kim, Sun Ha; Jeong, Yu Jeong; Kim, Cha Young; Lee, Joon Seol; Bae, Ji-Yeong; Ahn, Mi-Jeong; Jeong, Jae Cheol; Lee, Haeng-Soon; Kwak, Sang-Soo

    2015-04-01

    The R2R3-type protein IbMYB1 is a key regulator of anthocyanin biosynthesis in the storage roots of sweet potato [Ipomoea batatas (L.) Lam]. Previously, we demonstrated that IbMYB1 expression stimulated anthocyanin pigmentation in tobacco leaves and Arabidopsis. Here, we generated dual-pigmented transgenic sweet potato plants that accumulated high levels of both anthocyanins and carotenoids in a single sweet potato storage root. An orange-fleshed cultivar with high carotenoid levels was transformed with the IbMYB1 gene under the control of either the storage root-specific sporamin 1 (SPO1) promoter or the oxidative stress-inducible peroxidase anionic 2 (SWPA2) promoter. The SPO1-MYB transgenic lines exhibited higher anthocyanin levels in storage roots than empty vector control (EV) or SWPA2-MYB plants, but carotenoid content was unchanged. SWPA2-MYB transgenic lines exhibited higher levels of both anthocyanin and carotenoids than EV plants. Analysis of hydrolyzed anthocyanin extracts indicated that cyanidin and peonidin predominated in both overexpression lines. Quantitative reverse transcription-polymerase chain reaction analysis demonstrated that IbMYB1 expression in both IbMYB1 transgenic lines strongly induced the upregulation of several genes in the anthocyanin biosynthetic pathway, whereas the expression of carotenoid biosynthetic pathway genes varied between transgenic lines. Increased anthocyanin levels in transgenic plants also promoted the elevation of proanthocyanidin and total phenolic levels in fresh storage roots. Consequently, all IbMYB1 transgenic plants displayed much higher antioxidant activities than EV plants. In field cultivations, storage root yields varied between the transgenic lines. Taken together, our results indicate that overexpression of IbMYB1 is a highly promising strategy for the generation of transgenic plants with enhanced antioxidant capacity. © 2014 Scandinavian Plant Physiology Society.

  1. McMYB12 Transcription Factors Co-regulate Proanthocyanidin and Anthocyanin Biosynthesis in Malus Crabapple

    OpenAIRE

    Tian, Ji; Zhang, Jie; Han, Zhen-yun; Song, Ting-ting; Li, Jin-yan; Wang, Ya-ru; Yao, Yun-cong

    2017-01-01

    The flavonoid compounds, proanthocyanidins (PAs), protect plants from biotic stresses, contribute to the taste of many fruits, and are beneficial to human health in the form of dietary antioxidants. In this study, we functionally characterized two Malus crabapple R2R3-MYB transcription factors, McMYB12a and McMYB12b, which co-regulate PAs and anthocyanin biosynthesis. McMYB12a was shown to be mainly responsible for upregulating the expression of anthocyanin biosynthetic genes by binding to th...

  2. LcMYB1 Is a Key Determinant of Differential Anthocyanin Accumulation among Genotypes, Tissues, Developmental Phases and ABA and Light Stimuli in Litchi chinensis

    OpenAIRE

    Lai, Biao; Li, Xiao-Jing; Hu, Bing; Qin, Yong-Hua; Huang, Xu-Ming; Wang, Hui-Cong; Hu, Gui-Bing

    2014-01-01

    The red coloration of litchi fruit depends on the accumulation of anthocyanins. The anthocyanins level in litchi fruit varies widely among cultivars, developmental stages and environmental stimuli. Previous studies on various plant species demonstrate that anthocyanin biosynthesis is controlled at the transcriptional level. Here, we describe a litchi R2R3-MYB transcription factor gene, LcMYB1, which demonstrates a similar sequence as other known anthocyanin regulators. The transcription level...

  3. A MYB transcription factor, DcMYB6, is involved in regulating anthocyanin biosynthesis in purple carrot taproots.

    Science.gov (United States)

    Xu, Zhi-Sheng; Feng, Kai; Que, Feng; Wang, Feng; Xiong, Ai-Sheng

    2017-03-27

    Carrots are widely grown and enjoyed around the world. Purple carrots accumulate rich anthocyanins in the taproots, while orange, yellow, and red carrots accumulate rich carotenoids in the taproots. Our previous studies indicated that variation in the activity of regulatory genes may be responsible for variations in anthocyanin production among various carrot cultivars. In this study, an R2R3-type MYB gene, designated as DcMYB6, was isolated from a purple carrot cultivar. In a phylogenetic analysis, DcMYB6 was grouped into an anthocyanin biosynthesis-related MYB clade. Sequence analyses revealed that DcMYB6 contained the conserved bHLH-interaction motif and two atypical motifs of anthocyanin regulators. The expression pattern of DcMYB6 was correlated with anthocyanin production. DcMYB6 transcripts were detected at high levels in three purple carrot cultivars but at much lower levels in six non-purple carrot cultivars. Overexpression of DcMYB6 in Arabidopsis led to enhanced anthocyanin accumulation in both vegetative and reproductive tissues and upregulated transcript levels of all seven tested anthocyanin-related structural genes. Together, these results show that DcMYB6 is involved in regulating anthocyanin biosynthesis in purple carrots. Our results provide new insights into the regulation of anthocyanin synthesis in purple carrot cultivars.

  4. McMYB12 Transcription Factors Co-regulate Proanthocyanidin and Anthocyanin Biosynthesis in Malus Crabapple.

    Science.gov (United States)

    Tian, Ji; Zhang, Jie; Han, Zhen-Yun; Song, Ting-Ting; Li, Jin-Yan; Wang, Ya-Ru; Yao, Yun-Cong

    2017-03-03

    The flavonoid compounds, proanthocyanidins (PAs), protect plants from biotic stresses, contribute to the taste of many fruits, and are beneficial to human health in the form of dietary antioxidants. In this study, we functionally characterized two Malus crabapple R2R3-MYB transcription factors, McMYB12a and McMYB12b, which co-regulate PAs and anthocyanin biosynthesis. McMYB12a was shown to be mainly responsible for upregulating the expression of anthocyanin biosynthetic genes by binding to their promoters, but to be only partially responsible for regulating PAs biosynthetic genes. In contrast, McMYB12b showed preferential binding to the promoters of PAs biosynthetic genes. Overexpression of McMYB12a and McMYB12b in tobacco (Nicotiana tabacum) altered the expression of flavonoid biosynthetic genes and promoted the accumulation of PAs and anthocyanins in tobacco petals. Conversely, transient silencing their expression in crabapple plants, using a conserved gene region, resulted in reduced PAs and anthocyanin production a green leaf phenotype. Meanwhile, transient overexpression of the two genes and silenced McMYB12s in apple (Malus domestica) fruit had a similar effect as overexpression in tobacco and silenced in crabapple. This study reveals a new mechanism for the coordinated regulation of PAs and anthocyanin accumulation in crabapple leaves, which depends on an auto-regulatory balance involving McMYB12a and McMYB12b expression.

  5. Functional diversification of grapevine MYB5a and MYB5b in the control of flavonoid biosynthesis in a petunia anthocyanin regulatory mutant.

    Science.gov (United States)

    Cavallini, Erika; Zenoni, Sara; Finezzo, Laura; Guzzo, Flavia; Zamboni, Anita; Avesani, Linda; Tornielli, Giovanni Battista

    2014-03-01

    Flavonoids play a key role in grapevine physiology and also contribute substantially to the quality of berries and wines. VvMYB5a and VvMYB5b are R2R3-MYB transcription factors previously proposed to control the spatiotemporal expression of flavonoid structural genes during berry development. We investigated the functions of these two proteins in detail by heterologous expression in a petunia an2 mutant, which has negligible anthocyanin levels in the petals because it lacks the MYB protein PhAN2. We also expressed VvMYBA1, the grapevine ortholog of petunia PhAN2, in the same genetic background. The anthocyanin profiles induced by expressing these transgenes in the petals revealed that VvMYBA1 is the functional ortholog of PhAN2 and that, unlike VvMYB5a, VvMYB5b can partially complement the an2 mutation. Transcriptomic analysis of petals by microarray hybridization and quantitative PCR confirmed that VvMYB5b up-regulates a subset of anthocyanin structural genes, whereas VvMYB5a has a more limited impact on the expression of genes related to anthocyanin biosynthesis. Furthermore, we identified additional specific and common targets of these two regulators, related to vacuolar acidification and membrane remodeling. Taken together, these data provide insight into the role of VvMYB5a and VvMYB5b in flavonoid biosynthesis and provide evidence for additional regulatory roles in distinct pathways.

  6. Molecular characterization of Quercus suber MYB1, a transcription factor up-regulated in cork tissues.

    Science.gov (United States)

    Almeida, Tânia; Menéndez, Esther; Capote, Tiago; Ribeiro, Teresa; Santos, Conceição; Gonçalves, Sónia

    2013-01-15

    The molecular processes associated with cork development in Quercus suber L. are poorly understood. A previous molecular approach identified a list of genes potentially important for cork formation and differentiation, providing a new basis for further molecular studies. This report is the first molecular characterization of one of these candidate genes, QsMYB1, coding for an R2R3-MYB transcription factor. The R2R3-MYB gene sub-family has been described as being involved in the phenylpropanoid and lignin pathways, both involved in cork biosynthesis. The results showed that the expression of QsMYB1 is putatively mediated by an alternative splicing (AS) mechanism that originates two different transcripts (QsMYB1.1 and QsMYB1.2), differing only in the 5'-untranslated region, due to retention of the first intron in one of the variants. Moreover, within the retained intron, a simple sequence repeat (SSR) was identified. The upstream regulatory region of QsMYB1 was extended by a genome walking approach, which allowed the identification of the putative gene promoter region. The relative expression pattern of QsMYB1 transcripts determined by reverse transcription quantitative polymerase chain reaction (RT-qPCR) revealed that both transcripts were up-regulated in cork tissues; the detected expression was several times higher in newly formed cork harvested from trees producing virgin, second or reproduction cork when compared with wood. Moreover, the expression analysis of QsMYB1 in several Q. suber organs showed very low expression in young branches and roots, whereas in leaves, immature acorns or male flowers, no expression was detected. These preliminary results suggest that QsMYB1 may be related to secondary growth and, in particular, with the cork biosynthesis process with a possible alternative splicing mechanism associated with its regulatory function. Copyright © 2012 Elsevier GmbH. All rights reserved.

  7. Over-expression of TaMYB33 encoding a novel wheat MYB transcription factor increases salt and drought tolerance in Arabidopsis.

    Science.gov (United States)

    Qin, Yuxiang; Wang, Mengcheng; Tian, Yanchen; He, Wenxing; Han, Lu; Xia, Guangmin

    2012-06-01

    Salt and drought stresses often adversely affect plant growth and productivity, MYB transcription factors have been shown to participate in the response to these stresses. Here we identified a new R2R3-type MYB transcription factor gene TaMYB33 from wheat (Triticum aestivum). TaMYB33 was induced by NaCl, PEG and ABA treatments, and its promoter sequence contains putative ABRE, MYB and other abiotic stress related cis-elements. Ectopic over-expression of TaMYB33 in Arabidopsis thaliana remarkably enhanced its tolerance to drought and NaCl stresses, but not to LiCl and KCl treatments. The expressions of AtP5CS and AtZAT12 which mirror the activities of proline and ascorbate peroxidase synthesis respectively were induced in TaMYB33 over-expression lines, indicating TaMYB33 promotes the ability for osmotic pressure balance-reconstruction and reactive oxidative species (ROS) scavenging. The up-regulation of AtAAO3 along with down-regulation of AtABF3, AtABI1 in TaMYB33 over-expression lines indicated that ABA synthesis was elevated while its signaling was restricted. These results suggest that TaMYB33 enhances salt and drought tolerance partially through superior ability for osmotic balance reconstruction and ROS detoxification.

  8. Functional Characterization of Tea (Camellia sinensis MYB4a Transcription Factor Using an Integrative Approach

    Directory of Open Access Journals (Sweden)

    Mingzhuo Li

    2017-06-01

    Full Text Available Green tea (Camellia sinensis, Cs abundantly produces a diverse array of phenylpropanoid compounds benefiting human health. To date, the regulation of the phenylpropanoid biosynthesis in tea remains to be investigated. Here, we report a cDNA isolated from leaf tissues, which encodes a R2R3-MYB transcription factor. Amino acid sequence alignment and phylogenetic analysis indicate that it is a member of the MYB4-subgroup and named as CsMYB4a. Transcriptional and metabolic analyses show that the expression profile of CsMYB4a is negatively correlated to the accumulation of six flavan-3-ols and other phenolic acids. GFP fusion analysis shows CsMYB4a’s localization in the nucleus. Promoters of five tea phenylpropanoid pathway genes are isolated and characterized to contain four types of AC-elements, which are targets of MYB4 members. Interaction of CsMYB4a and five promoters shows that CsMYB4a decreases all five promoters’ activity. To further characterize its function, CsMYB4a is overexpressed in tobacco plants. The resulting transgenic plants show dwarf, shrinking and yellowish leaf, and early senescence phenotypes. A further genome-wide transcriptomic analysis reveals that the expression levels of 20 tobacco genes involved in the shikimate and the phenylpropanoid pathways are significantly downregulated in transgenic tobacco plants. UPLC-MS and HPLC based metabolic profiling reveals significant reduction of total lignin content, rutin, chlorogenic acid, and phenylalanine in CsMYB4a transgenic tobacco plants. Promoter sequence analysis of the 20 tobacco genes characterizes four types of AC-elements. Further CsMYB4a-AC element and CsMYB4a-promoter interaction analyses indicate that the negative regulation of CsMYB4a on the shikimate and phenylpropanoid pathways in tobacco is via reducing promoter activity. Taken together, all data indicate that CsMYB4a negatively regulates the phenylpropanoid and shikimate pathways.Highlight: A tea (Camellia

  9. Transgenic wheat expressing Thinopyrum intermedium MYB transcription factor TiMYB2R-1 shows enhanced resistance to the take-all disease.

    Science.gov (United States)

    Liu, Xin; Yang, Lihua; Zhou, Xianyao; Zhou, Miaoping; Lu, Yan; Ma, Lingjian; Ma, Hongxiang; Zhang, Zengyan

    2013-05-01

    The disease take-all, caused by the fungus Gaeumannomyces graminis, is one of the most destructive root diseases of wheat worldwide. Breeding resistant cultivars is an effective way to protect wheat from take-all. However, little progress has been made in improving the disease resistance level in commercial wheat cultivars. MYB transcription factors play important roles in plant responses to environmental stresses. In this study, an R2R3-MYB gene in Thinopyrum intermedium, TiMYB2R-1, was cloned and characterized. The gene sequence includes two exons and an intron. The expression of TiMYB2R-1 was significantly induced following G. graminis infection. An in vitro DNA binding assay proved that TiMYB2R-1 protein could bind to the MYB-binding site cis-element ACI. Subcellular localization assays revealed that TiMYB2R-1 was localized in the nucleus. TiMYB2R-1 transgenic wheat plants were generated, characterized molecularly, and evaluated for take-all resistance. PCR and Southern blot analyses confirmed that TiMYB2R-1 was integrated into the genomes of three independent transgenic wheat lines by distinct patterns and the transgene was heritable. Reverse transcription-PCR and western blot analyses revealed that TiMYB2R-1 was highly expressed in the transgenic wheat lines. Based on disease response assessments for three successive generations, the significantly enhanced resistance to take-all was observed in the three TiMYB2R-1-overexpressing transgenic wheat lines. Furthermore, the transcript levels of at least six wheat defence-related genes were significantly elevated in the TiMYB2R-1 transgenic wheat lines. These results suggest that engineering and overexpression of TiMYB2R-1 may be used for improving take-all resistance of wheat and other cereal crops.

  10. Identification and Regulation of c-Myb Target Genes in MCF-7 Cells

    International Nuclear Information System (INIS)

    Quintana, Anita M; Liu, Fan; O'Rourke, John P; Ness, Scott A

    2011-01-01

    The c-Myb transcription factor regulates differentiation and proliferation in hematopoietic cells, stem cells and epithelial cells. Although oncogenic versions of c-Myb were first associated with leukemias, over expression or rearrangement of the c-myb gene is common in several types of solid tumors, including breast cancers. Expression of the c-myb gene in human breast cancer cells is dependent on estrogen stimulation, but little is known about the activities of the c-Myb protein or what genes it regulates in estrogen-stimulated cells. We used chromatin immunoprecipitation coupled with whole genome promoter tiling microarrays to identify endogenous c-Myb target genes in human MCF-7 breast cancer cells and characterized the activity of c-Myb at a panel of target genes during different stages of estrogen deprivation and stimulation. By using different antibodies and different growth conditions, the c-Myb protein was found associated with over 10,000 promoters in MCF-7 cells, including many genes that encode cell cycle regulators or transcription factors and more than 60 genes that encode microRNAs. Several previously identified c-Myb target genes were identified, including CCNB1, MYC and CXCR4 and novel targets such as JUN, KLF4, NANOG and SND1. By studying a panel of these targets to validate the results, we found that estradiol stimulation triggered the association of c-Myb with promoters and that association correlated with increased target gene expression. We studied one target gene, CXCR4, in detail, showing that c-Myb associated with the CXCR4 gene promoter and activated a CXCR4 reporter gene in transfection assays. Our results show that c-Myb associates with a surprisingly large number of promoters in human cells. The results also suggest that estradiol stimulation leads to large-scale, genome-wide changes in c-Myb activity and subsequent changes in gene expression in human breast cancer cells

  11. Molecular characterization of the Jatropha curcas JcR1MYB1 gene encoding a putative R1-MYB transcription factor

    Directory of Open Access Journals (Sweden)

    Hui-Liang Li

    2014-09-01

    Full Text Available The cDNA encoding the R1-MYB transcription factor, designated as JcR1MYB1, was isolated from Jatropha curcas using rapid amplification of cDNA ends. JcR1MYB1 contains a 951 bp open reading frame that encodes 316 amino acids. The deduced JcR1MYB1 protein was predicted to possess the conserved, 56-amino acid-long DNA-binding domain, which consists of a single helix-turn-helix module and usually occurs in R1-MYBs. JcR1MYB1 is a member of the R1-MYB transcription factor subfamily. A subcellular localization study confirmed the nuclear localization of JcR1MYB1. Expression analysis showed that JcR1MYB1 transcripts accumulated in various examined tissues, with high expression levels in the root and low levels in the stem. JcR1MYB1 transcription was up-regulated by polyethylene glycol, NaCl, and cold treatments, as well as by abscisic acid, jasmonic acid, and ethylene treatment. Analysis of transgenic tobacco plants over-expressing JcR1MYB1 indicates an inportant function for this gene in salt stress.

  12. LcMYB1 is a key determinant of differential anthocyanin accumulation among genotypes, tissues, developmental phases and ABA and light stimuli in Litchi chinensis.

    Directory of Open Access Journals (Sweden)

    Biao Lai

    Full Text Available The red coloration of litchi fruit depends on the accumulation of anthocyanins. The anthocyanins level in litchi fruit varies widely among cultivars, developmental stages and environmental stimuli. Previous studies on various plant species demonstrate that anthocyanin biosynthesis is controlled at the transcriptional level. Here, we describe a litchi R2R3-MYB transcription factor gene, LcMYB1, which demonstrates a similar sequence as other known anthocyanin regulators. The transcription levels of the LcMYB1 and anthocyanin biosynthetic genes were investigated in samples with different anthocyanin levels. The expression of LcMYB1 was strongly associated with tissue anthocyanin content. LcMYB1 transcripts were only detected in anthocyanin-accumulating tissues and were positively correlated with anthocyanin accumulation in the pericarps of 12 genotypes. ABA and sunlight exposure promoted, whereas CPPU and bagging inhibited the expression of LcMYB1 and anthocyanin accumulation in the pericarp. Cis-elements associated with light responsiveness and abscisic acid responsiveness were identified in the promoter region of LcMYB1. Among the 6 structural genes tested, only LcUFGT was highly correlated with LcMYB1. These results suggest that LcMYB1 controls anthocyanin biosynthesis in litchi and LcUFGT might be the structural gene that is targeted and regulated by LcMYB1. Furthermore, the overexpression of LcMYB1 induced anthocyanin accumulation in all tissues in tobacco, confirming the function of LcMYB1 in the regulation of anthocyanin biosynthesis. The upregulation of NtAn1b in response to LcMYB1 overexpression seems to be essential for anthocyanin accumulation in the leaf and pedicel. In the reproductive tissues of transgenic tobacco, however, increased anthocyanin accumulation is independent of tobacco's endogenous MYB and bHLH transcriptional factors, but associated with the upregulation of specific structural genes.

  13. LcMYB1 is a key determinant of differential anthocyanin accumulation among genotypes, tissues, developmental phases and ABA and light stimuli in Litchi chinensis.

    Science.gov (United States)

    Lai, Biao; Li, Xiao-Jing; Hu, Bing; Qin, Yong-Hua; Huang, Xu-Ming; Wang, Hui-Cong; Hu, Gui-Bing

    2014-01-01

    The red coloration of litchi fruit depends on the accumulation of anthocyanins. The anthocyanins level in litchi fruit varies widely among cultivars, developmental stages and environmental stimuli. Previous studies on various plant species demonstrate that anthocyanin biosynthesis is controlled at the transcriptional level. Here, we describe a litchi R2R3-MYB transcription factor gene, LcMYB1, which demonstrates a similar sequence as other known anthocyanin regulators. The transcription levels of the LcMYB1 and anthocyanin biosynthetic genes were investigated in samples with different anthocyanin levels. The expression of LcMYB1 was strongly associated with tissue anthocyanin content. LcMYB1 transcripts were only detected in anthocyanin-accumulating tissues and were positively correlated with anthocyanin accumulation in the pericarps of 12 genotypes. ABA and sunlight exposure promoted, whereas CPPU and bagging inhibited the expression of LcMYB1 and anthocyanin accumulation in the pericarp. Cis-elements associated with light responsiveness and abscisic acid responsiveness were identified in the promoter region of LcMYB1. Among the 6 structural genes tested, only LcUFGT was highly correlated with LcMYB1. These results suggest that LcMYB1 controls anthocyanin biosynthesis in litchi and LcUFGT might be the structural gene that is targeted and regulated by LcMYB1. Furthermore, the overexpression of LcMYB1 induced anthocyanin accumulation in all tissues in tobacco, confirming the function of LcMYB1 in the regulation of anthocyanin biosynthesis. The upregulation of NtAn1b in response to LcMYB1 overexpression seems to be essential for anthocyanin accumulation in the leaf and pedicel. In the reproductive tissues of transgenic tobacco, however, increased anthocyanin accumulation is independent of tobacco's endogenous MYB and bHLH transcriptional factors, but associated with the upregulation of specific structural genes.

  14. Over-expression of the transcription factor HlMYB3 in transgenic hop (Humulus lupulus L. cv. Tettnanger) modulates the expression of genes involved in the biosynthesis of flavonoids and phloroglucinols

    Czech Academy of Sciences Publication Activity Database

    Gatica-Arias, A.; Stanke, M.; Häntzschel, K.R.; Matoušek, Jaroslav; Weber, G.

    2013-01-01

    Roč. 113, č. 2 (2013), s. 279-289 ISSN 0167-6857 R&D Projects: GA ČR GA521/08/0740 Institutional support: RVO:60077344 Keywords : Hop * R2R3 MYB transcription factors * Genetic transformation * Flavonoid biosynthesis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.612, year: 2013

  15. Identification and Regulation of c-Myb Target Genes in MCF-7 Cells

    Directory of Open Access Journals (Sweden)

    O'Rourke John P

    2011-01-01

    Full Text Available Abstract Background The c-Myb transcription factor regulates differentiation and proliferation in hematopoietic cells, stem cells and epithelial cells. Although oncogenic versions of c-Myb were first associated with leukemias, over expression or rearrangement of the c-myb gene is common in several types of solid tumors, including breast cancers. Expression of the c-myb gene in human breast cancer cells is dependent on estrogen stimulation, but little is known about the activities of the c-Myb protein or what genes it regulates in estrogen-stimulated cells. Methods We used chromatin immunoprecipitation coupled with whole genome promoter tiling microarrays to identify endogenous c-Myb target genes in human MCF-7 breast cancer cells and characterized the activity of c-Myb at a panel of target genes during different stages of estrogen deprivation and stimulation. Results By using different antibodies and different growth conditions, the c-Myb protein was found associated with over 10,000 promoters in MCF-7 cells, including many genes that encode cell cycle regulators or transcription factors and more than 60 genes that encode microRNAs. Several previously identified c-Myb target genes were identified, including CCNB1, MYC and CXCR4 and novel targets such as JUN, KLF4, NANOG and SND1. By studying a panel of these targets to validate the results, we found that estradiol stimulation triggered the association of c-Myb with promoters and that association correlated with increased target gene expression. We studied one target gene, CXCR4, in detail, showing that c-Myb associated with the CXCR4 gene promoter and activated a CXCR4 reporter gene in transfection assays. Conclusions Our results show that c-Myb associates with a surprisingly large number of promoters in human cells. The results also suggest that estradiol stimulation leads to large-scale, genome-wide changes in c-Myb activity and subsequent changes in gene expression in human breast cancer

  16. Phenylpropanoids accumulation in eggplant fruit: characterization of biosynthetic genes and regulation by a MYB transcription factor

    Directory of Open Access Journals (Sweden)

    Teresa eDocimo

    2016-01-01

    Full Text Available Phenylpropanoids are major secondary metabolites in eggplant (Solanum melongena fruits. Chlorogenic acid (CGA accounts for 70 to 90% of total phenolics in flesh tissues, while anthocyanins are mainly present in the fruit skin. As a contribution to the understanding of the peculiar accumulation of these health-promoting metabolites in eggplant, we report on metabolite abundance, regulation of CGA and anthocyanin biosynthesis, and characterization of candidate CGA biosynthetic genes in S. melongena.Higher contents of CGA, Delphinidin 3-rutinoside and rutin were found in eggplant fruits compared to other tissues, associated to an elevated transcript abundance of structural genes such as PAL, HQT, DFR and ANS, suggesting that active in situ biosynthesis contributes to anthocyanin and CGA accumulation in fruit tissues. Putative orthologs of the two CGA biosynthetic genes PAL and HQT, as well as a variant of a MYB1 transcription factor showing identity with group 6 MYBs, were isolated from an Occidental S. melongena traditional variety and demonstrated to differ from published sequences from Asiatic varieties.In silico analysis of the isolated SmPAL1, SmHQT1, SmANS, and SmMyb1 promoters revealed the presence of several Myb regulatory elements for the biosynthetic genes and unique elements for the TF, suggesting its involvement in other physiological roles beside phenylpropanoid biosynthesis regulation.Transient overexpression in Nicotiana benthamiana leaves of SmMyb1 and of a C-terminal SmMyb1 truncated form (SmMyb1Δ9 resulted in anthocyanin accumulation only of SmMyb1 agro-infiltrated leaves. A yeast two-hybrid assay confirmed the interaction of both SmMyb1 and SmMyb1Δ9 with an anthocyanin-related potato bHLH1 TF. Interestingly, a doubled amount of CGA was detected in both SmMyb1 and SmMyb1Δ9 agro-infiltrated leaves, thus suggesting that the N-terminal region of SmMyb1 is sufficient to activate its synthesis. These data suggest that a deletion of

  17. [MYB-like transcription factor SiMYB42 from foxtail millet (Setaria italica L.) enhances Arabidopsis tolerance to low-nitrogen stress].

    Science.gov (United States)

    Ding, Qing Qian; Wang, Xiao Ting; Hu, Li Qin; Qi, Xin; Ge, Lin Hao; Xu, Wei Ya; Xu, Zhao Shi; Zhou, Yong Bin; Jia, Guan Qing; Diao, Xian Min; Min, Dong Hong; Ma, You Zhi; Chen, Ming

    2018-04-20

    Myeloblastosis (MYB) transcription factors are one of the largest families of transcription factors in higher plants. They play an important role in plant development, defense response processes, and non-biological stresses, i.e., drought stress. Foxtail millet (Setaria italica L.), originated in China, is resistant to drought and low nutrition stresses and has been regarded as an ideal material for studying abiotic stress resistance in monocotyledon. In this study, we ran a transcription profile analysis of zheng 204 under low-nitrogen conditions and identified a MYB-like transcription factor SiMYB42, which was up-regulated under low-nitrogen stress. Phylogenetic tree analysis showed that SiMYB42 belongs to R2R3-MYB subfamily and has two MYB conserved domains. Expression pattern analysis showed that SiMYB42 was significantly up-regulated under various stress conditions, including low-nitrogen stress, high salt, drought and ABA conditions. The results of subcellular localization, quantitative real-time PCR and transcriptional activation analysis indicated that SiMYB42 protein localizes to the nucleus and cell membrane of plant cells, mainly expressed in the leaf or root of foxtail millet, and has transcription activation activity. Functional analysis showed that there was no significant difference between transgenic SiMYB42 Arabidopsis and wild-type (WT) Arabidopsis under normal conditions; however, under low-nitrogen condition, the root length, surface area and seedling fresh weight in transgenic SiMYB42 Arabidopsis, were significantly higher than their counterparts in WT. These results suggest that SiMYB42 transgenic plants exhibit higher tolerance to low-nitrogen stress. Expression levels of nitrate transporters genes NRT2.1, NRT2.4 and NRT2.5, which are the transcriptional targets of SiMYB42, were higher in transgenic SiMYB42 Arabidopsis plants than those in WT; the promoter regions of NRT2.1, NRT2.4 and NRT2.5 all have MYB binding sites. These results indicate

  18. DOF-binding sites additively contribute to guard cell-specificity of AtMYB60 promoter

    Directory of Open Access Journals (Sweden)

    Cominelli Eleonora

    2011-11-01

    Full Text Available Abstract Background We previously demonstrated that the Arabidopsis thaliana AtMYB60 protein is an R2R3MYB transcription factor required for stomatal opening. AtMYB60 is specifically expressed in guard cells and down-regulated at the transcriptional levels by the phytohormone ABA. Results To investigate the molecular mechanisms governing AtMYB60 expression, its promoter was dissected through deletion and mutagenesis analyses. By studying different versions of AtMYB60 promoter::GUS reporter fusions in transgenic plants we were able to demonstrate a modular organization for the AtMYB60 promoter. Particularly we defined: a minimal promoter sufficient to confer guard cell-specific activity to the reporter gene; the distinct roles of different DOF-binding sites organised in a cluster in the minimal promoter in determining guard cell-specific expression; the promoter regions responsible for the enhancement of activity in guard cells; a promoter region responsible for the negative transcriptional regulation by ABA. Moreover from the analysis of single and multiple mutants we could rule out the involvement of a group of DOF proteins, known as CDFs, already characterised for their involvement in flowering time, in the regulation of AtMYB60 expression. Conclusions These findings shed light on the regulation of gene expression in guard cells and provide new promoter modules as useful tools for manipulating gene expression in guard cells, both for physiological studies and future biotechnological applications.

  19. AtMYB44 regulates WRKY70 expression and modulates antagonistic interaction between salicylic acid and jasmonic acid signaling.

    Science.gov (United States)

    Shim, Jae Sung; Jung, Choonkyun; Lee, Sangjoon; Min, Kyunghun; Lee, Yin-Won; Choi, Yeonhee; Lee, Jong Seob; Song, Jong Tae; Kim, Ju-Kon; Choi, Yang Do

    2013-02-01

    The role of AtMYB44, an R2R3 MYB transcription factor, in signaling mediated by jasmonic acid (JA) and salicylic acid (SA) is examined. AtMYB44 is induced by JA through CORONATINE INSENSITIVE 1 (COI1). AtMYB44 over-expression down-regulated defense responses against the necrotrophic pathogen Alternaria brassicicola, but up-regulated WRKY70 and PR genes, leading to enhanced resistance to the biotrophic pathogen Pseudomonas syringae pv. tomato DC3000. The knockout mutant atmyb44 shows opposite effects. Induction of WRKY70 by SA is reduced in atmyb44 and npr1-1 mutants, and is totally abolished in atmyb44 npr1-1 double mutants, showing that WRKY70 is regulated independently through both NPR1 and AtMYB44. AtMYB44 over-expression does not change SA content, but AtMYB44 over-expression phenotypes, such as retarded growth, up-regulated PR1 and down-regulated PDF1.2 are reversed by SA depletion. The wrky70 mutation suppressed AtMYB44 over-expression phenotypes, including up-regulation of PR1 expression and down-regulation of PDF1.2 expression. β-estradiol-induced expression of AtMYB44 led to WRKY70 activation and thus PR1 activation. AtMYB44 binds to the WRKY70 promoter region, indicating that AtMYB44 acts as a transcriptional activator of WRKY70 by directly binding to a conserved sequence element in the WRKY70 promoter. These results demonstrate that AtMYB44 modulates antagonistic interaction by activating SA-mediated defenses and repressing JA-mediated defenses through direct control of WRKY70. © 2012 The Authors The Plant Journal © 2012 Blackwell Publishing Ltd.

  20. An atypical R2R3 MYB transcription factor increases cold hardiness by CBF-dependent and CBF-independent pathways in apple

    NARCIS (Netherlands)

    Xie, Yinpeng; Chen, Pengxiang; Yan, Yan; Bao, Chana; Li, Xuewei; Wang, Liping; Shen, Xiaoxia; Li, Haiyan; Liu, Xiaofang; Niu, Chundong; Zhu, Chen; Fang, Nan; Shao, Yun; Zhao, Tao; Yu, Jiantao; Zhu, Jianhua; Xu, Lingfei; Nocker, van Steven; Ma, Fengwang; Guan, Qingmei

    2018-01-01

    Apple (Malus × domestica) trees are vulnerable to freezing temperatures. However, there has been only limited success in developing cold-hardy cultivars. This lack of progress is due at least partly to lack of understanding of the molecular mechanisms of freezing tolerance in apple. In this study,

  1. PhMYB4 fine-tunes the floral volatile signature of Petunia x hybrida through PhC4H.

    Science.gov (United States)

    Colquhoun, Thomas A; Kim, Joo Young; Wedde, Ashlyn E; Levin, Laura A; Schmitt, Kyle C; Schuurink, Robert C; Clark, David G

    2011-01-01

    In Petunia × hybrida cv 'Mitchell Diploid' (MD), floral volatile benzenoid/phenylpropanoid (FVBP) biosynthesis is controlled spatially, developmentally, and daily at molecular, metabolic, and biochemical levels. Multiple genes have been shown to encode proteins that either directly catalyse a biochemical reaction yielding FVBP compounds or are involved in metabolite flux prior to the formation of FVBP compounds. It was hypothesized that multiple transcription factors are involved in the precise regulation of all necessary genes, resulting in the specific volatile signature of MD flowers. After acquiring all available petunia transcript sequences with homology to Arabidopsis thaliana R2R3-MYB transcription factors, PhMYB4 (named for its close identity to AtMYB4) was identified, cloned, and characterized. PhMYB4 transcripts accumulate to relatively high levels in floral tissues at anthesis and throughout open flower stages, which coincides with the spatial and developmental distribution of FVBP production and emission. Upon RNAi suppression of PhMYB4 (ir-PhMYB4) both petunia cinnamate-4-hydroxylase (PhC4H1 and PhC4H2) gene transcript levels were significantly increased. In addition, ir-PhMYB4 plants emit higher levels of FVBP compounds derived from p-coumaric acid (isoeugenol and eugenol) compared with MD. Together, these results indicate that PhMYB4 functions in the repression of C4H transcription, indirectly controlling the balance of FVBP production in petunia floral tissue (i.e. fine-tunes).

  2. A Myb transcription factor of Phytophthora sojae, regulated by MAP kinase PsSAK1, is required for zoospore development.

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    Meng Zhang

    Full Text Available PsSAK1, a mitogen-activated protein (MAP kinase from Phytophthora sojae, plays an important role in host infection and zoospore viability. However, the downstream mechanism of PsSAK1 remains unclear. In this study, the 3'-tag digital gene expression (DGE profiling method was applied to sequence the global transcriptional sequence of PsSAK1-silenced mutants during the cysts stage and 1.5 h after inoculation onto susceptible soybean leaf tissues. Compared with the gene expression levels of the recipient P. sojae strain, several candidates of Myb family were differentially expressed (up or down in response to the loss of PsSAK1, including of a R2R3-type Myb transcription factor, PsMYB1. qRT-PCR indicated that the transcriptional level of PsMYB1 decreased due to PsSAK1 silencing. The transcriptional level of PsMYB1 increased during sporulating hyphae, in germinated cysts, and early infection. Silencing of PsMYB1 results in three phenotypes: a no cleavage of the cytoplasm into uninucleate zoospores or release of normal zoospores, b direct germination of sporangia, and c afunction in zoospore-mediated plant infection. Our data indicate that the PsMYB1 transcription factor functions downstream of MAP kinase PsSAK1 and is required for zoospore development of P. sojae.

  3. Transcriptional Regulatory Network Analysis of MYB Transcription Factor Family Genes in Rice

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    Shuchi eSmita

    2015-12-01

    Full Text Available MYB transcription factor (TF is one of the largest TF families and regulates defense responses to various stresses, hormone signaling as well as many metabolic and developmental processes in plants. Understanding these regulatory hierarchies of gene expression networks in response to developmental and environmental cues is a major challenge due to the complex interactions between the genetic elements. Correlation analyses are useful to unravel co-regulated gene pairs governing biological process as well as identification of new candidate hub genes in response to these complex processes. High throughput expression profiling data are highly useful for construction of co-expression networks. In the present study, we utilized transcriptome data for comprehensive regulatory network studies of MYB TFs by top down and guide gene approaches. More than 50% of OsMYBs were strongly correlated under fifty experimental conditions with 51 hub genes via top down approach. Further, clusters were identified using Markov Clustering (MCL. To maximize the clustering performance, parameter evaluation of the MCL inflation score (I was performed in terms of enriched GO categories by measuring F-score. Comparison of co-expressed cluster and clads analyzed from phylogenetic analysis signifies their evolutionarily conserved co-regulatory role. We utilized compendium of known interaction and biological role with Gene Ontology enrichment analysis to hypothesize function of coexpressed OsMYBs. In the other part, the transcriptional regulatory network analysis by guide gene approach revealed 40 putative targets of 26 OsMYB TF hubs with high correlation value utilizing 815 microarray data. The putative targets with MYB-binding cis-elements enrichment in their promoter region, functional co-occurrence as well as nuclear localization supports our finding. Specially, enrichment of MYB binding regions involved in drought-inducibility implying their regulatory role in drought

  4. DNA binding-independent transcriptional activation of the vascular endothelial growth factor gene (VEGF) by the Myb oncoprotein

    International Nuclear Information System (INIS)

    Lutwyche, Jodi K.; Keough, Rebecca A.; Hunter, Julie; Coles, Leeanne S.; Gonda, Thomas J.

    2006-01-01

    Myb is a key transcription factor that can regulate proliferation, differentiation, and apoptosis, predominantly in the haemopoietic system. Abnormal expression of Myb is associated with a number of cancers, both haemopoietic and non-haemopoietic. In order to better understand the role of Myb in normal and tumorigenic processes, we undertook a cDNA array screen to identify genes that are regulated by this factor. In this way, we identified the gene encoding vascular endothelial growth factor (VEGF) as being potentially regulated by the Myb oncoprotein in myeloid cells. To determine whether this was a direct effect on VEGF gene transcription, we examined the activity of the murine VEGF promoter in the presence of either wild-type (WT) or mutant forms of Myb. It was found that WT Myb was able to activate the VEGF promoter and that a minimal promoter region of 120 bp was sufficient to confer Myb responsiveness. Surprisingly, activation of the VEGF promoter was independent of DNA binding by Myb. This was shown by the use of DNA binding-defective Myb mutants and by mutagenesis of a potential Myb-binding site in the minimal promoter. Mutation of Sp1 sites within this region abolished Myb-mediated regulation of a reporter construct, suggesting that Myb DNA binding-independent activation of VEGF expression occurs via these Sp1 binding elements. Regulation of VEGF production by Myb has implications for the potential role of Myb in myeloid leukaemias and in solid tumours where VEGF may be functioning as an autocrine growth factor

  5. Molecular Characterization of MYB28 Involved in Aliphatic Glucosinolate Biosynthesis in Chinese Kale (Brassica oleracea var. alboglabra Bailey

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    Ling Yin

    2017-06-01

    Full Text Available Glucosinolates are Brassicaceae-specific secondary metabolites that act as crop protectants, flavor precursors, and cancer-prevention agents, which shows strong evidences of anticarcinogentic, antioxidant, and antimicrobial activities. MYB28, the R2R3-MYB28 transcription factor, directly activates genes involved in aliphatic glucosinolate biosynthesis. In this study, the MYB28 homology (BoaMYB28 was identified in Chinese kale (Brassica oleracea var. alboglabra Bailey. Analysis of the nucleotide sequence indicated that the cDNA of BoaMYB28 was 1257 bp with an ORF of 1020 bp. The deduced BoaMYB28 protein was a polypeptide of 339 amino acid with a putative molecular mass of 38 kDa and a pI of 6.87. Sequence homology and phylogenetic analysis showed that BoaMYB28 was most closely related to MYB28 homologs from the Brassicaceae family. The expression levels of BoaMYB28 varies across the tissues and developmental stages. BoaMYB28 transcript levels were higher in leaves and stems compared with those in cotyledons, flowers, and siliques. BoaMYB28 was expressed across all developmental leaf stages, with higher transcript accumulation in mature and inflorescence leaves. Over-expression and RNAi studies showed that BoaMYB28 retains the basic MYB28 gene function as a major transcriptional regulator of aliphatic glucosinolate pathway. The results indicated that over-expression and RNAi lines showed no visible difference on plant morphology. The contents of aliphatic glucosinolates and transcript levels of aliphatic glucosinolate biosynthesis genes increased in over-expression lines and decreased in RNAi lines. In over-expression lines, aliphatic glucosinolate contents were 1.5- to 3-fold higher than those in the wild-type, while expression levels of aliphatic glucosinolate biosynthesis genes were 1.5- to 4-fold higher than those in the wild-type. In contrast, the contents of aliphatic glucosinolates and transcript levels of aliphatic glucosinolate

  6. Molecular Characterization of MYB28 Involved in Aliphatic Glucosinolate Biosynthesis in Chinese Kale (Brassica oleracea var. alboglabra Bailey).

    Science.gov (United States)

    Yin, Ling; Chen, Hancai; Cao, Bihao; Lei, Jianjun; Chen, Guoju

    2017-01-01

    Glucosinolates are Brassicaceae-specific secondary metabolites that act as crop protectants, flavor precursors, and cancer-prevention agents, which shows strong evidences of anticarcinogentic, antioxidant, and antimicrobial activities. MYB28 , the R2R3-MYB28 transcription factor, directly activates genes involved in aliphatic glucosinolate biosynthesis. In this study, the MYB28 homology ( BoaMYB28 ) was identified in Chinese kale ( Brassica oleracea var. alboglabra Bailey). Analysis of the nucleotide sequence indicated that the cDNA of BoaMYB28 was 1257 bp with an ORF of 1020 bp. The deduced BoaMYB28 protein was a polypeptide of 339 amino acid with a putative molecular mass of 38 kDa and a pI of 6.87. Sequence homology and phylogenetic analysis showed that BoaMYB28 was most closely related to MYB28 homologs from the Brassicaceae family. The expression levels of BoaMYB28 varies across the tissues and developmental stages. BoaMYB28 transcript levels were higher in leaves and stems compared with those in cotyledons, flowers, and siliques. BoaMYB28 was expressed across all developmental leaf stages, with higher transcript accumulation in mature and inflorescence leaves. Over-expression and RNAi studies showed that BoaMYB28 retains the basic MYB28 gene function as a major transcriptional regulator of aliphatic glucosinolate pathway. The results indicated that over-expression and RNAi lines showed no visible difference on plant morphology. The contents of aliphatic glucosinolates and transcript levels of aliphatic glucosinolate biosynthesis genes increased in over-expression lines and decreased in RNAi lines. In over-expression lines, aliphatic glucosinolate contents were 1.5- to 3-fold higher than those in the wild-type, while expression levels of aliphatic glucosinolate biosynthesis genes were 1.5- to 4-fold higher than those in the wild-type. In contrast, the contents of aliphatic glucosinolates and transcript levels of aliphatic glucosinolate biosynthesis genes in

  7. QsMYB1 expression is modulated in response to heat and drought stresses and during plant recovery in Quercus suber.

    Science.gov (United States)

    Almeida, Tânia; Pinto, Glória; Correia, Barbara; Santos, Conceição; Gonçalves, Sónia

    2013-12-01

    Cork oak is an economically important forest species showing a great tolerance to high temperatures and shortage of water. However, the mechanisms underlying this plasticity are still poorly understood. Among the stress regulators, transcription factors (TFs) are especially important since they can control a wide range of stress-inducible genes, which make them powerful targets for genetic engineering of stress tolerance. Here we evaluated the influence of increasing temperatures (up to 55 °C) or drought (18% field capacity, FC) on the expression profile of an R2R3-MYB transcription factor of cork oak, the QsMYB1. QsMYB1 was previously identified as being preferentially expressed in cork tissues and as having an associated alternative splicing mechanism, which results in two different transcripts (QsMYB1.1 and QsMYB1.2). Expression analysis by reverse transcription quantitative PCR (RT-qPCR) revealed that increasing temperatures led to a gradual down-regulation of QsMYB1 transcripts with more effect on QsMYB1.1 abundance. On the other hand, under drought condition, expression of QsMYB1 variants, mainly the QsMYB1.2, was transiently up-regulated shortly after the stress imposition. Recovery from each stress has also resulted in a differential response by both QsMYB1 transcripts. Several physiological and biochemical parameters (plant water status, chlorophyll fluorescence, lipid peroxidation and proline content) were determined in order to monitor the plant performance under stress and recovery. In conclusion, this report provides the first evidence that QsMYB1 TF may have a putative function in the regulatory network of cork oak response to heat and drought stresses and during plant recovery. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  8. The transcription factor VvMYB5b contributes to the regulation of anthocyanin and proanthocyanidin biosynthesis in developing grape berries.

    Science.gov (United States)

    Deluc, Laurent; Bogs, Jochen; Walker, Amanda R; Ferrier, Thilia; Decendit, Alain; Merillon, Jean-Michel; Robinson, Simon P; Barrieu, François

    2008-08-01

    Among the dramatic changes occurring during grape berry (Vitis vinifera) development, those affecting the flavonoid pathway have provoked a number of investigations in the last 10 years. In addition to producing several compounds involved in the protection of the berry and the dissemination of the seeds, final products of this pathway also play a critical role in berry and wine quality. In this article, we describe the cloning and functional characterization of VvMYB5b, a cDNA isolated from a grape berry (V. vinifera 'Cabernet Sauvignon') library. VvMYB5b encodes a protein belonging to the R2R3-MYB family of transcription factors and displays significant similarity with VvMYB5a, another MYB factor recently shown to regulate flavonoid synthesis in grapevine. The ability of VvMYB5a and VvMYB5b to activate the grapevine promoters of several structural genes of the flavonoid pathway was confirmed by transient expression of the corresponding cDNAs in grape cells. Overexpression of VvMYB5b in tobacco (Nicotiana tabacum) leads to an up-regulation of genes encoding enzymes of the flavonoid pathway and results in the accumulation of anthocyanin- and proanthocyanidin-derived compounds. The ability of VvMYB5b to regulate particularly the anthocyanin and the proanthocyanidin pathways is discussed in relation to other recently characterized MYB transcription factors in grapevine. Taken together, data presented in this article give insight into the transcriptional mechanisms associated with the regulation of the flavonoid pathway throughout grape berry development.

  9. The ABA receptor PYL8 promotes lateral root growth by enhancing MYB77-dependent transcription of auxin-responsive genes.

    Science.gov (United States)

    Zhao, Yang; Xing, Lu; Wang, Xingang; Hou, Yueh-Ju; Gao, Jinghui; Wang, Pengcheng; Duan, Cheng-Guo; Zhu, Xiaohong; Zhu, Jian-Kang

    2014-06-03

    The phytohormone abscisic acid (ABA) regulates plant growth, development, and abiotic stress responses. ABA signaling is mediated by a group of receptors known as the PYR1/PYL/RCAR family, which includes the pyrabactin resistance 1-like protein PYL8. Under stress conditions, ABA signaling activates SnRK2 protein kinases to inhibit lateral root growth after emergence from the primary root. However, even in the case of persistent stress, lateral root growth eventually recovers from inhibition. We showed that PYL8 is required for the recovery of lateral root growth, following inhibition by ABA. PYL8 directly interacted with the transcription factors MYB77, MYB44, and MYB73. The interaction of PYL8 and MYB77 increased the binding of MYB77 to its target MBSI motif in the promoters of multiple auxin-responsive genes. Compared to wild-type seedlings, the lateral root growth of pyl8 mutant seedlings and myb77 mutant seedlings was more sensitive to inhibition by ABA. The recovery of lateral root growth was delayed in pyl8 mutant seedlings in the presence of ABA, and the defect was rescued by exposing pyl8 mutant seedlings to the auxin IAA (3-indoleacetic acid). Thus, PYL8 promotes lateral root growth independently of the core ABA-SnRK2 signaling pathway by enhancing the activities of MYB77 and its paralogs, MYB44 and MYB73, to augment auxin signaling. Copyright © 2014, American Association for the Advancement of Science.

  10. Failure to launch: the self-regulating Md-MYB10 R6 gene from apple is active in flowers but not leaves of Petunia.

    Science.gov (United States)

    Boase, Murray R; Brendolise, Cyril; Wang, Lei; Ngo, Hahn; Espley, Richard V; Hellens, Roger P; Schwinn, Kathy E; Davies, Kevin M; Albert, Nick W

    2015-10-01

    The Md - MYB10 R6 gene from apple is capable of self-regulating in heterologous host species and enhancing anthocyanin pigmentation, but the activity of MYB10 is dependent on endogenous protein partners. Coloured foliage due to anthocyanin pigments (bronze/red/black) is an attractive trait that is often lacking in many bedding, ornamental and horticultural plants. Apples (Malus × domestica) containing an allelic variant of the anthocyanin regulator, Md-MYB10 R6 , are highly pigmented throughout the plant, due to autoregulation by MYB10 upon its own promoter. We investigated whether Md-MYB10 R6 from apple is capable of functioning within the heterologous host Petunia hybrida to generate plants with novel pigmentation patterns. The Md-MYB10 R6 transgene (MYB10-R6 pro :MYB10:MYB10 term ) activated anthocyanin synthesis when transiently expressed in Antirrhinum rosea (dorsea) petals and petunia leaf discs. Stable transgenic petunias containing Md-MYB10 R6 lacked foliar pigmentation but had coloured flowers, complementing the an2 phenotype of 'Mitchell' petunia. The absence of foliar pigmentation was due to the failure of the Md-MYB10 R6 gene to self-activate in vegetative tissues, suggesting that additional protein partners are required for Md-MYB10 to activate target genes in this heterologous system. In petunia flowers, where endogenous components including MYB-bHLH-WDR (MBW) proteins were present, expression of the Md-MYB10 R6 promoter was initiated, allowing auto-regulation to occur and activating anthocyanin production. Md-MYB10 is capable of operating within the petunia MBW gene regulation network that controls the expression of the anthocyanin biosynthesis genes, AN1 (bHLH) and MYBx (R3-MYB repressor) in petals.

  11. A single amino acid change within the R2 domain of the VvMYB5b transcription factor modulates affinity for protein partners and target promoters selectivity

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    Granier Thierry

    2011-08-01

    Full Text Available Abstract Background Flavonoid pathway is spatially and temporally controlled during plant development and the transcriptional regulation of the structural genes is mostly orchestrated by a ternary protein complex that involves three classes of transcription factors (R2-R3-MYB, bHLH and WDR. In grapevine (Vitis vinifera L., several MYB transcription factors have been identified but the interactions with their putative bHLH partners to regulate specific branches of the flavonoid pathway are still poorly understood. Results In this work, we describe the effects of a single amino acid substitution (R69L located in the R2 domain of VvMYB5b and predicted to affect the formation of a salt bridge within the protein. The activity of the mutated protein (name VvMYB5bL, the native protein being referred as VvMYB5bR was assessed in different in vivo systems: yeast, grape cell suspensions, and tobacco. In the first two systems, VvMYB5bL exhibited a modified trans-activation capability. Moreover, using yeast two-hybrid assay, we demonstrated that modification of VvMYB5b transcriptional properties impaired its ability to correctly interact with VvMYC1, a grape bHLH protein. These results were further substantiated by overexpression of VvMYB5bR and VvMYB5bL genes in tobacco. Flowers from 35S::VvMYB5bL transgenic plants showed a distinct phenotype in comparison with 35S::VvMYB5bR and the control plants. Finally, significant differences in transcript abundance of flavonoid metabolism genes were observed along with variations in pigments accumulation. Conclusions Taken together, our findings indicate that VvMYB5bL is still able to bind DNA but the structural consequences linked to the mutation affect the capacity of the protein to activate the transcription of some flavonoid genes by modifying the interaction with its co-partner(s. In addition, this study underlines the importance of an internal salt bridge for protein conformation and thus for the establishment

  12. Anthocyanin biosynthesis regulation of DhMYB2 and DhbHLH1 in Dendrobium hybrids petals.

    Science.gov (United States)

    Li, Chonghui; Qiu, Jian; Ding, Ling; Huang, Mingzhong; Huang, Surong; Yang, Guangsui; Yin, Junmei

    2017-03-01

    Dendrobium hybrids orchid are popular throughout the world. They have various floral color and pigmentation patterns that are mainly caused by anthocyanins. It is well established that anthocyanin biosynthesis is regulated by the interplay between MYB and bHLH transcription factors (TF) in most plants. In this study, we identified one R2R3-MYB gene, DhMYB2, and one bHLH gene, DhbHLH1, from a Dendrobium hybrid. Their expression profiles were related to anthocyanin pigmentation in Dendrobium petals. Transient over-expression of these two TF genes showed that both DhMYB2 and DhbHLH1 resulted in anthocyanin production in white petals. The interaction between the two TFs was observed in vitro. In different Dendrobium hybrids petals with various pigmentations, DhMYB2 and DhbHLH1 were co-expressed with DhDFR and DhANS, which are regarded as potential regulatory targets of the two TFs. In flowers with distinct purple lips but white or yellow petals/sepals, the expression of DhbHLH1 was only related to anthocyanin accumulation in the lips. Taken together, DhMYB2 interacted with DhbHLH1 to regulate anthocyanin production in Dendrobium hybrid petals. DhbHLH1 was also responsible for the distinct anthocyanin pigmentation in lip tissues. The functional characterization of DhMYB2 and DhbHLH1 will improve understanding of anthocyanin biosynthesis modulation in Dendrobium orchids. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  13. CPC, a single-repeat R3 MYB, is a negative regulator of anthocyanin biosynthesis in Arabidopsis.

    Science.gov (United States)

    Zhu, Hui-Fen; Fitzsimmons, Karen; Khandelwal, Abha; Kranz, Robert G

    2009-07-01

    Single-repeat R3 MYB transcription factors like CPC (CAPRICE) are known to play roles in developmental processes such as root hair differentiation and trichome initiation. However, none of the six Arabidopsis single-repeat R3 MYB members has been reported to regulate flavonoid biosynthesis. We show here that CPC is a negative regulator of anthocyanin biosynthesis. In the process of using CPC to test GAL4-dependent driver lines, we observed a repression of anthocyanin synthesis upon GAL4-mediated CPC overexpression. We demonstrated that this is not due to an increase in nutrient uptake because of more root hairs. Rather, CPC expression level tightly controls anthocyanin accumulation. Microarray analysis on the whole genome showed that, of 37 000 features tested, 85 genes are repressed greater than three-fold by CPC overexpression. Of these 85, seven are late anthocyanin biosynthesis genes. Also, anthocyanin synthesis genes were shown to be down-regulated in 35S::CPC overexpression plants. Transient expression results suggest that CPC competes with the R2R3-MYB transcription factor PAP1/2, which is an activator of anthocyanin biosynthesis genes. This report adds anthocyanin biosynthesis to the set of programs that are under CPC control, indicating that this regulator is not only for developmental programs (e.g. root hairs, trichomes), but can influence anthocyanin pigment synthesis.

  14. Mapping a candidate gene (MdMYB10 for red flesh and foliage colour in apple

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    Allan Andrew C

    2007-07-01

    Full Text Available Abstract Background Integrating plant genomics and classical breeding is a challenge for both plant breeders and molecular biologists. Marker-assisted selection (MAS is a tool that can be used to accelerate the development of novel apple varieties such as cultivars that have fruit with anthocyanin through to the core. In addition, determining the inheritance of novel alleles, such as the one responsible for red flesh, adds to our understanding of allelic variation. Our goal was to map candidate anthocyanin biosynthetic and regulatory genes in a population segregating for the red flesh phenotypes. Results We have identified the Rni locus, a major genetic determinant of the red foliage and red colour in the core of apple fruit. In a population segregating for the red flesh and foliage phenotype we have determined the inheritance of the Rni locus and DNA polymorphisms of candidate anthocyanin biosynthetic and regulatory genes. Simple Sequence Repeats (SSRs and Single Nucleotide Polymorphisms (SNPs in the candidate genes were also located on an apple genetic map. We have shown that the MdMYB10 gene co-segregates with the Rni locus and is on Linkage Group (LG 09 of the apple genome. Conclusion We have performed candidate gene mapping in a fruit tree crop and have provided genetic evidence that red colouration in the fruit core as well as red foliage are both controlled by a single locus named Rni. We have shown that the transcription factor MdMYB10 may be the gene underlying Rni as there were no recombinants between the marker for this gene and the red phenotype in a population of 516 individuals. Associating markers derived from candidate genes with a desirable phenotypic trait has demonstrated the application of genomic tools in a breeding programme of a horticultural crop species.

  15. Supra-optimal expression of the cold-regulated OsMyb4 transcription factor in transgenic rice changes the complexity of transcriptional network with major effects on stress tolerance and panicle development

    KAUST Repository

    Park, Myoungryoul

    2010-09-28

    The R2R3-type OsMyb4 transcription factor of rice has been shown to play a role in the regulation of osmotic adjustment in heterologous overexpression studies. However, the exact composition and organization of its underlying transcriptional network has not been established to be a robust tool for stress tolerance enhancement by regulon engineering. OsMyb4 network was dissected based on commonalities between the global chilling stress transcriptome and the transcriptome configured by OsMyb4 overexpression. OsMyb4 controls a hierarchical network comprised of several regulatory sub-clusters associated with cellular defense and rescue, metabolism and development. It regulates target genes either directly or indirectly through intermediary MYB, ERF, bZIP, NAC, ARF and CCAAT-HAP transcription factors. Regulatory sub-clusters have different combinations of MYB-like, GCC-box-like, ERD1-box-like, ABRE-like, G-box-like, as1/ocs/TGA-like, AuxRE-like, gibberellic acid response element (GARE)-like and JAre-like cis-elements. Cold-dependent network activity enhanced cellular antioxidant capacity through radical scavenging mechanisms and increased activities of phenylpropanoid and isoprenoid metabolic processes involving various abscisic acid (ABA), jasmonic acid (JA), salicylic acid (SA), ethylene and reactive oxygen species (ROS) responsive genes. OsMyb4 network is independent of drought response element binding protein/C-repeat binding factor (DREB/CBF) and its sub-regulons operate with possible co-regulators including nuclear factor-Y. Because of its upstream position in the network hierarchy, OsMyb4 functions quantitatively and pleiotrophically. Supra-optimal expression causes misexpression of alternative targets with costly trade-offs to panicle development. © 2010 Blackwell Publishing Ltd.

  16. Supra-optimal expression of the cold-regulated OsMyb4 transcription factor in transgenic rice changes the complexity of transcriptional network with major effects on stress tolerance and panicle development.

    Science.gov (United States)

    Park, Myoung-Ryoul; Yun, Kil-Young; Mohanty, Bijayalaxmi; Herath, Venura; Xu, Fuyu; Wijaya, Edward; Bajic, Vladimir B; Yun, Song-Joong; De Los Reyes, Benildo G

    2010-12-01

    The R2R3-type OsMyb4 transcription factor of rice has been shown to play a role in the regulation of osmotic adjustment in heterologous overexpression studies. However, the exact composition and organization of its underlying transcriptional network has not been established to be a robust tool for stress tolerance enhancement by regulon engineering. OsMyb4 network was dissected based on commonalities between the global chilling stress transcriptome and the transcriptome configured by OsMyb4 overexpression. OsMyb4 controls a hierarchical network comprised of several regulatory sub-clusters associated with cellular defense and rescue, metabolism and development. It regulates target genes either directly or indirectly through intermediary MYB, ERF, bZIP, NAC, ARF and CCAAT-HAP transcription factors. Regulatory sub-clusters have different combinations of MYB-like, GCC-box-like, ERD1-box-like, ABRE-like, G-box-like, as1/ocs/TGA-like, AuxRE-like, gibberellic acid response element (GARE)-like and JAre-like cis-elements. Cold-dependent network activity enhanced cellular antioxidant capacity through radical scavenging mechanisms and increased activities of phenylpropanoid and isoprenoid metabolic processes involving various abscisic acid (ABA), jasmonic acid (JA), salicylic acid (SA), ethylene and reactive oxygen species (ROS) responsive genes. OsMyb4 network is independent of drought response element binding protein/C-repeat binding factor (DREB/CBF) and its sub-regulons operate with possible co-regulators including nuclear factor-Y. Because of its upstream position in the network hierarchy, OsMyb4 functions quantitatively and pleiotrophically. Supra-optimal expression causes misexpression of alternative targets with costly trade-offs to panicle development. © 2010 Blackwell Publishing Ltd.

  17. Enhanced salt stress tolerance in transgenic potato plants expressing IbMYB1, a sweet potato transcription factor.

    Science.gov (United States)

    Cheng, Yu-Jie; Kim, Myoung-Duck; Deng, Xi-Ping; Kwak, Sang-Soo; Chen, Wei

    2013-12-01

    IbMYB1, a transcription factor (TF) for R2R3-type MYB TFs, is a key regulator of anthocyanin biosynthesis during storage of sweet potatoes. Anthocyanins provide important antioxidants of nutritional value to humans, and also protect plants from oxidative stress. This study aimed to increase transgenic potatoes' (Solanum tuberosum cv. LongShu No.3) tolerance to environmental stress and enhance their nutritional value. Transgenic potato plants expressing IbMYB1 genes under the control of an oxidative stress-inducible peroxidase (SWPA2) promoter (referred to as SM plants) were successfully generated through Agrobacterium-mediated transformation. Two representative transgenic SM5 and SM12 lines were evaluated for enhanced tolerance to salinity, UV-B rays, and drought conditions. Following treatment of 100 mM NaCl, seedlings of SM5 and SM12 lines showed less root damage and more shoot growth than control lines expressing only an empty vector. Transgenic potato plants in pots treated with 400 mM NaCl showed high amounts of secondary metabolites, including phenols, anthocyanins, and flavonoids, compared with control plants. After treatment of 400 mM NaCl, transgenic potato plants also showed high DDPH radical scavenging activity and high PS II photochemical efficiency compared with the control line. Furthermore, following treatment of NaCl, UV-B, and drought stress, the expression levels of IbMYB1 and several structural genes in the flavonoid biosynthesis such as CHS, DFR, and ANS in transgenic plants were found to be correlated with plant phenotype. The results suggest that enhanced IbMYB1 expression affects secondary metabolism, which leads to improved tolerance ability in transgenic potatoes.

  18. MYB transcription factor gene involved in sex determination in Asparagus officinalis.

    Science.gov (United States)

    Murase, Kohji; Shigenobu, Shuji; Fujii, Sota; Ueda, Kazuki; Murata, Takanori; Sakamoto, Ai; Wada, Yuko; Yamaguchi, Katsushi; Osakabe, Yuriko; Osakabe, Keishi; Kanno, Akira; Ozaki, Yukio; Takayama, Seiji

    2017-01-01

    Dioecy is a plant mating system in which individuals of a species are either male or female. Although many flowering plants evolved independently from hermaphroditism to dioecy, the molecular mechanism underlying this transition remains largely unknown. Sex determination in the dioecious plant Asparagus officinalis is controlled by X and Y chromosomes; the male and female karyotypes are XY and XX, respectively. Transcriptome analysis of A. officinalis buds showed that a MYB-like gene, Male Specific Expression 1 (MSE1), is specifically expressed in males. MSE1 exhibits tight linkage with the Y chromosome, specific expression in early anther development and loss of function on the X chromosome. Knockout of the MSE1 orthologue in Arabidopsis induces male sterility. Thus, MSE1 acts in sex determination in A. officinalis. © 2016 Molecular Biology Society of Japan and John Wiley & Sons Australia, Ltd.

  19. (1R,2R,3R,4R,5S-2,3-Bis[(2S′-2-acetoxy-2-phenylacetoxy]-4-azido-1-[(2,4-dinitrophenylhydrazonomethyl]bicyclo[3.1.0]hexane

    Directory of Open Access Journals (Sweden)

    Robert McDonald

    2008-02-01

    Full Text Available In the title compound, C38H29N7O12, the five-membered ring adopts an envelope conformation in which the `flap' is cis to the cyclopropane group. This conformation is similar to those of other bicyclo[3.1.0]hexane analogues for which crystal structures have been reported. The absolute configuration of the stereogenic centers on the cyclopentane ring, as determined by comparison with the known configurations of the stereogenic centers in the (2S-2-acetoxy-2-phenylacetoxy groups, is 1(R, 2(R, 3(R, 4(R and 5(S. An intramolecular N—H...O hydrogen bond is present.

  20. Plasma Triglyceride Levels May Be Modulated by Gene Expression of IQCJ, NXPH1, PHF17 and MYB in Humans

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    Bastien Vallée Marcotte

    2017-01-01

    Full Text Available A genome-wide association study (GWAS by our group identified loci associated with the plasma triglyceride (TG response to ω-3 fatty acid (FA supplementation in IQCJ, NXPH1, PHF17 and MYB. Our aim is to investigate potential mechanisms underlying the associations between single nucleotide polymorphisms (SNPs in the four genes and TG levels following ω-3 FA supplementation. 208 subjects received 3 g/day of ω-3 FA (1.9–2.2 g of EPA and 1.1 g of docosahexaenoic acid (DHA for six weeks. Plasma TG were measured before and after the intervention. 67 SNPs were selected to increase the density of markers near GWAS hits. Genome-wide expression and methylation analyses were conducted on respectively 30 and 35 participants’ blood sample together with in silico analyses. Two SNPs of IQCJ showed different affinities to splice sites depending on alleles. Expression levels were influenced by genotype for one SNP in NXPH1 and one in MYB. Associations between 12 tagged SNPs of IQCJ, 26 of NXPH1, seven of PHF17 and four of MYB and gene-specific CpG site methylation levels were found. The response of plasma TG to ω-3 FA supplementation may be modulated by the effect of DNA methylation on expression levels of genes revealed by GWAS.

  1. Distinct regulation of c-myb gene expression by HoxA9, Meis1 and Pbx proteins in normal hematopoietic progenitors and transformed myeloid cells

    International Nuclear Information System (INIS)

    Dassé, E; Volpe, G; Walton, D S; Wilson, N; Del Pozzo, W; O'Neill, L P; Slany, R K; Frampton, J; Dumon, S

    2012-01-01

    The proto-oncogenic protein c-Myb is an essential regulator of hematopoiesis and is frequently deregulated in hematological diseases such as lymphoma and leukemia. To gain insight into the mechanisms underlying the aberrant expression of c-Myb in myeloid leukemia, we analyzed and compared c-myb gene transcriptional regulation using two cell lines modeling normal hematopoietic progenitor cells (HPCs) and transformed myelomonocytic blasts. We report that the transcription factors HoxA9, Meis1, Pbx1 and Pbx2 bind in vivo to the c-myb locus and maintain its expression through different mechanisms in HPCs and leukemic cells. Our analysis also points to a critical role for Pbx2 in deregulating c-myb expression in murine myeloid cells cotransformed by the cooperative activity of HoxA9 and Meis1. This effect is associated with an intronic positioning of epigenetic marks and RNA polymerase II binding in the orthologous region of a previously described alternative promoter for c-myb. Taken together, our results could provide a first hint to explain the abnormal expression of c-myb in leukemic cells

  2. The role of MYB34, MYB51 and MYB122 in the regulation of camalexin biosynthesis in Arabidopsis thaliana

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    Henning eFrerigmann

    2015-08-01

    Full Text Available The indolic phytoalexin camalexin is a crucial defence metabolite in the model plant Arabidopsis. Indolic phytoalexins and glucosinolates appear to have a common evolutionary origin and are interconnected on the biosynthetic level: a key intermediate in the biosynthesis of camalexin, indole-3-acetaldoxime (IAOx, is also required for the biosynthesis of indolic glucosinolates and is under tight control by the transcription factors MYB34, MYB51 and MYB122. The abundance of camalexin was strongly reduced in myb34/51 and myb51/122 double and in triple myb mutant, suggesting that these transcription factors are important in camalexin biosynthesis. Furthermore, expression of MYB51 and MYB122 was significantly increased by biotic and abiotic camalexin-inducing agents. Feeding of the triple myb34/51/122 mutant with IAOx or indole-3-acetonitrile largely restored camalexin biosynthesis. Conversely, tryptophan could not complement the low camalexin phenotype of this mutant, which supports a role for the three MYB factors in camalexin biosynthesis upstream of IAOx. Consistently expression of the camalexin biosynthesis genes CYP71B15/PAD3 and CYP71A13 was not negatively affected in the triple myb mutant and the MYBs could not activate pCYP71B15::uidA expression in trans-activation assays with cultured Arabidopsis cells. In conclusion, this study reveals the importance of MYB factors regulating the generation of IAOx as precursor of camalexin.

  3. Metabolic engineering of apple by overexpression of the MdMyb10 gene

    Directory of Open Access Journals (Sweden)

    Khaled A.L. Rihani

    2017-06-01

    In the present study, the flavonoid pathway was successfully modified in apple by overexpressing the MdMyb10 transcription factor to validate the hypothesis of increased effect on plant disease resistance.

  4. Two LcbHLH transcription factors interacting with LcMYB1 in regulating late structural genes of anthocyanin biosynthesis in Nicotiana and Litchi chinensis during anthocyanin accumulation

    Directory of Open Access Journals (Sweden)

    Biao eLai

    2016-02-01

    Full Text Available Anthocyanin biosynthesis requires the MYB-bHLH-WD40 protein complex to activate the late biosynthetic genes. LcMYB1 was thought to act as key regulator in anthocyanin biosynthesis of litchi. However, basic helix-loop-helix proteins (bHLHs as partners have not been identified yet. The present study describes the functional characterization of three litchi bHLH candidate anthocyanin regulators, LcbHLH1, LcbHLH2 and LcbHLH3. Although these three litchi bHLHs phylogenetically clustered with bHLH proteins involved in anthcoyanin biosynthesis in other plant, only LcbHLH1 and LcbHLH3 were found to localize in the nucleus and physically interact with LcMYB1. The transcription levels of all these bHLHs were not coordinated with anthocyanin accumulation in different tissues and during development. However, when co-infiltrated with LcMYB1, both LcbHLH1 and LcbHLH3 enhanced anthocyanin accumulation in tobacco leaves with LcbHLH3 being the best inducer. Significant accumulation of anthocyanins in leaves transformed with the combination of LcMYB1 and LcbHLH3 were noticed, And this was associated with the up-regulation of two tobacco endogenous bHLH regulators, NtAn1a and NtAn1b, and late structural genes, like NtDFR and NtANS. Significant activity of the ANS promoter was observed in transient expression assays either with LcMYB1-LcbHLH1 or LcMYB1-LcbHLH3, while only minute activity was detected after transformation with only LcMYB1. In contrast, no activity was measured after induction with the combination of LcbHLH2 and LcMYB1. Higher DFR expression was also oberseved in paralleling with higher anthocyanins in co-transformed lines. LcbHLH1 and LcbHLH3 are essential partner of LcMYB1 in regulating the anthocyanin production in tobacco and probably also in litchi. The LcMYB1-LcbHLH complex enhanced anthocyanin accumulation may associate with activating the transcription of DFR and ANS.

  5. The purple cauliflower arises from activation of a MYB transcription factor.

    Science.gov (United States)

    Chiu, Li-Wei; Zhou, Xiangjun; Burke, Sarah; Wu, Xianli; Prior, Ronald L; Li, Li

    2010-11-01

    Anthocyanins are responsible for the color of many flowers, fruits, and vegetables. An interesting and unique Purple (Pr) gene mutation in cauliflower (Brassica oleracea var botrytis) confers an abnormal pattern of anthocyanin accumulation, giving the striking mutant phenotype of intense purple color in curds and a few other tissues. To unravel the nature of the Pr mutation in cauliflower, we isolated the Pr gene via a combination of candidate gene analysis and fine mapping. Pr encoded a R2R3 MYB transcription factor that exhibited tissue-specific expression, consistent with an abnormal anthocyanin accumulation pattern in the mutant. Transgenic Arabidopsis (Arabidopsis thaliana) and cauliflower plants expressing the Pr-D allele recapitulated the mutant phenotype, confirming the isolation of the Pr gene. Up-regulation of Pr specifically activated a basic helix-loop-helix transcription factor and a subset of anthocyanin structural genes encoding flavonoid 3'-hydroxylase, dihydroflavonol 4-reductase, and leucoanthocyanidin dioxygenase to confer ectopic accumulation of pigments in the purple cauliflower. Our results indicate that the genetic variation including a Harbinger DNA transposon insertion in the upstream regulatory region of the Pr-D allele is responsible for the up-regulation of the Pr gene in inducing phenotypic change in the plant. The successful isolation of Pr provides important information on the regulatory control of anthocyanin biosynthesis in Brassica vegetables, and offers a genetic resource for development of new varieties with enhanced health-promoting properties and visual appeal.

  6. The Purple Cauliflower Arises from Activation of a MYB Transcription Factor1[W][OA

    Science.gov (United States)

    Chiu, Li-Wei; Zhou, Xiangjun; Burke, Sarah; Wu, Xianli; Prior, Ronald L.; Li, Li

    2010-01-01

    Anthocyanins are responsible for the color of many flowers, fruits, and vegetables. An interesting and unique Purple (Pr) gene mutation in cauliflower (Brassica oleracea var botrytis) confers an abnormal pattern of anthocyanin accumulation, giving the striking mutant phenotype of intense purple color in curds and a few other tissues. To unravel the nature of the Pr mutation in cauliflower, we isolated the Pr gene via a combination of candidate gene analysis and fine mapping. Pr encoded a R2R3 MYB transcription factor that exhibited tissue-specific expression, consistent with an abnormal anthocyanin accumulation pattern in the mutant. Transgenic Arabidopsis (Arabidopsis thaliana) and cauliflower plants expressing the Pr-D allele recapitulated the mutant phenotype, confirming the isolation of the Pr gene. Up-regulation of Pr specifically activated a basic helix-loop-helix transcription factor and a subset of anthocyanin structural genes encoding flavonoid 3’-hydroxylase, dihydroflavonol 4-reductase, and leucoanthocyanidin dioxygenase to confer ectopic accumulation of pigments in the purple cauliflower. Our results indicate that the genetic variation including a Harbinger DNA transposon insertion in the upstream regulatory region of the Pr-D allele is responsible for the up-regulation of the Pr gene in inducing phenotypic change in the plant. The successful isolation of Pr provides important information on the regulatory control of anthocyanin biosynthesis in Brassica vegetables, and offers a genetic resource for development of new varieties with enhanced health-promoting properties and visual appeal. PMID:20855520

  7. CACTA-superfamily transposable element is inserted in MYB transcription factor gene of soybean line producing variegated seeds.

    Science.gov (United States)

    Yan, Fan; Di, Shaokang; Takahashi, Ryoji

    2015-08-01

    The R gene of soybean, presumably encoding a MYB transcription factor, controls seed coat color. The gene consists of multiple alleles, R (black), r-m (black spots and (or) concentric streaks on brown seed), and r (brown seed). This study was conducted to determine the structure of the MYB transcription factor gene in a near-isogenic line (NIL) having r-m allele. PCR amplification of a fragment of the candidate gene Glyma.09G235100 generated a fragment of about 1 kb in the soybean cultivar Clark, whereas a fragment of about 14 kb in addition to fragments of 1 and 1.4 kb were produced in L72-2040, a Clark 63 NIL with the r-m allele. Clark 63 is a NIL of Clark with the rxp and Rps1 alleles. A DNA fragment of 13 060 bp was inserted in the intron of Glyma.09G235100 in L72-2040. The fragment had the CACTA motif at both ends, imperfect terminal inverted repeats (TIR), inverse repetition of short sequence motifs close to the 5' and 3' ends, and a duplication of three nucleotides at the site of integration, indicating that it belongs to a CACTA-superfamily transposable element. We designated the element as Tgm11. Overall nucleotide sequence, motifs of TIR, and subterminal repeats were similar to those of Tgm1 and Tgs1, suggesting that these elements comprise a family.

  8. The molecular mechanism underlying anthocyanin metabolism in apple using the MdMYB16 and MdbHLH33 genes.

    Science.gov (United States)

    Xu, Haifeng; Wang, Nan; Liu, Jingxuan; Qu, Changzhi; Wang, Yicheng; Jiang, Shenghui; Lu, Ninglin; Wang, Deyun; Zhang, Zongying; Chen, Xuesen

    2017-05-01

    MdMYB16 forms homodimers and directly inhibits anthocyanin synthesis via its C-terminal EAR repressor. It weakened the inhibitory effect of MdMYB16 on anthocyanin synthesis when overexpressing MdbHLH33 in callus overexpressing MdMYB16. MdMYB16 could interact with MdbHLH33. Anthocyanins are strong antioxidants that play a key role in the prevention of cardiovascular disease, cancer, and diabetes. The germplasm of Malus sieversii f. neidzwetzkyana is important for the study of anthocyanin metabolism. To date, only limited studies have examined the negative regulatory mechanisms underlying anthocyanin synthesis in apple. Here, we analyzed the relationship between anthocyanin levels and MdMYB16 expression in mature Red Crisp 1-5 apple (M. domestica) fruit, generated an evolutionary tree, and identified an EAR suppression sequence and a bHLH binding motif of the MdMYB16 protein using protein sequence analyses. Overexpression of MdMYB16 or MdMYB16 without bHLH binding sequence (LBSMdMYB16) in red-fleshed callus inhibited MdUFGT and MdANS expression and anthocyanin synthesis. However, overexpression of MdMYB16 without the EAR sequence (LESMdMYB16) in red-fleshed callus had no inhibitory effect on anthocyanin. The yeast one-hybrid assay showed that MdMYB16 and LESMdMYB16 interacted the promoters of MdANS and MdUFGT, respectively. Yeast two-hybrid, pull-down, and bimolecular fluorescence complementation assays showed that MdMYB16 formed homodimers and interacted with MdbHLH33, however, the LBSMdMYB16 could not interact with MdbHLH33. We overexpressed MdbHLH33 in callus overexpressing MdMYB16 and found that it weakened the inhibitory effect of MdMYB16 on anthocyanin synthesis. Together, these results suggested that MdMYB16 and MdbHLH33 may be important part of the regulatory network controlling the anthocyanin biosynthetic pathway.

  9. Coordinated transcriptional regulation of two key genes in the lignin branch pathway--CAD and CCR--is mediated through MYB- binding sites.

    Science.gov (United States)

    Rahantamalala, Anjanirina; Rech, Philippe; Martinez, Yves; Chaubet-Gigot, Nicole; Grima-Pettenati, Jacqueline; Pacquit, Valérie

    2010-06-28

    Cinnamoyl CoA reductase (CCR) and cinnamyl alcohol dehydrogenase (CAD) catalyze the final steps in the biosynthesis of monolignols, the monomeric units of the phenolic lignin polymers which confer rigidity, imperviousness and resistance to biodegradation to cell walls. We have previously shown that the Eucalyptus gunnii CCR and CAD2 promoters direct similar expression patterns in vascular tissues suggesting that monolignol production is controlled, at least in part, by the coordinated transcriptional regulation of these two genes. Although consensus motifs for MYB transcription factors occur in most gene promoters of the whole phenylpropanoid pathway, functional evidence for their contribution to promoter activity has only been demonstrated for a few of them. Here, in the lignin-specific branch, we studied the functional role of MYB elements as well as other cis-elements identified in the regulatory regions of EgCAD2 and EgCCR promoters, in the transcriptional activity of these gene promoters. By using promoter deletion analysis and in vivo footprinting, we identified an 80 bp regulatory region in the Eucalyptus gunnii EgCAD2 promoter that contains two MYB elements, each arranged in a distinct module with newly identified cis-elements. A directed mutagenesis approach was used to introduce block mutations in all putative cis-elements of the EgCAD2 promoter and in those of the 50 bp regulatory region previously delineated in the EgCCR promoter. We showed that the conserved MYB elements in EgCAD2 and EgCCR promoters are crucial both for the formation of DNA-protein complexes in EMSA experiments and for the transcriptional activation of EgCAD2 and EgCCR promoters in vascular tissues in planta. In addition, a new regulatory cis-element that modulates the balance between two DNA-protein complexes in vitro was found to be important for EgCAD2 expression in the cambial zone. Our assignment of functional roles to the identified cis-elements clearly demonstrates the

  10. The Arabidopsis Transcription Factor MYB112 Promotes Anthocyanin Formation during Salinity and under High Light Stress.

    Science.gov (United States)

    Lotkowska, Magda E; Tohge, Takayuki; Fernie, Alisdair R; Xue, Gang-Ping; Balazadeh, Salma; Mueller-Roeber, Bernd

    2015-11-01

    MYB transcription factors (TFs) are important regulators of flavonoid biosynthesis in plants. Here, we report MYB112 as a formerly unknown regulator of anthocyanin accumulation in Arabidopsis (Arabidopsis thaliana). Expression profiling after chemically induced overexpression of MYB112 identified 28 up- and 28 down-regulated genes 5 h after inducer treatment, including MYB7 and MYB32, which are both induced. In addition, upon extended induction, MYB112 also positively affects the expression of PRODUCTION OF ANTHOCYANIN PIGMENT1, a key TF of anthocyanin biosynthesis, but acts negatively toward MYB12 and MYB111, which both control flavonol biosynthesis. MYB112 binds to an 8-bp DNA fragment containing the core sequence (A/T/G)(A/C)CC(A/T)(A/G/T)(A/C)(T/C). By electrophoretic mobility shift assay and chromatin immunoprecipitation coupled to quantitative polymerase chain reaction, we show that MYB112 binds in vitro and in vivo to MYB7 and MYB32 promoters, revealing them as direct downstream target genes. We further show that MYB112 expression is up-regulated by salinity and high light stress, environmental parameters that both require the MYB112 TF for anthocyanin accumulation under these stresses. In contrast to several other MYB TFs affecting anthocyanin biosynthesis, MYB112 expression is not controlled by nitrogen limitation or an excess of carbon. Thus, MYB112 constitutes a regulator that promotes anthocyanin accumulation under abiotic stress conditions. © 2015 American Society of Plant Biologists. All Rights Reserved.

  11. Two showy traits, scent emission and pigmentation, are finely coregulated by the MYB transcription factor PH4 in petunia flowers.

    Science.gov (United States)

    Cna'ani, Alon; Spitzer-Rimon, Ben; Ravid, Jasmin; Farhi, Moran; Masci, Tania; Aravena-Calvo, Javiera; Ovadis, Marianna; Vainstein, Alexander

    2015-11-01

    The mechanism underlying the emission of phenylpropanoid volatiles is poorly understood. Here, we reveal the involvement of PH4, a petunia MYB-R2R3 transcription factor previously studied for its role in vacuolar acidification, in floral volatile emission. We used the virus-induced gene silencing (VIGS) approach to knock down PH4 expression in petunia, measured volatile emission and internal pool sizes by GC-MS, and analyzed transcript abundances of scent-related phenylpropanoid genes in flowers. Silencing of PH4 resulted in a marked decrease in floral phenylpropanoid volatile emission, with a concurrent increase in internal pool levels. Expression of scent-related phenylpropanoid genes was not affected. To identify putative scent-related targets of PH4, we silenced PH5, a tonoplast-localized H(+) -ATPase that maintains vacuolar pH homeostasis. Suppression of PH5 did not yield the reduced-emission phenotype, suggesting that PH4 does not operate in the context of floral scent through regulation of vacuolar pH. We conclude that PH4 is a key floral regulator that integrates volatile production and emission processes and interconnects two essential floral traits - color and scent. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  12. Molecular characterization of BrMYB28 and BrMYB29 paralogous transcription factors involved in the regulation of aliphatic glucosinolate profiles in Brassica rapa ssp. pekinensis.

    Science.gov (United States)

    Baskar, Venkidasamy; Park, Se Won

    2015-07-01

    Glucosinolates (GSL) are one of the major secondary metabolites of the Brassicaceae family. In the present study, we aim at characterizing the multiple paralogs of aliphatic GSL regulators, such as BrMYB28 and BrMYB29 genes in Brassica rapa ssp. pekinensis, by quantitative real-time PCR (qRT-PCR) analysis in different tissues and at various developmental stages. An overlapping gene expression pattern between the BrMYBs as well as their downstream genes (DSGs) was found at different developmental stages. Among the BrMYB28 and BrMYB29 paralogous genes, the BrMYB28.3 and BrMYB29.1 genes were dominantly expressed in most of the developmental stages, compared to the other paralogs of the BrMYB genes. Furthermore, the differential expression pattern of the BrMYBs was observed under various stress treatments. Interestingly, BrMYB28.2 showed the least expression in most developmental stages, while its expression was remarkably high in different stress conditions. More specifically, the BrMYB28.2, BrMYB28.3, and BrMYB29.1 genes were highly responsive to various abiotic and biotic stresses, further indicating their possible role in stress tolerance. Moreover, the in silico cis motif analysis in the upstream regulatory regions of BrMYBs showed the presence of various putative stress-specific motifs, which further indicated their responsiveness to biotic and abiotic stresses. These observations suggest that the dominantly expressed BrMYBs, both in different developmental stages and under various stress treatments (BrMYB28.3 and BrMYB29.1), may be potential candidate genes for altering the GSL level through genetic modification studies in B. rapa ssp. pekinensis. Copyright © 2015. Published by Elsevier SAS.

  13. NTL8 Regulates Trichome Formation in Arabidopsis by Directly Activating R3 MYB Genes TRY and TCL1.

    Science.gov (United States)

    Tian, Hainan; Wang, Xianling; Guo, Hongyan; Cheng, Yuxin; Hou, Chunjiang; Chen, Jin-Gui; Wang, Shucai

    2017-08-01

    The NAM, ATAF1/2, and CUC (NAC) are plant-specific transcription factors that regulate multiple aspects of plant growth and development and plant response to environmental stimuli. We report here the identification of NTM1-LIKE8 (NTL8), a membrane-associated NAC transcription factor, as a novel regulator of trichome formation in Arabidopsis ( Arabidopsis thaliana ). From an activation-tagged Arabidopsis population, we identified a dominant, gain-of-function mutant with glabrous inflorescence stem. By using plasmid rescue and RT-PCR analyses, we found that NTL8 was tagged; thus, the mutant was named ntl8-1 Dominant ( ntl8-1D ). Recapitulation experiment further confirmed that the phenotype observed in the ntl8-1D mutant was caused by elevated expression of NTL8 Quantitative RT-PCR results showed that the expression level of the single-repeat R3 MYB genes TRIPTYCHON ( TRY ) and TRICHOMELESS1 ( TCL1 ) was elevated in the ntl8-1D mutant. Genetic analyses demonstrated that NTL8 acts upstream of TRY and TCL1 in the regulation of trichome formation. When recruited to the promoter region of the reporter gene Gal4:GUS by a fused GAL4 DNA-binding domain, NTL8 activated the expression of the reporter gene. Chromatin immunoprecipitation results indicated that TRY and TCL1 are direct targets of NTL8. However, NTL8 did not interact with SQUAMOSA PROMOTER BINDING PROTEIN LIKE9, another transcription factor that regulates the expression of TRY and TCL1 , in yeast and plant cells. Taken together, our results suggest that NTL8 negatively regulates trichome formation in Arabidopsis by directly activating the expression of TRY and TCL1 . © 2017 American Society of Plant Biologists. All Rights Reserved.

  14. A putative functional MYB transcription factor induced by low temperature regulates anthocyanin biosynthesis in purple kale (Brassica Oleracea var. acephala f. tricolor).

    Science.gov (United States)

    Zhang, Bin; Hu, Zongli; Zhang, Yanjie; Li, Yali; Zhou, Shuang; Chen, Guoping

    2012-02-01

    The purple kale (Brassica Oleracea var. acephala f. tricolor) is a mutation in kales, giving the mutant phenotype of brilliant purple color in the interior. Total anthocyanin analysis showed that the amount of anthocyanins in the purple kale was up to 1.73 mg g(-1) while no anthocyanin was detected in the white kale. To elucidate the molecular mechanism of the anthocyanin biosynthesis in the purple kale, we analyzed the expression of structural genes and some transcription factors associated with anthocyanin biosynthesis in the purple cultivar "Red Dove" and the white cultivar "White Dove". The result showed that nearly all the anthocyanin biosynthetic genes showed higher expression levels in the purple cultivar than in the white cultivar, especially for DFR and ANS, they were barely detected in the white cultivar. Interestingly, the fact that a R2R3 MYB transcription factor named BoPAP1 was extremely up-regulated in the purple kale and induced by low temperature attracted our attention. Further sequence analysis showed that BoPAP1 shared high similarity with AtPAP1 and BoMYB1. In addition, the anthocyanin accumulation in the purple kale is strongly induced by the low temperature stress. The total anthocyanin contents in the purple kale under low temperature were about 50-fold higher than the plants grown in the greenhouse. The expression of anthocyanin biosynthetic genes C4H, F3H, DFR, ANS and UFGT were all enhanced under the low temperature. These evidences strongly suggest that BoPAP1 may play an important role in activating the anthocyanin structural genes for the abundant anthocyanin accumulation in the purple kale.

  15. Selection of housekeeping genes for normalization by real-time RT-PCR: analysis of Or-MYB1 gene expression in Orobanche ramosa development.

    Science.gov (United States)

    González-Verdejo, C I; Die, J V; Nadal, S; Jiménez-Marín, A; Moreno, M T; Román, B

    2008-08-15

    Real-time PCR has become the method of choice for accurate and in-depth expression studies of candidate genes. To avoid bias, real-time PCR is referred to one or several internal control genes that should not fluctuate among treatments. A need for reference genes in the parasitic plant Orobanche ramosa has emerged, and the studies in this area have not yet been evaluated. In this study, the genes 18S rRNA, Or-act1, Or-tub1, and Or-ubq1 were compared in terms of expression stability using the BestKeeper software program. Among the four common endogenous control genes, Or-act1 and Or-ubq1 were the most stable in O. ramosa samples. In parallel, a study was carried out studying the expression of the transcription factor Or-MYB1 that seemed to be implicated during preinfection stages. The normalization strategy presented here is a prerequisite to accurate real-time PCR expression profiling that, among other things, opens up the possibility of studying messenger RNA levels of low-copy-number-like transcription factors.

  16. The Arabidopsis Transcription Factor MYB112 Promotes Anthocyanin Formation during Salinity and under High Light Stress1[OPEN

    Science.gov (United States)

    Lotkowska, Magda E.; Tohge, Takayuki; Fernie, Alisdair R.; Xue, Gang-Ping; Balazadeh, Salma; Mueller-Roeber, Bernd

    2015-01-01

    MYB transcription factors (TFs) are important regulators of flavonoid biosynthesis in plants. Here, we report MYB112 as a formerly unknown regulator of anthocyanin accumulation in Arabidopsis (Arabidopsis thaliana). Expression profiling after chemically induced overexpression of MYB112 identified 28 up- and 28 down-regulated genes 5 h after inducer treatment, including MYB7 and MYB32, which are both induced. In addition, upon extended induction, MYB112 also positively affects the expression of PRODUCTION OF ANTHOCYANIN PIGMENT1, a key TF of anthocyanin biosynthesis, but acts negatively toward MYB12 and MYB111, which both control flavonol biosynthesis. MYB112 binds to an 8-bp DNA fragment containing the core sequence (A/T/G)(A/C)CC(A/T)(A/G/T)(A/C)(T/C). By electrophoretic mobility shift assay and chromatin immunoprecipitation coupled to quantitative polymerase chain reaction, we show that MYB112 binds in vitro and in vivo to MYB7 and MYB32 promoters, revealing them as direct downstream target genes. We further show that MYB112 expression is up-regulated by salinity and high light stress, environmental parameters that both require the MYB112 TF for anthocyanin accumulation under these stresses. In contrast to several other MYB TFs affecting anthocyanin biosynthesis, MYB112 expression is not controlled by nitrogen limitation or an excess of carbon. Thus, MYB112 constitutes a regulator that promotes anthocyanin accumulation under abiotic stress conditions. PMID:26378103

  17. Transcription arrest by a G quadruplex forming-trinucleotide repeat sequence from the human c-myb gene.

    Science.gov (United States)

    Broxson, Christopher; Beckett, Joshua; Tornaletti, Silvia

    2011-05-17

    Non canonical DNA structures correspond to genomic regions particularly susceptible to genetic instability. The transcription process facilitates formation of these structures and plays a major role in generating the instability associated with these genomic sites. However, little is known about how non canonical structures are processed when encountered by an elongating RNA polymerase. Here we have studied the behavior of T7 RNA polymerase (T7RNAP) when encountering a G quadruplex forming-(GGA)(4) repeat located in the human c-myb proto-oncogene. To make direct correlations between formation of the structure and effects on transcription, we have taken advantage of the ability of the T7 polymerase to transcribe single-stranded substrates and of G4 DNA to form in single-stranded G-rich sequences in the presence of potassium ions. Under physiological KCl concentrations, we found that T7 RNAP transcription was arrested at two sites that mapped to the c-myb (GGA)(4) repeat sequence. The extent of arrest did not change with time, indicating that the c-myb repeat represented an absolute block and not a transient pause to T7 RNAP. Consistent with G4 DNA formation, arrest was not observed in the absence of KCl or in the presence of LiCl. Furthermore, mutations in the c-myb (GGA)(4) repeat, expected to prevent transition to G4, also eliminated the transcription block. We show T7 RNAP arrest at the c-myb repeat in double-stranded DNA under conditions mimicking the cellular concentration of biomolecules and potassium ions, suggesting that the G4 structure formed in the c-myb repeat may represent a transcription roadblock in vivo. Our results support a mechanism of transcription-coupled DNA repair initiated by arrest of transcription at G4 structures.

  18. Overexpression of the kiwifruit SVP3 gene affects reproductive development and suppresses anthocyanin biosynthesis in petals, but has no effect on vegetative growth, dormancy, or flowering time.

    Science.gov (United States)

    Wu, Rongmei; Wang, Tianchi; McGie, Tony; Voogd, Charlotte; Allan, Andrew C; Hellens, Roger P; Varkonyi-Gasic, Erika

    2014-09-01

    SVP-like MADS domain transcription factors have been shown to regulate flowering time and both inflorescence and flower development in annual plants, while having effects on growth cessation and terminal bud formation in perennial species. Previously, four SVP genes were described in woody perennial vine kiwifruit (Actinidia spp.), with possible distinct roles in bud dormancy and flowering. Kiwifruit SVP3 transcript was confined to vegetative tissues and acted as a repressor of flowering as it was able to rescue the Arabidopsis svp41 mutant. To characterize kiwifruit SVP3 further, ectopic expression in kiwifruit species was performed. Ectopic expression of SVP3 in A. deliciosa did not affect general plant growth or the duration of endodormancy. Ectopic expression of SVP3 in A. eriantha also resulted in plants with normal vegetative growth, bud break, and flowering time. However, significantly prolonged and abnormal flower, fruit, and seed development were observed, arising from SVP3 interactions with kiwifruit floral homeotic MADS-domain proteins. Petal pigmentation was reduced as a result of SVP3-mediated interference with transcription of the kiwifruit flower tissue-specific R2R3 MYB regulator, MYB110a, and the gene encoding the key anthocyanin biosynthetic step, F3GT1. Constitutive expression of SVP3 had a similar impact on reproductive development in transgenic tobacco. The flowering time was not affected in day-neutral and photoperiod-responsive Nicotiana tabacum cultivars, but anthesis and seed germination were significantly delayed. The accumulation of anthocyanin in petals was reduced and the same underlying mechanism of R2R3 MYB NtAN2 transcript reduction was demonstrated. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  19. Genome-Wide Classification and Evolutionary and Expression Analyses of Citrus MYB Transcription Factor Families in Sweet Orange

    Science.gov (United States)

    Hou, Xiao-Jin; Li, Si-Bei; Liu, Sheng-Rui; Hu, Chun-Gen; Zhang, Jin-Zhi

    2014-01-01

    MYB family genes are widely distributed in plants and comprise one of the largest transcription factors involved in various developmental processes and defense responses of plants. To date, few MYB genes and little expression profiling have been reported for citrus. Here, we describe and classify 177 members of the sweet orange MYB gene (CsMYB) family in terms of their genomic gene structures and similarity to their putative Arabidopsis orthologs. According to these analyses, these CsMYBs were categorized into four groups (4R-MYB, 3R-MYB, 2R-MYB and 1R-MYB). Gene structure analysis revealed that 1R-MYB genes possess relatively more introns as compared with 2R-MYB genes. Investigation of their chromosomal localizations revealed that these CsMYBs are distributed across nine chromosomes. Sweet orange includes a relatively small number of MYB genes compared with the 198 members in Arabidopsis, presumably due to a paralog reduction related to repetitive sequence insertion into promoter and non-coding transcribed region of the genes. Comparative studies of CsMYBs and Arabidopsis showed that CsMYBs had fewer gene duplication events. Expression analysis revealed that the MYB gene family has a wide expression profile in sweet orange development and plays important roles in development and stress responses. In addition, 337 new putative microsatellites with flanking sequences sufficient for primer design were also identified from the 177 CsMYBs. These results provide a useful reference for the selection of candidate MYB genes for cloning and further functional analysis forcitrus. PMID:25375352

  20. Gene dosage induction of silencing directed against an Arabidopsis Myb transgene in tobacco

    Science.gov (United States)

    An unexpected reduction in petal pigmentation on petunia plants genetically engineered for enhanced flower color was one of the first experimental demonstrations of the natural process of RNA-associated gene silencing. The obvious visual nature of such alterations to pigment patterns of transgenic ...

  1. Role of c-Myb in chondrogenesis.

    Science.gov (United States)

    Oralová, V; Matalová, E; Janečková, E; Drobná Krejčí, E; Knopfová, L; Šnajdr, P; Tucker, A S; Veselá, I; Šmarda, J; Buchtová, M

    2015-07-01

    The Myb locus encodes the c-Myb transcription factor involved in controlling a broad variety of cellular processes. Recently, it has been shown that c-Myb may play a specific role in hard tissue formation; however, all of these results were gathered from an analysis of intramembranous ossification. To investigate a possible role of c-Myb in endochondral ossification, we carried out our study on the long bones of mouse limbs during embryonic development. Firstly, the c-myb expression pattern was analyzed by in situ hybridization during endochondral ossification of long bones. c-myb positive areas were found in proliferating as well as hypertrophic zones of the growth plate. At early embryonic stages, localized expression was also observed in the perichondrium and interdigital areas. The c-Myb protein was found in proliferating chondrocytes and in the perichondrium of the forelimb bones (E14.5-E17.5). Furthermore, protein was detected in pre-hypertrophic as well as hypertrophic chondrocytes. Gain-of-function and loss-of-function approaches were used to test the effect of altered c-myb expression on chondrogenesis in micromass cultures established from forelimb buds of mouse embryos. A loss-of-function approach using c-myb specific siRNA decreased nodule formation, as well as downregulated the level of Sox9 expression, a major marker of chondrogenesis. Transient c-myb overexpression markedly increased the formation of cartilage nodules and the production of extracellular matrix as detected by intense staining with Alcian blue. Moreover, the expression of early chondrogenic genes such as Sox9, Col2a1 and activity of a Col2-LUC reporter were increased in the cells overexpressing c-myb while late chondrogenic markers such as Col10a1 and Mmp13 were not significantly changed or were downregulated. Taken together, the results of this study demonstrate that the c-Myb transcription factor is involved in the regulation and promotion of endochondral bone formation. Copyright

  2. MYB Transcription Factors in Chinese Pear (Pyrus bretschneideri Rehd.: Genome-Wide Identification, Classification and Expression Profiling during Fruit Development

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    Yun Peng eCao

    2016-04-01

    Full Text Available The MYB family is one of the largest families of transcription factors in plants. Although some MYBs have been reported to play roles in secondary metabolism, no comprehensive study of the MYB family in Chinese pear (Pyrus bretschneideri Rehd. has been reported. In the present study, we performed genome-wide analysis of MYB genes in Chinese pear, designated as PbMYBs, including analyses of their phylogenic relationships, structures, chromosomal locations, promoter regions, GO annotations and collinearity. A total of 129 PbMYB genes were identified in the pear genome and were divided into 31 subgroups based on phylogenetic analysis. These PbMYBs were unevenly distributed among 16 chromosomes (total of 17 chromosomes. The occurrence of gene duplication events indicated that whole-genome duplication and segmental duplication likely played key roles in expansion of the PbMYB gene family. Ka/Ks analysis suggested that the duplicated PbMYBs mainly experienced purifying selection with restrictive functional divergence after the duplication events. Interspecies microsynteny analysis revealed maximum orthology between pear and peach, followed by plum and strawberry. Subsequently, the expression patterns of 20 PbMYB genes that may be involved in lignin biosynthesis according to their phylogenetic relationships were examined throughout fruit development. Among the twenty genes examined, PbMYB25 and PbMYB52 exhibited expression patterns consistent with the typical variations in the lignin content previously reported. Moreover, sub-cellular localization analysis revealed that two proteins PbMYB25 and PbMYB52 were localized to the nucleus. All together, PbMYB25 and PbMYB52 were inferred to be candidate genes involved in the regulation of lignin biosynthesis during the development of pear fruit. This study provides useful information for further functional analysis of the MYB gene family in pear.

  3. The poplar MYB master switches bind to the SMRE site and activate the secondary wall biosynthetic program during wood formation.

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    Ruiqin Zhong

    Full Text Available Wood is mainly composed of secondary walls, which constitute the most abundant stored carbon produced by vascular plants. Understanding the molecular mechanisms controlling secondary wall deposition during wood formation is not only an important issue in plant biology but also critical for providing molecular tools to custom-design wood composition suited for diverse end uses. Past molecular and genetic studies have revealed a transcriptional network encompassing a group of wood-associated NAC and MYB transcription factors that are involved in the regulation of the secondary wall biosynthetic program during wood formation in poplar trees. Here, we report the functional characterization of poplar orthologs of MYB46 and MYB83 that are known to be master switches of secondary wall biosynthesis in Arabidopsis. In addition to the two previously-described PtrMYB3 and PtrMYB20, two other MYBs, PtrMYB2 and PtrMYB21, were shown to be MYB46/MYB83 orthologs by complementation and overexpression studies in Arabidopsis. The functional roles of these PtrMYBs in regulating secondary wall biosynthesis were further demonstrated in transgenic poplar plants showing an ectopic deposition of secondary walls in PtrMYB overexpressors and a reduction of secondary wall thickening in their dominant repressors. Furthermore, PtrMYB2/3/20/21 together with two other tree MYBs, the Eucalyptus EgMYB2 and the pine PtMYB4, were shown to differentially bind to and activate the eight variants of the 7-bp SMRE consensus sequence, composed of ACC(A/TA(A/C(T/C. Together, our results indicate that the tree MYBs, PtrMYB2/3/20/21, EgMYB2 and PtMYB4, are master transcriptional switches that activate the SMRE sites in the promoters of target genes and thereby regulate secondary wall biosynthesis during wood formation.

  4. The Jasmonate-ZIM-domain proteins interact with the WD-Repeat/bHLH/MYB complexes to regulate Jasmonate-mediated anthocyanin accumulation and trichome initiation in Arabidopsis thaliana.

    Science.gov (United States)

    Qi, Tiancong; Song, Susheng; Ren, Qingcuo; Wu, Dewei; Huang, Huang; Chen, Yan; Fan, Meng; Peng, Wen; Ren, Chunmei; Xie, Daoxin

    2011-05-01

    Jasmonates (JAs) mediate plant responses to insect attack, wounding, pathogen infection, stress, and UV damage and regulate plant fertility, anthocyanin accumulation, trichome formation, and many other plant developmental processes. Arabidopsis thaliana Jasmonate ZIM-domain (JAZ) proteins, substrates of the CORONATINE INSENSITIVE1 (COI1)-based SCF(COI1) complex, negatively regulate these plant responses. Little is known about the molecular mechanism for JA regulation of anthocyanin accumulation and trichome initiation. In this study, we revealed that JAZ proteins interact with bHLH (Transparent Testa8, Glabra3 [GL3], and Enhancer of Glabra3 [EGL3]) and R2R3 MYB transcription factors (MYB75 and Glabra1), essential components of WD-repeat/bHLH/MYB transcriptional complexes, to repress JA-regulated anthocyanin accumulation and trichome initiation. Genetic and physiological evidence showed that JA regulates WD-repeat/bHLH/MYB complex-mediated anthocyanin accumulation and trichome initiation in a COI1-dependent manner. Overexpression of the MYB transcription factor MYB75 and bHLH factors (GL3 and EGL3) restored anthocyanin accumulation and trichome initiation in the coi1 mutant, respectively. We speculate that the JA-induced degradation of JAZ proteins abolishes the interactions of JAZ proteins with bHLH and MYB factors, allowing the transcriptional function of WD-repeat/bHLH/MYB complexes, which subsequently activate respective downstream signal cascades to modulate anthocyanin accumulation and trichome initiation.

  5. The Jasmonate-ZIM-Domain Proteins Interact with the WD-Repeat/bHLH/MYB Complexes to Regulate Jasmonate-Mediated Anthocyanin Accumulation and Trichome Initiation in Arabidopsis thaliana[C][W

    Science.gov (United States)

    Qi, Tiancong; Song, Susheng; Ren, Qingcuo; Wu, Dewei; Huang, Huang; Chen, Yan; Fan, Meng; Peng, Wen; Ren, Chunmei; Xie, Daoxin

    2011-01-01

    Jasmonates (JAs) mediate plant responses to insect attack, wounding, pathogen infection, stress, and UV damage and regulate plant fertility, anthocyanin accumulation, trichome formation, and many other plant developmental processes. Arabidopsis thaliana Jasmonate ZIM-domain (JAZ) proteins, substrates of the CORONATINE INSENSITIVE1 (COI1)–based SCFCOI1 complex, negatively regulate these plant responses. Little is known about the molecular mechanism for JA regulation of anthocyanin accumulation and trichome initiation. In this study, we revealed that JAZ proteins interact with bHLH (Transparent Testa8, Glabra3 [GL3], and Enhancer of Glabra3 [EGL3]) and R2R3 MYB transcription factors (MYB75 and Glabra1), essential components of WD-repeat/bHLH/MYB transcriptional complexes, to repress JA-regulated anthocyanin accumulation and trichome initiation. Genetic and physiological evidence showed that JA regulates WD-repeat/bHLH/MYB complex-mediated anthocyanin accumulation and trichome initiation in a COI1-dependent manner. Overexpression of the MYB transcription factor MYB75 and bHLH factors (GL3 and EGL3) restored anthocyanin accumulation and trichome initiation in the coi1 mutant, respectively. We speculate that the JA-induced degradation of JAZ proteins abolishes the interactions of JAZ proteins with bHLH and MYB factors, allowing the transcriptional function of WD-repeat/bHLH/MYB complexes, which subsequently activate respective downstream signal cascades to modulate anthocyanin accumulation and trichome initiation. PMID:21551388

  6. Transactivation mediated by B-Myb is dependent on TAF(II)250.

    Science.gov (United States)

    Bartusel, Thorsten; Klempnauer, Karl-Heinz

    2003-05-15

    B-Myb is a highly conserved member of the Myb family of transcription factors, which has been implicated in cell cycle regulation. B-Myb is expressed in most proliferating cells and its activity is highly regulated around the G1/S-phase border of the cell cycle. It is generally assumed that B-Myb regulates the expression of genes that are crucial for cell proliferation; however, the identity of these genes, the molecular mechanisms by which B-Myb stimulates their expression and the involvement of other proteins have not been sufficiently clarified. We have employed the hamster cell line ts13 as a tool to demonstrate a functional link between B-Myb and the coactivator TAF(II)250, a key component of the transcriptional machinery which itself is essential for cell proliferation. ts13 cells express a point-mutated version of TAF(II)250 whose intrinsic histone acetyl transferase activity is temperature sensitive. Transactivation of Myb-responsive reporter genes by B-Myb is temperature-dependent in ts13 cells but not in ts13 cells, which have been rescued by transfection with an expression vector for wild-type TAF(II)250. Furthermore, B-Myb and TAF(II)250 can be coprecipitated, suggesting that both proteins are present in a complex. The formation of this complex is dependent on the DNA-binding domain of B-Myb and not on its transactivation domain. Taken together, these observations provide the first evidence that the coactivator TAF(II)250 is involved in the activation of Myb responsive promoters by B-Myb. The finding that B-Myb transactivation is dependent on a key coactivator involved in cell cycle control is consistent with and strengthens the idea that B-Myb plays a crucial role as a transcription factor in proliferating cells.

  7. Arabidopsis MYB-Related HHO2 Exerts a Regulatory Influence on a Subset of Root Traits and Genes Governing Phosphate Homeostasis.

    Science.gov (United States)

    Nagarajan, Vinay K; Satheesh, Viswanathan; Poling, Michael D; Raghothama, Kashchandra G; Jain, Ajay

    2016-06-01

    Phosphate (Pi), an essential macronutrient required for growth and development of plants, is often limiting in soils. Pi deficiency modulates the expression of Pi starvation-responsive (PSR) genes including transcription factors (TFs). Here, we elucidated the role of the MYB-related TF HYPERSENSITIVITY TO LOW PHOSPHATE-ELICITED PRIMARY ROOT SHORTENING1 HOMOLOG2 (HHO2, At1g68670) in regulating Pi acquisition and signaling in Arabidopsis thaliana HHO2 was specifically and significantly induced in different tissues in response to Pi deprivation. Transgenic seedlings expressing 35S::GFP::HHO2 confirmed the localization of HHO2 to the nucleus. Knockout mutants of HHO2 showed significant reduction in number and length of first- and higher-order lateral roots and Pi content of different tissues compared with the wild-type irrespective of the Pi regime. In contrast, HHO2-overexpressing lines exhibited augmented lateral root development, enhanced Pi uptake rate and higher Pi content in leaf compared with the wild-type. Expression levels of PSR genes involved in Pi sensing and signaling in mutants and overexpressors were differentially regulated as compared with the wild-type. Attenuation in the expression of HHO2 in the phr1 mutant suggested a likely influence of PHR1 in HHO2-mediated regulation of a subset of traits governing Pi homeostasis. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  8. Dominant Repression by Arabidopsis Transcription Factor MYB44 Causes Oxidative Damage and Hypersensitivity to Abiotic Stress

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    Helene Persak

    2014-02-01

    Full Text Available In any living species, stress adaptation is closely linked with major changes of the gene expression profile. As a substrate protein of the rapidly stress-induced mitogen-activated protein kinase MPK3, Arabidopsis transcription factor MYB44 likely acts at the front line of stress-induced re-programming. We recently characterized MYB44 as phosphorylation-dependent positive regulator of salt stress signaling. Molecular events downstream of MYB44 are largely unknown. Although MYB44 binds to the MBSII element in vitro, it has no discernible effect on MBSII-driven reporter gene expression in plant co-transfection assays. This may suggest limited abundance of a synergistic co-regulator. MYB44 carries a putative transcriptional repression (Ethylene responsive element binding factor-associated Amphiphilic Repression, EAR motif. We employed a dominant repressor strategy to gain insights into MYB44-conferred stress resistance. Overexpression of a MYB44-REP fusion markedly compromised salt and drought stress tolerance—the opposite was seen in MYB44 overexpression lines. MYB44-mediated resistance likely results from induction of tolerance-enhancing, rather than from repression of tolerance-diminishing factors. Salt stress-induced accumulation of destructive reactive oxygen species is efficiently prevented in transgenic MYB44, but accelerated in MYB44-REP lines. Furthermore, heterologous overexpression of MYB44-REP caused tissue collapse in Nicotiana. A mechanistic model of MAPK-MYB-mediated enhancement in the antioxidative capacity and stress tolerance is proposed. Genetic engineering of MYB44 variants with higher trans-activating capacity may be a means to further raise stress resistance in crops.

  9. Myb transcription factors and light regulate sporulation in the oomycete Phytophthora infestans.

    Science.gov (United States)

    Xiang, Qijun; Judelson, Howard S

    2014-01-01

    Life cycle progression in eukaryotic microbes is often influenced by environment. In the oomycete Phytophthora infestans, which causes late blight on potato and tomato, sporangia have been reported to form mostly at night. By growing P. infestans under different light regimes at constant temperature and humidity, we show that light contributes to the natural pattern of sporulation by delaying sporulation until the following dark period. However, illumination does not permanently block sporulation or strongly affect the total number of sporangia that ultimately form. Based on measurements of sporulation-induced genes such as those encoding protein kinase Pks1 and Myb transcription factors Myb2R1 and Myb2R3, it appears that most spore-associated transcripts start to rise four to eight hours before sporangia appear. Their mRNA levels oscillate with the light/dark cycle and increase with the amount of sporangia. An exception to this pattern of expression is Myb2R4, which is induced several hours before the other genes and declines after cultures start to sporulate. Transformants over-expressing Myb2R4 produce twice the number of sporangia and ten-fold higher levels of Myb2R1 mRNA than wild-type, and chromatin immunoprecipitation showed that Myb2R4 binds the Myb2R1 promoter in vivo. Myb2R4 thus appears to be an early regulator of sporulation. We attempted to silence eight Myb genes by DNA-directed RNAi, but succeeded only with Myb2R3, which resulted in suppressed sporulation. Ectopic expression studies of seven Myb genes revealed that over-expression frequently impaired vegetative growth, and in the case of Myb3R6 interfered with sporangia dormancy. We observed that the degree of silencing induced by a hairpin construct was correlated with its copy number, and ectopic expression was often unstable due to epigenetic silencing and transgene excision.

  10. Myb transcription factors and light regulate sporulation in the oomycete Phytophthora infestans.

    Directory of Open Access Journals (Sweden)

    Qijun Xiang

    Full Text Available Life cycle progression in eukaryotic microbes is often influenced by environment. In the oomycete Phytophthora infestans, which causes late blight on potato and tomato, sporangia have been reported to form mostly at night. By growing P. infestans under different light regimes at constant temperature and humidity, we show that light contributes to the natural pattern of sporulation by delaying sporulation until the following dark period. However, illumination does not permanently block sporulation or strongly affect the total number of sporangia that ultimately form. Based on measurements of sporulation-induced genes such as those encoding protein kinase Pks1 and Myb transcription factors Myb2R1 and Myb2R3, it appears that most spore-associated transcripts start to rise four to eight hours before sporangia appear. Their mRNA levels oscillate with the light/dark cycle and increase with the amount of sporangia. An exception to this pattern of expression is Myb2R4, which is induced several hours before the other genes and declines after cultures start to sporulate. Transformants over-expressing Myb2R4 produce twice the number of sporangia and ten-fold higher levels of Myb2R1 mRNA than wild-type, and chromatin immunoprecipitation showed that Myb2R4 binds the Myb2R1 promoter in vivo. Myb2R4 thus appears to be an early regulator of sporulation. We attempted to silence eight Myb genes by DNA-directed RNAi, but succeeded only with Myb2R3, which resulted in suppressed sporulation. Ectopic expression studies of seven Myb genes revealed that over-expression frequently impaired vegetative growth, and in the case of Myb3R6 interfered with sporangia dormancy. We observed that the degree of silencing induced by a hairpin construct was correlated with its copy number, and ectopic expression was often unstable due to epigenetic silencing and transgene excision.

  11. The genome sequence of the most widely cultivated cacao type and its use to identify candidate genes regulating pod color.

    Science.gov (United States)

    Motamayor, Juan C; Mockaitis, Keithanne; Schmutz, Jeremy; Haiminen, Niina; Livingstone, Donald; Cornejo, Omar; Findley, Seth D; Zheng, Ping; Utro, Filippo; Royaert, Stefan; Saski, Christopher; Jenkins, Jerry; Podicheti, Ram; Zhao, Meixia; Scheffler, Brian E; Stack, Joseph C; Feltus, Frank A; Mustiga, Guiliana M; Amores, Freddy; Phillips, Wilbert; Marelli, Jean Philippe; May, Gregory D; Shapiro, Howard; Ma, Jianxin; Bustamante, Carlos D; Schnell, Raymond J; Main, Dorrie; Gilbert, Don; Parida, Laxmi; Kuhn, David N

    2013-06-03

    Theobroma cacao L. cultivar Matina 1-6 belongs to the most cultivated cacao type. The availability of its genome sequence and methods for identifying genes responsible for important cacao traits will aid cacao researchers and breeders. We describe the sequencing and assembly of the genome of Theobroma cacao L. cultivar Matina 1-6. The genome of the Matina 1-6 cultivar is 445 Mbp, which is significantly larger than a sequenced Criollo cultivar, and more typical of other cultivars. The chromosome-scale assembly, version 1.1, contains 711 scaffolds covering 346.0 Mbp, with a contig N50 of 84.4 kbp, a scaffold N50 of 34.4 Mbp, and an evidence-based gene set of 29,408 loci. Version 1.1 has 10x the scaffold N50 and 4x the contig N50 as Criollo, and includes 111 Mb more anchored sequence. The version 1.1 assembly has 4.4% gap sequence, while Criollo has 10.9%. Through a combination of haplotype, association mapping and gene expression analyses, we leverage this robust reference genome to identify a promising candidate gene responsible for pod color variation. We demonstrate that green/red pod color in cacao is likely regulated by the R2R3 MYB transcription factor TcMYB113, homologs of which determine pigmentation in Rosaceae, Solanaceae, and Brassicaceae. One SNP within the target site for a highly conserved trans-acting siRNA in dicots, found within TcMYB113, seems to affect transcript levels of this gene and therefore pod color variation. We report a high-quality sequence and annotation of Theobroma cacao L. and demonstrate its utility in identifying candidate genes regulating traits.

  12. The genome sequence of the most widely cultivated cacao type and its use to identify candidate genes regulating pod color

    Science.gov (United States)

    2013-01-01

    Background Theobroma cacao L. cultivar Matina 1-6 belongs to the most cultivated cacao type. The availability of its genome sequence and methods for identifying genes responsible for important cacao traits will aid cacao researchers and breeders. Results We describe the sequencing and assembly of the genome of Theobroma cacao L. cultivar Matina 1-6. The genome of the Matina 1-6 cultivar is 445 Mbp, which is significantly larger than a sequenced Criollo cultivar, and more typical of other cultivars. The chromosome-scale assembly, version 1.1, contains 711 scaffolds covering 346.0 Mbp, with a contig N50 of 84.4 kbp, a scaffold N50 of 34.4 Mbp, and an evidence-based gene set of 29,408 loci. Version 1.1 has 10x the scaffold N50 and 4x the contig N50 as Criollo, and includes 111 Mb more anchored sequence. The version 1.1 assembly has 4.4% gap sequence, while Criollo has 10.9%. Through a combination of haplotype, association mapping and gene expression analyses, we leverage this robust reference genome to identify a promising candidate gene responsible for pod color variation. We demonstrate that green/red pod color in cacao is likely regulated by the R2R3 MYB transcription factor TcMYB113, homologs of which determine pigmentation in Rosaceae, Solanaceae, and Brassicaceae. One SNP within the target site for a highly conserved trans-acting siRNA in dicots, found within TcMYB113, seems to affect transcript levels of this gene and therefore pod color variation. Conclusions We report a high-quality sequence and annotation of Theobroma cacao L. and demonstrate its utility in identifying candidate genes regulating traits. PMID:23731509

  13. McMYB10 regulates coloration via activating McF3'H and later structural genes in ever-red leaf crabapple.

    Science.gov (United States)

    Tian, Ji; Peng, Zhen; Zhang, Jie; Song, Tingting; Wan, Huihua; Zhang, Meiling; Yao, Yuncong

    2015-09-01

    The ever-red leaf trait, which is important for breeding ornamental and higher anthocyanin plants, rarely appears in Malus families, but little is known about the regulation of anthocyanin biosynthesis involved in the red leaves. In our study, HPLC analysis showed that the anthocyanin concentration in ever-red leaves, especially cyanidin, was significantly higher than that in evergreen leaves. The transcript level of McMYB10 was significantly correlated with anthocyanin synthesis between the 'Royalty' and evergreen leaf 'Flame' cultivars during leaf development. We also found the ever-red leaf colour cultivar 'Royalty' contained the known R6 : McMYB10 sequence, but was not in the evergreen leaf colour cultivar 'Flame', which have been reported in apple fruit. The distinction in promoter region maybe is the main reason why higher expression level of McMYB10 in red foliage crabapple cultivar. Furthermore, McMYB10 promoted anthocyanin biosynthesis in crabapple leaves and callus at low temperatures and during long-day treatments. Both heterologous expression in tobacco (Nicotiana tabacum) and Arabidopsis pap1 mutant, and homologous expression in crabapple and apple suggested that McMYB10 could promote anthocyanins synthesis and enhanced anthocyanin accumulation in plants. Interestingly, electrophoretic mobility shift assays, coupled with yeast one-hybrid analysis, revealed that McMYB10 positively regulates McF3'H via directly binding to AACCTAAC and TATCCAACC motifs in the promoter. To sum up, our results demonstrated that McMYB10 plays an important role in ever-red leaf coloration, by positively regulating McF3'H in crabapple. Therefore, our work provides new perspectives for ornamental fruit tree breeding. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  14. The strawberry FaMYB1 transcription factor suppresses anthocyanin and flavonol accumulation in transgenic tobacco.

    Science.gov (United States)

    Aharoni, A; De Vos, C H; Wein, M; Sun, Z; Greco, R; Kroon, A; Mol, J N; O'Connell, A P

    2001-11-01

    Fruit ripening is characterized by dramatic changes in gene expression, enzymatic activities and metabolism. Although the process of ripening has been studied extensively, we still lack valuable information on how the numerous metabolic pathways are regulated and co-ordinated. In this paper we describe the characterization of FaMYB1, a ripening regulated strawberry gene member of the MYB family of transcription factors. Flowers of transgenic tobacco lines overexpressing FaMYB1 showed a severe reduction in pigmentation. A reduction in the level of cyanidin 3-rutinoside (an anthocyanin) and of quercetin-glycosides (flavonols) was observed. Expression of late flavonoid biosynthesis genes and their enzyme activities were adversely affected by FaMYB1 overexpression. Two-hybrid assays in yeast showed that FaMYB1 could interact with other known anthocyanin regulators, but it does not act as a transcriptional activator. Interestingly, the C-terminus of FaMYB1 contains the motif pdLNL(D)/(E)Lxi(G)/S. This motif is contained in a region recently proposed to be involved in the repression of transcription by AtMYB4, an Arabidopsis MYB protein. Our results suggest that FaMYB1 may play a key role in regulating the biosynthesis of anthocyanins and flavonols in strawberry. It may act to repress transcription in order to balance the levels of anthocyanin pigments produced at the latter stages of strawberry fruit maturation, and/or to regulate metabolite levels in various branches of the flavonoid biosynthetic pathway.

  15. Heterologous expression of gentian MYB1R transcription factors suppresses anthocyanin pigmentation in tobacco flowers.

    Science.gov (United States)

    Nakatsuka, Takashi; Yamada, Eri; Saito, Misa; Fujita, Kohei; Nishihara, Masahiro

    2013-12-01

    Single-repeat MYB transcription factors, GtMYB1R1 and GtMYB1R9 , were isolated from gentian. Overexpression of these genes reduced anthocyanin accumulation in tobacco flowers, demonstrating their applicability to modification of flower color. RNA interference (RNAi) has recently been used to successfully modify flower color intensity in several plant species. In most floricultural plants, this technique requires prior isolation of target flavonoid biosynthetic genes from the same or closely related species. To overcome this limitation, we developed a simple and efficient method for reducing floral anthocyanin accumulation based on genetic engineering using novel transcription factor genes isolated from Japanese gentians. We identified two single-repeat MYB genes--GtMYB1R and GtMYB1R9--predominantly expressed in gentian petals. Transgenic tobacco plants expressing these genes were produced, and their flowers were analyzed for flavonoid components and expression of flavonoid biosynthetic genes. Transgenic tobacco plants expressing GtMYB1R1 or GtMYB1R9 exhibited significant reductions in floral anthocyanin accumulation, resulting in white-flowered phenotypes. Expression levels of chalcone isomerase (CHI), dihydroflavonol 4-reductase (DFR), and anthocyanidin synthase (ANS) genes were preferentially suppressed in these transgenic tobacco flowers. A yeast two-hybrid assay demonstrated that both GtMYB1R1 and GtMYB1R9 proteins interacted with the GtbHLH1 protein, previously identified as an anthocyanin biosynthesis regulator in gentian flowers. In addition, a transient expression assay indicated that activation of the gentian GtDFR promoter by the GtMYB3-GtbHLH1 complex was partly canceled by addition of GtMYB1R1 or GtMYB1R9. These results suggest that GtMYB1R1 and GtMYB1R9 act as antagonistic transcription factors of anthocyanin biosynthesis in gentian flowers. These genes should consequently be useful for manipulating anthocyanin accumulation via genetic engineering in

  16. Animal-specific C-terminal domain links myeloblastosis oncoprotein (Myb) to an ancient repressor complex

    Science.gov (United States)

    Andrejka, Laura; Wen, Hong; Ashton, Jonathan; Grant, Megan; Iori, Kevin; Wang, Amy; Manak, J. Robert; Lipsick, Joseph S.

    2011-01-01

    Members of the Myb oncoprotein and E2F-Rb tumor suppressor protein families are present within the same highly conserved multiprotein transcriptional repressor complex, named either as Myb and synthetic multivuval class B (Myb-MuvB) or as Drosophila Rb E2F and Myb-interacting proteins (dREAM). We now report that the animal-specific C terminus of Drosophila Myb but not the more highly conserved N-terminal DNA-binding domain is necessary and sufficient for (i) adult viability, (ii) proper localization to chromosomes in vivo, (iii) regulation of gene expression in vivo, and (iv) interaction with the highly conserved core of the MuvB/dREAM transcriptional repressor complex. In addition, we have identified a conserved peptide motif that is required for this interaction. Our results imply that an ancient function of Myb in regulating G2/M genes in both plants and animals appears to have been transferred from the DNA-binding domain to the animal-specific C-terminal domain. Increased expression of B-MYB/MYBL2, the human ortholog of Drosophila Myb, correlates with poor prognosis in human patients with breast cancer. Therefore, our results imply that the specific interaction of the C terminus of Myb with the MuvB/dREAM core complex may provide an attractive target for the development of cancer therapeutics. PMID:21969598

  17. The Arabidopsis MYB96 transcription factor plays a role in seed dormancy.

    Science.gov (United States)

    Lee, Hong Gil; Lee, Kyounghee; Seo, Pil Joon

    2015-03-01

    Seed dormancy facilitates to endure environmental disadvantages by confining embryonic growth until the seeds encounter favorable environmental conditions for germination. Abscisic acid (ABA) and gibberellic acid (GA) play a pivotal role in the determination of the seed dormancy state. ABA establishes seed dormancy, while GA triggers seed germination. Here, we demonstrate that MYB96 contributes to the fine-tuning of seed dormancy regulation through the coordination of ABA and GA metabolism. The MYB96-deficient myb96-1 seeds germinated earlier than wild-type seeds, whereas delayed germination was observed in the activation-tagging myb96-1D seeds. The differences in germination rate disappeared after stratification or after-ripening. The MYB96 transcription factor positively regulates ABA biosynthesis genes 9-CIS-EPOXYCAROTENOID DIOXYGENASE 2 (NCED2), NCED5, NCED6, and NCED9, and also affects GA biosynthetic genes GA3ox1 and GA20ox1. Notably, MYB96 directly binds to the promoters of NCED2 and NCED6, primarily modulating ABA biosynthesis, which subsequently influences GA metabolism. In agreement with this, hyperdormancy of myb96-1D seeds was recovered by an ABA biosynthesis inhibitor fluridone, while hypodormancy of myb96-1 seeds was suppressed by a GA biosynthesis inhibitor paclobutrazol (PAC). Taken together, the metabolic balance of ABA and GA underlies MYB96 control of primary seed dormancy.

  18. The A-myb transcription factor in neoplastic and normal B cells.

    Science.gov (United States)

    Golay, J; Facchinetti, V; Ying, G; Introna, M

    1997-07-01

    The myb family of transcription factors has been strongly implicated in the regulation of cell growth and differentiation in the haematopoietic system. The v-myb oncogene, carried by avian defective retroviruses, causes leukaemias in the chicken and transforms haematopoietic cells in vitro. Its normal cellular equivalent c-myb, has been shown to promote the proliferation and block the differentiation of haematopoietic cells in several experimental models and is required for fetal haematopoiesis. Two other members of the family have been cloned more recently, A-myb and B-myb, which show sequence homology with c-myb in several domains, of which the DNA binding domain as well as other regulatory domains. Both have been shown to be transcription factors. B-myb is also involved in the control of proliferation and differentiation, but, unlike c-myb, it is expressed in many cell types. The third member of the family, A-myb, shows the most restricted pattern of expression, suggesting a very specific role for this transcription factor. A-myb is expressed in a subpopulation of normal B lymphocytes activated in vivo and localised in the germinal center of peripheral lymphoid organs and is not detected at significant levels in all other mature or immature haematopoietic populations studied, including bone marrow cells, T lymphocytes, granulocytes, monocytes, either at rest or after in vitro activation. These studies indicate that A-myb plays a role during a narrow window of normal B cell differentiation. A-myb expression has also been studied in a wide range of neoplastic B cells, representing the whole spectrum of B cell differentiation. A-myb is strongly expressed in Burkitt's lymphomas (BL) and slg+ B-acute lymphoblastic leukaemias (B-ALL) and not in all other leukaemias/lymphomas tested, with the exception of a subset of CLL (about 25% of cases). It is intriguing that the A-myb genome has been localised relatively close to the c-myc gene on chromosome 8, suggesting that

  19. Transcriptional activation of a MYB gene controls the tissue-specific anthocyanin accumulation in a purple cauliflower mutant

    Science.gov (United States)

    Flavonoids such as anthocyanins possess significant health benefits to humans and play important physiological roles in plants. An interesting Purple gene mutation in cauliflower confers an abnormal pattern of anthocyanin accumulation, giving intense purple color in very young leaves, curds, and see...

  20. An N-terminal region of a Myb-like protein is involved in its intracellular localization and activation of a gibberellin-inducible proteinase gene in germinated rice seeds.

    Science.gov (United States)

    Sutoh, Keita; Washio, Kenji; Imai, Ryozo; Wada, Masamitsu; Nakai, Tomonori; Yamauchi, Daisuke

    2015-01-01

    The expression of the gene for a proteinase (Rep1) is upregulated by gibberellins. The CAACTC regulatory element (CARE) of the Rep1 promoter is involved in the gibberellin response. We isolated a cDNA for a CARE-binding protein containing a Myb domain in its carboxyl-terminal region and designated the gene Carboxyl-terminal Myb1 (CTMyb1). This gene encodes two polypeptides of two distinctive lengths, CTMyb1L and CTMyb1S, which include or exclude 213 N-terminal amino acid residues, respectively. CTMyb1S transactivated the Rep1 promoter in the presence of OsGAMyb, but not CTMyb1L. We observed an interaction between CTMyb1S and the rice prolamin box-binding factor (RPBF). A bimolecular fluorescence complex analysis detected the CTMyb1S and RPBF complex in the nucleus, but not the CTMyb1L and RPBF complex. The results suggest that the arrangement of the transfactors is involved in gibberellin-inducible expression of Rep1.

  1. Characterization of the regulatory network of BoMYB2 in controlling anthocyanin biosynthesis in purple cauliflower.

    Science.gov (United States)

    Chiu, Li-Wei; Li, Li

    2012-10-01

    Purple cauliflower (Brassica oleracea L. var. botrytis) Graffiti represents a unique mutant in conferring ectopic anthocyanin biosynthesis, which is caused by the tissue-specific activation of BoMYB2, an ortholog of Arabidopsis PAP2 or MYB113. To gain a better understanding of the regulatory network of anthocyanin biosynthesis, we investigated the interaction among cauliflower MYB-bHLH-WD40 network proteins and examined the interplay of BoMYB2 with various bHLH transcription factors in planta. Yeast two-hybrid studies revealed that cauliflower BoMYBs along with the other regulators formed the MYB-bHLH-WD40 complexes and BobHLH1 acted as a bridge between BoMYB and BoWD40-1 proteins. Different BoMYBs exhibited different binding activity to BobHLH1. Examination of the BoMYB2 transgenic lines in Arabidopsis bHLH mutant backgrounds demonstrated that TT8, EGL3, and GL3 were all involved in the BoMYB2-mediated anthocyanin biosynthesis. Expression of BoMYB2 in Arabidopsis caused up-regulation of AtTT8 and AtEGL3 as well as a subset of anthocyanin structural genes encoding flavonoid 3'-hydroxylase, dihydroflavonol 4-reductase, and leucoanthocyanidin dioxygenase. Taken together, our results show that MYB-bHLH-WD40 network transcription factors regulated the bHLH gene expression, which may represent a critical feature in the control of anthocyanin biosynthesis. BoMYB2 together with various BobHLHs specifically regulated the late anthocyanin biosynthetic pathway genes for anthocyanin biosynthesis. Our findings provide additional information for the complicated regulatory network of anthocyanin biosynthesis and the transcriptional regulation of transcription factors in vegetable crops.

  2. Identification and molecular characterization of MYB Transcription Factor Superfamily in C4 model plant foxtail millet (Setaria italica L.).

    Science.gov (United States)

    Muthamilarasan, Mehanathan; Khandelwal, Rohit; Yadav, Chandra Bhan; Bonthala, Venkata Suresh; Khan, Yusuf; Prasad, Manoj

    2014-01-01

    MYB proteins represent one of the largest transcription factor families in plants, playing important roles in diverse developmental and stress-responsive processes. Considering its significance, several genome-wide analyses have been conducted in almost all land plants except foxtail millet. Foxtail millet (Setaria italica L.) is a model crop for investigating systems biology of millets and bioenergy grasses. Further, the crop is also known for its potential abiotic stress-tolerance. In this context, a comprehensive genome-wide survey was conducted and 209 MYB protein-encoding genes were identified in foxtail millet. All 209 S. italica MYB (SiMYB) genes were physically mapped onto nine chromosomes of foxtail millet. Gene duplication study showed that segmental- and tandem-duplication have occurred in genome resulting in expansion of this gene family. The protein domain investigation classified SiMYB proteins into three classes according to number of MYB repeats present. The phylogenetic analysis categorized SiMYBs into ten groups (I-X). SiMYB-based comparative mapping revealed a maximum orthology between foxtail millet and sorghum, followed by maize, rice and Brachypodium. Heat map analysis showed tissue-specific expression pattern of predominant SiMYB genes. Expression profiling of candidate MYB genes against abiotic stresses and hormone treatments using qRT-PCR revealed specific and/or overlapping expression patterns of SiMYBs. Taken together, the present study provides a foundation for evolutionary and functional characterization of MYB TFs in foxtail millet to dissect their functions in response to environmental stimuli.

  3. Identification and molecular characterization of MYB Transcription Factor Superfamily in C4 model plant foxtail millet (Setaria italica L..

    Directory of Open Access Journals (Sweden)

    Mehanathan Muthamilarasan

    Full Text Available MYB proteins represent one of the largest transcription factor families in plants, playing important roles in diverse developmental and stress-responsive processes. Considering its significance, several genome-wide analyses have been conducted in almost all land plants except foxtail millet. Foxtail millet (Setaria italica L. is a model crop for investigating systems biology of millets and bioenergy grasses. Further, the crop is also known for its potential abiotic stress-tolerance. In this context, a comprehensive genome-wide survey was conducted and 209 MYB protein-encoding genes were identified in foxtail millet. All 209 S. italica MYB (SiMYB genes were physically mapped onto nine chromosomes of foxtail millet. Gene duplication study showed that segmental- and tandem-duplication have occurred in genome resulting in expansion of this gene family. The protein domain investigation classified SiMYB proteins into three classes according to number of MYB repeats present. The phylogenetic analysis categorized SiMYBs into ten groups (I-X. SiMYB-based comparative mapping revealed a maximum orthology between foxtail millet and sorghum, followed by maize, rice and Brachypodium. Heat map analysis showed tissue-specific expression pattern of predominant SiMYB genes. Expression profiling of candidate MYB genes against abiotic stresses and hormone treatments using qRT-PCR revealed specific and/or overlapping expression patterns of SiMYBs. Taken together, the present study provides a foundation for evolutionary and functional characterization of MYB TFs in foxtail millet to dissect their functions in response to environmental stimuli.

  4. Characterization of Flavan-3-ols and Expression of MYB and Late Pathway Genes Involved in Proanthocyanidin Biosynthesis in Foliage of Vitis bellula

    Directory of Open Access Journals (Sweden)

    Ke-Gang Li

    2013-03-01

    Full Text Available Proanthocyanidins (PAs are fundamental nutritional metabolites in different types of grape products consumed by human beings. Although the biosynthesis of PAs in berry of Vitis vinifera has gained intensive investigations, the understanding of PAs in other Vitis species is limited. In this study, we report PA formation and characterization of gene expression involved in PA biosynthesis in leaves of V. bellula, a wild edible grape species native to south and south-west China. Leaves are collected at five developmental stages defined by sizes ranging from 0.5 to 5 cm in length. Analyses of thin layer chromatography (TLC and high performance liquid chromatography-photodiode array detector (HPLC-PAD show the formation of (+-catechin, (−-epicatechin, (+-gallocatechin and (−-epigallocatechin during the entire development of leaves. Analyses of butanol-HCl boiling cleavage coupled with spectrometry measurement at 550 nm show a temporal trend of extractable PA levels, which is characterized by an increase from 0.5 cm to 1.5 cm long leaves followed by a decrease in late stages. TLC and HPLC-PAD analyses identify cyanidin, delphinidin and pelargonidin produced from the cleavage of PAs in the butanol-HCl boiling, showing that the foliage PAs of V. bellula include three different types of extension units. Four cDNAs, which encode VbANR, VbDFR, VbLAR1 and VbLAR2, respectively, are cloned from young leaves. The expression patterns of VbANR and VbLAR2 but not VbLAR1 and VbDFR follow a similar trend as the accumulation patterns of PAs. Two cDNAs encoding VbMYBPA1 and VbMYB5a, the homologs of which have been demonstrated to regulate the expression of both ANR and LAR in V. vinifera, are also cloned and their expression profiles are similar to those of VbANR and VbLAR2. In contrast, the expression profiles of MYBA1 and 2 homologs involved in anthocyanin biosynthesis are different from those of VbANR and VbLAR2. Our data show that both ANR and LAR branches are

  5. Analysis list: Myb [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Myb Blood,Gonad + mm9 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Myb.1.t...sv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Myb.5.tsv http://dbarchive.biosciencedbc.jp/kyushu-...u/mm9/target/Myb.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Myb.Blood.tsv,http://dbarchive.bioscience...dbc.jp/kyushu-u/mm9/colo/Myb.Gonad.tsv http://dbarchive.biosciencedbc.jp.../kyushu-u/mm9/colo/Blood.gml,http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Gonad.gml ...

  6. Myb proteins: angels and demons in normal and transformed cells.

    Science.gov (United States)

    Zhou, Ye; Ness, Scott A

    2011-01-01

    A key regulator of proliferation, differentiation and cell fate, the c-Myb transcription factor regulates the expression of hundreds of genes and is in turn regulated by numerous pathways and protein interactions. However, the most unique feature of c-Myb is that it can be converted into an oncogenic transforming protein through a few mutations that completely change its activity and specificity. The c-Myb protein is a myriad of interactions and activities rolled up in a protein that controls proliferation and differentiation in many different cell types. Here we discuss the background and recent progress that have led to a better understanding of this complex protein, and outline the questions that have yet to be answered.

  7. Regulation of the anthocyanin biosynthetic pathway by the TTG1/bHLH/Myb transcriptional complex in Arabidopsis seedlings.

    Science.gov (United States)

    Gonzalez, Antonio; Zhao, Mingzhe; Leavitt, John M; Lloyd, Alan M

    2008-03-01

    In all higher plants studied to date, the anthocyanin pigment pathway is regulated by a suite of transcription factors that include Myb, bHLH and WD-repeat proteins. However, in Arabidopsis thaliana, the Myb regulators remain to be conclusively identified, and little is known about anthocyanin pathway regulation by TTG1-dependent transcriptional complexes. Previous overexpression of the PAP1 Myb suggested that genes from the entire phenylpropanoid pathway are targets of regulation by Myb/bHLH/WD-repeat complexes in Arabidopsis, in contrast to other plants. Here we demonstrate that overexpression of Myb113 or Myb114 results in substantial increases in pigment production similar to those previously seen as a result of over-expression of PAP1, and pigment production in these overexpressors remains TTG1- and bHLH-dependent. Also, plants harboring an RNAi construct targeting PAP1 and three Myb candidates (PAP2, Myb113 and Myb114) showed downregulated Myb gene expression and obvious anthocyanin deficiencies. Correlated with these anthocyanin deficiencies is downregulation of the same late anthocyanin structural genes that are downregulated in ttg1 and bHLH anthocyanin mutants. Expression studies using GL3:GR and TTG1:GR fusions revealed direct regulation of the late biosynthetic genes only. Functional diversification between GL3 and EGL3 with regard to activation of gene targets was revealed by GL3:GR studies in single and double bHLH mutant seedlings. Expression profiles for Myb and bHLH regulators are also presented in the context of pigment production in young seedlings.

  8. Effector Regulatory T Cell Differentiation and Immune Homeostasis Depend on the Transcription Factor Myb.

    Science.gov (United States)

    Dias, Sheila; D'Amico, Angela; Cretney, Erika; Liao, Yang; Tellier, Julie; Bruggeman, Christine; Almeida, Francisca F; Leahy, Jamie; Belz, Gabrielle T; Smyth, Gordon K; Shi, Wei; Nutt, Stephen L

    2017-01-17

    FoxP3-expressing regulatory T (Treg) cells are essential for maintaining immune homeostasis. Activated Treg cells undergo further differentiation into an effector state that highly expresses genes critical for Treg cell function, although how this process is coordinated on a transcriptional level is poorly understood. Here, we demonstrate that mice lacking the transcription factor Myb in Treg cells succumbed to a multi-organ inflammatory disease. Myb was specifically expressed in, and required for the differentiation of, thymus-derived effector Treg cells. The combination of transcriptome and genomic footprint analyses revealed that Myb directly regulated a large proportion of the gene expression specific to effector Treg cells, identifying Myb as a critical component of the gene regulatory network controlling effector Treg cell differentiation and function. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. HIPK1 interacts with c-Myb and modulates its activity through phosphorylation

    International Nuclear Information System (INIS)

    Matre, Vilborg; Nordgard, Oddmund; Alm-Kristiansen, Anne Hege; Ledsaak, Marit; Gabrielsen, Odd Stokke

    2009-01-01

    The transcription factor v-Myb is a potent inducer of myeloid leukaemias, and its cellular homologue c-Myb plays a crucial role in the regulation of haematopoiesis. In a yeast two-hybrid (Y2H) screening we identified the nuclear kinase HIPK1 as an interaction partner for human c-Myb. The interaction involves a C-terminal region of HIPK1, while a bipartite interaction surface was identified in c-Myb, including regions in its N-terminal DNA-binding domain as well as in its C-terminal region. HIPK1 and c-Myb co-localize in distinct nuclear foci upon co-transfection. c-Myb appears to be phosphorylated by HIPK1 in its negative regulatory domain as supported by both in vivo and in vitro data. A functional assay revealed that HIPK1 repressed the ability of c-Myb to activate a chromatin embedded target gene, mim-1, in haematopoetic cells. Our findings point to a novel link between an important kinase and a key regulator of haematopoiesis.

  10. c-myb stimulates cell growth by regulation of insulin-like growth factor (IGF) and IGF-binding protein-3 in K562 leukemia cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Min-Sun; Kim, Sun-Young; Arunachalam, Sankarganesh [Department of Pediatrics, School of Medicine, Chonbuk National University, Jeonju 561-712 (Korea, Republic of); Hwang, Pyoung-Han [Department of Pediatrics, School of Medicine, Chonbuk National University, Jeonju 561-712 (Korea, Republic of); Research Institute of Clinical Medicine, School of Medicine, Chonbuk National University, Jeonju 561-712 (Korea, Republic of); Yi, Ho-Keun [Department of Biochemistry, School of Dentistry, Chonbuk National University, Jeonju 561-712 (Korea, Republic of); Nam, Sang-Yun [Department of Alternative Therapy, School of Alternative Medicine and Health Science, Jeonju University, Jeonju 561-712 (Korea, Republic of); Lee, Dae-Yeol, E-mail: leedy@chonbuk.ac.kr [Department of Pediatrics, School of Medicine, Chonbuk National University, Jeonju 561-712 (Korea, Republic of); Research Institute of Clinical Medicine, School of Medicine, Chonbuk National University, Jeonju 561-712 (Korea, Republic of)

    2009-07-17

    c-myb plays an important role in the regulation of cell growth and differentiation, and is highly expressed in immature hematopoietic cells. The human chronic myelogenous leukemia cell K562, highly expresses IGF-I, IGF-II, IGF-IR, and IGF-induced cellular proliferation is mediated by IGF-IR. To characterize the impact of c-myb on the IGF-IGFBP-3 axis in leukemia cells, we overexpressed c-myb using an adenovirus gene transfer system in K562 cells. The overexpression of c-myb induced cell proliferation, compared to control, and c-myb induced cell growth was inhibited by anti-IGF-IR antibodies. c-myb overexpression resulted in a significant increase in the expression of IGF-I, IGF-II, and IGF-IR, and a decrease in IGFBP-3 expression. By contrast, disruption of c-myb function by DN-myb overexpression resulted in significant reduction of IGF-I, IGF-II, IGF-IR, and elevation of IGFBP-3 expression. In addition, exogenous IGFBP-3 inhibited the proliferation of K562 cells, and c-myb induced cell growth was blocked by IGFBP-3 overexpression in a dose-dependent manner. The growth-promoting effects of c-myb were mediated through two major intracellular signaling pathways, Akt and Erk. Activation of Akt and Erk by c-myb was completely blocked by IGF-IR and IGFBP-3 antibodies. These findings suggest that c-myb stimulates cell growth, in part, by regulating expression of the components of IGF-IGFBP axis in K562 cells. In addition, disruption of c-myb function by DN-myb may provide a useful strategy for treatment of leukemia.

  11. c-myb stimulates cell growth by regulation of insulin-like growth factor (IGF) and IGF-binding protein-3 in K562 leukemia cells

    International Nuclear Information System (INIS)

    Kim, Min-Sun; Kim, Sun-Young; Arunachalam, Sankarganesh; Hwang, Pyoung-Han; Yi, Ho-Keun; Nam, Sang-Yun; Lee, Dae-Yeol

    2009-01-01

    c-myb plays an important role in the regulation of cell growth and differentiation, and is highly expressed in immature hematopoietic cells. The human chronic myelogenous leukemia cell K562, highly expresses IGF-I, IGF-II, IGF-IR, and IGF-induced cellular proliferation is mediated by IGF-IR. To characterize the impact of c-myb on the IGF-IGFBP-3 axis in leukemia cells, we overexpressed c-myb using an adenovirus gene transfer system in K562 cells. The overexpression of c-myb induced cell proliferation, compared to control, and c-myb induced cell growth was inhibited by anti-IGF-IR antibodies. c-myb overexpression resulted in a significant increase in the expression of IGF-I, IGF-II, and IGF-IR, and a decrease in IGFBP-3 expression. By contrast, disruption of c-myb function by DN-myb overexpression resulted in significant reduction of IGF-I, IGF-II, IGF-IR, and elevation of IGFBP-3 expression. In addition, exogenous IGFBP-3 inhibited the proliferation of K562 cells, and c-myb induced cell growth was blocked by IGFBP-3 overexpression in a dose-dependent manner. The growth-promoting effects of c-myb were mediated through two major intracellular signaling pathways, Akt and Erk. Activation of Akt and Erk by c-myb was completely blocked by IGF-IR and IGFBP-3 antibodies. These findings suggest that c-myb stimulates cell growth, in part, by regulating expression of the components of IGF-IGFBP axis in K562 cells. In addition, disruption of c-myb function by DN-myb may provide a useful strategy for treatment of leukemia.

  12. RFX2 is a candidate downstream amplifier of A-MYB regulation in mouse spermatogenesis

    Directory of Open Access Journals (Sweden)

    Kistler Malathi K

    2009-12-01

    Full Text Available Abstract Background Mammalian spermatogenesis involves formation of haploid cells from the male germline and then a complex morphological transformation to generate motile sperm. Focusing on meiotic prophase, some tissue-specific transcription factors are known (A-MYB or suspected (RFX2 to play important roles in modulating gene expression in pachytene spermatocytes. The current work was initiated to identify both downstream and upstream regulatory connections for Rfx2. Results Searches of pachytene up-regulated genes identified high affinity RFX binding sites (X boxes in promoter regions of several new genes: Adam5, Pdcl2, and Spag6. We confirmed a strong promoter-region X-box for Alf, a germ cell-specific variant of general transcription factor TFIIA. Using Alf as an example of a target gene, we showed that its promoter is stimulated by RFX2 in transfected cells and used ChIP analysis to show that the promoter is occupied by RFX2 in vivo. Turning to upstream regulation of the Rfx2 promoter, we identified a cluster of three binding sites (MBS for the MYB family of transcription factors. Because testis is one of the few sites of A-myb expression, and because spermatogenesis arrests in pachytene in A-myb knockout mice, the MBS cluster implicates Rfx2 as an A-myb target. Electrophoretic gel-shift, ChIP, and co-transfection assays all support a role for these MYB sites in Rfx2 expression. Further, Rfx2 expression was virtually eliminated in A-myb knockout testes. Immunohistology on testis sections showed that A-MYB expression is up-regulated only after pachytene spermatocytes have clearly moved away from the tubule wall, which correlates with onset of RFX2 expression, whereas B-MYB expression, by contrast, is prevalent only in earlier spermatocytes and spermatogonia. Conclusion With an expanding list of likely target genes, RFX2 is potentially an important transcriptional regulator in pachytene spermatocytes. Rfx2 itself is a good candidate to be

  13. Functional Characterization of NAC and MYB Transcription Factors Involved in Regulation of Biomass Production in Switchgrass (Panicum virgatum.

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    Ruiqin Zhong

    Full Text Available Switchgrass is a promising biofuel feedstock due to its high biomass production and low agronomic input requirements. Because the bulk of switchgrass biomass used for biofuel production is lignocellulosic secondary walls, studies on secondary wall biosynthesis and its transcriptional regulation are imperative for designing strategies for genetic improvement of biomass production in switchgrass. Here, we report the identification and functional characterization of a group of switchgrass transcription factors, including several NACs (PvSWNs and a MYB (PvMYB46A, for their involvement in regulating secondary wall biosynthesis. PvSWNs and PvMYB46A were found to be highly expressed in stems and their expression was closely associated with sclerenchyma cells. Overexpression of PvSWNs and PvMYB46A in Arabidopsis was shown to result in activation of the biosynthetic genes for cellulose, xylan and lignin and ectopic deposition of secondary walls in normally parenchymatous cells. Transactivation and complementation studies demonstrated that PvSWNs were able to activate the SNBE-driven GUS reporter gene and effectively rescue the secondary wall defects in the Arabidopsis snd1 nst1 double mutant, indicating that they are functional orthologs of Arabidopsis SWNs. Furthermore, we showed that PvMYB46A could activate the SMRE-driven GUS reporter gene and complement the Arabidopsis myb46 myb83 double mutant, suggesting that it is a functional ortholog of Arabidopsis MYB46/MYB83. Together, these results indicate that PvSWNs and PvMYB46A are transcriptional switches involved in regulating secondary wall biosynthesis, which provides molecular tools for genetic manipulation of biomass production in switchgrass.

  14. MYB and bHLH transcription factor transgenes increase anthocyanin pigmentation in petunia and lisianthus plants, and the petunia phenotypes are strongly enhanced under field conditions

    Directory of Open Access Journals (Sweden)

    Kathy E Schwinn

    2014-11-01

    Full Text Available Petunia line Mitchell [MP, Petunia axillaris × (P. axillaris × P. hybrida] and Eustoma grandiflorum (lisianthus plants were produced containing a transgene for over-expression of the R2R3-MYB transcription factor (ROSEA1 that up-regulates flavonoid biosynthesis in Antirrhinum majus. The petunia lines were also crossed with previously produced MP lines containing a Zea mays flavonoid-related bHLH transcription factor transgene (LEAF COLOR, LC, which induces strong vegetative pigmentation when these 35S:LC plants are exposed to high light levels. 35S:ROS1 lisianthus transgenics had limited changes in anthocyanin pigmentation, specifically, precocious pigmentation of flower petals and increased pigmentation of sepals. RNA transcript levels for two anthocyanin biosynthetic genes, chalcone synthase and anthocyanidin synthase, were increased in the 35S:ROS1 lisianthus petals compared to those of control lines. With MP, the 35S:ROS1 calli showed novel red pigmentation in culture, but this was generally not seen in tissue culture plantlets regenerated from the calli or young plants transferred to soil in the greenhouse. Anthocyanin pigmentation was enhanced in the stems of mature 35S:ROS1 MP plants, but the MP white-flower phenotype was not complemented. Progeny from a 35S:ROS1×35S:LC cross had novel pigmentation phenotypes that were not present in either parental line or MP. In particular, there was increased pigment accumulation in the petal throat region, and the anthers changed from yellow to purple colour. An outdoor field trial was conducted with the 35S:ROS1, 35S:LC, 35S:ROS1×35S:LC and control MP lines. Field conditions rapidly induced intense foliage pigmentation in 35S:LC plants, a phenotype not observed in control MP or equivalent 35S:LC plants maintained in a greenhouse. No difference in plant stature, seed germination, or plant survival was observed between transgenic and control plants.

  15. MYB and bHLH transcription factor transgenes increase anthocyanin pigmentation in petunia and lisianthus plants, and the petunia phenotypes are strongly enhanced under field conditions

    Science.gov (United States)

    Schwinn, Kathy E.; Boase, Murray R.; Bradley, J. Marie; Lewis, David H.; Deroles, Simon C.; Martin, Cathie R.; Davies, Kevin M.

    2014-01-01

    Petunia line Mitchell [MP, Petunia axillaris × (P. axillaris × P. hybrida)] and Eustoma grandiflorum (lisianthus) plants were produced containing a transgene for over-expression of the R2R3-MYB transcription factor [TF; ROSEA1 (ROS1)] that up-regulates flavonoid biosynthesis in Antirrhinum majus. The petunia lines were also crossed with previously produced MP lines containing a Zea mays flavonoid-related basic helix-loop-helix TF transgene (LEAF COLOR, LC), which induces strong vegetative pigmentation when these 35S:LC plants are exposed to high-light levels. 35S:ROS1 lisianthus transgenics had limited changes in anthocyanin pigmentation, specifically, precocious pigmentation of flower petals and increased pigmentation of sepals. RNA transcript levels for two anthocyanin biosynthetic genes, chalcone synthase and anthocyanidin synthase, were increased in the 35S:ROS1 lisianthus petals compared to those of control lines. With MP, the 35S:ROS1 calli showed novel red pigmentation in culture, but this was generally not seen in tissue culture plantlets regenerated from the calli or young plants transferred to soil in the greenhouse. Anthocyanin pigmentation was enhanced in the stems of mature 35S:ROS1 MP plants, but the MP white-flower phenotype was not complemented. Progeny from a 35S:ROS1 × 35S:LC cross had novel pigmentation phenotypes that were not present in either parental line or MP. In particular, there was increased pigment in the petal throat region, and the anthers changed from yellow to purple pigmentation. An outdoor field trial was conducted with the 35S:ROS1, 35S:LC, 35S:ROS1 × 35S:LC and control MP lines. Field conditions rapidly induced intense foliage pigmentation in 35S:LC plants, a phenotype not observed in control MP or equivalent 35S:LC plants maintained in a greenhouse. No difference in plant stature, seed germination, or plant survival was observed between transgenic and control plants. PMID:25414715

  16. Gene-Transformation-Induced Changes in Chemical Functional Group Features and Molecular Structure Conformation in Alfalfa Plants Co-Expressing Lc-bHLH and C1-MYB Transcriptive Flavanoid Regulatory Genes: Effects of Single-Gene and Two-Gene Insertion.

    Science.gov (United States)

    Heendeniya, Ravindra G; Yu, Peiqiang

    2017-03-20

    Alfalfa ( Medicago sativa L.) genotypes transformed with Lc-bHLH and Lc transcription genes were developed with the intention of stimulating proanthocyanidin synthesis in the aerial parts of the plant. To our knowledge, there are no studies on the effect of single-gene and two-gene transformation on chemical functional groups and molecular structure changes in these plants. The objective of this study was to use advanced molecular spectroscopy with multivariate chemometrics to determine chemical functional group intensity and molecular structure changes in alfalfa plants when co-expressing Lc-bHLH and C1-MYB transcriptive flavanoid regulatory genes in comparison with non-transgenic (NT) and AC Grazeland (ACGL) genotypes. The results showed that compared to NT genotype, the presence of double genes ( Lc and C1 ) increased ratios of both the area and peak height of protein structural Amide I/II and the height ratio of α-helix to β-sheet. In carbohydrate-related spectral analysis, the double gene-transformed alfalfa genotypes exhibited lower peak heights at 1370, 1240, 1153, and 1020 cm -1 compared to the NT genotype. Furthermore, the effect of double gene transformation on carbohydrate molecular structure was clearly revealed in the principal component analysis of the spectra. In conclusion, single or double transformation of Lc and C1 genes resulted in changing functional groups and molecular structure related to proteins and carbohydrates compared to the NT alfalfa genotype. The current study provided molecular structural information on the transgenic alfalfa plants and provided an insight into the impact of transgenes on protein and carbohydrate properties and their molecular structure's changes.

  17. Single molecule analysis of c-myb alternative splicing reveals novel classifiers for precursor B-ALL.

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    Ye E Zhou

    Full Text Available The c-Myb transcription factor, a key regulator of proliferation and differentiation in hematopoietic and other cell types, has an N-terminal DNA binding domain and a large C-terminal domain responsible for transcriptional activation, negative regulation and determining target gene specificity. Overexpression and rearrangement of the c-myb gene (MYB has been reported in some patients with leukemias and other types of cancers, implicating activated alleles of c-myb in the development of human tumors. Alternative RNA splicing can produce variants of c-myb with qualitatively distinct transcriptional activities that may be involved in transformation and leukemogenesis. Here, by performing a detailed, single molecule assay we found that c-myb alternative RNA splicing was elevated and much more complex in leukemia samples than in cell lines or CD34+ hematopoietic progenitor cells from normal donors. The results revealed that leukemia samples express more than 60 different c-myb splice variants, most of which have multiple alternative splicing events and were not detectable by conventional microarray or PCR approaches. For example, the single molecule assay detected 21 and 22 splice variants containing the 9B and 9S exons, respectively, most of which encoded unexpected variant forms of c-Myb protein. Furthermore, the detailed analysis identified some splice variants whose expression correlated with poor survival in a small cohort of precursor B-ALL samples. Our findings indicate that single molecule assays can reveal complexities in c-myb alternative splicing that have potential as novel biomarkers and could help explain the role of c-Myb variants in the development of human leukemia.

  18. Mybs in mouse hair follicle development

    Czech Academy of Sciences Publication Activity Database

    Veselá, Barbora; Švandová, Eva; Šmarda, J.; Matalová, Eva

    2014-01-01

    Roč. 46, č. 5 (2014), s. 352-355 ISSN 0040-8166 R&D Projects: GA ČR GCP302/12/J059 Institutional support: RVO:67985904 Keywords : hair follicle * stem cells * c-Myb * B-Myb * development Subject RIV: EA - Cell Biology Impact factor: 1.252, year: 2014

  19. Expression Differences of Pigment Structural Genes and Transcription Factors Explain Flesh Coloration in Three Contrasting Kiwifruit Cultivars

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    Yanfei Liu

    2017-09-01

    Full Text Available Fruits of kiwifruit cultivars (Actinidia chinensis and A. deliciosa generally have green or yellow flesh when ripe. A small number of genotypes have red flesh but this coloration is usually restricted to the inner pericarp. Three kiwifruit cultivars having red (‘Hongyang’, or yellow (‘Jinnong-2’, or green (‘Hayward’ flesh were investigated for their color characteristics and pigment contents during development and ripening. The results show the yellow of the ‘Jinnong-2’ fruit is due to the combined effects of chlorophyll degradation and of beta-carotene accumulation. The red inner pericarps of ‘Hongyang’ fruit are due to anthocyanin accumulation. Expression differences of the pathway genes in the inner pericarps of the three different kiwifruits suggest that stay-green (SGR controls the degradation of chlorophylls, while lycopene beta-cyclase (LCY-β controls the biosynthesis of beta-carotene. The abundance of anthocyanin in the inner pericarps of the ‘Hongyang’ fruit is the results of high expressions of UDP flavonoid glycosyltransferases (UFGT. At the same time, expressions of anthocyanin transcription factors show that AcMYBF110 expression parallels changes in anthocyanin concentration, so seems to be a key R2R3 MYB, regulating anthocyanin biosynthesis. Further, transient color assays reveal that AcMYBF110 can autonomously induce anthocyanin accumulation in Nicotiana tabacum leaves by activating the transcription of dihydroflavonol 4-reductase (NtDFR, anthocyanidin synthase (NtANS and NtUFGT. For basic helix-loop-helix proteins (bHLHs and WD-repeat proteins (WD40s, expression differences show these may depend on AcMYBF110 forming a MYB-bHLH-WD40 complex to regulate anthocyanin biosynthesis, instead of it having a direct involvement.

  20. The oncoprotein v-Myb activates transcription of Gremlin 2 during in vitro differentiation of the chicken neural crest to melanoblasts

    Czech Academy of Sciences Publication Activity Database

    Starostová, Michaela; Čermák, Vladimír; Dvořáková, Marta; Karafiát, Vít; Kosla, Jan; Dvořák, Michal

    2014-01-01

    Roč. 540, č. 1 (2014), s. 122-129 ISSN 0378-1119 R&D Projects: GA AV ČR KAN200520801 Institutional support: RVO:68378050 Keywords : Melanocyte development * Tamoxifen-inducible v-Myb * v-Myb-dependent genes * PRDC * KRT19 Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.138, year: 2014

  1. Hoxa9 and Hoxa10 induce CML myeloid blast crisis development through activation of Myb expression.

    Science.gov (United States)

    Negi, Vijay; Vishwakarma, Bandana A; Chu, Su; Oakley, Kevin; Han, Yufen; Bhatia, Ravi; Du, Yang

    2017-11-17

    Mechanisms underlying the progression of Chronic Myeloid Leukemia (CML) from chronic phase to myeloid blast crisis are poorly understood. Our previous studies have suggested that overexpression of SETBP1 can drive this progression by conferring unlimited self-renewal capability to granulocyte macrophage progenitors (GMPs). Here we show that overexpression of Hoxa9 or Hoxa10 , both transcriptional targets of Setbp1 , is also sufficient to induce self-renewal of primary myeloid progenitors, causing their immortalization in culture. More importantly, both are able to cooperate with BCR/ABL to consistently induce transformation of mouse GMPs and development of aggressive leukemias resembling CML myeloid blast crisis, suggesting that either gene can drive CML progression by promoting the self-renewal of GMPs. We further identify Myb as a common critical target for Hoxa9 and Hoxa10 in inducing self-renewal of myeloid progenitors as Myb knockdown significantly reduced colony-forming potential of myeloid progenitors immortalized by the expression of either gene. Interestingly, Myb is also capable of immortalizing primary myeloid progenitors in culture and cooperating with BCR/ABL to induce leukemic transformation of mouse GMPs. Significantly increased levels of MYB transcript also were detected in all human CML blast crisis samples examined over chronic phase samples, further suggesting the possibility that MYB overexpression may play a prevalent role in driving human CML myeloid blast crisis development. In summary, our results identify overexpression of HOXA9 , HOXA10 , and MYB as critical drivers of CML progression, and suggest MYB as a key therapeutic target for inhibiting the self-renewal of leukemia-initiating cells in CML myeloid blast crisis patients.

  2. Identification and expression pattern analysis of BoMYB51 involved in indolic glucosinolate biosynthesis from broccoli (Brassica oleracea var. italica).

    Science.gov (United States)

    Yu, Qingyue; Hao, Guodong; Zhou, Jianxin; Wang, Jingying; Evivie, Ejiroghene Ruona; Li, Jing

    2018-06-22

    Glucosinolates are a class of amino acid-derived specialized metabolites characteristic of the Brassicales order. Trp derived indolic glucosinolates are essential for the effective plant defense responses to a wide range of pathogens and herbivores. In Arabidopsis, MYB51 is the key transcription factor positively regulates indolic glucosinolate production by activating certain biosynthetic genes. In this study, we report the isolation and identification of a MYB51 from broccoli designated as BoMYB51. Overexpression of BoMYB51 in Arabidopsis increased indolic glucosinolate production by upregulating biosynthetic genes and resulted in enhanced flagellin22 (Flg22) induced callose deposition. The spatial expression pattern and responsive expression of BoMYB51 to several hormones and stress treatments were investigated by expressing the β-glucuronidase (GUS) reporter gene driven by BoMYB51 promotor in Arabidopsis and quantitative real-time PCR analysis in broccoli. Our study provides information on molecular characteristics of BoMYB51 and possible physiological process BoMYB51 may involve. Copyright © 2018 Elsevier Inc. All rights reserved.

  3. The crucial role of PpMYB10.1 in anthocyanin accumulation in peach and relationships between its allelic type and skin color phenotype.

    Science.gov (United States)

    Tuan, Pham Anh; Bai, Songling; Yaegaki, Hideaki; Tamura, Takayuki; Hihara, Seisuke; Moriguchi, Takaya; Oda, Kenji

    2015-11-18

    Red coloration of fruit skin is one of the most important traits in peach (Prunus persica), and it is mainly due to the accumulation of anthocyanins. Three MYB10 genes, PpMYB10.1, PpMYB10.2, and PpMYB10.3, have been reported as important regulators of red coloration and anthocyanin biosynthesis in peach fruit. In this study, contribution of PpMYB10.1/2/3 to anthocyanin accumulation in the fruit skin was investigated in the Japanese peach cultivars, white-skinned 'Mochizuki' and red-skinned 'Akatsuki'. We then investigated the relationships between allelic type of PpMYB10.1 and skin color phenotype in 23 Japanese peach cultivars for future establishment of DNA-marker. During the fruit development of 'Mochizuki' and 'Akatsuki', anthocyanin accumulation was observed only in the skin of red 'Akatsuki' fruit in the late ripening stages concomitant with high mRNA levels of the last step gene leading to anthocyanin accumulation, UDP-glucose:flavonoid-3-O-glucosyltransferase (UFGT). This was also correlated with the expression level of PpMYB10.1. Unlike PpMYB10.1, expression levels of PpMYB10.2/3 were low in the skin of both 'Mochizuki' and 'Akatsuki' throughout fruit development. Moreover, only PpMYB10.1 revealed expression levels associated with total anthocyanin accumulation in the leaves and flowers of 'Mochizuki' and 'Akatsuki'. Introduction of PpMYB10.1 into tobacco increased the expression of tobacco UFGT, resulting in higher anthocyanin accumulation and deeper red transgenic tobacco flowers; however, overexpression of PpMYB10.2/3 did not alter anthocyanin content and color of transgenic tobacco flowers when compared with wild-type flowers. Dual-luciferase assay showed that the co-infiltration of PpMYB10.1 with PpbHLH3 significantly increased the activity of PpUFGT promoter. We also found close relationships of two PpMYB10.1 allelic types, MYB10.1-1/MYB10.1-2, with the intensity of red skin coloration. We showed that PpMYB10.1 is a major regulator of anthocyanin

  4. Identification of warm day and cool night conditions induced flowering-related genes in a Phalaenopsis orchid hybrid by suppression subtractive hybridization.

    Science.gov (United States)

    Li, D M; Lü, F B; Zhu, G F; Sun, Y B; Xu, Y C; Jiang, M D; Liu, J W; Wang, Z

    2014-02-14

    The influence of warm day and cool night conditions on induction of spikes in Phalaenopsis orchids has been studied with respect to photosynthetic efficiency, metabolic cycles and physiology. However, molecular events involved in spike emergence induced by warm day and cool night conditions are not clearly understood. We examined gene expression induced by warm day and cool night conditions in the Phalaenopsis hybrid Fortune Saltzman through suppression subtractive hybridization, which allowed identification of flowering-related genes in warm day and cool night conditions in spikes and leaves at vegetative phase grown under warm daily temperatures. In total, 450 presumably regulated expressed sequence tags (ESTs) were identified and classified into functional categories, including metabolism, development, transcription factor, signal transduction, transportation, cell defense, and stress. Furthermore, database comparisons revealed a notable number of Phalaenopsis hybrid Fortune Saltzman ESTs that matched genes with unknown function. The expression profiles of 24 genes (from different functional categories) have been confirmed by quantitative real-time PCR in induced spikes and juvenile apical leaves. The results of the real-time PCR showed that, compared to the vegetative apical leaves, the transcripts of genes encoding flowering locus T, AP1, AP2, KNOX1, knotted1-like homeobox protein, R2R3-like MYB, adenosine kinase 2, S-adenosylmethionine synthetase, dihydroflavonol 4-reductase, and naringenin 3-dioxygenase accumulated significantly higher levels, and genes encoding FCA, retrotransposon protein Ty3 and C3HC4-type RING finger protein accumulated remarkably lower levels in spikes of early developmental stages. These results suggested that the genes of two expression changing trends may play positive and negative roles in the early floral transition of Phalaenopsis orchids. In conclusion, spikes induced by warm day and cool night conditions were complex in

  5. Novel bioresources for studies of Brassica oleracea: identification of a kale MYB transcription factor responsible for glucosinolate production.

    Science.gov (United States)

    Araki, Ryoichi; Hasumi, Akiko; Nishizawa, Osamu Ishizaki; Sasaki, Katsunori; Kuwahara, Ayuko; Sawada, Yuji; Totoki, Yasushi; Toyoda, Atsushi; Sakaki, Yoshiyuki; Li, Yimeng; Saito, Kazuki; Ogawa, Toshiya; Hirai, Masami Yokota

    2013-10-01

    Plants belonging to the Brassicaceae family exhibit species-specific profiles of glucosinolates (GSLs), a class of defence compounds against pathogens and insects. GSLs also exhibit various human health-promoting properties. Among them, glucoraphanin (aliphatic 4-methylsulphinylbutyl GSL) has attracted the most attention because it hydrolyses to form a potent anticancer compound. Increased interest in developing commercial varieties of Brassicaceae crops with desirable GSL profiles has led to attempts to identify genes that are potentially valuable for controlling GSL biosynthesis. However, little attention has been focused on genes of kale (Brassica oleracea var. acephala). In this study, we established full-length kale cDNA libraries containing 59 904 clones, which were used to generate an expressed sequence tag (EST) data set with 119 204 entries. The EST data set clarified genes related to the GSL biosynthesis pathway in kale. We specifically focused on BoMYB29, a homolog of Arabidopsis MYB29/PMG2/HAG3, not only to characterize its function but also to demonstrate its usability as a biological resource. BoMYB29 overexpression in wild-type Arabidopsis enhanced the expression of aliphatic GSL biosynthetic genes and the accumulation of aliphatic GSLs. When expressed in the myb28myb29 mutant, which exhibited no detectable aliphatic GSLs, BoMYB29 restored the expression of biosynthetic genes and aliphatic GSL accumulation. Interestingly, the ratio of methylsulphinyl GSL content, including glucoraphanin, to that of methylthio GSLs was greatly increased, indicating the suitability of BoMYB29 as a regulator for increasing methylsulphinyl GSL content. Our results indicate that these biological resources can facilitate further identification of genes useful for modifications of GSL profiles and accumulation in kale. © 2013 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  6. WRKY2/34–VQ20 Modules in Arabidopsis thaliana Negatively Regulate Expression of a Trio of Related MYB Transcription Factors During Pollen Development

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    Rihua Lei

    2018-03-01

    Full Text Available Male gametogenesis in plants is tightly controlled and involves the complex and precise regulation of transcriptional reprogramming. Interactions between WRKY proteins and VQ motif-containing proteins are required to control these complicated transcriptional networks. However, our understanding of the mechanisms by which these complexes affect downstream gene expression is quite limited. In this study, we found that WRKY2 and WKRY34 repress MYB97, MYB101, and MYB120 expression during male gametogenesis. MYB expression was up-regulated in the wrky2-1 wrky34-1 vq20-1 triple mutant during male gametogenesis. The expression levels of six potential targets of the three MYBs increased the most in the wrky2-1 wrky34-1 vq20-1 triple mutant, followed by the wrky2-1 wrky34-1 double mutant, compared with in wild-type. Yeast one-hybrid and dual luciferase reporter assays indicated that WRKY2 and WRKY34 recognized the MYB97 promoter by binding to its W-boxes. MYB97 overexpression caused defects in pollen germination and pollen tube length, which impacted male fertility. Thus, WRKY2/34–VQ20 complexes appear to negatively regulate the expression of certain MYBs during plant male gametogenesis.

  7. Primary root growth in Arabidopsis thaliana is inhibited by the miR159 mediated repression of MYB33, MYB65 and MYB101.

    Science.gov (United States)

    Xue, Tao; Liu, Zhenhua; Dai, Xuehuan; Xiang, Fengning

    2017-09-01

    Organ growth is a fundamental developmental process basing on cell proliferation and differentiation. The growth of the plant root is sustained by the activity of the root meristem, a process controlled in part by various transcription factors. Here, the miR159 has been identified as a post transcriptional repressor of root growth, on the basis that the mir159ab double mutant developed a larger meristem than did the wild type, and that it formed longer roots. In the mutant, the abundance of MYB33, MYB65 and MYB101 transcript was substantially increased. When MYB33, MYB65 and MYB101 were replaced by the miR159-resistant forms mMYB33, mMYB65 and mMYB101 respectively, the root meristem was similarly enlarged and the growth of the primary root enhanced. MYB65 activity promoted cell division in the root meristem by accelerating the cell cycle. The data suggest that miR159 acts as a key repressor of the primary root's growth, acting through its repression of MYB65 and consequent blocking of the cell cycle. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Mining for Candidate Genes in an Introgression Line by Using RNA Sequencing: The Anthocyanin Overaccumulation Phenotype in Brassica

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    Lulu Xie

    2016-08-01

    Full Text Available Introgression breeding is a widely used method for the genetic improvement of crop plants; however, the mechanism underlying candidate gene flow patterns during hybridization is poorly understood. In this study, we used a powerful pipeline to investigate a Chinese cabbage (Brassica rapa L. ssp. pekinensis introgression line with the anthocyanin overaccumulation phenotype. Our purpose was to analyze the gene flow patterns during hybridization and elucidate the genetic factors responsible for the accumulation of this important pigment compound. We performed RNA-seq analysis by using two pipelines, one with and one without a reference sequence, to obtain transcriptome data. We identified 930 significantly differentially expressed genes (DEGs between the purple-leaf introgression line and B. rapa green cultivar, namely, 389 up-regulated and 541 down-regulated DEGs that mapped to the B. rapa reference genome. Since only one anthocyanin pathway regulatory gene was identified, i.e., Bra037887 (bHLH, we mined unmapped reads, revealing 2,031 de novo assembled unigenes, including c3563g1i2. Phylogenetic analysis suggested that c3563g1i2, which was transferred from the Brassica B genome of the donor parental line Brassica juncea, may represent an R2R3-MYB transcription factor that participates in the ternary transcriptional activation complex responsible for the anthocyanin overaccumulation phenotype of the B. rapa introgression line. We also identified genes involved in cold and light reaction pathways that were highly upregulated in the introgression line, as confirmed using quantitative real-time PCR analysis. The results of this study shed light on the mechanisms underlying the purple leaf trait in Brassica plants and may facilitate the use of introgressive hybridization for many traits of interest.

  9. The B-MYB transcriptional network guides cell cycle progression and fate decisions to sustain self-renewal and the identity of pluripotent stem cells.

    Science.gov (United States)

    Zhan, Ming; Riordon, Daniel R; Yan, Bin; Tarasova, Yelena S; Bruweleit, Sarah; Tarasov, Kirill V; Li, Ronald A; Wersto, Robert P; Boheler, Kenneth R

    2012-01-01

    Embryonic stem cells (ESCs) are pluripotent and have unlimited self-renewal capacity. Although pluripotency and differentiation have been examined extensively, the mechanisms responsible for self-renewal are poorly understood and are believed to involve an unusual cell cycle, epigenetic regulators and pluripotency-promoting transcription factors. Here we show that B-MYB, a cell cycle regulated phosphoprotein and transcription factor critical to the formation of inner cell mass, is central to the transcriptional and co-regulatory networks that sustain normal cell cycle progression and self-renewal properties of ESCs. Phenotypically, B-MYB is robustly expressed in ESCs and induced pluripotent stem cells (iPSCs), and it is present predominantly in a hypo-phosphorylated state. Knockdown of B-MYB results in functional cell cycle abnormalities that involve S, G2 and M phases, and reduced expression of critical cell cycle regulators like ccnb1 and plk1. By conducting gene expression profiling on control and B-MYB deficient cells, ChIP-chip experiments, and integrative computational analyses, we unraveled a highly complex B-MYB-mediated transcriptional network that guides ESC self-renewal. The network encompasses critical regulators of all cell cycle phases and epigenetic regulators, pluripotency transcription factors, and differentiation determinants. B-MYB along with E2F1 and c-MYC preferentially co-regulate cell cycle target genes. B-MYB also co-targets genes regulated by OCT4, SOX2 and NANOG that are significantly associated with stem cell differentiation, embryonic development, and epigenetic control. Moreover, loss of B-MYB leads to a breakdown of the transcriptional hierarchy present in ESCs. These results coupled with functional studies demonstrate that B-MYB not only controls and accelerates cell cycle progression in ESCs it contributes to fate decisions and maintenance of pluripotent stem cell identity.

  10. MYT3, a Myb-like transcription factor, affects fungal development and pathogenicity of Fusarium graminearum.

    Directory of Open Access Journals (Sweden)

    Yongsoo Kim

    Full Text Available We previously characterized members of the Myb protein family, MYT1 and MYT2, in Fusarium graminearum. MYT1 and MYT2 are involved in female fertility and perithecium size, respectively. To expand knowledge of Myb proteins in F. graminearum, in this study, we characterized the functions of the MYT3 gene, which encodes a putative Myb-like transcription factor containing two Myb DNA-binding domains and is conserved in the subphylum Pezizomycotina of Ascomycota. MYT3 proteins were localized in nuclei during most developmental stages, suggesting the role of MYT3 as a transcriptional regulator. Deletion of MYT3 resulted in impairment of conidiation, germination, and vegetative growth compared to the wild type, whereas complementation of MYT3 restored the wild-type phenotype. Additionally, the Δmyt3 strain grew poorly on nitrogen-limited media; however, the mutant grew robustly on minimal media supplemented with ammonium. Moreover, expression level of nitrate reductase gene in the Δmyt3 strain was decreased in comparison to the wild type and complemented strain. On flowering wheat heads, the Δmyt3 strain exhibited reduced pathogenicity, which corresponded with significant reductions in trichothecene production and transcript levels of trichothecene biosynthetic genes. When the mutant was selfed, mated as a female, or mated as a male for sexual development, perithecia were not observed on the cultures, indicating that the Δmyt3 strain lost both male and female fertility. Taken together, these results demonstrate that MYT3 is required for pathogenesis and sexual development in F. graminearum, and will provide a robust foundation to establish the regulatory networks for all Myb-like proteins in F. graminearum.

  11. Dramatic repositioning of c-Myb to different promoters during the cell cycle observed by combining cell sorting with chromatin immunoprecipitation.

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    Anita M Quintana

    2011-02-01

    Full Text Available The c-Myb transcription factor is a critical regulator of proliferation and stem cell differentiation, and mutated alleles of c-Myb are oncogenic, but little is known about changes in c-Myb activity during the cell cycle. To map the association of c-Myb with specific target genes during the cell cycle, we developed a novel Fix-Sort-ChIP approach, in which asynchronously growing cells were fixed with formaldehyde, stained with Hoechst 33342 and separated into different cell cycle fractions by flow sorting, then processed for chromatin immunoprecipitation (ChIP assays. We found that c-Myb actively repositions, binding to some genes only in specific cell cycle phases. In addition, the specificity of c-Myb is dramatically different in small subpopulations of cells, for example cells in the G2/M phase of the cell cycle, than in the bulk population. The repositioning of c-Myb during the cell cycle is not due to changes in its expression and also occurs with ectopically expressed, epitope-tagged versions of c-Myb. The repositioning occurs in established cell lines, in primary human CD34+ hematopoietic progenitors and in primary human acute myeloid leukemia cells. The combination of fixation, sorting and ChIP analysis sheds new light on the dynamic nature of gene regulation during the cell cycle and provides a new type of tool for the analysis of gene regulation in small subsets of cells, such as cells in a specific phase of the cell cycle.

  12. Analysis of the transcriptome of Erigeron breviscapus uncovers putative scutellarin and chlorogenic acids biosynthetic genes and genetic markers.

    Science.gov (United States)

    Jiang, Ni-Hao; Zhang, Guang-Hui; Zhang, Jia-Jin; Shu, Li-Ping; Zhang, Wei; Long, Guang-Qiang; Liu, Tao; Meng, Zheng-Gui; Chen, Jun-Wen; Yang, Sheng-Chao

    2014-01-01

    Erigeron breviscapus (Vant.) Hand-Mazz. is a famous medicinal plant. Scutellarin and chlorogenic acids are the primary active components in this herb. However, the mechanisms of biosynthesis and regulation for scutellarin and chlorogenic acids in E. breviscapus are considerably unknown. In addition, genomic information of this herb is also unavailable. Using Illumina sequencing on GAIIx platform, a total of 64,605,972 raw sequencing reads were generated and assembled into 73,092 non-redundant unigenes. Among them, 44,855 unigenes (61.37%) were annotated in the public databases Nr, Swiss-Prot, KEGG, and COG. The transcripts encoding the known enzymes involved in flavonoids and in chlorogenic acids biosynthesis were discovered in the Illumina dataset. Three candidate cytochrome P450 genes were discovered which might encode flavone 6-hydroase converting apigenin to scutellarein. Furthermore, 4 unigenes encoding the homologues of maize P1 (R2R3-MYB transcription factors) were defined, which might regulate the biosynthesis of scutellarin. Additionally, a total of 11,077 simple sequence repeat (SSR) were identified from 9,255 unigenes. Of SSRs, tri-nucleotide motifs were the most abundant motif. Thirty-six primer pairs for SSRs were randomly selected for validation of the amplification and polymorphism. The result revealed that 34 (94.40%) primer pairs were successfully amplified and 19 (52.78%) primer pairs exhibited polymorphisms. Using next generation sequencing (NGS) technology, this study firstly provides abundant genomic data for E. breviscapus. The candidate genes involved in the biosynthesis and transcriptional regulation of scutellarin and chlorogenic acids were obtained in this study. Additionally, a plenty of genetic makers were generated by identification of SSRs, which is a powerful tool for molecular breeding and genetics applications in this herb.

  13. Analysis of the transcriptome of Erigeron breviscapus uncovers putative scutellarin and chlorogenic acids biosynthetic genes and genetic markers.

    Directory of Open Access Journals (Sweden)

    Ni-Hao Jiang

    Full Text Available Erigeron breviscapus (Vant. Hand-Mazz. is a famous medicinal plant. Scutellarin and chlorogenic acids are the primary active components in this herb. However, the mechanisms of biosynthesis and regulation for scutellarin and chlorogenic acids in E. breviscapus are considerably unknown. In addition, genomic information of this herb is also unavailable.Using Illumina sequencing on GAIIx platform, a total of 64,605,972 raw sequencing reads were generated and assembled into 73,092 non-redundant unigenes. Among them, 44,855 unigenes (61.37% were annotated in the public databases Nr, Swiss-Prot, KEGG, and COG. The transcripts encoding the known enzymes involved in flavonoids and in chlorogenic acids biosynthesis were discovered in the Illumina dataset. Three candidate cytochrome P450 genes were discovered which might encode flavone 6-hydroase converting apigenin to scutellarein. Furthermore, 4 unigenes encoding the homologues of maize P1 (R2R3-MYB transcription factors were defined, which might regulate the biosynthesis of scutellarin. Additionally, a total of 11,077 simple sequence repeat (SSR were identified from 9,255 unigenes. Of SSRs, tri-nucleotide motifs were the most abundant motif. Thirty-six primer pairs for SSRs were randomly selected for validation of the amplification and polymorphism. The result revealed that 34 (94.40% primer pairs were successfully amplified and 19 (52.78% primer pairs exhibited polymorphisms.Using next generation sequencing (NGS technology, this study firstly provides abundant genomic data for E. breviscapus. The candidate genes involved in the biosynthesis and transcriptional regulation of scutellarin and chlorogenic acids were obtained in this study. Additionally, a plenty of genetic makers were generated by identification of SSRs, which is a powerful tool for molecular breeding and genetics applications in this herb.

  14. Human Induced Pluripotent Stem Cell-Derived Macrophages Share Ontogeny with MYB-Independent Tissue-Resident Macrophages

    Directory of Open Access Journals (Sweden)

    Julian Buchrieser

    2017-02-01

    Full Text Available Tissue-resident macrophages, such as microglia, Kupffer cells, and Langerhans cells, derive from Myb-independent yolk sac (YS progenitors generated before the emergence of hematopoietic stem cells (HSCs. Myb-independent YS-derived resident macrophages self-renew locally, independently of circulating monocytes and HSCs. In contrast, adult blood monocytes, as well as infiltrating, gut, and dermal macrophages, derive from Myb-dependent HSCs. These findings are derived from the mouse, using gene knockouts and lineage tracing, but their applicability to human development has not been formally demonstrated. Here, we use human induced pluripotent stem cells (iPSCs as a tool to model human hematopoietic development. By using a CRISPR-Cas9 knockout strategy, we show that human iPSC-derived monocytes/macrophages develop in an MYB-independent, RUNX1-, and SPI1 (PU.1-dependent fashion. This result makes human iPSC-derived macrophages developmentally related to and a good model for MYB-independent tissue-resident macrophages, such as alveolar and kidney macrophages, microglia, Kupffer cells, and Langerhans cells.

  15. Characterization of a New Pink-Fruited Tomato Mutant Results in the Identification of a Null Allele of the SlMYB12 Transcription Factor.

    Science.gov (United States)

    Fernandez-Moreno, Josefina-Patricia; Tzfadia, Oren; Forment, Javier; Presa, Silvia; Rogachev, Ilana; Meir, Sagit; Orzaez, Diego; Aharoni, Aspah; Granell, Antonio

    2016-07-01

    The identification and characterization of new tomato (Solanum lycopersicum) mutants affected in fruit pigmentation and nutritional content can provide valuable insights into the underlying biology, as well as a source of new alleles for breeding programs. To date, all characterized pink-pigmented tomato fruit mutants appear to result from low SlMYB12 transcript levels in the fruit skin. Two new mutant lines displaying a pink fruit phenotype (pf1 and pf2) were characterized in this study. In the pf mutants, SlMYB12 transcripts accumulated to wild-type levels but exhibited the same truncation, which resulted in the absence of the essential MYB activation domain coding region. Allelism and complementation tests revealed that both pf mutants were allelic to the y locus and showed the same recessive null allele in homozygosis: Δy A set of molecular and metabolic effects, reminiscent of those observed in the Arabidopsis (Arabidopsis thaliana) myb11 myb12 myb111 triple mutant, were found in the tomato Δy mutants. To our knowledge, these have not been described previously, and our data support the idea of their being null mutants, in contrast to previously described transcriptional hypomorphic pink fruit lines. We detected a reduction in the expression of several flavonol glycosides and some associated glycosyl transferases. Transcriptome analysis further revealed that the effects of the pf mutations extended beyond the flavonoid pathway into the interface between primary and secondary metabolism. Finally, screening for Myb-binding sites in the candidate gene promoter sequences revealed that 141 of the 152 co-down-regulated genes may be direct targets of SlMYB12 regulation. © 2016 American Society of Plant Biologists. All Rights Reserved.

  16. Gene Expression and Metabolite Profiling of Developing Highbush Blueberry Fruit Indicates Transcriptional Regulation of Flavonoid Metabolism and Activation of Abscisic Acid Metabolism1[W][OA

    Science.gov (United States)

    Zifkin, Michael; Jin, Alena; Ozga, Jocelyn A.; Zaharia, L. Irina; Schernthaner, Johann P.; Gesell, Andreas; Abrams, Suzanne R.; Kennedy, James A.; Constabel, C. Peter

    2012-01-01

    Highbush blueberry (Vaccinium corymbosum) fruits contain substantial quantities of flavonoids, which are implicated in a wide range of health benefits. Although the flavonoid constituents of ripe blueberries are known, the molecular genetics underlying their biosynthesis, localization, and changes that occur during development have not been investigated. Two expressed sequence tag libraries from ripening blueberry fruit were constructed as a resource for gene identification and quantitative real-time reverse transcription-polymerase chain reaction primer design. Gene expression profiling by quantitative real-time reverse transcription-polymerase chain reaction showed that flavonoid biosynthetic transcript abundance followed a tightly regulated biphasic pattern, and transcript profiles were consistent with the abundance of the three major classes of flavonoids. Proanthocyanidins (PAs) and corresponding biosynthetic transcripts encoding anthocyanidin reductase and leucoanthocyanidin reductase were most concentrated in young fruit and localized predominantly to the inner fruit tissue containing the seeds and placentae. Mean PA polymer length was seven to 8.5 subunits, linked predominantly via B-type linkages, and was relatively constant throughout development. Flavonol accumulation and localization patterns were similar to those of the PAs, and the B-ring hydroxylation pattern of both was correlated with flavonoid-3′-hydroxylase transcript abundance. By contrast, anthocyanins accumulated late in maturation, which coincided with a peak in flavonoid-3-O-glycosyltransferase and flavonoid-3′5′-hydroxylase transcripts. Transcripts of VcMYBPA1, which likely encodes an R2R3-MYB transcriptional regulator of PA synthesis, were prominent in both phases of development. Furthermore, the initiation of ripening was accompanied by a substantial rise in abscisic acid, a growth regulator that may be an important component of the ripening process and contribute to the regulation

  17. HrpNEa-induced deterrent effect on phloem feeding of the green ...

    Indian Academy of Sciences (India)

    In response to the phloem-feeding stress, plants defend themselves by .... was quantified as a percentage decrease in the number of feeding aphids .... increased with time during the course of 24 h monitoring ... spent outside the cuticle (nonpenetration; figure 3A, np) ..... R2R3-MYB gene family from Arabidopsis thaliana.

  18. Regulation of FeLV-945 by c-Myb binding and CBP recruitment to the LTR

    Directory of Open Access Journals (Sweden)

    Finstad Samantha L

    2004-09-01

    Full Text Available Abstract Background Feline leukemia virus (FeLV induces degenerative, proliferative and malignant hematologic disorders in its natural host, the domestic cat. FeLV-945 is a viral variant identified as predominant in a cohort of naturally infected animals. FeLV-945 contains a unique sequence motif in the long terminal repeat (LTR comprised of a single copy of transcriptional enhancer followed by a 21-bp sequence triplicated in tandem. The LTR is precisely conserved among independent cases of multicentric lymphoma, myeloproliferative disease and anemia in animals from the cohort. The 21-bp triplication was previously shown to act as a transcriptional enhancer preferentially in hematopoietic cells and to confer a replicative advantage. The objective of the present study was to examine the molecular mechanism by which the 21-bp triplication exerts its influence and the selective advantage responsible for its precise conservation. Results Potential binding sites for the transcription factor, c-Myb, were identified across the repeat junctions of the 21-bp triplication. Such sites would not occur in the absence of the repeat; thus, a requirement for c-Myb binding to the repeat junctions of the triplication would exert a selective pressure to conserve its sequence precisely. Electrophoretic mobility shift assays demonstrated specific binding of c-Myb to the 21-bp triplication. Reporter gene assays showed that the triplication-containing LTR is responsive to c-Myb, and that responsiveness requires the presence of both c-Myb binding sites. Results further indicated that c-Myb in complex with the 21-bp triplication recruits the transcriptional co-activator, CBP, a regulator of normal hematopoiesis. FeLV-945 replication was shown to be positively regulated by CBP in a manner dependent on the presence of the 21-bp triplication. Conclusion Binding sites for c-Myb across the repeat junctions of the 21-bp triplication may account for its precise conservation in

  19. An overview of the gene regulatory network controlling trichome development in the model plant, Arabidopsis

    Directory of Open Access Journals (Sweden)

    Sitakanta ePattanaik

    2014-06-01

    Full Text Available Trichomes are specialized epidermal cells located on aerial parts of plants and are associated with a wide array of biological processes. Trichomes protect plants from adverse conditions including UV light and herbivore attack and are also an important source of a number of phytochemicals. The simple unicellular trichomes of Arabidopsis serve as an excellent model to study molecular mechanism of cell differentiation and pattern formation in plants. The emerging picture suggests that the developmental process is controlled by a transcriptional network involving three major groups of transcription factors: the R2R3 MYB, basic helix-loop-helix (bHLH and WD40 repeat (WDR protein. These regulatory proteins form a trimeric activator complex that positively regulates trichome development. The single repeat R3 MYBs act as negative regulators of trichome development. They compete with the R2R3 MYBs to bind the bHLH factor and form a repressor complex. In addition to activator-repressor mechanism, a depletion mechanism may operate in parallel during trichome development. In this mechanism, the bHLH factor traps the WDR protein which results in depletion of WDR protein in neighboring cells. Consequently, the cells with high levels of bHLH and WDR proteins are developed into trichomes. A group of C2H2 zinc finger TFs has also been implicated in trichome development. Phytohormones, including gibberellins and jasmonic acid, play significant roles in this developmental process. Recently, microRNAs have been shown to be involved in trichome development. Furthermore, it has been demonstrated that the activities of the key regulatory proteins involved in trichome development are controlled by the 26S/ubiquitin proteasome system (UPS, highlighting the complexity of the regulatory network controlling this developmental process. To complement several excellent recent relevant reviews, this review focuses on the transcriptional network and hormonal interplay

  20. The small ubiquitin-like modifier E3 ligase MdSIZ1 promotes anthocyanin accumulation by sumoylating MdMYB1 under low-temperature conditions in apple.

    Science.gov (United States)

    Zhou, Li-Jie; Li, Yuan-Yuan; Zhang, Rui-Fen; Zhang, Chun-Ling; Xie, Xing-Bin; Zhao, Cheng; Hao, Yu-Jin

    2017-10-01

    MdMYB1 acts as a crucial component of the MYB-bHLH-WD40 complex to regulate anthocyanin biosynthesis in red-skinned apples (Malus domestica), but little is known about its post-translational regulation. Here, a small ubiquitin-like modifier E3 ligase MdSIZ1 was screened out as an MdMYB1-interacting protein with a yeast two-hybridization approach. The interaction between MdSIZ1 and MdMYB1 was further verified with pull-down and CoIP assays. Furthermore, it was found that MdSIZ1 directly sumoylated MdMYB1 proteins in vivo and in vitro, especially under moderately low temperature (17 °C) conditions, and that this sumoylation was required for MdMYB1 protein stability. Moreover, the transcription level of MdSIZ1 gene was remarkably induced by low temperature and phosphorus deficiency, and MdSIZ1 overexpression exerted a large positive influence on anthocyanin accumulation and red fruit coloration, suggesting its important role in the regulation of anthocyanin biosynthesis under stress conditions. Our findings reveal an important role for a small ubiquitin-like modifier modification of MYB transcription factors in regulation of anthocyanin biosynthesis in plants. © 2017 John Wiley & Sons Ltd.

  1. CMYB1 Encoding a MYB Transcriptional Activator Is Involved in Abiotic Stress and Circadian Rhythm in Rice

    Directory of Open Access Journals (Sweden)

    Min Duan

    2014-01-01

    Full Text Available Through analysis of cold-induced transcriptome, a novel gene encoding a putative MYB transcription factor was isolated and designated Cold induced MYB 1 (CMYB1. Tissue-specific gene expression analysis revealed that CMYB1 was highly expressed in rice stems and nodes. qRT-PCR assay indicated that CMYB1 was dramatically induced by cold stress (>100-folds and induced by exogenous ABA and osmotic stress. Interestingly, CMYB1 showed rhythmic expression profile in rice leaves at different developmental stages. Subcellular localization assay suggested that CMYB1-GFP (green fluorescent protein fusion protein was localized in the nuclei. Moreover, CMYB1 exhibited the transcriptional activation activity when transiently expressed in rice protoplast cells. Taken together, CMYB1 probably functions as a transcriptional activator in mediating stress and rhythm responsive gene expression in rice.

  2. Low expression of Mda-7/IL-24 and high expression of C-myb in tumour tissues are predictors of poor prognosis for Burkitt lymphoma patients.

    Science.gov (United States)

    Ma, Ming; Zhao, Riyang; Yang, Xingxiao; Zhao, Lianmei; Liu, Lihua; Zhang, Cong; Wang, Xuexiao; Shan, Baoen

    2018-02-08

    Burkitt lymphoma is one of the most common types of haematopoietic malignancy in children and adolescents. Mda-7/IL-24 had been identified as a differentiation inducer of Burkitt lymphoma cells. Previous studies have revealed that knockdown of C-myb can also lead to the terminal differentiation of Burkitt lymphoma cells. The aim of the present study was to investigate the correlation between the expression of Mda-7/IL-24 and C-myb, as well as their prognostic significance, for Burkitt lymphoma patients. The tumour tissues were collected from 59 cases of Burkitt lymphoma patients and detected with Western blotting and immunohistochemistry. The results showed that the expression of Mda-7/IL-24 was lower, whereas the expression of C-myb was higher in Burkitt lymphoma tissues compared to specimens of normal lymph node tissues. Furthermore, C-myb expression was negatively correlated with Mda-7/IL-24 expression at the protein level in Burkitt lymphoma tissues and cell lines. Both the expression of Mda-7/IL-24 and C-myb in Burkitt lymphoma tissues was associated with some clinicopathological parameters, such as clinical stage, infiltration in the bone marrow, Ki67 and overall survival rates. These results indicated that low expression of Mda-7/IL-24 along with high expression of C-myb are predictors for poor prognosis of Burkitt lymphoma patients; this outcome suggests that Mda-7/IL-24 and C-myb might be potential targets for clinical treatment of Burkitt lymphoma. Mda-7/IL-24: melanoma differentiation associated gene7/interleukin 24; FCM: flow cytometry; Ecog: Eastern Cooperative Oncology Group; IPI: International lymphoma prognosis index.

  3. Expression of p89c-Mybex9b, an alternatively spliced form of c-Myb, is required for proliferation and survival of p210BCR/ABL-expressing cells

    International Nuclear Information System (INIS)

    Manzotti, G; Mariani, S A; Corradini, F; Bussolari, R; Cesi, V; Vergalli, J; Ferrari-Amorotti, G; Fragliasso, V; Soliera, A R; Cattelani, S; Raschellà, G; Holyoake, T L; Calabretta, B

    2012-01-01

    The c-Myb gene encodes the p75 c-Myb isoform and less-abundant proteins generated by alternatively spliced transcripts. Among these, the best known is p c-Mybex9b , which contains 121 additional amino acids between exon 9 and 10, in a domain involved in protein–protein interactions and negative regulation. In hematopoietic cells, expression of p c-Mybex9b accounts for 10–15% of total c-Myb; these levels may be biologically relevant because modest changes in c-Myb expression affects proliferation and survival of leukemic cells and lineage choice and frequency of normal hematopoietic progenitors. In this study, we assessed biochemical activities of p c-Mybex9b and the consequences of perturbing its expression in K562 and primary chronic myeloid leukemia (CML) progenitor cells. Compared with p75 c-Myb , p c-Mybex9b is more stable and more effective in transactivating Myb-regulated promoters. Ectopic expression of p c-Mybex9b enhanced proliferation and colony formation and reduced imatinib (IM) sensitivity of K562 cells; conversely, specific downregulation of p c-Mybex9b reduced proliferation and colony formation, enhanced IM sensitivity of K562 cells and markedly suppressed colony formation of CML CD34 + cells, without affecting the levels of p75 c-Myb . Together, these studies indicate that expression of the low-abundance p c-Mybex9b isoform has an important role for the overall biological effects of c-Myb in BCR/ABL-transformed cells

  4. MdCOP1 Ubiquitin E3 Ligases Interact with MdMYB1 to Regulate Light-Induced Anthocyanin Biosynthesis and Red Fruit Coloration in Apple1[W][OA

    Science.gov (United States)

    Li, Yuan-Yuan; Mao, Ke; Zhao, Cheng; Zhao, Xian-Yan; Zhang, Hua-Lei; Shu, Huai-Rui; Hao, Yu-Jin

    2012-01-01

    MdMYB1 is a crucial regulator of light-induced anthocyanin biosynthesis and fruit coloration in apple (Malus domestica). In this study, it was found that MdMYB1 protein accumulated in the light but degraded via a ubiquitin-dependent pathway in the dark. Subsequently, the MdCOP1-1 and MdCOP1-2 genes were isolated from apple fruit peel and were functionally characterized in the Arabidopsis (Arabidopsis thaliana) cop1-4 mutant. Yeast (Saccharomyces cerevisiae) two-hybrid, bimolecular fluorescence complementation, and coimmunoprecipitation assays showed that MdMYB1 interacts with the MdCOP1 proteins. Furthermore, in vitro and in vivo experiments indicated that MdCOP1s are necessary for the ubiquitination and degradation of MdMYB1 protein in the dark and are therefore involved in the light-controlled stability of the MdMYB1 protein. Finally, a viral vector-based transformation approach demonstrated that MdCOP1s negatively regulate the peel coloration of apple fruits by modulating the degradation of the MdMYB1 protein. Our findings provide new insight into the mechanism by which light controls anthocyanin accumulation and red fruit coloration in apple and even other plant species. PMID:22855936

  5. MdMYB9 and MdMYB11 are involved in the regulation of the JA-induced biosynthesis of anthocyanin and proanthocyanidin in apples.

    Science.gov (United States)

    An, Xiu-Hong; Tian, Yi; Chen, Ke-Qin; Liu, Xiao-Juan; Liu, Dan-Dan; Xie, Xing-Bin; Cheng, Cun-Gang; Cong, Pei-Hua; Hao, Yu-Jin

    2015-04-01

    Anthocyanin and proanthocyanidin (PA) are important secondary metabolites and beneficial to human health. Their biosynthesis is induced by jasmonate (JA) treatment and regulated by MYB transcription factors (TFs). However, which and how MYB TFs regulate this process is largely unknown in apple. In this study, MdMYB9 and MdMYB11 which were induced by methyl jasmonate (MeJA) were functionally characterized. Overexpression of MdMYB9 or MdMYB11 promoted not only anthocyanin but also PA accumulation in apple calluses, and the accumulation was further enhanced by MeJA. Subsequently, yeast two-hybrid, pull-down and bimolecular fluorescence complementation assays showed that both MYB proteins interact with MdbHLH3. Moreover, Jasmonate ZIM-domain (MdJAZ) proteins interact with MdbHLH3. Furthermore, chromatin immunoprecipitation-quantitative PCR and yeast one-hybrid assays demonstrated that both MdMYB9 and MdMYB11 bind to the promoters of ANS, ANR and LAR, whereas MdbHLH3 is recruited to the promoters of MdMYB9 and MdMYB11 and regulates their transcription. In addition, transient expression assays indicated that overexpression of MdJAZ2 inhibits the recruitment of MdbHLH3 to the promoters of MdMYB9 and MdMYB11. Our findings provide new insight into the mechanism of how MeJA regulates anthocyanin and PA accumulation in apple. © The Author 2014. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  6. Identification of lignin genes and regulatory sequences involved in secondary cell wall formation in Acacia auriculiformis and Acacia mangium via de novo transcriptome sequencing

    Directory of Open Access Journals (Sweden)

    Cannon Charles H

    2011-07-01

    Full Text Available Abstract Background Acacia auriculiformis × Acacia mangium hybrids are commercially important trees for the timber and pulp industry in Southeast Asia. Increasing pulp yield while reducing pulping costs are major objectives of tree breeding programs. The general monolignol biosynthesis and secondary cell wall formation pathways are well-characterized but genes in these pathways are poorly characterized in Acacia hybrids. RNA-seq on short-read platforms is a rapid approach for obtaining comprehensive transcriptomic data and to discover informative sequence variants. Results We sequenced transcriptomes of A. auriculiformis and A. mangium from non-normalized cDNA libraries synthesized from pooled young stem and inner bark tissues using paired-end libraries and a single lane of an Illumina GAII machine. De novo assembly produced a total of 42,217 and 35,759 contigs with an average length of 496 bp and 498 bp for A. auriculiformis and A. mangium respectively. The assemblies of A. auriculiformis and A. mangium had a total length of 21,022,649 bp and 17,838,260 bp, respectively, with the largest contig 15,262 bp long. We detected all ten monolignol biosynthetic genes using Blastx and further analysis revealed 18 lignin isoforms for each species. We also identified five contigs homologous to R2R3-MYB proteins in other plant species that are involved in transcriptional regulation of secondary cell wall formation and lignin deposition. We searched the contigs against public microRNA database and predicted the stem-loop structures of six highly conserved microRNA families (miR319, miR396, miR160, miR172, miR162 and miR168 and one legume-specific family (miR2086. Three microRNA target genes were predicted to be involved in wood formation and flavonoid biosynthesis. By using the assemblies as a reference, we discovered 16,648 and 9,335 high quality putative Single Nucleotide Polymorphisms (SNPs in the transcriptomes of A. auriculiformis and A. mangium

  7. A spontaneous dominant-negative mutation within a 35S::AtMYB90 transgene inhibits flower pigment production in tobacco.

    Science.gov (United States)

    Velten, Jeff; Cakir, Cahid; Cazzonelli, Christopher I

    2010-03-29

    In part due to the ease of visual detection of phenotypic changes, anthocyanin pigment production has long been the target of genetic and molecular research in plants. Specific members of the large family of plant myb transcription factors have been found to play critical roles in regulating expression of anthocyanin biosynthetic genes and these genes continue to serve as important tools in dissecting the molecular mechanisms of plant gene regulation. A spontaneous mutation within the coding region of an Arabidopsis 35S::AtMYB90 transgene converted the activator of plant-wide anthocyanin production to a dominant-negative allele (PG-1) that inhibits normal pigment production within tobacco petals. Sequence analysis identified a single base change that created a premature nonsense codon, truncating the encoded myb protein. The resulting mutant protein lacks 78 amino acids from the wild type C-terminus and was confirmed as the source of the white-flower phenotype. A putative tobacco homolog of AtMYB90 (NtAN2) was isolated and found to be expressed in flower petals but not leaves of all tobacco plants tested. Using transgenic tobacco constitutively expressing the NtAN2 gene confirmed the NtAN2 protein as the likely target of PG-1-based inhibition of tobacco pigment production. Messenger RNA and anthocyanin analysis of PG-1Sh transgenic lines (and PG-1Sh x purple 35S::NtAN2 seedlings) support a model in which the mutant myb transgene product acts as a competitive inhibitor of the native tobacco NtAN2 protein. This finding is important to researchers in the field of plant transcription factor analysis, representing a potential outcome for experiments analyzing in vivo protein function in test transgenic systems that over-express or mutate plant transcription factors.

  8. An oncogenic MYB feedback loop drives alternate cell fates in adenoid cystic carcinoma

    Science.gov (United States)

    Drier, Yotam; Cotton, Matthew J.; Williamson, Kaylyn E.; Gillespie, Shawn M.; Ryan, Russell J.H.; Kluk, Michael J.; Carey, Christopher D.; Rodig, Scott J.; Sholl, Lynette M; Afrogheh, Amir H.; Faquin, William C.; Queimado, Lurdes; Qi, Jun; Wick, Michael J.; El-Naggar, Adel K.; Bradner, James E.; Moskaluk, Christopher A.; Aster, Jon C.; Knoechel, Birgit; Bernstein, Bradley E.

    2016-01-01

    Translocation events are frequent in cancer and may create chimeric fusions or ‘regulatory rearrangements’ that drive oncogene overexpression. Here we identify super-enhancer translocations that drive overexpression of the oncogenic transcription factor MYB as a recurrent theme in adenoid cystic carcinoma (ACC). Whole-genome sequencing data and chromatin maps reveal distinct chromosomal rearrangements that juxtapose super-enhancers to the MYB locus. Chromosome conformation capture confirms that the translocated enhancers interact with the MYB promoter. Remarkably, MYB protein binds to the translocated enhancers, creating a positive feedback loop that sustains its expression. MYB also binds enhancers that drive different regulatory programs in alternate cell lineages in ACC, cooperating with TP63 in myoepithelial cells and a Notch program in luminal epithelial cells. Bromodomain inhibitors slow tumor growth in ACC primagraft models in vivo. Thus, our study identifies super-enhancer translocations that drive MYB expression and provides insight into downstream MYB functions in the alternate ACC lineages. PMID:26829750

  9. Engineering the anthocyanin regulatory complex of strawberry (Fragaria vesca

    Directory of Open Access Journals (Sweden)

    Kui eLin-Wang

    2014-11-01

    Full Text Available The woodland strawberry, Fragaria vesca is a model fruit for a number of rosaceous crops. We have engineered altered concentrations of anthocyanin in F. vesca, to determine the impact on plant growth and fruit quality. Anthocyanin concentrations were significantly increased by over-expression or decreased by knock-down of the R2R3 MYB activator, MYB10. In contrast, a potential bHLH partner for MYB10 (bHLH33 did not affect the anthocyanin pathway when knocked down using RNAi constructs. Metabolic analysis of fruits revealed that, of all the polyphenolics surveyed, only cyanidin and pelargonidin glucoside, and coumaryl hexose were significantly affected by over-expression and knock down of MYB10. Using the F. vesca genome sequence, members of the MYB, bHLH and WD40 families were examined. Global analysis of gene expression and targeted qPCR analysis of biosynthetic genes and regulators confirmed the effects of altering MYB10 expression, as well as the knock-down of bHLH33. Other members of the MYB transcription factor family were affected by the transgenes. Transient expression of strawberry genes in Nicotiana benthamiana revealed that MYB10 can auto-regulate itself, and potential repressors of MYB10. In tobacco, MYB10’s activation of biosynthetic steps is inhibited by the strawberry repressor MYB1.

  10. Overexpression of MYB115, AAD2, or AAD3 in Arabidopsis thaliana seeds yields contrasting omega-7 contents

    Science.gov (United States)

    To, Alexandra; Barthole, Guillaume; Lepiniec, Loïc

    2018-01-01

    Omega-7 monoenoic fatty acids (ω-7 FAs) are increasingly exploited both for their positive effects on health and for their industrial potential. Some plant species produce fruits or seeds with high amounts of ω-7 FAs. However, the low yields and poor agronomic properties of these plants preclude their commercial use. As an alternative, the metabolic engineering of oilseed crops for sustainable ω-7 FA production has been proposed. Two palmitoyl-ACP desaturases (PADs) catalyzing ω-7 FA biosynthesis were recently identified and characterized in Arabidopsis thaliana, together with MYB115 and MYB118, two transcription factors that positively control the expression of the corresponding PAD genes. In the present research, we examine the biotechnological potential of these new actors of ω-7 metabolism for the metabolic engineering of plant-based production of ω-7 FAs. We placed the PAD and MYB115 coding sequences under the control of a promoter strongly induced in seeds and evaluated these different constructs in A. thaliana. Seeds were obtained that exhibit ω-7 FA contents ranging from 10 to >50% of the total FAs, and these major compositional changes have no detrimental effect on seed germination. PMID:29381741

  11. Molecular survey of Tamyb10-1 genes and their association with ...

    Indian Academy of Sciences (India)

    To investigate allelic variation of Myb10-1 genes in Chinese wheat and to examine its association with germination level in wheat, a total of 582 Chinese bread wheat cultivars and 110 Aegilops tauschii accessions were used to identify allelic variations of three Myb10-1 genes. Identification results indicated that there is a ...

  12. Mouse Incisor Stem Cell Niche and Myb Transcription Factors

    Czech Academy of Sciences Publication Activity Database

    Švandová, Eva; Veselá, Barbora; Šmarda, J.; Hampl, A.; Radlanski, R.J.; Matalová, Eva

    2015-01-01

    Roč. 44, č. 5 (2015), s. 338-344 ISSN 0340-2096 R&D Projects: GA ČR GAP304/11/1418; GA ČR GCP302/12/J059 Institutional support: RVO:67985904 Keywords : c-Myb * stem cell niches Subject RIV: EA - Cell Biology Impact factor: 0.615, year: 2015

  13. A role of c-Myb in ossification

    Czech Academy of Sciences Publication Activity Database

    Oralová, Veronika; Matalová, Eva; Knopfová, L.; Švandová, Eva; Šmarda, J.; Buchtová, Marcela

    2015-01-01

    Roč. 159, Suppl 1 (2015), S30-S31 ISSN 1213-8118. [Morphology 2015. International Congress of the Czech Anatomical Society /49./. Lojda Symposium on Histochemistry /52./. 06.09.2015-08.09.2015, Olomouc] R&D Projects: GA ČR GB14-37368G Institutional support: RVO:67985904 Keywords : c-Myb Subject RIV: EA - Cell Biology

  14. GWA Mapping of Anthocyanin Accumulation Reveals Balancing Selection of MYB90 in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Johanna A Bac-Molenaar

    Full Text Available Induction of anthocyanin accumulation by osmotic stress was assessed in 360 accessions of Arabidopsis thaliana. A wide range of natural variation, with phenotypes ranging from green to completely red/purple rosettes, was observed. A genome wide association (GWA mapping approach revealed that sequence diversity in a small 15 kb region on chromosome 1 explained 40% of the variation observed. Sequence and expression analyses of alleles of the candidate gene MYB90 identified a causal polymorphism at amino acid (AA position 210 of this transcription factor of the anthocyanin biosynthesis pathway. This amino acid discriminates the two most frequent alleles of MYB90. Both alleles are present in a substantial part of the population, suggesting balancing selection between these two alleles. Analysis of the geographical origin of the studied accessions suggests that the macro climate is not the driving force behind positive or negative selection for anthocyanin accumulation. An important role for local climatic conditions is, therefore, suggested. This study emphasizes that GWA mapping is a powerful approach to identify alleles that are under balancing selection pressure in nature.

  15. Utilization of circular dichroism and electrospray ionization mass spectrometry to understand the formation and conversion of G-quadruplex DNA at the human c-myb proto-oncogene.

    Science.gov (United States)

    Fu, Hengqing; Yang, Pengfei; Hai, Jinhui; Li, Huihui

    2018-10-05

    G-quadruplex DNAs are involved in a number of key biological processes, including gene expression, transcription, and apoptosis. The c-myb oncogene contains a number of GGA repeats in its promoter which forms G-quadruplex, thus it could be used as a target in cancer therapeutics. Several in-vitro studies have used Circular Dichroism (CD) spectroscopy or electrospray ionization mass spectrometry (ESI-MS) to demonstrate formation and stability of G-quadruplex DNA structure in the promoter region of human c-myb oncogene. The factors affecting the c-myb G-quadruplex structures were investigated, such as cations (i.e. K + , NH 4 + and Na + ) and co-solutes (methanol and polyethylene glycol). The results indicated that the presence of cations and co-solutes could change the G-quadruplex structural population and promote its thermodynamic stabilization as indicated by CD melting curves. It indicated that the co-solutes preferentially stabilize the c-myb G-quadruplex structure containing both homo- and hetero-stacking. In addition, protopine was demonstrated as a binder of c-myb G-quadruplex as screened from a library of natural alkaloids using ESI-MS method. CD spectra showed that it could selectively stabilize the c-myb G-quadruplex structure compared to other six G-quadruplexes from tumor-related G-rich sequences and the duplex DNAs (both long and short-chain ones). The binding of protopine could induce the change in the G-quadruplex structural populations. Therefore, protopine with its high binding specificity could be considered as a precursor for the design of drugs to target and regulate c-myb oncogene transcription. Copyright © 2018 Elsevier B.V. All rights reserved.

  16. The MIEL1 E3 Ubiquitin Ligase Negatively Regulates Cuticular Wax Biosynthesis in Arabidopsis Stems.

    Science.gov (United States)

    Lee, Hong Gil; Kim, Juyoung; Suh, Mi Chung; Seo, Pil Joon

    2017-07-01

    Cuticular wax is an important hydrophobic layer that covers the plant aerial surface. Cuticular wax biosynthesis is shaped by multiple layers of regulation. In particular, a pair of R2R3-type MYB transcription factors, MYB96 and MYB30, are known to be the main participants in cuticular wax accumulation. Here, we report that the MYB30-INTERACTING E3 LIGASE 1 (MIEL1) E3 ubiquitin ligase controls the protein stability of the two MYB transcription factors and thereby wax biosynthesis in Arabidopsis. MIEL1-deficient miel1 mutants exhibit increased wax accumulation in stems, with up-regulation of wax biosynthetic genes targeted by MYB96 and MYB30. Genetic analysis reveals that wax accumulation of the miel1 mutant is compromised by myb96 or myb30 mutation, but MYB96 is mainly epistatic to MIEL1, playing a predominant role in cuticular wax deposition. These observations indicate that the MIEL1-MYB96 module is important for balanced cuticular wax biosynthesis in developing inflorescence stems. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  17. Human Vav1 expression in hematopoietic and cancer cell lines is regulated by c-Myb and by CpG methylation.

    Directory of Open Access Journals (Sweden)

    Lena Ilan

    Full Text Available Vav1 is a signal transducer protein that functions as a guanine nucleotide exchange factor for the Rho/Rac GTPases in the hematopoietic system where it is exclusively expressed. Recently, Vav1 was shown to be involved in several human malignancies including neuroblastoma, lung cancer, and pancreatic ductal adenocarcinoma (PDA. Although some factors that affect vav1 expression are known, neither the physiological nor pathological regulation of vav1 expression is completely understood. We demonstrate herein that mutations in putative transcription factor binding sites at the vav1 promoter affect its transcription in cells of different histological origin. Among these sites is a consensus site for c-Myb, a hematopoietic-specific transcription factor that is also found in Vav1-expressing lung cancer cell lines. Depletion of c-Myb using siRNA led to a dramatic reduction in vav1 expression in these cells. Consistent with this, co-transfection of c-Myb activated transcription of a vav1 promoter-luciferase reporter gene construct in lung cancer cells devoid of Vav1 expression. Together, these results indicate that c-Myb is involved in vav1 expression in lung cancer cells. We also explored the methylation status of the vav1 promoter. Bisulfite sequencing revealed that the vav1 promoter was completely unmethylated in human lymphocytes, but methylated to various degrees in tissues that do not normally express vav1. The vav1 promoter does not contain CpG islands in proximity to the transcription start site; however, we demonstrated that methylation of a CpG dinucleotide at a consensus Sp1 binding site in the vav1 promoter interferes with protein binding in vitro. Our data identify two regulatory mechanisms for vav1 expression: binding of c-Myb and CpG methylation of 5' regulatory sequences. Mutation of other putative transcription factor binding sites suggests that additional factors regulate vav1 expression as well.

  18. C-myb Regulates Autophagy for Pulp Vitality in Glucose Oxidative Stress.

    Science.gov (United States)

    Lee, Y H; Kim, H S; Kim, J S; Yu, M K; Cho, S D; Jeon, J G; Yi, H K

    2016-04-01

    Diabetes mellitus is closely related to oral-complicated diseases by oxidative stress. This study investigates whether cellular myeloblastosis (c-myb) could protect human dental pulp cells against glucose oxidative stress and regulate autophagy activity for pulp vitality. Diabetes mellitus was induced by streptozotocin in Sprague-Dawley rats, and their pulp tissue in teeth was analyzed in terms of pulp cavity and molecules by hematoxylin and eosin and immunohistochemistry staining. Human dental pulp cells were serially subcultured and treated with glucose oxidase in the presence of elevated glucose to generate glucose oxidative stress. The replication-deficient adenovirus c-myb and small interfering RNA c-myb were introduced for c-myb expression. The pulp tissue from the diabetic rats was structurally different from normal tissue in terms of narrow pulp capacity, reduced c-myb, and dentinogenesis molecules. Glucose oxidase treatment decreased c-myb and dentinogenesis molecules (bone morphogenetic protein 2 and 7, dentin matrix protein 1, and dentin sialophosphoprotein) in human dental pulp cells. However, overexpression of c-myb by adenovirus c-myb increased dentinogenesis, autophagy molecules (autophagy protein 5, microtubule-associated protein 1A/1B-light chain 3, and Beclin-1), and cell survival via p-AMPK/AKT signaling even with glucose oxidative stress. In contrast, the lack of c-myb decreased the above molecules and cell survival by downregulating p-AMPK/AKT signaling. The results indicate that diabetes leads to irreversible damage to dental pulp, which is related to downexpression of autophagy via the p-AMPK/AKT pathway by decline of c-myb. The findings of this study provide a new insight that c-myb could ameliorate autophagy activity and that it is applicable for monitoring complicated diseases of dental pulp. The involvement of c-myb in pulp pathology could serve a therapeutic target in oral-complicated diseases. © International & American Associations

  19. Situational Awareness: Regulation of the Myb Transcription Factor in Differentiation, the Cell Cycle and Oncogenesis

    Energy Technology Data Exchange (ETDEWEB)

    George, Olivia L.; Ness, Scott A., E-mail: sness@salud.unm.edu [Department of Internal Medicine, Section of Molecular Medicine, University of New Mexico Health Sciences Center, MSC07 4025-CRF 121, 1 University of New Mexico, Albuquerque, NM 87131 (United States)

    2014-10-02

    This review summarizes the mechanisms that control the activity of the c-Myb transcription factor in normal cells and tumors, and discusses how c-Myb plays a role in the regulation of the cell cycle. Oncogenic versions of c-Myb contribute to the development of leukemias and solid tumors such as adenoid cystic carcinoma, breast cancer and colon cancer. The activity and specificity of the c-Myb protein seems to be controlled through changes in protein-protein interactions, so understanding how it is regulated could lead to the development of novel therapeutic strategies.

  20. Cyclin F suppresses B-Myb activity to promote cell cycle checkpoint control

    DEFF Research Database (Denmark)

    Klein, Ditte Kjærsgaard; Hoffmann, Saskia; Ahlskog, Johanna K

    2015-01-01

    an important role in checkpoint control following ionizing radiation. Cyclin F-depleted cells initiate checkpoint signalling after ionizing radiation, but fail to maintain G2 phase arrest and progress into mitosis prematurely. Importantly, cyclin F suppresses the B-Myb-driven transcriptional programme...... that promotes accumulation of crucial mitosis-promoting proteins. Cyclin F interacts with B-Myb via the cyclin box domain. This interaction is important to suppress cyclin A-mediated phosphorylation of B-Myb, a key step in B-Myb activation. In summary, we uncover a regulatory mechanism linking the F-box protein...

  1. MYB52 Negatively Regulates Pectin Demethylesterification in Seed Coat Mucilage.

    Science.gov (United States)

    Shi, Dachuan; Ren, Angyan; Tang, Xianfeng; Qi, Guang; Xu, Zongchang; Chai, Guohua; Hu, Ruibo; Zhou, Gongke; Kong, Yingzhen

    2018-04-01

    Pectin, which is a major component of the plant primary cell walls, is synthesized and methyl-esterified in the Golgi apparatus and then demethylesterified by pectin methylesterases (PMEs) located in the cell wall. The degree of methylesterification affects the functional properties of pectin, and thereby influences plant growth, development and defense. However, little is known about the mechanisms that regulate pectin demethylesterification. Here, we show that in Arabidopsis ( Arabidopsis thaliana ) seed coat mucilage, the absence of the MYB52 transcription factor is correlated with an increase in PME activity and a decrease in the degree of pectin methylesterification. Decreased methylesterification in the myb52 mutant is also correlated with an increase in the calcium content of the seed mucilage. Chromatin immunoprecipitation analysis and molecular genetic studies suggest that MYB52 transcriptionally activates PECTIN METHYLESTERASE INHIBITOR6 ( PMEI6 ), PMEI14 , and SUBTILISIN-LIKE SER PROTEASE1.7 ( SBT1.7 ) by binding to their promoters. PMEI6 and SBT1.7 have previously been shown to be involved in seed coat mucilage demethylesterification. Our characterization of two PMEI14 mutants suggests that PMEI14 has a role in seed coat mucilage demethylesterification, although its activity may be confined to the seed coat in contrast to PMEI6, which functions in the whole seed. Our demonstration that MYB52 negatively regulates pectin demethylesterification in seed coat mucilage, and the identification of components of the molecular network involved, provides new insight into the regulatory mechanism controlling pectin demethylesterification and increases our understanding of the transcriptional regulation network involved in seed coat mucilage formation. © 2018 American Society of Plant Biologists. All Rights Reserved.

  2. Expression and characterization of c-Myb in prenatal odontogenesis

    Czech Academy of Sciences Publication Activity Database

    Matalová, Eva; Buchtová, Marcela; Tucker, A. S.; Bender, T. P.; Janečková, Eva; Lungová, V.; Balková, Simona; Šmarda, J.

    2011-01-01

    Roč. 53, č. 6 (2011), s. 793-803 ISSN 0012-1592 R&D Projects: GA AV ČR KJB500450802; GA ČR GAP304/11/1418; GA ČR(CZ) GP304/08/P289; GA ČR GC524/08/J032 Institutional research plan: CEZ:AV0Z50450515 Keywords : morphogenesis * mouse * Myb Subject RIV: FF - HEENT, Dentistry Impact factor: 2.210, year: 2011

  3. Transcrition factor c-Myb is involved in the regulation of the epithelial-mesenchymal transition in the avian neural crest

    Czech Academy of Sciences Publication Activity Database

    Karafiát, Vít; Dvořáková, Marta; Krejčí, E.; Králová, Jarmila; Pajer, Petr; Šnajdr, P.; Mandíková, Sonja; Bartůněk, Petr; Grim, M.; Dvořák, Michal

    2005-01-01

    Roč. 62, č. 21 (2005), s. 2516-2525 ISSN 1420-682X R&D Projects: GA ČR GA304/03/0463; GA AV ČR IAA5052309 Institutional research plan: CEZ:AV0Z50520514 Keywords : c-myb gene * epithelial-mesenchymal transition * neural crest Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.582, year: 2005

  4. Supra-optimal expression of the cold-regulated OsMyb4 transcription factor in transgenic rice changes the complexity of transcriptional network with major effects on stress tolerance and panicle development

    KAUST Repository

    Park, Myoungryoul; Yun, Kilyoung; Mohanty, Bijayalaxmi; Herath, Venura; Xu, Fuyu; Wijaya, Edward; Bajic, Vladimir B.; Yun, Songjoong; De Los Reyes, Benildo G.

    2010-01-01

    acid (JA), salicylic acid (SA), ethylene and reactive oxygen species (ROS) responsive genes. OsMyb4 network is independent of drought response element binding protein/C-repeat binding factor (DREB/CBF) and its sub-regulons operate with possible co

  5. Functional characterization of TRICHOMELESS2, a new single-repeat R3 MYB transcription factor in the regulation of trichome patterning in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Gan Lijun

    2011-12-01

    Full Text Available Abstract Background Single-repeat R3 MYB transcription factors (single-repeat MYBs play important roles in controlling trichome patterning in Arabidopsis. It was proposed that single-repeat MYBs negatively regulate trichome formation by competing with GLABRA1 (GL1 for binding GLABRA3/ENHANCER OF GLABRA3 (GL3/EGL3, thus inhibiting the formation of activator complex TTG1(TRANSPARENT TESTA GLABRA1-GL3/EGL3-GL1 that is required for the activation of GLABRA2 (GL2, whose product is a positive regulator of trichome formation. Previously we identified a novel single-repeat MYB transcription factor, TRICHOMELESS1 (TCL1, which negatively regulates trichome formation on the inflorescence stems and pedicels by directly suppressing the expression of GL1. Results We analyzed here the role of TRICHOMELESS2 (TCL2, a previously-uncharacterized single-repeat MYB transcription factor in trichome patterning in Arabidopsis. We showed that TCL2 is closely related to TCL1, and like TCL1 and other single-repeat MYBs, TCL2 interacts with GL3. Overexpression of TCL2 conferred glabrous phenotype while knockdown of TCL2 via RNAi induced ectopic trichome formation on the inflorescence stems and pedicels, a phenotype that was previously observed in tcl1 mutants. These results suggested that TCL2 may have overlapping function with TCL1 in controlling trichome formation on inflorescences. On the other hand, although the transcription of TCL2, like TCL1, is not controlled by the activator complex formed by GL1 and GL3, and TCL2 and TCL1 proteins are more than 80% identical at the amino acid level, the expression of TCL2 under the control of TCL1 promoter only partially recovered the mutant phenotype of tcl1, implying that TCL2 and TCL1 are not fully functional equivalent. Conclusions TCL2 function redundantly with TCL1 in controlling trichome formation on inflorescences, but they are not fully functional equivalent. Transcription of TCL2 is not controlled by activator complex

  6. (1R,2R,3R,4S,5S-3-Methyl-8-oxabicyclo[3.2.1]oct-6-ene-2,4-diyl diacetate

    Directory of Open Access Journals (Sweden)

    Viktor A. Tafeenko

    2011-08-01

    Full Text Available The molecule of the title compound, C12H16O5, has crystallographically imposed mirror symmetry with the mirror plane passing through the endocyclic O atom and the mid-point of the double bond. In the crystal, molecules are linked by C—H...O hydrogen bonds, forming chains running along the a axis.

  7. Overexpression of a repressor MdMYB15L negatively regulates anthocyanin and cold tolerance in red-fleshed callus.

    Science.gov (United States)

    Xu, Haifeng; Yang, Guanxian; Zhang, Jing; Wang, Yicheng; Zhang, Tianliang; Wang, Nan; Jiang, Shenghui; Zhang, Zongying; Chen, Xuesen

    2018-04-14

    The cold-induced metabolic pathway and anthocyanin biosynthesis play important roles in plant growth. In this study, we identified a bHLH binding motif in the MdMYB15L protein using protein sequence analyses. Yeast two-hybrid and pull-down assays showed that MdMYB15L could interact with MdbHLH33. Overexpressing MdMYB15L in red-fleshed callus inhibited the expression of MdCBF2 and resulted in reduced cold tolerance but did not affect anthocyanin levels. Chip-PCR and EMSA analysis showed that MdMYB15L could bind the type II cis-acting element found in the MdCBF2 promoter. Overexpressing MdMYB15L in red-fleshed callus overexpressing MdbHLH33 also reduced cold tolerance and reduced MdbHLH33-induced anthocyanin biosynthesis. Knocking out the bHLH binding sequence of MdMYB15L (LBSMdMYB15L) prevented LBSMdMYB15L from interacting with MdbHLH33. Overexpressing LBSMdMYB15L in red-fleshed callus overexpressing MdbHLH33 also reduced cold tolerance and reduced MdbHLH33-induced anthocyanin biosynthesis. Together, these results suggested that an apple repressor MdMYB15L might play a key role in the cold signaling and anthocyanin metabolic pathways. Copyright © 2018 Elsevier Inc. All rights reserved.

  8. A single-repeat R3-MYB transcription factor MYBC1 negatively regulates freezing tolerance in Arabidopsis

    International Nuclear Information System (INIS)

    Zhai, Hong; Bai, Xi; Zhu, Yanming; Li, Yong; Cai, Hua; Ji, Wei; Ji, Zuojun; Liu, Xiaofei; Liu, Xin; Li, Jing

    2010-01-01

    We had previously identified the MYBC1 gene, which encodes a single-repeat R3-MYB protein, as a putative osmotic responding gene; however, no R3-MYB transcription factor has been reported to regulate osmotic stress tolerance. Thus, we sought to elucidate the function of MYBC1 in response to osmotic stresses. Real-time RT-PCR analysis indicated that MYBC1 expression responded to cold, dehydration, salinity and exogenous ABA at the transcript level. mybc1 mutants exhibited an increased tolerance to freezing stress, whereas 35S::MYBC1 transgenic plants exhibited decreased cold tolerance. Transcript levels of some cold-responsive genes, including CBF/DREB genes, KIN1, ADC1, ADC2 and ZAT12, though, were not altered in the mybc1 mutants or the 35S::MYBC1 transgenic plants in response to cold stress, as compared to the wild type. Microarray analysis results that are publically available were investigated and found transcript level of MYBC1 was not altered by overexpression of CBF1, CBF2, and CBF3, suggesting that MYBC1 is not down regulated by these CBF family members. Together, these results suggested that MYBC1is capable of negatively regulating the freezing tolerance of Arabidopsis in the CBF-independent pathway. In transgenic Arabidopsis carrying an MYBC1 promoter driven β-glucuronidase (GUS) construct, GUS activity was observed in all tissues and was relatively stronger in the vascular tissues. Fused MYBC1 and GFP protein revealed that MYBC1 was localized exclusively in the nuclear compartment.

  9. MicroRNA-193b-3p acts as a tumor suppressor by targeting the MYB oncogene in T-cell acute lymphoblastic leukemia

    OpenAIRE

    Mets, E; Van der Meulen, J; Van Peer, G; Boice, M; Mestdagh, P; Van de Walle, I; Lammens, T; Goossens, S; De Moerloose, B; Benoit, Y; Van Roy, N; Clappier, E; Poppe, B; Vandesompele, J; Wendel, H-G

    2014-01-01

    The MYB oncogene is a leucine zipper transcription factor essential for normal and malignant hematopoiesis. In T-cell acute lymphoblastic leukemia (T-ALL), elevated MYB levels can arise directly through T-cell receptor-mediated MYB translocations, genomic MYB duplications or enhanced TAL1 complex binding at the MYB locus or indirectly through the TAL1/miR-223/FBXW7 regulatory axis. In this study, we used an unbiased MYB 3′untranslated region–microRNA (miRNA) library screen and identified 33 p...

  10. GATA-1 and c-myb crosstalk during red blood cell differentiation through GATA-1 binding sites in the c-myb promoter

    Czech Academy of Sciences Publication Activity Database

    Bartůněk, Petr; Králová, Jarmila; Blendiger, G.; Dvořák, Michal; Zenke, M.

    2003-01-01

    Roč. 22, č. 13 (2003), s. 1927-1935 ISSN 0950-9232 R&D Projects: GA ČR GV301/98/K042 Institutional research plan: CEZ:AV0Z5052915 Keywords : GATA-1 * c-myb * erythropoiesis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 6.495, year: 2003

  11. Effect of ischemic preconditioning on the expression of c-myb in the CA1 region of the gerbil hippocampus after ischemia/reperfusion injury

    Directory of Open Access Journals (Sweden)

    Hui Young Lee

    2016-06-01

    Conclusion: Our results show that a lethal transient ischemia significantly decreased c-myb immunoreactivity in the SP of the CA1 region and that IPC well preserved c-myb immunoreactivity in the SP of the CA1 region. We suggest that the maintenance of c-myb might be related with IPC-mediated neuroprotection after a lethal ischemic insult.

  12. Identification of Arabidopsis MYB56 as a novel substrate for CRL3(BPM) E3 ligases.

    Science.gov (United States)

    Chen, Liyuan; Bernhardt, Anne; Lee, JooHyun; Hellmann, Hanjo

    2015-02-01

    Controlled stability of proteins is a highly efficient mechanism to direct diverse processes in living cells. A key regulatory system for protein stability is given by the ubiquitin proteasome pathway, which uses E3 ligases to mark specific proteins for degradation. In this work, MYB56 is identified as a novel target of a CULLIN3 (CUL3)-based E3 ligase. Its stability depends on the presence of MATH-BTB/POZ (BPM) proteins, which function as substrate adaptors to the E3 ligase. Genetic studies have indicated that MYB56 is a negative regulator of flowering, while BPMs positively affect this developmental program. The interaction between BPMs and MYB56 occurs at the promoter of FLOWERING LOCUS T (FT), a key regulator in initiating flowering in Arabidopsis, and results in instability of MYB56. Overall the work establishes MYB transcription factors as substrates of BPM proteins, and provides novel information on components that participate in controlling flowering time in plants. Copyright © 2015 The Author. Published by Elsevier Inc. All rights reserved.

  13. Identification of Arabidopsis MYB56 as a novel substrate for CRL3BPM E3 ligases.

    Science.gov (United States)

    Chen, Liyuan; Bernhardt, Anne; Lee, JooHyun; Hellmann, Hanjo

    2014-10-24

    Controlled stability of proteins is a highly efficient mechanism to direct diverse processes in living cells. A key regulatory system for protein stability is given by the ubiquitin proteasome pathway, which uses E3 ligases to mark specific proteins for degradation. In this work MYB56 is identified as a novel target of a CULLIN3 (CUL3)-based E3 ligase. Its stability depends on the presence of MATH-BTB/POZ (BPM) proteins, which function as substrate adaptors to the E3 ligase. Genetic studies pointed out that MYB56 is a negative regulator of flowering, while BPMs positively affect this developmental program. The interaction between BPMs and MYB56 occurs at the promoter of FLOWERING LOCUS T (FT), a key regulator in initiating flowering in Arabidopsis, and results in instability of MYB56. Overall the work establishes MYB transcription factors as substrates of BPM proteins, and provides novel information on components that participate in controlling the flowering time point in plants. © The Author 2014. Published by the Molecular Plant Shanghai Editorial Office in association with Oxford University Press on behalf of CSPB and IPPE, SIBS, CAS.

  14. The Transcriptional Repressor MYB2 Regulates Both Spatial and Temporal Patterns of Proanthocyandin and Anthocyanin Pigmentation in Medicago truncatula.

    Science.gov (United States)

    Jun, Ji Hyung; Liu, Chenggang; Xiao, Xirong; Dixon, Richard A

    2015-10-01

    Accumulation of anthocyanins and proanthocyanidins (PAs) is limited to specific cell types and developmental stages, but little is known about how antagonistically acting transcriptional regulators work together to determine temporal and spatial patterning of pigmentation at the cellular level, especially for PAs. Here, we characterize MYB2, a transcriptional repressor regulating both anthocyanin and PA biosynthesis in the model legume Medicago truncatula. MYB2 was strongly upregulated by MYB5, a major regulator of PA biosynthesis in M. truncatula and a component of MYB-basic helix loop helix-WD40 (MBW) activator complexes. Overexpression of MYB2 abolished anthocyanin and PA accumulation in M. truncatula hairy roots and Arabidopsis thaliana seeds, respectively. Anthocyanin deposition was expanded in myb2 mutant seedlings and flowers accompanied by increased anthocyanin content. PA mainly accumulated in the epidermal layer derived from the outer integument in the M. truncatula seed coat, starting from the hilum area. The area of PA accumulation and ANTHOCYANIDIN REDUCTASE expression was expanded into the seed body at the early stage of seed development in the myb2 mutant. Genetic, biochemical, and cell biological evidence suggests that MYB2 functions as part of a multidimensional regulatory network to define the temporal and spatial pattern of anthocyanin and PA accumulation linked to developmental processes. © 2015 American Society of Plant Biologists. All rights reserved.

  15. c-Myb is required for plasma cell migration to bone marrow after immunization or infection

    Science.gov (United States)

    O’Donnell, Kristy; Belz, Gabrielle T.; Nutt, Stephen L.

    2015-01-01

    Plasma cell migration is crucial to immunity, but little is known about the molecular regulators of their migratory programs. Here, we detail the critical role of the transcription factor c-Myb in determining plasma cell location. In the absence of c-Myb, no IgG+ antigen-specific plasma cells were detected in the bone marrow after immunization or virus infection. This was correlated with a dramatic reduction of plasma cells in peripheral blood, mislocalization in spleen, and an inability of c-Myb–deficient plasma cells to migrate along a CXCL12 gradient. Therefore, c-Myb plays an essential, novel role in establishing the long-lived plasma cell population in the BM via responsiveness to chemokine migration cues. PMID:26077717

  16. A and MdMYB1 allele-specific markers controlling apple (Malus x domestica Borkh.) skin color and suitability for marker-assisted selection.

    Science.gov (United States)

    Zhang, X J; Wang, L X; Chen, X X; Liu, Y L; Meng, R; Wang, Y J; Zhao, Z Y

    2014-10-31

    Pre-selection for fruit skin color at the seedling stage would be highly advantageous, with marker-assisted selection offering a potential method for apple pre-selection. A and MdMYB1 alleles are allele-specific DNA markers that are potentially associated with apple skin color, and co-segregate with the Rf and Rni loci, respectively. Here, we assessed the potential application of these 2 alleles for marker-assisted breeding across 30 diverse cultivars and 2 apple seedling progenies. The red skin color phenotype was usually associated with the MdMYB1-1 allele and A(1) allele, respectively, while the 2 molecular markers provided approximately 91% predictability in the 'Fuji' x 'Cripps Pink' and 'Fuji' x 'Gala' progenies. The results obtained from the 30 cultivars and 2 progenies were consistent for the 2 molecular markers. Hence, the results supported that Rf and Rni could be located in a gene cluster, or even correspond to alleles of the same gene. Our results are consistent with the hypothesis that red/yellow dimorphism is controlled by a monogenic system, with the presence of the red anthocyanin pigmentation being dominant. In addition, our results supported that the practical utilization of the 2 function markers to efficiently and accurately select red-skinned apple cultivars in apple scion breeding programs.

  17. Tc-MYBPA an Arabidopsis TT2-like transcription factor and functions in the regulation of proanthocyanidin synthesis in Theobroma cacao.

    Science.gov (United States)

    Liu, Yi; Shi, Zi; Maximova, Siela N; Payne, Mark J; Guiltinan, Mark J

    2015-06-25

    The flavan-3-ols catechin and epicatechin, and their polymerized oligomers, the proanthocyanidins (PAs, also called condensed tannins), accumulate to levels of up to 15 % of the total weight of dry seeds of Theobroma cacao L. These compounds have been associated with several health benefits in humans. They also play important roles in pest and disease defense throughout the plant. In Arabidopsis, the R2R3 type MYB transcription factor TT2 regulates the major genes leading to the synthesis of PA. To explore the transcriptional regulation of the PA synthesis pathway in cacao, we isolated and characterized an R2R3 type MYB transcription factor MYBPA from cacao. We examined the spatial and temporal gene expression patterns of the Tc-MYBPA gene and found it to be developmentally expressed in a manner consistent with its involvement in PAs and anthocyanin synthesis. Functional complementation of an Arabidopsis tt2 mutant with Tc-MYBPA suggested that it can functionally substitute the Arabidopsis TT2 gene. Interestingly, in addition to PA accumulation in seeds of the Tc-MYBPA expressing plants, we also observed an obvious increase of anthocyanidin accumulation in hypocotyls. We observed that overexpression of the Tc-MYBPA gene resulted in increased expression of several key genes encoding the major structural enzymes of the PA and anthocyanidin pathway, including DFR (dihydroflavanol reductase), LDOX (leucoanthocyanidin dioxygenase) and BAN (ANR, anthocyanidin reductase). We conclude that the Tc-MYBPA gene that encodes an R2R3 type MYB transcription factor is an Arabidopsis TT2 like transcription factor, and may be involved in the regulation of both anthocyanin and PA synthesis in cacao. This research may provide molecular tools for breeding of cacao varieties with improved disease resistance and enhanced flavonoid profiles for nutritional and pharmaceutical applications.

  18. c-Myb and its target Bmi1 are required for p190BCR/ABL leukemogenesis in mouse and human cells.

    Science.gov (United States)

    Waldron, T; De Dominici, M; Soliera, A R; Audia, A; Iacobucci, I; Lonetti, A; Martinelli, G; Zhang, Y; Martinez, R; Hyslop, T; Bender, T P; Calabretta, B

    2012-04-01

    Expression of c-Myb is required for normal hematopoiesis and for proliferation of myeloid leukemia blasts and a subset of T-cell leukemia, but its role in B-cell leukemogenesis is unknown. We tested the role of c-Myb in p190(BCR/ABL)-dependent B-cell leukemia in mice transplanted with p190(BCR/ABL)-transduced marrow cells with a c-Myb allele (Myb(f/d)) and in double transgenic p190(BCR/ABL)/Myb(w/d) mice. In both models, loss of a c-Myb allele caused a less aggressive B-cell leukemia. In p190(BCR/ABL)-expressing human B-cell leukemia lines, knockdown of c-Myb expression suppressed proliferation and colony formation. Compared with c-Myb(w/f) cells, expression of Bmi1, a regulator of stem cell proliferation and maintenance, was decreased in pre-B cells from Myb(w/d) p190(BCR/ABL) transgenic mice. Ectopic expression of a mutant c-Myb or Bmi1 enhanced the proliferation and colony formation of Myb(w/d) p190(BCR/ABL) B-cells; by contrast, Bmi1 downregulation inhibited colony formation of p190(BCR/ABL)-expressing murine B cells and human B-cell leukemia lines. Moreover, c-Myb interacted with a segment of the human Bmi1 promoter and enhanced its activity. In blasts from 19 Ph(1) adult acute lymphoblastic leukemia patients, levels of c-Myb and Bmi1 showed a positive correlation. Together, these findings support the existence of a c-Myb-Bmi1 transcription-regulatory pathway required for p190(BCR/ABL) leukemogenesis.

  19. Overexpression of SbMyb60 in sorghum bicolor impacts both primary and secondary metabolism

    Science.gov (United States)

    Few transcription factors have been identified in C4 grasses that either positively or negatively regulate monolignol biosynthesis. Previously, overexpression of SbMyb60 in sorghum (Sorghum bicolor (L.) Moench) was shown to induce monolignol synthesis, which led to elevated lignin deposition and al...

  20. Trichostatin a suppresses transformation by the v-myb oncogene in BM2 cells

    Czech Academy of Sciences Publication Activity Database

    Nemajerová, A.; Šmarda, J.; Jurdic, P.; Kubala, Lukáš; Souček, Karel; Šmardová, J.

    2003-01-01

    Roč. 12, č. 2 (2003), s. 225-235 ISSN 1525-8165 Institutional research plan: CEZ:AV0Z5004920 Keywords : v-myb * trichostatin A * differentation Subject RIV: BO - Biophysics Impact factor: 1.800, year: 2003

  1. Localization of c-MYB in differentiated cells during postnatal molar and alveolar bone development

    Czech Academy of Sciences Publication Activity Database

    Lungová, Vlasta; Buchtová, Marcela; Janečková, Eva; Tucker, A.S.; Knopfová, L.; Šmarda, J.; Matalová, Eva

    2012-01-01

    Roč. 120, č. 6 (2012), 495-504 ISSN 0909-8836 R&D Projects: GA ČR GCP302/12/J059 Institutional research plan: CEZ:AV0Z50450515 Keywords : c-myb * tooth * postnatal Subject RIV: FF - HEENT, Dentistry Impact factor: 1.420, year: 2012

  2. Different patterns of gene expression in rice varieties undergoing a ...

    African Journals Online (AJOL)

    Some genes specifically up-regulated in infected 9804-Rxo1 were defenserelated, including the genes encoding pathogenesis-related protein, terpene synthase family, transcription factors (TFs) AP2 domain containing protein, myb-like deoxyribonucleic acid (DNA)- binding domain containing protein, and C2H2-type ...

  3. Overexpression of SbMyb60 impacts phenylpropanoid biosynthesis and alters secondary cell wall composition in sorghum bicolor

    Science.gov (United States)

    The phenylpropanoid biosynthesis pathway that generates lignin subunits represents a significant target to alter the abundance and composition of lignin. The major regulators of phenylpropanoid metabolism are myb transcription factors, which have been shown to modulate secondary cell wall compositi...

  4. The Melanocyte Fate in Neural Crest is Triggered by Myb Proteins through Activation of c-kit

    Czech Academy of Sciences Publication Activity Database

    Karafiát, Vít; Dvořáková, Marta; Pajer, Petr; Čermák, Vladimír; Dvořák, Michal

    2007-01-01

    Roč. 64, č. 21 (2007), s. 2975-2984 ISSN 1420-682X R&D Projects: GA MŠk(CZ) LC06061; GA ČR GA204/06/1728 Institutional research plan: CEZ:AV0Z50520514 Keywords : c-myb proto-oncogene * v-mybAMV oncogene * neural crest * cell fate determination * melanocytes * c-kit signal Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.239, year: 2007

  5. Genetic Variants at BCL11A and HBS1L-MYB loci Influence Hb F Levels in Chinese Zhuang β-Thalassemia Intermedia Patients.

    Science.gov (United States)

    Lai, Yunli; Chen, Yun; Chen, Biyan; Zheng, Haiyang; Yi, Sheng; Li, Guojian; Wei, Hongwei; He, Sheng; Zheng, Chenguang

    2016-11-01

    Increased Hb F levels can ameliorate the symptoms of β-thalassemia (β-thal). Due to the genetic heterogenicity of β-thal, the relationship between genetic variants in modifier genes and Hb F level has been studied in different populations. The Chinese Zhuang has the second largest population in China and has 6.78% prevalence of β-thal. However, the effects of these single nucleotide polymorphism (SNP) variants on the Hb F levels of β-thal intermedia (β-TI) patients in this population have not been reported. To explore the association between modifier loci (β-globin gene cluster, HBS1L-MYB intergenic region and BCL11A) and Hb F levels in Chinese Zhuang β-TI patients, 96 unrelated β-TI patients (50 males and 46 females) with different Hb F levels were recruited and genotyped by mass spectrometry. A total of 13 SNPs were confirmed to be in a significant relationship with Hb F levels in this population. Of these, high-risk genotypes of six Hb F-associated SNPs, rs9376090, rs7776054, rs9399137, rs9389268, rs9402685 in the HBS1L-MYB intergenic region and rs189984760 in the BCL11A locus, showed association with high Hb F levels, especially for SNPs in linkage disequilibrium. One novel Hb F-associated SNP, rs189984760, was identified in our study. Our findings will be of valuable reference for correlation between modifier genes and Hb F in Chinese Zhuang populations and may lead to better understand the modifying mechanisms for β-thal.

  6. miR-150 Regulates Memory CD8 T Cell Differentiation via c-Myb

    Directory of Open Access Journals (Sweden)

    Zeyu Chen

    2017-09-01

    Full Text Available MicroRNAs play an important role in T cell responses. However, how microRNAs regulate CD8 T cell memory remains poorly defined. Here, we found that miR-150 negatively regulates CD8 T cell memory in vivo. Genetic deletion of miR-150 disrupted the balance between memory precursor and terminal effector CD8 T cells following acute viral infection. Moreover, miR-150-deficient memory CD8 T cells were more protective upon rechallenge. A key circuit whereby miR-150 repressed memory CD8 T cell development through the transcription factor c-Myb was identified. Without miR-150, c-Myb was upregulated and anti-apoptotic targets of c-Myb, such as Bcl-2 and Bcl-xL, were also increased, suggesting a miR-150-c-Myb survival circuit during memory CD8 T cell development. Indeed, overexpression of non-repressible c-Myb rescued the memory CD8 T cell defects caused by overexpression of miR-150. Overall, these results identify a key role for miR-150 in memory CD8 T cells through a c-Myb-controlled enhanced survival circuit.

  7. MicroRNA-193b-3p acts as a tumor suppressor by targeting the MYB oncogene in T-cell acute lymphoblastic leukemia.

    Science.gov (United States)

    Mets, E; Van der Meulen, J; Van Peer, G; Boice, M; Mestdagh, P; Van de Walle, I; Lammens, T; Goossens, S; De Moerloose, B; Benoit, Y; Van Roy, N; Clappier, E; Poppe, B; Vandesompele, J; Wendel, H-G; Taghon, T; Rondou, P; Soulier, J; Van Vlierberghe, P; Speleman, F

    2015-04-01

    The MYB oncogene is a leucine zipper transcription factor essential for normal and malignant hematopoiesis. In T-cell acute lymphoblastic leukemia (T-ALL), elevated MYB levels can arise directly through T-cell receptor-mediated MYB translocations, genomic MYB duplications or enhanced TAL1 complex binding at the MYB locus or indirectly through the TAL1/miR-223/FBXW7 regulatory axis. In this study, we used an unbiased MYB 3'untranslated region-microRNA (miRNA) library screen and identified 33 putative MYB-targeting miRNAs. Subsequently, transcriptome data from two independent T-ALL cohorts and different subsets of normal T-cells were used to select miRNAs with relevance in the context of normal and malignant T-cell transformation. Hereby, miR-193b-3p was identified as a novel bona fide tumor-suppressor miRNA that targets MYB during malignant T-cell transformation thereby offering an entry point for efficient MYB targeting-oriented therapies for human T-ALL.

  8. The Expression of c-Myb Correlates with the Levels of Rhabdomyosarcoma-specific Marker Myogenin

    Czech Academy of Sciences Publication Activity Database

    Kašpar, Petr; Zíková, Martina; Bartůněk, Petr; Štěrba, J.; Strnad, Hynek; Křen, L.; Sedláček, Radislav

    2015-01-01

    Roč. 5, Oct 14 (2015) ISSN 2045-2322 R&D Projects: GA ČR GAP305/10/2133; GA ČR GAP301/12/1478; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:68378050 Keywords : c-Myb * Rhabdomyosarcomas * C2C12 myoblast cell line * myogenin Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.228, year: 2015

  9. p53 induces differentiation but not apoptosis of v-Myb-transformed monoblasts

    Czech Academy of Sciences Publication Activity Database

    Navrátilová, J.; Horváth, Viktor; Kozubík, Alois; Lojek, Antonín; Šmarda, J.

    2006-01-01

    Roč. 18, č. 1 (2006), S38-S38 ISSN 1107-3756. [The 11th World Congress on Advances in Oncology and 9th International Symposium on Molecular Medicine . 12.10.2006-14.10.2006, Hersonissos] R&D Projects: GA ČR(CZ) GA301/06/0036 Institutional research plan: CEZ:AV0Z50040507 Keywords : p53 * v-Myb * BM2 Subject RIV: BO - Biophysics

  10. Retinoic acid enhances differentiation of v-myb-transformed monoblasts induced by okadaic acid

    Czech Academy of Sciences Publication Activity Database

    Beneš, P.; Macečková, V.; Zatloukalová, Jiřina; Kovářová, L.; Šmardová, J.; Šmarda, J.

    2007-01-01

    Roč. 31, č. 10 (2007), s. 1421-1431 ISSN 0145-2126 Grant - others:GA ČR(CZ) GP301/03/D022; GA ČR(CZ) GA301/06/0036 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : v-myb * monoblast * macrophage Subject RIV: BO - Biophysics Impact factor: 2.561, year: 2007

  11. A candidate-gene association study for berry colour and anthocyanin content in Vitis vinifera L.

    Directory of Open Access Journals (Sweden)

    Silvana Cardoso

    Full Text Available Anthocyanin content is a trait of major interest in Vitis vinifera L. These compounds affect grape and wine quality, and have beneficial effects on human health. A candidate-gene approach was used to identify genetic variants associated with anthocyanin content in grape berries. A total of 445 polymorphisms were identified in 5 genes encoding transcription factors and 10 genes involved in either the biosynthetic pathway or transport of anthocyanins. A total of 124 SNPs were selected to examine association with a wide range of phenotypes based on RP-HPLC analysis and visual characterization. The phenotypes were total skin anthocyanin (TSA concentration but also specific types of anthocyanins and relative abundance. The visual assessment was based on OIV (Organisation Internationale de la Vigne et du Vin descriptors for berry and skin colour. The genes encoding the transcription factors MYB11, MYBCC and MYC(B were significantly associated with TSA concentration. UFGT and MRP were associated with several different types of anthocyanins. Skin and pulp colour were associated with nine genes (MYB11, MYBCC, MYC(B, UFGT, MRP, DFR, LDOX, CHI and GST. Pulp colour was associated with a similar group of 11 genes (MYB11, MYBCC, MYC(B, MYC(A, UFGT, MRP, GST, DFR, LDOX, CHI and CHS(A. Statistical interactions were observed between SNPs within the transcription factors MYB11, MYBCC and MYC(B. SNPs within LDOX interacted with MYB11 and MYC(B, while SNPs within CHI interacted with MYB11 only. Together, these findings suggest the involvement of these genes in anthocyanin content and on the regulation of anthocyanin biosynthesis. This work forms a benchmark for replication and functional studies.

  12. Modulation of flavonoid metabolites in Arabidopsis thaliana through overexpression of the MYB75 transcription factor: role of kaempferol-3,7-dirhamnoside in resistance to the specialist insect herbivore Pieris brassicae

    NARCIS (Netherlands)

    Onkokesung, N.; Reichelt, M.; Doorn, van A.; Schuurink, R.C.; Loon, van J.J.A.; Dicke, M.

    2014-01-01

    Anthocyanins and flavonols are secondary metabolites that can function in plant defence against herbivores. In Arabidopsis thaliana, anthocyanin and flavonol biosynthesis are regulated by MYB transcription factors. Overexpression of MYB75 (oxMYB75) in Arabidopsis results in increasing anthocyanin

  13. In utero exposure to benzene increases embryonic c-Myb and Pim-1 protein levels in CD-1 mice

    International Nuclear Information System (INIS)

    Wan, Joanne; Winn, Louise M.

    2008-01-01

    Benzene is a known human leukemogen, but its role as an in utero leukemogen remains controversial. Epidemiological studies have correlated parental exposure to benzene with an increased incidence of childhood leukemias. We hypothesize that in utero exposure to benzene may cause leukemogenesis by affecting the embryonic c-Myb/Pim-1 signaling pathway and that this is mediated by oxidative stress. To investigate this hypothesis, pregnant CD-1 mice were treated with either 800 mg/kg of benzene or corn oil (i.p.) on days 10 and 11 of gestation and in some cases pretreated with 25 kU/kg of PEG-catalase. Phosphorylated and total embryonic c-Myb and Pim-1 protein levels were assessed using Western blotting and maternal and embryonic oxidative stress were assessed by measuring reduced to oxidized glutathione ratios. Our results show increased oxidative stress at 4 and 24 h after exposure, increased phosphorylated Pim-1 protein levels 4 h after benzene exposure, and increased Pim-1 levels at 24 and 48 h after benzene exposure. Embryonic c-Myb levels were elevated at 24 h after exposure. PEG-catalase pretreatment prevented benzene-mediated increases in embryonic c-Myb and Pim-1 protein levels, and benzene-induced oxidative stress. These results support a role for ROS in c-Myb and Pim-1 alterations after in utero benzene exposure

  14. The Transcriptional Repressor MYB2 Regulates Both Spatial and Temporal Patterns of Proanthocyandin and Anthocyanin Pigmentation in Medicago truncatula[OPEN

    Science.gov (United States)

    2015-01-01

    Accumulation of anthocyanins and proanthocyanidins (PAs) is limited to specific cell types and developmental stages, but little is known about how antagonistically acting transcriptional regulators work together to determine temporal and spatial patterning of pigmentation at the cellular level, especially for PAs. Here, we characterize MYB2, a transcriptional repressor regulating both anthocyanin and PA biosynthesis in the model legume Medicago truncatula. MYB2 was strongly upregulated by MYB5, a major regulator of PA biosynthesis in M. truncatula and a component of MYB-basic helix loop helix-WD40 (MBW) activator complexes. Overexpression of MYB2 abolished anthocyanin and PA accumulation in M. truncatula hairy roots and Arabidopsis thaliana seeds, respectively. Anthocyanin deposition was expanded in myb2 mutant seedlings and flowers accompanied by increased anthocyanin content. PA mainly accumulated in the epidermal layer derived from the outer integument in the M. truncatula seed coat, starting from the hilum area. The area of PA accumulation and ANTHOCYANIDIN REDUCTASE expression was expanded into the seed body at the early stage of seed development in the myb2 mutant. Genetic, biochemical, and cell biological evidence suggests that MYB2 functions as part of a multidimensional regulatory network to define the temporal and spatial pattern of anthocyanin and PA accumulation linked to developmental processes. PMID:26410301

  15. Heterologous expression of AtMYB12 in kale (Brassica oleracea var. acephala) leads to high flavonol accumulation.

    Science.gov (United States)

    Lännenpää, Mika

    2014-08-01

    Overexpression of Arabidopsis AtMYB12 transcription factor greatly increases the total phenolic and flavonol content in transgenic kale leaves. Flavonoids are a diverse group of plant secondary metabolites exhibiting a number of health-promoting effects. There has been a growing interest to develop biotechnological methods for the enhanced production of flavonoids in crop plants. AtMYB12 is an Arabidopsis transcription factor which specifically activates flavonol synthesis and its overexpression has led to increased flavonol accumulation in several transgenic plants. In the present study, AtMYB12 was overexpressed in a commercial cultivar of kale and the transgenic plants were tested both in in vitro and in semi-field conditions in cages under natural light. Using this method, a severalfold increase in both total phenolics content and flavonol accumulation was achieved. This study provides a reliable and efficient transformation protocol for kale and suggests the potential of this flavonol-enriched vegetable for the production of kaempferol.

  16. c-Myb Regulates the T-Bet-Dependent Differentiation Program in B Cells to Coordinate Antibody Responses

    Directory of Open Access Journals (Sweden)

    Dana Piovesan

    2017-04-01

    Full Text Available Summary: Humoral immune responses are tailored to the invading pathogen through regulation of key transcription factors and their networks. This is critical to establishing effective antibody-mediated responses, yet it is unknown how B cells integrate pathogen-induced signals to drive or suppress transcriptional programs specialized for each class of pathogen. Here, we detail the key role of the transcription factor c-Myb in regulating the T-bet-mediated anti-viral program. Deletion of c-Myb in mature B cells significantly increased serum IgG2c and CXCR3 expression by upregulating T-bet, normally suppressed during Th2-cell-mediated responses. Enhanced expression of T-bet resulted in aberrant plasma cell differentiation within the germinal center, mediated by CXCR3 expression. These findings identify a dual role for c-Myb in limiting inappropriate effector responses while coordinating plasma cell differentiation with germinal center egress. Identifying such intrinsic regulators of specialized antibody responses can assist in vaccine design and therapeutic intervention in B-cell-mediated immune disorders. : Piovesan et al. examine how B cells establish transcriptional programs that result in tailored responses to invading pathogens. The authors find that the transcription factor c-Myb represses the T-bet-mediated anti-viral program in B cells. c-Myb limits inappropriate effector responses while coordinating plasma cell differentiation with germinal center egress. Keywords: B cells, c-Myb, T-bet, immunoglobulin, CXCR3, plasma cell, germinal center

  17. Study on the Effect of cellulolytic strain MYB3 for Corn Stover Fermentation

    Science.gov (United States)

    Yan, Han; Bai, Bing; Cheng, Xiao-Xiao; Li, Guang-Chun; Huang, Shi-Chen; Piao, Chun-Xiang

    2018-03-01

    The effects of corn stover fermentation with the Bacillus megaterium MYB3 was studied in this paper. The results showed that the decomposition rates of cellulose and hemicellulose were 49.6%, 43.46% after 20 days respectively, after fermentation, pH was changed to 5.68, and adjusted to corn stover initial pH 3 to achieve the purpose of sterilization. The decomposition rate was significantly increased by adding corn flour. After adjusting fermentation composes with the ratio of the corn stove to corn flour was 15 : 1, the decomposition rate of cellulose would be 52.37% for 10 days.

  18. An .I.ex vivo ./I.model to study v-Myb-induced leukemogenicity

    Czech Academy of Sciences Publication Activity Database

    Dvořáková, Marta; Králová, Jarmila; Karafiát, Vít; Bartůněk, Petr; Dvořák, Michal

    2001-01-01

    Roč. 27, č. 2 (2001), s. 437-445 ISSN 1079-9796 R&D Projects: GA ČR GV301/98/K042; GA ČR GA204/00/0554; GA AV ČR IPP2052002 Grant - others:HHMI(US) 75195-540401 Institutional research plan: CEZ:AV0Z5052915 Keywords : v-Myb oncoprotein * PEST domain * leucine zipper Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.703, year: 2001

  19. Characterization of Genes Encoding Key Enzymes Involved in Anthocyanin Metabolism of Kiwifruit during Storage Period.

    Science.gov (United States)

    Li, Boqiang; Xia, Yongxiu; Wang, Yuying; Qin, Guozheng; Tian, Shiping

    2017-01-01

    'Hongyang' is a red fleshed kiwifruit with high anthocyanin content. In this study, we mainly investigated effects of different temperatures (25 and 0°C) on anthocyanin biosynthesis in harvested kiwifruit, and characterized the genes encoding key enzymes involved in anthocyanin metabolism, as well as evaluated the mode of the action, by which low temperature regulates anthocyanin accumulation in 'Hongyang' kiwifruit during storage period. The results showed that low temperature could effectively enhance the anthocyanin accumulation of kiwifruit in the end of storage period (90 days), which related to the increase in mRNA levels of ANS1, ANS2, DRF1, DRF2 , and UGFT2 . Moreover, the transcript abundance of MYBA1-1 and MYB5-1 , the genes encoding an important component of MYB-bHLH-WD40 (MBW) complex, was up-regulated, possibly contributing to the induction of specific anthocyanin biosynthesis genes under the low temperature. To further investigate the roles of AcMYB5-1/5-2/A1-1 in regulation of anthocyanin biosynthesis, genes encoding the three transcription factors were transiently transformed in Nicotiana benthamiana leaves. Overexpression of AcMYB5-1/5-2/A1-1 activated the gene expression of NtANS and NtDFR in tobacco. Our results suggested that low temperature storage could stimulate the anthocyanin accumulation in harvested kiwifruit via regulating several structural and regulatory genes involved in anthocyanin biosynthesis.

  20. Interaction of the transactivation domain of B-Myb with the TAZ2 domain of the coactivator p300: molecular features and properties of the complex.

    Directory of Open Access Journals (Sweden)

    Ojore Oka

    Full Text Available The transcription factor B-Myb is a key regulator of the cell cycle in vertebrates, with activation of transcription involving the recognition of specific DNA target sites and the recruitment of functional partner proteins, including the coactivators p300 and CBP. Here we report the results of detailed studies of the interaction between the transactivation domain of B-Myb (B-Myb TAD and the TAZ2 domain of p300. The B-Myb TAD was characterized using circular dichroism, fluorescence and NMR spectroscopy, which revealed that the isolated domain exists as a random coil polypeptide. Pull-down and spectroscopic experiments clearly showed that the B-Myb TAD binds to p300 TAZ2 to form a moderately tight (K(d ~1.0-10 µM complex, which results in at least partial folding of the B-Myb TAD. Significant changes in NMR spectra of p300 TAZ2 suggest that the B-Myb TAD binds to a relatively large patch on the surface of the domain (~1200 Å(2. The apparent B-Myb TAD binding site on p300 TAZ2 shows striking similarity to the surface of CBP TAZ2 involved in binding to the transactivation domain of the transcription factor signal transducer and activator of transcription 1 (STAT1, which suggests that the structure of the B-Myb TAD-p300 TAZ2 complex may share many features with that reported for STAT1 TAD-p300 TAZ2.

  1. Selection of reference genes for quantitative gene expression normalization in flax (Linum usitatissimum L.

    Directory of Open Access Journals (Sweden)

    Neutelings Godfrey

    2010-04-01

    Full Text Available Abstract Background Quantitative real-time PCR (qRT-PCR is currently the most accurate method for detecting differential gene expression. Such an approach depends on the identification of uniformly expressed 'housekeeping genes' (HKGs. Extensive transcriptomic data mining and experimental validation in different model plants have shown that the reliability of these endogenous controls can be influenced by the plant species, growth conditions and organs/tissues examined. It is therefore important to identify the best reference genes to use in each biological system before using qRT-PCR to investigate differential gene expression. In this paper we evaluate different candidate HKGs for developmental transcriptomic studies in the economically-important flax fiber- and oil-crop (Linum usitatissimum L. Results Specific primers were designed in order to quantify the expression levels of 20 different potential housekeeping genes in flax roots, internal- and external-stem tissues, leaves and flowers at different developmental stages. After calculations of PCR efficiencies, 13 HKGs were retained and their expression stabilities evaluated by the computer algorithms geNorm and NormFinder. According to geNorm, 2 Transcriptional Elongation Factors (TEFs and 1 Ubiquitin gene are necessary for normalizing gene expression when all studied samples are considered. However, only 2 TEFs are required for normalizing expression in stem tissues. In contrast, NormFinder identified glyceraldehyde-3-phosphate dehydrogenase (GADPH as the most stably expressed gene when all samples were grouped together, as well as when samples were classed into different sub-groups. qRT-PCR was then used to investigate the relative expression levels of two splice variants of the flax LuMYB1 gene (homologue of AtMYB59. LuMYB1-1 and LuMYB1-2 were highly expressed in the internal stem tissues as compared to outer stem tissues and other samples. This result was confirmed with both ge

  2. Selection of reference genes for quantitative gene expression normalization in flax (Linum usitatissimum L.).

    Science.gov (United States)

    Huis, Rudy; Hawkins, Simon; Neutelings, Godfrey

    2010-04-19

    Quantitative real-time PCR (qRT-PCR) is currently the most accurate method for detecting differential gene expression. Such an approach depends on the identification of uniformly expressed 'housekeeping genes' (HKGs). Extensive transcriptomic data mining and experimental validation in different model plants have shown that the reliability of these endogenous controls can be influenced by the plant species, growth conditions and organs/tissues examined. It is therefore important to identify the best reference genes to use in each biological system before using qRT-PCR to investigate differential gene expression. In this paper we evaluate different candidate HKGs for developmental transcriptomic studies in the economically-important flax fiber- and oil-crop (Linum usitatissimum L). Specific primers were designed in order to quantify the expression levels of 20 different potential housekeeping genes in flax roots, internal- and external-stem tissues, leaves and flowers at different developmental stages. After calculations of PCR efficiencies, 13 HKGs were retained and their expression stabilities evaluated by the computer algorithms geNorm and NormFinder. According to geNorm, 2 Transcriptional Elongation Factors (TEFs) and 1 Ubiquitin gene are necessary for normalizing gene expression when all studied samples are considered. However, only 2 TEFs are required for normalizing expression in stem tissues. In contrast, NormFinder identified glyceraldehyde-3-phosphate dehydrogenase (GADPH) as the most stably expressed gene when all samples were grouped together, as well as when samples were classed into different sub-groups.qRT-PCR was then used to investigate the relative expression levels of two splice variants of the flax LuMYB1 gene (homologue of AtMYB59). LuMYB1-1 and LuMYB1-2 were highly expressed in the internal stem tissues as compared to outer stem tissues and other samples. This result was confirmed with both geNorm-designated- and Norm

  3. A dominant-negative mutation within AtMYB90 blocks flower pigment production in transgenic tobacco.

    Science.gov (United States)

    During de novo shoot induction in cultured transgenic tobacco callus a spontaneous mutation within the coding region of a AtMYB90 transgene produced a plant line in which the original transgene-induced over-pigmented phenotype (dark red/purple from anthocyanin overproduction in most tissues) was los...

  4. Differential effects of v-Jun and c-Jun proteins on v-myb-transformed monoblasts

    Czech Academy of Sciences Publication Activity Database

    Ševčíková, S.; Souček, Karel; Kubala, Lukáš; Bryja, Vítězslav; Šmarda, J.

    2002-01-01

    Roč. 59, č. 10 (2002), s. 1690-1705 ISSN 1420-682X R&D Projects: GA ČR GA301/01/0040 Institutional research plan: CEZ:AV0Z5004920 Keywords : v-myb * Jun * differentiation Subject RIV: BO - Biophysics Impact factor: 5.259, year: 2002

  5. Los factores de transcripción tipo Myb, una familia de reguladores de la diferenciación celular conservada en los organismos eucariontes

    OpenAIRE

    Arratia, Jenny; Aguirre, Jesús

    2013-01-01

    La familia de proteínas Myb, ubicua en los eucariontes, se caracteriza por la presencia de un dominio de unión al ADN característico denominado dominio Myb. Éste consiste en una secuencia de aminoácidos conservados (50-53 aminoácidos) que puede estar repetida entre dos (dominio mínimo de unión al ADN) y hasta cuatro veces en la misma proteína. En las plantas, la familia Myb es muy numerosa, mientras que en los animales sólo se encuentran tres miembros, y en otros eucariontes se ha identificad...

  6. Activation of Arabidopsis seed hair development by cotton fiber-related genes.

    Directory of Open Access Journals (Sweden)

    Xueying Guan

    Full Text Available Each cotton fiber is a single-celled seed trichome or hair, and over 20,000 fibers may develop semi-synchronously on each seed. The molecular basis for seed hair development is unknown but is likely to share many similarities with leaf trichome development in Arabidopsis. Leaf trichome initiation in Arabidopsis thaliana is activated by GLABROUS1 (GL1 that is negatively regulated by TRIPTYCHON (TRY. Using laser capture microdissection and microarray analysis, we found that many putative MYB transcription factor and structural protein genes were differentially expressed in fiber and non-fiber tissues. Gossypium hirsutum MYB2 (GhMYB2, a putative GL1 homolog, and its downstream gene, GhRDL1, were highly expressed during fiber cell initiation. GhRDL1, a fiber-related gene with unknown function, was predominately localized around cell walls in stems, sepals, seed coats, and pollen grains. GFP:GhRDL1 and GhMYB2:YFP were co-localized in the nuclei of ectopic trichomes in siliques. Overexpressing GhRDL1 or GhMYB2 in A. thaliana Columbia-0 (Col-0 activated fiber-like hair production in 4-6% of seeds and had on obvious effects on trichome development in leaves or siliques. Co-overexpressing GhRDL1 and GhMYB2 in A. thaliana Col-0 plants increased hair formation in ∼8% of seeds. Overexpressing both GhRDL1 and GhMYB2 in A. thaliana Col-0 try mutant plants produced seed hair in ∼10% of seeds as well as dense trichomes inside and outside siliques, suggesting synergistic effects of GhRDL1 and GhMYB2 with try on development of trichomes inside and outside of siliques and seed hair in A. thaliana. These data suggest that a different combination of factors is required for the full development of trichomes (hairs in leaves, siliques, and seeds. A. thaliana can be developed as a model a system for discovering additional genes that control seed hair development in general and cotton fiber in particular.

  7. Regulation of anthocyanin biosynthesis in peach fruits.

    Science.gov (United States)

    Rahim, Md Abdur; Busatto, Nicola; Trainotti, Livio

    2014-11-01

    MYB10.1 and MYB10.3, with bHLH3, are the likely regulators of anthocyanin biosynthesis in peach fruit. MYB10.1/2/3 forms a cluster on the same genomic fragment where the Anther color ( Ag ) trait is located. Anthocyanins are bioactive compounds responsible for the pigmentation of many plant parts such as leaves, flowers, fruits and roots, and have potential benefits to human health. In peach [Prunus persica (L.) Batsch], peel color is a key determinant for fruit quality and is regulated by flavonoids including anthocyanins. The R2R3 MYB transcription factors (TFs) control the expression of anthocyanin biosynthetic genes with the help of co-activators belonging to the basic-helix-loop-helix (bHLH) and WD40 repeat families. In the peach genome six MYB10-like and three bHLH-like TFs were identified as candidates to be the regulators of the anthocyanin accumulation, which, in yellow flesh fruits, is highest in the peel, abundant in the part of the mesocarp surrounding the stone and lowest in the mesocarp. The expression of MYB10.1 and MYB10.3 correlates with anthocyanin levels of different peach parts. They also have positive correlation with the expression of key structural genes of the anthocyanin pathway, such as CHS, F3H, and UFGT. Functions of peach MYB10s were tested in tobacco and shown to activate key genes in the anthocyanin pathway when bHLHs were co-expressed as partners. Overexpression of MYB10.1/bHLH3 and MYB10.3/bHLH3 activated anthocyanin production by up-regulating NtCHS, NtDFR and NtUFGT while other combinations were not, or much less, effective. As three MYB10 genes are localized in a genomic region where the Ag trait, responsible for anther pigmentation, is localized, it is proposed they are key determinant to introduce new peach cultivars with higher antioxidant level and pigmented fruit.

  8. Downregulation of B-myb promotes senescence via the ROS-mediated p53/p21 pathway, in vascular endothelial cells.

    Science.gov (United States)

    Zhou, Zhihui; Yin, Yanlin; Chang, Qun; Sun, Guanqun; Lin, Jiahui; Dai, Yalei

    2017-04-01

    To reveal whether B-myb is involved in preventing senescence of vascular endothelial cells, and if so, to identify possible mechanisms for it. C57/BL6 male mice and primary human aortic endothelial cells (HAECs) were used. Bleomycin was applied to induce stress-related premature senescence. B-myb knockdown was achieved using an siRNA technique and cell senescence was assessed using the senescence-associated β-galactosidase (SA-β-gal) assay. Intracellular reactive oxygen species (ROS) production was analysed using an ROS assay kit and cell proliferation was evaluated using KFluor488 EdU kit. Capillary tube network formation was determined by Matrigel assay. Expressions of mRNA and protein levels were detected by real-time PCR and western blotting. B-myb expression significantly decreased, while p53 and p21 expressions increased in the aortas of aged mice. This expression pattern was also found in replicative senescent HAECs and senescent HAECs induced by bleomycin. B-myb knockdown resulted in upregulation of p22 phox , ROS accumulation and cell senescence of HAECs. Downregulation of B-myb significantly inhibited cell proliferation and capillary tube network formation and activated the p53/p21 signalling pathway. Blocking ROS production or inhibiting p53 activation remarkably attenuated SA-β-gal activity and delayed cell senescence induced by B-myb-silencing. Downregulation of B-myb induced senescence by upregulation of p22 phox and activation of the ROS/p53/p21 pathway, in our vascular endothelial cells, suggesting that B-myb may be a novel candidate for regulating cell senescence to protect against endothelial senescence-related cardiovascular diseases. © 2016 John Wiley & Sons Ltd.

  9. Conformational control of the binding of the transactivation domain of the MLL protein and c-Myb to the KIX domain of CREB.

    Directory of Open Access Journals (Sweden)

    Elif Nihal Korkmaz

    Full Text Available The KIX domain of CBP is a transcriptional coactivator. Concomitant binding to the activation domain of proto-oncogene protein c-Myb and the transactivation domain of the trithorax group protein mixed lineage leukemia (MLL transcription factor lead to the biologically active ternary MLL∶KIX∶c-Myb complex which plays a role in Pol II-mediated transcription. The binding of the activation domain of MLL to KIX enhances c-Myb binding. Here we carried out molecular dynamics (MD simulations for the MLL∶KIX∶c-Myb ternary complex, its binary components and KIX with the goal of providing a mechanistic explanation for the experimental observations. The dynamic behavior revealed that the MLL binding site is allosterically coupled to the c-Myb binding site. MLL binding redistributes the conformational ensemble of KIX, leading to higher populations of states which favor c-Myb binding. The key element in the allosteric communication pathways is the KIX loop, which acts as a control mechanism to enhance subsequent binding events. We tested this conclusion by in silico mutations of loop residues in the KIX∶MLL complex and by comparing wild type and mutant dynamics through MD simulations. The loop assumed MLL binding conformation similar to that observed in the KIX∶c-Myb state which disfavors the allosteric network. The coupling with c-Myb binding site faded, abolishing the positive cooperativity observed in the presence of MLL. Our major conclusion is that by eliciting a loop-mediated allosteric switch between the different states following the binding events, transcriptional activation can be regulated. The KIX system presents an example how nature makes use of conformational control in higher level regulation of transcriptional activity and thus cellular events.

  10. A WD40-repeat protein controls proanthocyanidin and phytomelanin pigmentation in the seed coats of the Japanese morning glory.

    Science.gov (United States)

    Park, Kyeung-Il; Hoshino, Atsushi

    2012-03-15

    The protein complex composed of the transcriptional regulators containing R2R3-MYB domains, bHLH domains, and WDR in plants controls various epidermal traits, including anthocyanin and proanthocyanidin pigmentation, trichome and root hair formation, and vacuolar pH. In the Japanese morning glory (Ipomoea nil), InMYB1 having R2R3-MYB domains and InWDR1 containing WDR were shown to regulate anthocyanin pigmentation in flowers, and InWDR1 was reported to control dark-brown pigmentation and trichome formation on seed coats. Here, we report that the seed pigments of I. nil mainly comprise proanthocyanidins and phytomelanins and that these pigments are drastically reduced in the ivory seed coats of an InWDR1 mutant. In addition, a transgenic plant of the InWDR1 mutant carrying the active InWDR1 gene produced dark-brown seeds, further confirming that InWDR1 regulates seed pigmentation. Early steps in anthocyanin and proanthocyanidin biosynthetic pathways are thought to be common. In the InWDR1 mutant, none of the structural genes for anthocyanin biosynthesis that showed reduced expression in the white flowers were down-regulated in the ivory seeds, which suggests that InWDR1 may activate different sets of the structural genes for anthocyanin biosynthesis in flowers and proanthocyanidin production in seeds. As in the flowers, however, we noticed that the expression of InbHLH2 encoding a bHLH regulator was down-regulated in the seeds of the InWDR1 mutant. We discuss the implications of these results with respect to the proanthocyanidin biosynthesis in the seed coats. Copyright © 2011 Elsevier GmbH. All rights reserved.

  11. Gene

    Data.gov (United States)

    U.S. Department of Health & Human Services — Gene integrates information from a wide range of species. A record may include nomenclature, Reference Sequences (RefSeqs), maps, pathways, variations, phenotypes,...

  12. Antisense myb inhibition of purified erythroid progenitors in development and differentiation is linked to cycling activity and expression of DNA polymerase alpha

    International Nuclear Information System (INIS)

    Valtieri, M.; Venturelli, D.; Care, A.; Fossati, C.; Pelosi, E.; Labbaye, C.; Mattia, G.; Gewirtz, A.M.; Calabretta, B.; Peschle, C.

    1991-01-01

    These studies aimed to determine the expression and functional role of c-myb in erythroid progenitors with different cycling activities. In the first series of experiments the erythroid burst-forming unit (BFU-E) and colony-forming unit (CFU-E) populations from adult peripheral blood (PB), bone marrow (BM), and embryonic-fetal liver (FL) were treated with either c-myb antisense oligomers or 3H-thymidine (3H-TdR). A direct correlation was always observed between the inhibitory effect of anti-myb oligomers and the level of cycling activity. Thus, the inhibitory effect of antisense c-myb on the number of BFU-E colonies was 28.3% +/- 15.8% in PB, 53.4% +/- 9.3% in BM, and 68.2% +/- 24.5% in FL. Both adult and embryonic CFU-E were markedly inhibited. Using purified PB progenitors, we observed a similar pattern, although with slightly lower inhibitory effects. In the 3H-TdR suicide assay the killing index of BFU-E was 8.9% +/- 4.2% in PB, 29.4% +/- 6.5% in BM, and 40.1% +/- 9.6% in FL. The values for adult and embryonic CFU-E were 55.7% +/- 7.9% and 60.98% +/- 6.6%, respectively. We then investigated the kinetics of c-myb mRNA level during the erythroid differentiation of purified adult PB and FL BFU-E, as evaluated in liquid-phase culture by reverse transcription-polymerase chain reaction. Adult erythroid precursors showed a gradual increase of c-myb mRNA from day 4 through day 8 of culture and a sharp decrease at later times, whereas the expression of c-myb mRNA and protein in differentiation embryonic precursors peaked 2 days earlier. In both cases, c-myb mRNA level peaked at the CFU-E stage of differentiation. Finally, highly purified adult PB BFU-E were stimulated into cycling by a 3-day treatment with interleukin-3 in liquid phase: both the sensitivity to c-myb antisense oligomers and the 3H-TdR suicide index showed a gradual, strictly parallel increase

  13. Los factores de transcripción tipo Myb, una familia de reguladores de la diferenciación celular conservada en los organismos eucariontes

    Directory of Open Access Journals (Sweden)

    Jenny Arratia

    2013-01-01

    Full Text Available La familia de proteínas Myb, ubicua en los eucariontes, se caracteriza por la presencia de un dominio de unión al ADN característico denominado dominio Myb. Éste consiste en una secuencia de aminoácidos conservados (50-53 aminoácidos que puede estar repetida entre dos (dominio mínimo de unión al ADN y hasta cuatro veces en la misma proteína. En las plantas, la familia Myb es muy numerosa, mientras que en los animales sólo se encuentran tres miembros, y en otros eucariontes se ha identificado al menos a un miembro de esta familia. Las proteínas Myb participan como activadores o represores transcripcionales en la regulación de procesos celulares fundamentales en el metabolismo o la diferenciación celular. La actividad de las proteínas Myb se regula a través de diversas modificaciones post-traduccionales dentro de las que destacan el estado redox, la fosforilación y la ubiquitinación.

  14. Modulation of flavonoid metabolites in Arabidopsis thaliana through overexpression of the MYB75 transcription factor: role of kaempferol-3,7-dirhamnoside in resistance to the specialist insect herbivore Pieris brassicae.

    Science.gov (United States)

    Onkokesung, Nawaporn; Reichelt, Michael; van Doorn, Arjen; Schuurink, Robert C; van Loon, Joop J A; Dicke, Marcel

    2014-05-01

    Anthocyanins and flavonols are secondary metabolites that can function in plant defence against herbivores. In Arabidopsis thaliana, anthocyanin and flavonol biosynthesis are regulated by MYB transcription factors. Overexpression of MYB75 (oxMYB75) in Arabidopsis results in increasing anthocyanin and flavonol levels which enhances plant resistance to generalist caterpillars. However, how these metabolites affect specialist herbivores has remained unknown. Performance of a specialist aphid (Brevicoryne brassicae) was unaffected after feeding on oxMYB75 plants, whereas a specialist caterpillar (Pieris brassicae) gained significantly higher body mass when feeding on this plant. An increase in anthocyanin and total flavonol glycoside levels correlated negatively with the body mass of caterpillars fed on oxMYB75 plants. However, a significant reduction of kaempferol-3,7-dirhamnoside (KRR) corresponded to an increased susceptibility of oxMYB75 plants to caterpillar feeding. Pieris brassicae caterpillars also grew less on an artificial diet containing KRR or on oxMYB75 plants that were exogenously treated with KRR, supporting KRR's function in direct defence against this specialist caterpillar. The results show that enhancing the activity of the anthocyanin pathway in oxMYB75 plants results in re-channelling of quercetin/kaempferol metabolites which has a negative effect on the accumulation of KRR, a novel defensive metabolite against a specialist caterpillar.

  15. Transcriptome analysis of an apple (Malus × domestica) yellow fruit somatic mutation identifies a gene network module highly associated with anthocyanin and epigenetic regulation.

    Science.gov (United States)

    El-Sharkawy, Islam; Liang, Dong; Xu, Kenong

    2015-12-01

    Using RNA-seq, this study analysed an apple (Malus×domestica) anthocyanin-deficient yellow-skin somatic mutant 'Blondee' (BLO) and its red-skin parent 'Kidd's D-8' (KID), the original name of 'Gala', to understand the molecular mechanisms underlying the mutation. A total of 3299 differentially expressed genes (DEGs) were identified between BLO and KID at four developmental stages and/or between two adjacent stages within BLO and/or KID. A weighted gene co-expression network analysis (WGCNA) of the DEGs uncovered a network module of 34 genes highly correlated (r=0.95, P=9.0×10(-13)) with anthocyanin contents. Although 12 of the 34 genes in the WGCNA module were characterized and known of roles in anthocyanin, the remainder 22 appear to be novel. Examining the expression of ten representative genes in the module in 14 diverse apples revealed that at least eight were significantly correlated with anthocyanin variation. MdMYB10 (MDP0000259614) and MdGST (MDP0000252292) were among the most suppressed module member genes in BLO despite being undistinguishable in their corresponding sequences between BLO and KID. Methylation assay of MdMYB10 and MdGST in fruit skin revealed that two regions (MR3 and MR7) in the MdMYB10 promoter exhibited remarkable differences between BLO and KID. In particular, methylation was high and progressively increased alongside fruit development in BLO while was correspondingly low and constant in KID. The methylation levels in both MR3 and MR7 were negatively correlated with anthocyanin content as well as the expression of MdMYB10 and MdGST. Clearly, the collective repression of the 34 genes explains the loss-of-colour in BLO while the methylation in MdMYB10 promoter is likely causal for the mutation. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  16. Large-scale transcriptional profiling of lignified tissues in Tectona grandis.

    Science.gov (United States)

    Galeano, Esteban; Vasconcelos, Tarcísio Sales; Vidal, Mabel; Mejia-Guerra, Maria Katherine; Carrer, Helaine

    2015-09-15

    Currently, Tectona grandis is one of the most valuable trees in the world and no transcript dataset related to secondary xylem is available. Considering how important the secondary xylem and sapwood transition from young to mature trees is, little is known about the expression differences between those successional processes and which transcription factors could regulate lignin biosynthesis in this tropical tree. Although MYB transcription factors are one of the largest superfamilies in plants related to secondary metabolism, it has not yet been characterized in teak. These results will open new perspectives for studies of diversity, ecology, breeding and genomic programs aiming to understand deeply the biology of this species. We present a widely expressed gene catalog for T. grandis using Illumina technology and the de novo assembly. A total of 462,260 transcripts were obtained, with 1,502 and 931 genes differentially expressed for stem and branch secondary xylem, respectively, during age transition. Analysis of stem and branch secondary xylem indicates substantial similarity in gene ontologies including carbohydrate enzymes, response to stress, protein binding, and allowed us to find transcription factors and heat-shock proteins differentially expressed. TgMYB1 displays a MYB domain and a predicted coiled-coil (CC) domain, while TgMYB2, TgMYB3 and TgMYB4 showed R2R3-MYB domain and grouped with MYBs from several gymnosperms and flowering plants. TgMYB1, TgMYB4 and TgCES presented higher expression in mature secondary xylem, in contrast with TgMYB2, TgHsp1, TgHsp2, TgHsp3, and TgBi whose expression is higher in young lignified tissues. TgMYB3 is expressed at lower level in secondary xylem. Expression patterns of MYB transcription factors and heat-shock proteins in lignified tissues are dissimilar when tree development was evaluated, obtaining more expression of TgMYB1 and TgMYB4 in lignified tissues of 60-year-old trees, and more expression in TgHsp1, TgHsp2, Tg

  17. c-Myb regulates matrix metalloproteinases 1/9, and cathepsin D: implications for matrix-dependent breast cancer cell invasion and metastasis

    Czech Academy of Sciences Publication Activity Database

    Knopfová, L.; Beneš, P.; Pekarčíková, L.; Hermanová, M.; Masařík, M.; Pernicová, Zuzana; Souček, Karel; Šmarda, J.

    2012-01-01

    Roč. 11, MAR 23 (2012), ID 15 ISSN 1476-4598 R&D Projects: GA MZd NS9600 Grant - others:GA AV ČR(CZ) IAA501630901 Institutional support: RVO:68081707 Keywords : c-Myb * Metastasis * Breast cancer Subject RIV: BO - Biophysics Impact factor: 5.134, year: 2012

  18. Gene expression from plants grown on the International Space Station

    Science.gov (United States)

    Stimpson, Alexander; Pereira, Rhea; Kiss, John Z.; Correll, Melanie

    Three experiments were performed on the International Space Station (ISS) in 2006 as part of the TROPI experiments. These experiments were performed to study graviTROPIsm and photoTROPIsm responses of Arabidopsis in microgravity (µg). Seedlings were grown with a variety of light and gravitational treatments for approximately five days. The frozen samples were returned to Earth during three space shuttle missions in 2007 and stored at -80° C. Due to the limited amount of plant biomass returned, new protocols were developed to minimize the amount of material needed for RNA extraction as a preparation for microarray analysis. Using these new protocols, RNA was extracted from several sets of seedlings grown in red light followed by blue light with one sample from 1.0g treatment and the other at µg. Using a 2-fold change criterion, microarray (Affymetrix, GeneChip) results showed that 613 genes were upregulated in the µg sample while 757 genes were downregulated. Upregulated genes in response to µg included transcription factors from the WRKY (15 genes), MYB (3) and ZF (8) families as well as those that are involved in auxin responses (10). Downregulated genes also included transcription factors such as MYB (5) and Zinc finger (10) but interestingly only two WRKY family genes were down-regulated during the µg treatment. Studies are underway to compare these results with other samples to identify the genes involved in the gravity and light signal transduction pathways (this project is Supported By: NASA NCC2-1200).

  19. Transcript Quantification by RNA-Seq Reveals Differentially Expressed Genes in the Red and Yellow Fruits of Fragaria vesca.

    Directory of Open Access Journals (Sweden)

    Yuchao Zhang

    Full Text Available Fragaria vesca (2n = 2x = 14, the woodland strawberry, is a perennial herbaceous plant with a small sequenced genome (240 Mb. It is commonly used as a genetic model plant for the Fragaria genus and the Rosaceae family. Fruit skin color is one of the most important traits for both the commercial and esthetic value of strawberry. Anthocyanins are the most prominent pigments in strawberry that bring red, pink, white, and yellow hues to the fruits in which they accumulate. In this study, we conducted a de novo assembly of the fruit transcriptome of woodland strawberry and compared the gene expression profiles with yellow (Yellow Wonder, YW and red (Ruegen, RG fruits. De novo assembly yielded 75,426 unigenes, 21.3% of which were longer than 1,000 bp. Among the high-quality unique sequences, 45,387 (60.2% had at least one significant match to an existing gene model. A total of 595 genes, representing 0.79% of total unigenes, were differentially expressed in YW and RG. Among them, 224 genes were up-regulated and 371 genes were down-regulated in the fruit of YW. Particularly, some flavonoid biosynthetic pathway genes, including C4H, CHS, CHI, F3H, DFR and ANS, as well as some transcription factors (TFs, including MYB (putative MYB86 and MYB39, WDR and MADS, were down-regulated in YW fruit, concurrent with a reduction in anthocyanin accumulation in the yellow pigment phenotype, whereas a putative transcription repressor MYB1R was up-regulated in YW fruit. The altered expression levels of the genes encoding flavonoid biosynthetic enzymes and TFs were confirmed by quantitative RT-PCR. Our study provides important insights into the molecular mechanisms underlying the yellow pigment phenotype in F. vesca.

  20. nalyot, a mutation of the Drosophila myb-related Adf1 transcription factor, disrupts synapse formation and olfactory memory.

    Science.gov (United States)

    DeZazzo, J; Sandstrom, D; de Belle, S; Velinzon, K; Smith, P; Grady, L; DelVecchio, M; Ramaswami, M; Tully, T

    2000-07-01

    nalyot (nal) is a novel olfactory memory mutant of Drosophila, encoding Adf1, a myb-related transcription factor. Following extended training sessions, Adf1 mutants show normal early memory but defective longterm memory. Adf1 shows widespread spatiotemporal expression, yet mutant alleles reveal no discernible disruptions in gross morphology of the nervous system. Studies at the larval neuromuscular junction, however, reveal a role for Adf1 in the modulation of synaptic growth-in contrast to the role established for dCREB2 in the control of synaptic function (Davis et al., 1996). These findings suggest that Adf1 and dCREB2 regulate distinct transcriptional cascades involved in terminal stages of synapse maturation. More generally, Adf1 provides a novel link between molecular mechanisms of developmental and behavioral plasticity.

  1. Peripheral blood transcriptome sequencing reveals rejection-relevant genes in long-term heart transplantation.

    Science.gov (United States)

    Chen, Yan; Zhang, Haibo; Xiao, Xue; Jia, Yixin; Wu, Weili; Liu, Licheng; Jiang, Jun; Zhu, Baoli; Meng, Xu; Chen, Weijun

    2013-10-03

    Peripheral blood-based gene expression patterns have been investigated as biomarkers to monitor the immune system and rule out rejection after heart transplantation. Recent advances in the high-throughput deep sequencing (HTS) technologies provide new leads in transcriptome analysis. By performing Solexa/Illumina's digital gene expression (DGE) profiling, we analyzed gene expression profiles of PBMCs from 6 quiescent (grade 0) and 6 rejection (grade 2R&3R) heart transplant recipients at more than 6 months after transplantation. Subsequently, quantitative real-time polymerase chain reaction (qRT-PCR) was carried out in an independent validation cohort of 47 individuals from three rejection groups (ISHLT, grade 0,1R, 2R&3R). Through DGE sequencing and qPCR validation, 10 genes were identified as informative genes for detection of cardiac transplant rejection. A further clustering analysis showed that the 10 genes were not only effective for distinguishing patients with acute cardiac allograft rejection, but also informative for discriminating patients with renal allograft rejection based on both blood and biopsy samples. Moreover, PPI network analysis revealed that the 10 genes were connected to each other within a short interaction distance. We proposed a 10-gene signature for heart transplant patients at high-risk of developing severe rejection, which was found to be effective as well in other organ transplant. Moreover, we supposed that these genes function systematically as biomarkers in long-time allograft rejection. Further validation in broad transplant population would be required before the non-invasive biomarkers can be generally utilized to predict the risk of transplant rejection. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  2. Anthocyanin accumulation and molecular analysis of anthocyanin biosynthesis-associated genes in eggplant (Solanum melongena L.).

    Science.gov (United States)

    Zhang, Yanjie; Hu, Zongli; Chu, Guihua; Huang, Cheng; Tian, Shibing; Zhao, Zhiping; Chen, Guoping

    2014-04-02

    Eggplant (Solanum melongena L.) is an edible fruit vegetable cultivated and consumed worldwide. The purple eggplant is more eye-catching and popular for the health-promoting anthocyanins contained in the fruit skin. Two kinds of anthocyanin were separated and identified from purple cultivar (Zi Chang) by high-performance liquid chromatography-electrospray ionization tandem mass spectrometry. To investigate the molecular mechanisms of anthocyanin accumulation in eggplant, the transcripts of anthocyanin biosynthetic and regulatory genes were analyzed in the fruit skin and the flesh of the purple cultivar and the white cultivar (Bai Xue). Compared with the other tissues, SmMYB1 and all anthocyanin biosynthetic genes except PAL were dramatically upregulated in the fruit skin of the purple cultivar. Overexpression of SmMYB1 activated abundant anthocyanin accumulation in the regenerating shoots of eggplant. These results prove that transcriptional activation of SmMYB1 accounts for constitutive upregulation of most anthocyanin biosynthetic genes and the onset of anthocyanin biosynthesis in the purple cultivar.

  3. Light and the E3 ubiquitin ligase COP1/SPA control the protein stability of the MYB transcription factors PAP1 and PAP2 involved in anthocyanin accumulation in Arabidopsis.

    Science.gov (United States)

    Maier, Alexander; Schrader, Andrea; Kokkelink, Leonie; Falke, Christian; Welter, Bastian; Iniesto, Elisa; Rubio, Vicente; Uhrig, Joachim F; Hülskamp, Martin; Hoecker, Ute

    2013-05-01

    Anthocyanins are natural pigments that accumulate only in light-grown and not in dark-grown Arabidopsis plants. Repression of anthocyanin accumulation in darkness requires the CONSTITUTIVELY PHOTOMORPHOGENIC1/SUPPRESSOR OF PHYA-105 (COP1/SPA) ubiquitin ligase, as cop1 and spa mutants produce anthocyanins also in the dark. Here, we show that COP1 and SPA proteins interact with the myeloblastosis (MYB) transcription factors PRODUCTION OF ANTHOCYANIN PIGMENT1 (PAP)1 and PAP2, two members of a small protein family that is required for anthocyanin accumulation and for the expression of structural genes in the anthocyanin biosynthesis pathway. The increased anthocyanin levels in cop1 mutants requires the PAP1 gene family, indicating that COP1 functions upstream of the PAP1 gene family. PAP1 and PAP2 proteins are degraded in the dark and this degradation is dependent on the proteasome and on COP1. Hence, the light requirement for anthocyanin biosynthesis results, at least in part, from the light-mediated stabilization of PAP1 and PAP2. Consistent with this conclusion, moderate overexpression of PAP1 leads to an increase in anthocyanin levels only in the light and not in darkness. Here we show that SPA genes are also required for reducing PAP1 and PAP2 transcript levels in dark-grown seedlings. Taken together, these results indicate that the COP1/SPA complex affects PAP1 and PAP2 both transcriptionally and post-translationally. Thus, our findings have identified mechanisms via which the COP1/SPA complex controls anthocyanin levels in Arabidopsis that may be useful for applications in biotechnology directed towards increasing anthocyanin content in plants. © 2013 The Authors The Plant Journal © 2013 John Wiley & Sons Ltd.

  4. PhERF6, interacting with EOBI, negatively regulates fragrance biosynthesis in petunia flowers.

    Science.gov (United States)

    Liu, Fei; Xiao, Zhina; Yang, Li; Chen, Qian; Shao, Lu; Liu, Juanxu; Yu, Yixun

    2017-09-01

    In petunia, the production of volatile benzenoids/phenylpropanoids determines floral aroma, highly regulated by development, rhythm and ethylene. Previous studies identified several R2R3-type MYB trans-factors as positive regulators of scent biosynthesis in petunia flowers. Ethylene response factors (ERFs) have been shown to take part in the signal transduction of hormones, and regulation of metabolism and development processes in various plant species. Using virus-induced gene silencing technology, a negative regulator of volatile benzenoid biosynthesis, PhERF6, was identified by a screen for regulators of the expression of genes related to scent production. PhERF6 expression was temporally and spatially connected with scent production and was upregulated by exogenous ethylene. Up-/downregulation of the mRNA level of PhERF6 affected the expression of ODO1 and several floral scent-related genes. PhERF6 silencing led to a significant increase in the concentrations of volatiles emitted by flowers. Yeast two-hybrid, bimolecular fluorescence complementation and co-immunoprecipitation assays indicated that PhERF6 interacted with the N-terminus of EOBI, which includes two DNA binding domains. Our results show that PhERF6 negatively regulates volatile production in petunia flowers by competing for the binding of the c-myb domains of the EOBI protein with the promoters of genes related to floral scent. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  5. Gene expression and yeast two-hybrid studies of transcription factors mediating drought stress response in root tissues of chickpea (Cicer arietinum L.

    Directory of Open Access Journals (Sweden)

    Abirami eRamalingam

    2015-12-01

    Full Text Available Drought stress has been one of the serious constraints affecting chickpea productivity to a great extent. Genomic assisted breeding in chickpea has been effective in providing a yield advantage of up to 24 %, thus having a potential to accelerate breeding precisely and efficiently. In order to do so, understanding the molecular mechanisms for drought tolerance and identification of candidate genes are crucial. Transcription factors (TFs have important roles in the regulation of plant stress related genes. In this context, quantitative real time-PCR (qRT-PCR was used to study the differential gene expression of selected TFs, identified from large-scale gene expression analysis, in contrasting drought responsive genotypes. Root tissues of ICC 4958 (tolerant, ICC 1882 (sensitive, JG 11 (elite and JG 11+ (introgression line were used for the study. Subsequently, a candidate single repeat MYB gene (1R-MYB that was remarkably induced in the drought tolerant genotypes under drought stress was cloned and subjected to Y2H analysis by screening a root cDNA library. The protein-protein interaction study identified three interacting peptides, a galactinol-sucrose galactosyltransferase 2, a CBL (Calcineurin B-like-interacting serine/threonine-protein kinase 25 and an ABA responsive 17-like, which were confirmed by the co-transformation of candidate plasmids in yeast. These findings provide preliminary insights into the ability of 1R-MYB TF to co-regulate drought tolerance mechanism in chickpea roots.

  6. Transcription factor c-Myb inhibits breast cancer lung metastasis by suppression of tumor cell seeding

    Czech Academy of Sciences Publication Activity Database

    Knopfová, L.; Biglieri, E.; Volodko, N.; Masařík, M.; Hermanová, M.; Garzon, J.F.G.; Ducka, M.; Kučírková, T.; Souček, Karel; Šmarda, J.; Beneš, P.; Borsig, L.

    2018-01-01

    Roč. 37, č. 8 (2018), s. 1020-1030 ISSN 0950-9232 Institutional support: RVO:68081707 Keywords : inflammatory chemokines * colorectal-carcinoma * gene Subject RIV: CE - Biochemistry OBOR OECD: Biochemistry and molecular biology Impact factor: 7.519, year: 2016

  7. C-myb Plays an Essential Role in the Protective Function of IGF-1 on Cytotoxicity Induced by Aβ25-35 via the PI3K/Akt Pathway.

    Science.gov (United States)

    Zhang, Jingyu; Shu, Yongwei; Qu, Yang; Zhang, Lina; Chu, Tingting; Zheng, Yonghui; Zhao, Hong

    2017-12-01

    There have been numerous reports about neurodegenerative diseases, including Alzheimer's disease. Nevertheless, the molecules responsible for the neurodegeneration in Alzheimer's disease are basically unknown. Recent findings indicate that the cellular myeloblastosis (c-myb) regulates neural progenitor cell proliferation. In the current study, the function of insulin-like growth factor-1 (IGF-1) against cell toxicity in SH-SY5Y cells induced by β-amyloid 25-35 (Aβ 25-35 ) and its molecular mechanism were investigated. It was found that p25 protein production was raised by Aβ 25-35 (25 μM), similar to the increased expression of μ-calpain. The results also showed that Aβ 25-35 reduced c-myb, elevated tau hyper-phosphorylation, and induced death of SH-SY5Y cells. Loss of cell viability and apoptosis of SH-SY5Y cells induced by Aβ 25-35 were attenuated by IGF-1 pretreatment in a dose-dependent manner. In addition, IGF-1 blocked μ-calpain expression, which was induced by Aβ 25-35 and reduced p25 formation and tau hyper-phosphorylation. Moreover, the expression of c-myb in SH-SY5Y cells was increased by combining IGF-1 with Aβ 25-35 or IGF-1 alone. The neuroprotective function of IGF-1 was attenuated in the SH-SY5Y cells, which were transfected with a c-myb small interfering RNA. Furthermore, LY294002, a specific PI3K inhibitor, reduced c-myb expression and abolished IGF-1's protective function in SH-SY5Y cell apoptosis induced by Aβ 25-35 . The facts above indicate that c-myb has a role in IGF-1-mediated protection from Aβ 25-35 -induced cytotoxicity via the PI3K/Akt pathway.

  8. Technical advances in trigger-induced RNA interference gene silencing in the parasite Entamoeba histolytica.

    Science.gov (United States)

    Khalil, Mohamed I; Foda, Bardees M; Suresh, Susmitha; Singh, Upinder

    2016-03-01

    Entamoeba histolytica has a robust endogenous RNA interference (RNAi) pathway. There are abundant 27 nucleotide (nt) anti-sense small RNAs (AS sRNAs) that target genes for silencing and the genome encodes many genes involved in the RNAi pathway such as Argonaute proteins. Importantly, an E. histolytica gene with numerous AS sRNAs can function as a "trigger" to induce silencing of a gene that is fused to the trigger. Thus, the amebic RNAi pathway regulates gene expression relevant to amebic biology and has additionally been harnessed as a tool for genetic manipulation. In this study we have further improved the trigger-induced gene silencing method. We demonstrate that rather than using the full-length gene, a short portion of the coding region fused to a trigger is sufficient to induce silencing; the first 537 bp of the E. histolytica rhomboid gene (EhROM1) fused in-frame to the trigger was sufficient to silence EhROM1. We also demonstrated that the trigger method could silence two amebic genes concomitantly; fusion of the coding regions of EhROM1 and transcription factor, EhMyb, in-frame to a trigger gene resulted in both genes being silenced. Alternatively, two genes can be silenced sequentially: EhROM1-silenced parasites with no drug selection plasmid were transfected with trigger-EhMyb, resulting in parasites with both EhROM1 and EhMyb silenced. With all approaches tested, the trigger-mediated silencing was substantive and silencing was maintained despite loss of the G418 selectable marker. All gene silencing was associated with generation of AS sRNAs to the silenced gene. We tested the reversibility of the trigger system using inhibitors of histone modifications but found that the silencing was highly stable. This work represents a technical advance in the trigger gene silencing method in E. histolytica. Approaches that readily silence multiple genes add significantly to the genetic toolkit available to the ameba research community. Copyright © 2016

  9. Elucidating the biosynthetic and regulatory mechanisms of flavonoid-derived bioactive components in Epimedium sagittatum

    Directory of Open Access Journals (Sweden)

    Wenjun eHuang

    2015-09-01

    Full Text Available Herba epimedii (Epimedium, a traditional Chinese medicine, has been widely used as a kidney tonic and antirheumatic medicine for thousands of years. In Epimedium, flavonoids have been demonstrated to be the main bioactive components (BCs. However, the molecular biosynthetic and regulatory mechanisms of flavonoid-derived BCs remain obscure. In this study, we isolated twelve structural genes and two putative transcription factors (TFs in the flavonoid pathway. Phytochemical analysis showed that the total content of four representative BCs (epimedin A, B, C and icariin decreased slightly or dramatically in two lines of E. sagittatum during leaf development. Transcriptional analysis revealed that two R2R3-MYB TFs (EsMYBA1 and EsMYBF1, together with a bHLH TF (EsGL3 and WD40 protein (EsTTG1, were supposed to coordinately regulate the anthocyanin and flavonol-derived BCs biosynthesis in leaves. Overexpression of EsFLS (flavonol synthase in tobacco resulted in increased flavonols content and decreased anthocyanins content in flowers. Moreover, EsMYB12 negatively correlated with the accumulation of the four BCs, and might act as a transcriptional repressor in the flavonoid pathway. Therefore, the anthocyanin pathway may coordinate with the flavonol-derived BCs pathway in Epimedium leaves. A better understanding of the flavonoid biosynthetic and regulatory mechanisms in E. sagittatum will facilitate functional characterization, metabolic engineering and molecular breeding studies of Epimedium species.

  10. Integration of TP53, DREAM, MMB-FOXM1 and RB-E2F target gene analyses identifies cell cycle gene regulatory networks.

    Science.gov (United States)

    Fischer, Martin; Grossmann, Patrick; Padi, Megha; DeCaprio, James A

    2016-07-27

    Cell cycle (CC) and TP53 regulatory networks are frequently deregulated in cancer. While numerous genome-wide studies of TP53 and CC-regulated genes have been performed, significant variation between studies has made it difficult to assess regulation of any given gene of interest. To overcome the limitation of individual studies, we developed a meta-analysis approach to identify high confidence target genes that reflect their frequency of identification in independent datasets. Gene regulatory networks were generated by comparing differential expression of TP53 and CC-regulated genes with chromatin immunoprecipitation studies for TP53, RB1, E2F, DREAM, B-MYB, FOXM1 and MuvB. RNA-seq data from p21-null cells revealed that gene downregulation by TP53 generally requires p21 (CDKN1A). Genes downregulated by TP53 were also identified as CC genes bound by the DREAM complex. The transcription factors RB, E2F1 and E2F7 bind to a subset of DREAM target genes that function in G1/S of the CC while B-MYB, FOXM1 and MuvB control G2/M gene expression. Our approach yields high confidence ranked target gene maps for TP53, DREAM, MMB-FOXM1 and RB-E2F and enables prediction and distinction of CC regulation. A web-based atlas at www.targetgenereg.org enables assessing the regulation of any human gene of interest. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  11. Comparative Bioinformatics Analysis of Transcription Factor Genes Indicates Conservation of Key Regulatory Domains among Babesia bovis, Babesia microti, and Theileria equi.

    Science.gov (United States)

    Alzan, Heba F; Knowles, Donald P; Suarez, Carlos E

    2016-11-01

    Apicomplexa tick-borne hemoparasites, including Babesia bovis, Babesia microti, and Theileria equi are responsible for bovine and human babesiosis and equine theileriosis, respectively. These parasites of vast medical, epidemiological, and economic impact have complex life cycles in their vertebrate and tick hosts. Large gaps in knowledge concerning the mechanisms used by these parasites for gene regulation remain. Regulatory genes coding for DNA binding proteins such as members of the Api-AP2, HMG, and Myb families are known to play crucial roles as transcription factors. Although the repertoire of Api-AP2 has been defined and a HMG gene was previously identified in the B. bovis genome, these regulatory genes have not been described in detail in B. microti and T. equi. In this study, comparative bioinformatics was used to: (i) identify and map genes encoding for these transcription factors among three parasites' genomes; (ii) identify a previously unreported HMG gene in B. microti; (iii) define a repertoire of eight conserved Myb genes; and (iv) identify AP2 correlates among B. bovis and the better-studied Plasmodium parasites. Searching the available transcriptome of B. bovis defined patterns of transcription of these three gene families in B. bovis erythrocyte stage parasites. Sequence comparisons show conservation of functional domains and general architecture in the AP2, Myb, and HMG proteins, which may be significant for the regulation of common critical parasite life cycle transitions in B. bovis, B. microti, and T. equi. A detailed understanding of the role of gene families encoding DNA binding proteins will provide new tools for unraveling regulatory mechanisms involved in B. bovis, B. microti, and T. equi life cycles and environmental adaptive responses and potentially contributes to the development of novel convergent strategies for improved control of babesiosis and equine piroplasmosis.

  12. Comparative Bioinformatics Analysis of Transcription Factor Genes Indicates Conservation of Key Regulatory Domains among Babesia bovis, Babesia microti, and Theileria equi.

    Directory of Open Access Journals (Sweden)

    Heba F Alzan

    2016-11-01

    Full Text Available Apicomplexa tick-borne hemoparasites, including Babesia bovis, Babesia microti, and Theileria equi are responsible for bovine and human babesiosis and equine theileriosis, respectively. These parasites of vast medical, epidemiological, and economic impact have complex life cycles in their vertebrate and tick hosts. Large gaps in knowledge concerning the mechanisms used by these parasites for gene regulation remain. Regulatory genes coding for DNA binding proteins such as members of the Api-AP2, HMG, and Myb families are known to play crucial roles as transcription factors. Although the repertoire of Api-AP2 has been defined and a HMG gene was previously identified in the B. bovis genome, these regulatory genes have not been described in detail in B. microti and T. equi. In this study, comparative bioinformatics was used to: (i identify and map genes encoding for these transcription factors among three parasites' genomes; (ii identify a previously unreported HMG gene in B. microti; (iii define a repertoire of eight conserved Myb genes; and (iv identify AP2 correlates among B. bovis and the better-studied Plasmodium parasites. Searching the available transcriptome of B. bovis defined patterns of transcription of these three gene families in B. bovis erythrocyte stage parasites. Sequence comparisons show conservation of functional domains and general architecture in the AP2, Myb, and HMG proteins, which may be significant for the regulation of common critical parasite life cycle transitions in B. bovis, B. microti, and T. equi. A detailed understanding of the role of gene families encoding DNA binding proteins will provide new tools for unraveling regulatory mechanisms involved in B. bovis, B. microti, and T. equi life cycles and environmental adaptive responses and potentially contributes to the development of novel convergent strategies for improved control of babesiosis and equine piroplasmosis.

  13. Expression of a maize Myb transcription factor driven by a putative silk-specific promoter significantly enhances resistance to Helicoverpa zea in transgenic maize.

    Science.gov (United States)

    Johnson, Eric T; Berhow, Mark A; Dowd, Patrick F

    2007-04-18

    Hi II maize (Zea mays) plants were engineered to express maize p1 cDNA, a Myb transcription factor, controlled by a putative silk specific promoter, for secondary metabolite production and corn earworm resistance. Transgene expression did not enhance silk color, but about half of the transformed plant silks displayed browning when cut, which indicated the presence of p1-produced secondary metabolites. Levels of maysin, a secondary metabolite with insect toxicity, were highest in newly emerged browning silks. The insect resistance of transgenic silks was also highest at emergence, regardless of maysin levels, which suggests that other unidentified p1-induced molecules likely contributed to larval mortality. Mean survivor weights of corn earworm larvae fed mature browning transgenic silks were significantly lower than weights of those fed mature nonbrowning transgenic silks. Some transgenic pericarps browned with drying and contained similar molecules found in pericarps expressing a dominant p1 allele, suggesting that the promoter may not be silk-specific.

  14. Transcriptional regulatory network triggered by oxidative signals configures the early response mechanisms of japonica rice to chilling stress

    Directory of Open Access Journals (Sweden)

    Wijaya Edward

    2010-01-01

    Full Text Available Abstract Background The transcriptional regulatory network involved in low temperature response leading to acclimation has been established in Arabidopsis. In japonica rice, which can only withstand transient exposure to milder cold stress (10°C, an oxidative-mediated network has been proposed to play a key role in configuring early responses and short-term defenses. The components, hierarchical organization and physiological consequences of this network were further dissected by a systems-level approach. Results Regulatory clusters responding directly to oxidative signals were prominent during the initial 6 to 12 hours at 10°C. Early events mirrored a typical oxidative response based on striking similarities of the transcriptome to disease, elicitor and wounding induced processes. Targets of oxidative-mediated mechanisms are likely regulated by several classes of bZIP factors acting on as1/ocs/TGA-like element enriched clusters, ERF factors acting on GCC-box/JAre-like element enriched clusters and R2R3-MYB factors acting on MYB2-like element enriched clusters. Temporal induction of several H2O2-induced bZIP, ERF and MYB genes coincided with the transient H2O2 spikes within the initial 6 to 12 hours. Oxidative-independent responses involve DREB/CBF, RAP2 and RAV1 factors acting on DRE/CRT/rav1-like enriched clusters and bZIP factors acting on ABRE-like enriched clusters. Oxidative-mediated clusters were activated earlier than ABA-mediated clusters. Conclusion Genome-wide, physiological and whole-plant level analyses established a holistic view of chilling stress response mechanism of japonica rice. Early response regulatory network triggered by oxidative signals is critical for prolonged survival under sub-optimal temperature. Integration of stress and developmental responses leads to modulated growth and vigor maintenance contributing to a delay of plastic injuries.

  15. Transcriptional regulatory network triggered by oxidative signals configures the early response mechanisms of japonica rice to chilling stress

    KAUST Repository

    Yun, Kil-Young

    2010-01-25

    Background: The transcriptional regulatory network involved in low temperature response leading to acclimation has been established in Arabidopsis. In japonica rice, which can only withstand transient exposure to milder cold stress (10C), an oxidative-mediated network has been proposed to play a key role in configuring early responses and short-term defenses. The components, hierarchical organization and physiological consequences of this network were further dissected by a systems-level approach.Results: Regulatory clusters responding directly to oxidative signals were prominent during the initial 6 to 12 hours at 10C. Early events mirrored a typical oxidative response based on striking similarities of the transcriptome to disease, elicitor and wounding induced processes. Targets of oxidative-mediated mechanisms are likely regulated by several classes of bZIP factors acting on as1/ocs/TGA-like element enriched clusters, ERF factors acting on GCC-box/JAre-like element enriched clusters and R2R3-MYB factors acting on MYB2-like element enriched clusters.Temporal induction of several H2O2-induced bZIP, ERF and MYB genes coincided with the transient H2O2spikes within the initial 6 to 12 hours. Oxidative-independent responses involve DREB/CBF, RAP2 and RAV1 factors acting on DRE/CRT/rav1-like enriched clusters and bZIP factors acting on ABRE-like enriched clusters. Oxidative-mediated clusters were activated earlier than ABA-mediated clusters.Conclusion: Genome-wide, physiological and whole-plant level analyses established a holistic view of chilling stress response mechanism of japonica rice. Early response regulatory network triggered by oxidative signals is critical for prolonged survival under sub-optimal temperature. Integration of stress and developmental responses leads to modulated growth and vigor maintenance contributing to a delay of plastic injuries. 2010 Yun et al; licensee BioMed Central Ltd.

  16. Tissue and cell-specific transcriptomes in cotton reveal the subtleties of gene regulation underlying the diversity of plant secondary cell walls.

    Science.gov (United States)

    MacMillan, Colleen P; Birke, Hannah; Chuah, Aaron; Brill, Elizabeth; Tsuji, Yukiko; Ralph, John; Dennis, Elizabeth S; Llewellyn, Danny; Pettolino, Filomena A

    2017-07-18

    Knowledge of plant secondary cell wall (SCW) regulation and deposition is mainly based on the Arabidopsis model of a 'typical' lignocellulosic SCW. However, SCWs in other plants can vary from this. The SCW of mature cotton seed fibres is highly cellulosic and lacks lignification whereas xylem SCWs are lignocellulosic. We used cotton as a model to study different SCWs and the expression of the genes involved in their formation via RNA deep sequencing and chemical analysis of stem and seed fibre. Transcriptome comparisons from cotton xylem and pith as well as from a developmental series of seed fibres revealed tissue-specific and developmentally regulated expression of several NAC transcription factors some of which are likely to be important as top tier regulators of SCW formation in xylem and/or seed fibre. A so far undescribed hierarchy was identified between the top tier NAC transcription factors SND1-like and NST1/2 in cotton. Key SCW MYB transcription factors, homologs of Arabidopsis MYB46/83, were practically absent in cotton stem xylem. Lack of expression of other lignin-specific MYBs in seed fibre relative to xylem could account for the lack of lignin deposition in seed fibre. Expression of a MYB103 homolog correlated with temporal expression of SCW CesAs and cellulose synthesis in seed fibres. FLAs were highly expressed and may be important structural components of seed fibre SCWs. Finally, we made the unexpected observation that cell walls in the pith of cotton stems contained lignin and had a higher S:G ratio than in xylem, despite that tissue's lacking many of the gene transcripts normally associated with lignin biosynthesis. Our study in cotton confirmed some features of the currently accepted gene regulatory cascade for 'typical' plant SCWs, but also revealed substantial differences, especially with key downstream NACs and MYBs. The lignocellulosic SCW of cotton xylem appears to be achieved differently from that in Arabidopsis. Pith cell walls in

  17. Agrobacterium rhizogenes-mediated transformation of Arachis hypogaea: an efficient tool for functional study of genes

    Directory of Open Access Journals (Sweden)

    Shuai Liu

    2016-09-01

    Full Text Available We have developed a technique for efficient transformation of hairy roots of Arachis hypogaea L. using Agrobacterium rhizogenes K599, and have validated this approach for the investigation of gene function. As a model transgene, AhAREB1, a drought-resistance gene from peanut, was fused to green fluorescent protein, and four parameters that might influence the transformation efficiency were tested. The optimal procedure involved the use of petioles with four expanded leaves as explants, infection by K599 at optical density (OD600 of 0.6 for 15 min and co-cultivation for 2 d, giving transformation efficiencies of up to 91%. Hairy roots from transgenic peanut plants overexpressing AhAREB1 were unaffected by treatment with polyethylene glycol (PEG, demonstrating increased drought tolerance, whereas control roots showed clear signs of plasmolysis. Transgenic roots accumulated less superoxide anion (O2− than control roots under drought conditions. Additionally, transgenic roots displayed upregulation of four stress-response genes encoding WRKY transcription factor (WRKY33, MYB transcription factor (MYB92, abscisic acid receptor (PYL5 and dehydrin 2 (DHN2.

  18. Ethylene and pollination decrease transcript abundance of an ethylene receptor gene in Dendrobium petals.

    Science.gov (United States)

    Thongkum, Monthathip; Burns, Parichart; Bhunchoth, Anjana; Warin, Nuchnard; Chatchawankanphanich, Orawan; van Doorn, Wouter G

    2015-03-15

    We studied the expression of a gene encoding an ethylene receptor, called Ethylene Response Sensor 1 (Den-ERS1), in the petals of Dendrobium orchid flowers. Transcripts accumulated during the young floral bud stage and declined by the time the flowers had been open for several days. Pollination or exposure to exogenous ethylene resulted in earlier flower senescence, an increase in ethylene production and a lower Den-ERS1 transcript abundance. Treatment with 1-methylcyclopropene (1-MCP), an inhibitor of the ethylene receptor, decreased ethylene production and resulted in high transcript abundance. The literature indicates two kinds of ethylene receptor genes with regard to the effects of ethylene. One group shows ethylene-induced down-regulated transcription, while the other has ethylene-induced up-regulation. The present gene is an example of the first group. The 5' flanking region showed binding sites for Myb and myb-like, homeodomain, MADS domain, NAC, TCP, bHLH and EIN3-like transcription factors. The binding site for the EIN3-like factor might explain the ethylene effect on transcription. A few other transcription factors (RAV1 and NAC) seem also related to ethylene effects. Copyright © 2015 Elsevier GmbH. All rights reserved.

  19. The Neurospora rca-1 gene complements an Aspergillus flbD sporulation mutant but has no identifiable role in Neurospora sporulation.

    OpenAIRE

    Shen, W C; Wieser, J; Adams, T H; Ebbole, D J

    1998-01-01

    The Aspergillus nidulans flbD gene encodes a protein with a Myb-like DNA-binding domain that is proposed to act in concert with other developmental regulators to control initiation of conidiophore development. We have identified a Neurospora crassa gene called rca-1 (regulator of conidiation in Aspergillus) based on its sequence similarity to flbD. We found that N. crassa rca-1 can complement the conidiation defect of an A. nidulans flbD mutant and that induced expression of rca-1 caused coni...

  20. Genes and Gene Therapy

    Science.gov (United States)

    ... correctly, a child can have a genetic disorder. Gene therapy is an experimental technique that uses genes to ... or prevent disease. The most common form of gene therapy involves inserting a normal gene to replace an ...

  1. The relationship between codon usage bias and cold resistant genes

    International Nuclear Information System (INIS)

    Barozai, M.Y.; Din, M.

    2014-01-01

    This research is based on synonymous codon usage which has been well-known as a feature that affects typical expression level of protein in an organism. Different organisms prefer different codons for same amino acid and this is called Codon Usage Bias (CUB). The codon usage directly affects the level or even direction of changes in protein expression in responses to environmental stimuli. Cold stress is a major abiotic factor that limits the agricultural productivity of plants. In the recent study CUB has been studied in Arabidopsis thaliana cold resistant and housekeeping genes and their homologs in rice (Oryza sativa) to understand the cold stress and housekeeping genes relation with CUB. Six cold resistant and three housekeeping genes in Arabidopsis thaliana and their homologs in rice, were subjected to CUB analysis. The three cold resistant genes (DREB1B, RCI and MYB15) showed more than 50% (52%, 61% and 66% respectively) similar codon usage bias for Arabidopsis thaliana and rice. On the other hand three cold resistant genes (MPK3, ICE1 and ZAT12) showed less than 50% (38%, 38% and 47% respectively) similar codon usage bias for Arabidopsis thaliana and rice. The three housekeeping genes (Actin, Tubulin and Ubiquitin) showed 76% similar codon usage bias for Arabidopsis thaliana and rice. This study will help to manage the plant gene expression through codon optimization under the cold stress. (author)

  2. Overexpression of AmRosea1 Gene Confers Drought and Salt Tolerance in Rice

    Directory of Open Access Journals (Sweden)

    Mingzhu Dou

    2016-12-01

    Full Text Available Ectopic expression of the MYB transcription factor of AmROSEA1 from Antirrhinum majus has been reported to change anthocyanin and other metabolites in several species. In this study, we found that overexpression of AmRosea1 significantly improved the tolerance of transgenic rice to drought and salinity stresses. Transcriptome analysis revealed that a considerable number of stress-related genes were affected by exogenous AmRosea1 during both drought and salinity stress treatments. These affected genes are involved in stress signal transduction, the hormone signal pathway, ion homeostasis and the enzymes that remove peroxides. This work suggests that the AmRosea1 gene is a potential candidate for genetic engineering of crops.

  3. Testing the utility of fluorescent proteins in Mimulus lewisii by an Agrobacterium-mediated transient assay.

    Science.gov (United States)

    Ding, Baoqing; Yuan, Yao-Wu

    2016-04-01

    The Agrobacterium -mediated transient expression assay by leaf infiltration in Mimulus lewisii is robust. Fluorescent proteins EGFP, EYFP and DsRed give bright fluorescence signals in the infiltrated tissue. Mimulus lewisii is an emerging developmental genetic model system. Recently developed genomic and genetic resources and a stable transformation protocol have greatly facilitated the identification and functional characterization of genes controlling the development of ecologically important floral traits using this species. To further expedite gene and protein function analyses in M. lewisii, we adopted and simplified the Agrobacterium-mediated transient gene expression method routinely used in tobacco plants. With the validated transient assay, we examined the performance of fluorescent proteins EGFP, EYFP and DsRed in M. lewisii. All three proteins gave bright fluorescence signals when transiently expressed in agroinfiltrated leaves. Furthermore, we demonstrated the utility of fluorescent proteins in M. lewisii by showing the nuclear localization of Reduced Carotenoid Pigmentation 1 (RCP1), a recently discovered R2R3-MYB transcription factor that regulates carotenoid pigmentation during flower development. Both the transient assay and the fluorescent proteins are valuable additions to the M. lewisii toolbox, making this emerging genetic and developmental model system even more powerful.

  4. Identification and expression analysis of glucosinolate biosynthetic genes and estimation of glucosinolate contents in edible organs of Brassica oleracea subspecies.

    Science.gov (United States)

    Yi, Go-Eun; Robin, Arif Hasan Khan; Yang, Kiwoung; Park, Jong-In; Kang, Jong-Goo; Yang, Tae-Jin; Nou, Ill-Sup

    2015-07-20

    Glucosinolates are anti-carcinogenic, anti-oxidative biochemical compounds that defend plants from insect and microbial attack. Glucosinolates are abundant in all cruciferous crops, including all vegetable and oilseed Brassica species. Here, we studied the expression of glucosinolate biosynthesis genes and determined glucosinolate contents in the edible organs of a total of 12 genotypes of Brassica oleracea: three genotypes each from cabbage, kale, kohlrabi and cauliflower subspecies. Among the 81 genes analyzed by RT-PCR, 19 are transcription factor-related, two different sets of 25 genes are involved in aliphatic and indolic biosynthesis pathways and the rest are breakdown-related. The expression of glucosinolate-related genes in the stems of kohlrabi was remarkably different compared to leaves of cabbage and kale and florets of cauliflower as only eight genes out of 81 were expressed in the stem tissues of kohlrabi. In the stem tissue of kohlrabi, only one aliphatic transcription factor-related gene, Bol036286 (MYB28) and one indolic transcription factor-related gene, Bol030761 (MYB51), were expressed. The results indicated the expression of all genes is not essential for glucosinolate biosynthesis. Using HPLC analysis, a total of 16 different types of glucosinolates were identified in four subspecies, nine of them were aliphatic, four of them were indolic and one was aromatic. Cauliflower florets measured the highest number of 14 glucosinolates. Among the aliphatic glucosinolates, only gluconapin was found in the florets of cauliflower. Glucoiberverin and glucobrassicanapin contents were the highest in the stems of kohlrabi. The indolic methoxyglucobrassicin and aromatic gluconasturtiin accounted for the highest content in the florets of cauliflower. A further detailed investigation and analyses is required to discern the precise roles of each of the genes for aliphatic and indolic glucosinolate biosynthesis in the edible organs.

  5. Identification and Expression Analysis of Glucosinolate Biosynthetic Genes and Estimation of Glucosinolate Contents in Edible Organs of Brassica oleracea Subspecies

    Directory of Open Access Journals (Sweden)

    Go-Eun Yi

    2015-07-01

    Full Text Available Glucosinolates are anti-carcinogenic, anti-oxidative biochemical compounds that defend plants from insect and microbial attack. Glucosinolates are abundant in all cruciferous crops, including all vegetable and oilseed Brassica species. Here, we studied the expression of glucosinolate biosynthesis genes and determined glucosinolate contents in the edible organs of a total of 12 genotypes of Brassica oleracea: three genotypes each from cabbage, kale, kohlrabi and cauliflower subspecies. Among the 81 genes analyzed by RT-PCR, 19 are transcription factor-related, two different sets of 25 genes are involved in aliphatic and indolic biosynthesis pathways and the rest are breakdown-related. The expression of glucosinolate-related genes in the stems of kohlrabi was remarkably different compared to leaves of cabbage and kale and florets of cauliflower as only eight genes out of 81 were expressed in the stem tissues of kohlrabi. In the stem tissue of kohlrabi, only one aliphatic transcription factor-related gene, Bol036286 (MYB28 and one indolic transcription factor-related gene, Bol030761 (MYB51, were expressed. The results indicated the expression of all genes is not essential for glucosinolate biosynthesis. Using HPLC analysis, a total of 16 different types of glucosinolates were identified in four subspecies, nine of them were aliphatic, four of them were indolic and one was aromatic. Cauliflower florets measured the highest number of 14 glucosinolates. Among the aliphatic glucosinolates, only gluconapin was found in the florets of cauliflower. Glucoiberverin and glucobrassicanapin contents were the highest in the stems of kohlrabi. The indolic methoxyglucobrassicin and aromatic gluconasturtiin accounted for the highest content in the florets of cauliflower. A further detailed investigation and analyses is required to discern the precise roles of each of the genes for aliphatic and indolic glucosinolate biosynthesis in the edible organs.

  6. The transcription factor AtMYB75/PAP1 regulates the expression of flavonoid biosynthesis genes in transgenic hop (Humulus lupulus L.)

    Czech Academy of Sciences Publication Activity Database

    Gatica-Arias, A.; Farag, M.A.; Häntzschel, K.R.; Matoušek, Jaroslav; Weber, G.

    2012-01-01

    Roč. 65, 7-8 (2012), s. 103-111 ISSN 1866-5195 R&D Projects: GA ČR GA521/08/0740 Institutional research plan: CEZ:AV0Z50510513 Institutional support: RVO:60077344 Keywords : metabolic engineering * Humulus lupulus L. * transcription factors * flavonoid biosynthesis Subject RIV: EB - Genetic s ; Molecular Biology

  7. Biochemical and molecular analysis of pink tomatoes: deregulated expression of the gene encoding transcription factor SlMYB12 leads to pink tomato fruit colour

    NARCIS (Netherlands)

    Ballester, A.R.; Molthoff, J.W.; Vos, de C.H.; Lintel Hekkert, B.; Orzaez, D.; Fernandez-Moreno, J.P.; Tripodi, S.; Grandillo, S.; Martin, C.; Heldens, J.; Ykema, M.; Granell, A.; Bovy, A.G.

    2010-01-01

    The color of tomato fruit is mainly determined by carotenoids and flavonoids. Phenotypic analysis of an introgression line (IL) population derived from a cross between Solanum lycopersicum 'Moneyberg' and the wild species Solanum chmielewskii revealed three ILs with a pink fruit color. These lines

  8. Myb-binding protein 1a (Mybbp1a) regulates levels and processing of pre-ribosomal RNA.

    Science.gov (United States)

    Hochstatter, Julia; Hölzel, Michael; Rohrmoser, Michaela; Schermelleh, Lothar; Leonhardt, Heinrich; Keough, Rebecca; Gonda, Thomas J; Imhof, Axel; Eick, Dirk; Längst, Gernot; Németh, Attila

    2012-07-13

    Ribosomal RNA gene transcription, co-transcriptional processing, and ribosome biogenesis are highly coordinated processes that are tightly regulated during cell growth. In this study we discovered that Mybbp1a is associated with both the RNA polymerase I complex and the ribosome biogenesis machinery. Using a reporter assay that uncouples transcription and RNA processing, we show that Mybbp1a represses rRNA gene transcription. In addition, overexpression of the protein reduces RNA polymerase I loading on endogenous rRNA genes as revealed by chromatin immunoprecipitation experiments. Accordingly, depletion of Mybbp1a results in an accumulation of the rRNA precursor in vivo but surprisingly also causes growth arrest of the cells. This effect can be explained by the observation that the modulation of Mybbp1a protein levels results in defects in pre-rRNA processing within the cell. Therefore, the protein may play a dual role in the rRNA metabolism, potentially linking and coordinating ribosomal DNA transcription and pre-rRNA processing to allow for the efficient synthesis of ribosomes.

  9. ODORANT1 Regulates Fragrance Biosynthesis in Petunia FlowersW⃞

    Science.gov (United States)

    Verdonk, Julian C.; Haring, Michel A.; van Tunen, Arjen J.; Schuurink, Robert C.

    2005-01-01

    Floral scent is important to plant reproduction because it attracts pollinators to the sexual organs. Therefore, volatile emission is usually tuned to the foraging activity of the pollinators. In Petunia hybrida, volatile benzenoids determine the floral aroma. Although the pathways for benzenoid biosynthesis have been characterized, the enzymes involved are less well understood. How production and emission are regulated is unknown. By targeted transcriptome analyses, we identified ODORANT1 (ODO1), a member of the R2R3-type MYB family, as a candidate for the regulation of volatile benzenoids in Petunia hybrida cv W115 (Mitchell) flowers. These flowers are only fragrant in the evening and at night. Transcript levels of ODO1 increased before the onset of volatile emission and decreased when volatile emission declined. Downregulation of ODO1 in transgenic P. hybrida Mitchell plants strongly reduced volatile benzenoid levels through decreased synthesis of precursors from the shikimate pathway. The transcript levels of several genes in this pathway were reduced by suppression of ODO1 expression. Moreover, ODO1 could activate the promoter of the 5-enol-pyruvylshikimate-3-phosphate synthase gene. Flower pigmentation, which is furnished from the same shikimate precursors, was not influenced because color and scent biosynthesis occur at different developmental stages. Our studies identify ODO1 as a key regulator of floral scent biosynthesis. PMID:15805488

  10. Transcription Factor Repertoire of Necrotrophic Fungal Phytopathogen Ascochyta rabiei: Predominance of MYB Transcription Factors As Potential Regulators of Secretome

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    Sandhya Verma

    2017-06-01

    Full Text Available Transcription factors (TFs are the key players in gene expression and their study is highly significant for shedding light on the molecular mechanisms and evolutionary history of organisms. During host–pathogen interaction, extensive reprogramming of gene expression facilitated by TFs is likely to occur in both host and pathogen. To date, the knowledge about TF repertoire in filamentous fungi is in infancy. The necrotrophic fungus Ascochyta rabiei, that causes destructive Ascochyta blight (AB disease of chickpea (Cicer arietinum, demands more comprehensive study for better understanding of Ascochyta-legume pathosystem. In the present study, we performed the genome-wide identification and analysis of TFs in A. rabiei. Taking advantage of A. rabiei genome sequence, we used a bioinformatic approach to predict the TF repertoire of A. rabiei. For identification and classification of A. rabiei TFs, we designed a comprehensive pipeline using a combination of BLAST and InterProScan software. A total of 381 A. rabiei TFs were predicted and divided into 32 fungal specific families of TFs. The gene structure, domain organization and phylogenetic analysis of abundant families of A. rabiei TFs were also carried out. Comparative study of A. rabiei TFs with that of other necrotrophic, biotrophic, hemibiotrophic, symbiotic, and saprotrophic fungi was performed. It suggested presence of both conserved as well as unique features among them. Moreover, cis-acting elements on promoter sequences of earlier predicted A. rabiei secretome were also identified. With the help of published A. rabiei transcriptome data, the differential expression of TF and secretory protein coding genes was analyzed. Furthermore, comprehensive expression analysis of few selected A. rabiei TFs using quantitative real-time polymerase chain reaction revealed variety of expression patterns during host colonization. These genes were expressed in at least one of the time points tested post

  11. The Impact of XmnI-HBG2, BCL11A and HBS1L-MYB Single Nucleotide Polymorphisms on Hb F Variation of Hematologically Normal Iranian Individuals.

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    Keyhani, Elaheh; Jafari Vesiehsari, Mahjoobeh; Talebi Kakroodi, Setareh; Darabi, Elham; Zamani, Fahimeh; Karimlou, Masoud; Kamali, Koorosh; Neishabury, Maryam

    2016-06-01

    The impact of Hb F on severity of sickle cell disease and β-thalassemia (β-thal) is well documented. The XmnI-HBG2, BCL11A and HBS1L-MYB single nucleotide polymorphisms (SNPs) have been introduced as the most important factors causing variation in fetal hemoglobin (Hb F) levels in different population studies. However, the extent of their effect could be population-specific. In this study, multivariate linear regression analysis was used to evaluate the association of Hb F with age, sex, and eight SNPs, including XmnI-HBG2, four BCL11A, two HBS1L-MYB SNPs and the polymorphic palindromic 5' hypersensitive 4-locus control region (5'HS4-LCR). One hundred and twenty-two hematologically normal individuals, from a previous study cohort, constituted our study population. In multivariate regression analyses, no association of Hb F was observed with age or sex of the individuals and SNPs in this study. We conducted a univariate regression analysis to further investigate the results, which among all the factors only detected XmnI-HBG2 and 5'HS4 SNPs as significant modifiers of Hb F. The significance of these two factors disappeared in a bivariate analysis. These results suggest that either XmnI-HBG2 or 5'HS4-LCR have a stronger contribution in Hb F variations of the Iranian population than BCL11A and HBS1L-MYB SNPs. Furthermore, the effect of low population size and technical limitations on obtained results could not be ruled out.

  12. Low glutathione regulates gene expression and the redox potentials of the nucleus and cytosol in Arabidopsis thaliana.

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    Schnaubelt, Daniel; Queval, Guillaume; Dong, Yingping; Diaz-Vivancos, Pedro; Makgopa, Matome Eugene; Howell, Gareth; De Simone, Ambra; Bai, Juan; Hannah, Matthew A; Foyer, Christine H

    2015-02-01

    Reduced glutathione (GSH) is considered to exert a strong influence on cellular redox homeostasis and to regulate gene expression, but these processes remain poorly characterized. Severe GSH depletion specifically inhibited root meristem development, while low root GSH levels decreased lateral root densities. The redox potential of the nucleus and cytosol of Arabidopsis thaliana roots determined using roGFP probes was between -300 and -320 mV. Growth in the presence of the GSH-synthesis inhibitor buthionine sulfoximine (BSO) increased the nuclear and cytosolic redox potentials to approximately -260 mV. GSH-responsive genes including transcription factors (SPATULA, MYB15, MYB75), proteins involved in cell division, redox regulation (glutaredoxinS17, thioredoxins, ACHT5 and TH8) and auxin signalling (HECATE), were identified in the GSH-deficient root meristemless 1-1 (rml1-1) mutant, and in other GSH-synthesis mutants (rax1-1, cad2-1, pad2-1) as well as in the wild type following the addition of BSO. Inhibition of auxin transport had no effect on organ GSH levels, but exogenous auxin decreased the root GSH pool. We conclude that GSH depletion significantly increases the redox potentials of the nucleus and cytosol, and causes arrest of the cell cycle in roots but not shoots, with accompanying transcript changes linked to altered hormone responses, but not oxidative stress. © 2013 John Wiley & Sons Ltd.

  13. FUNCTIONAL SPECIALIZATION OF DUPLICATED FLAVONOID BIOSYNTHESIS GENES IN WHEAT

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    Khlestkina E.

    2012-08-01

    Full Text Available Gene duplication followed by subfunctionalization and neofunctionalization is of a great evolutionary importance. In plant genomes, duplicated genes may result from either polyploidization (homoeologous genes or segmental chromosome duplications (paralogous genes. In allohexaploid wheat Triticum aestivum L. (2n=6x=42, genome BBAADD, both homoeologous and paralogous copies were found for the regulatory gene Myc encoding MYC-like transcriptional factor in the biosynthesis of flavonoid pigments, anthocyanins, and for the structural gene F3h encoding one of the key enzymes of flavonoid biosynthesis, flavanone 3-hydroxylase. From the 5 copies (3 homoeologous and 2 paralogous of the Myc gene found in T. aestivum, only one plays a regulatory role in anthocyanin biosynthesis, interacting complementary with another transcriptional factor (MYB-like to confer purple pigmentation of grain pericarp in wheat. The role and functionality of the other 4 copies of the Myc gene remain unknown. From the 4 functional copies of the F3h gene in T. aestivum, three homoeologues have similar function. They are expressed in wheat organs colored with anthocyanins or in the endosperm, participating there in biosynthesis of uncolored flavonoid substances. The fourth copy (the B-genomic paralogue is transcribed neither in wheat organs colored with anthocyanins nor in seeds, however, it’s expression has been noticed in roots of aluminium-stressed plants, where the three homoeologous copies are not active. Functional diversification of the duplicated flavonoid biosynthesis genes in wheat may be a reason for maintenance of the duplicated copies and preventing them from pseudogenization.The study was supported by RFBR (11-04-92707. We also thank Ms. Galina Generalova for technical assistance.

  14. Salicylic acid promotes plant growth and salt-related gene expression in Dianthus superbus L. (Caryophyllaceae) grown under different salt stress conditions.

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    Zheng, Jian; Ma, Xiaohua; Zhang, Xule; Hu, Qingdi; Qian, Renjuan

    2018-03-01

    Salt stress is a critical factor that affects the growth and development of plants. Salicylic acid (SA) is an important signal molecule that mitigates the negative effects of salt stress on plants. To elucidate salt tolerance in large pink Dianthus superbus L. (Caryophyllaceae) and the regulatory mechanism of exogenous SA on D. superbus under different salt stresses, we conducted a pot experiment to evaluate leaf biomass, leaf anatomy, soluble protein and sugar content, and the relative expression of salt-induced genes in D. superbus under 0.3, 0.6, and 0.9% NaCl conditions with and without 0.5 mM SA. The result showed that exposure of D. superbus to salt stress lead to a decrease in leaf growth, soluble protein and sugar content, and mesophyll thickness, together with an increase in the expression of MYB and P5CS genes. Foliar application of SA effectively increased leaf biomass, soluble protein and sugar content, and upregulated the expression of MYB and P5CS in the D. superbus , which facilitated in the acclimation of D. superbus to moderate salt stress. However, when the plants were grown under severe salt stress (0.9% NaCl), no significant difference in plant physiological responses and relevant gene expression between plants with and without SA was observed. The findings of this study suggest that exogenous SA can effectively counteract the adverse effects of moderate salt stress on D. superbus growth and development.

  15. Identification of Candidate Genes and Biosynthesis Pathways Related to Fertility Conversion by Wheat KTM3315A Transcriptome Profiling

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    Lingli Zhang

    2017-04-01

    Full Text Available The Aegilops kotschyi thermo-sensitive cytoplasmic male sterility (K-TCMS system may facilitate hybrid wheat (Triticum aestivum L. seed multiplication and production. The K-TCMS line is completely male sterile during the normal wheat-growing season, whereas its fertility can be restored in a high-temperature environment. To elucidate the molecular mechanisms responsible for male sterility/fertility conversion and candidate genes involved with pollen development in K-TCMS, we employed RNA-seq to sequence the transcriptomes of anthers from K-TCMS line KTM3315A during development under sterile and fertile conditions. We identified 16840 differentially expressed genes (DEGs in different stages including15157 known genes (15135 nuclear genes and 22 plasmagenes and 1683 novel genes. Bioinformatics analysis identified possible metabolic pathways involved with fertility based on KEGG pathway enrichment of the DEGs expressed in fertile and sterile plants. We found that most of the genes encoding key enzyme in the phenylpropanoid biosynthesis and jasmonate biosynthesis pathways were significant upregulated in uninucleate, binuclate or trinucleate stage, which both interact with MYB transcription factors, and that link between all play essential roles in fertility conversion. The relevant DEGs were verified by quantitative RT-PCR. Thus, we suggested that phenylpropanoid biosynthesis and jasmonate biosynthesis pathways were involved in fertility conversion of K-TCMS wheat. This will provide a new perspective and an effective foundation for the research of molecular mechanisms of fertility conversion of CMS wheat. Fertility conversion mechanism in thermo-sensitive cytoplasmic male sterile/fertile wheat involves the phenylpropanoid biosynthesis pathway, jasmonate biosynthesis pathway, and MYB transcription factors.

  16. Genetic and molecular characterization of photoperiod and thermo-sensitive male sterility in rice.

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    Fan, Yourong; Zhang, Qifa

    2018-03-01

    A review on photoperiod and temperature-sensitive genic male sterility in rice. Male sterility in plants, facilitating the development of hybrid crops, has made great contribution to crop productivity worldwide. Environment-sensitive genic male sterility (EGMS), including photoperiod-sensitive genic male sterility (PGMS) and temperature-sensitive genic male sterility (TGMS), has provided a special class of germplasms for the breeding of "two-line" hybrids in several crops. In rice, the finding of the PGMS NK58S mutant in 1973 started the journey of research and breeding of two-line hybrids. Genetic and molecular characterization of these germplasms demonstrated diverse genes and molecular mechanisms of male sterility regulation. Two loci identified from NK58S, PMS1 and PMS3, both encode long noncoding RNAs. A major TGMS locus, TMS5, found in the TGMS line Annong S-1, encodes an RNase Z. A reverse PGMS mutant carbon starved anther encodes an R2R3 MYB transcription factor. Breeding efforts in the last three decades have resulted in hundreds of EGMS lines and two-line hybrids released to rice production, which have greatly elevated the yield potential and grain quality of rice varieties. The enhanced molecular understanding will offer new strategies for the development of EGMS lines thus further improving two-line hybrid breeding of rice as well as other crops.

  17. The effects of microgravity on gene expression of Arabidopsis

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    Correll, Melanie; Stimpson, Alexander; Pereira, Rhea; Kiss, John Z.

    TROPI (for TROPIsms) consisted of a series of experiments on the International Space Station to study the interaction between phototropism and gravitropism. As part of TROPI, we received frozen Arabidopsis seedlings from the ISS on three shuttle missions (STS-116, STS-117 and STS-120). These seedlings are being used for gene expression studies. Unfortunately, the quality of RNA returned from the first return mission was poor while that from the second and third missions were of high quality. This indicates that some environmental parameters were not maintained during first return mission since all of these samples were stored in the same location at -80° C on the ISS. Therefore, due to the loss during the first sample return, we had to develop new protocols to maximize RNA yields and optimize labeling techniques for microarray analysis. Using these new protocols, RNA was extracted from several sets of seedlings grown in various light treatments and µg levels and microarray analyses performed. Hundreds of genes were shown to be regulated in response to microgravity and include transcription factors (WRKY, MYB, ZF families) and those involved in plant hormone signaling (auxin, ethylene, and ABA responsive genes). The characterization of the regulated pathways and genes specific to gravity and light treatments is underway. (This project is Supported By: NASA NCC2-1200).

  18. Genome-wide identification and characterization of microRNA genes and their targets in flax (Linum usitatissimum): Characterization of flax miRNA genes.

    Science.gov (United States)

    Barvkar, Vitthal T; Pardeshi, Varsha C; Kale, Sandip M; Qiu, Shuqing; Rollins, Meaghen; Datla, Raju; Gupta, Vidya S; Kadoo, Narendra Y

    2013-04-01

    MicroRNAs (miRNAs) are small (20-24 nucleotide long) endogenous regulatory RNAs that play important roles in plant growth and development. They regulate gene expression at the post-transcriptional level by translational repression or target degradation and gene silencing. In this study, we identified 116 conserved miRNAs belonging to 23 families from the flax (Linum usitatissimum L.) genome using a computational approach. The precursor miRNAs varied in length; while most of the mature miRNAs were 21 nucleotide long, intergenic and showed conserved signatures of RNA polymerase II transcripts in their upstream regions. Promoter region analysis of the flax miRNA genes indicated prevalence of MYB transcription factor binding sites. Four miRNA gene clusters containing members of three phylogenetic groups were identified. Further, 142 target genes were predicted for these miRNAs and most of these represent transcriptional regulators. The miRNA encoding genes were expressed in diverse tissues as determined by digital expression analysis as well as real-time PCR. The expression of fourteen miRNAs and nine target genes was independently validated using the quantitative reverse transcription PCR (qRT-PCR). This study suggests that a large number of conserved plant miRNAs are also found in flax and these may play important roles in growth and development of flax.

  19. Exogenous Methyl Jasmonate and Salicylic Acid Induce Subspecies-Specific Patterns of Glucosinolate Accumulation and Gene Expression in Brassica oleracea L.

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    Yi, Go-Eun; Robin, Arif Hasan Khan; Yang, Kiwoung; Park, Jong-In; Hwang, Byung Ho; Nou, Ill-Sup

    2016-10-24

    Glucosinolates have anti-carcinogenic properties. In the recent decades, the genetics of glucosinolate biosynthesis has been widely studied, however, the expression of specific genes involved in glucosinolate biosynthesis under exogenous phytohormone treatment has not been explored at the subspecies level in Brassica oleracea . Such data are vital for strategies aimed at selective exploitation of glucosinolate profiles. This study quantified the expression of 38 glucosinolate biosynthesis-related genes in three B. oleracea subspecies, namely cabbage, broccoli and kale, and catalogued associations between gene expression and increased contents of individual glucosinolates under methyl jasmonate (MeJA) and salicylic acid (SA) treatments. Glucosinolate accumulation and gene expression in response to phytohormone elicitation was subspecies specific. For instance, cabbage leaves showed enhanced accumulation of the aliphatic glucoiberin, progoitrin, sinigrin and indolic neoglucobrassicin under both MeJA and SA treatment. MeJA treatment induced strikingly higher accumulation of glucobrassicin (GBS) in cabbage and kale and of neoglucobrassicin (NGBS) in broccoli compared to controls. Notably higher expression of ST5a (Bol026200), CYP81F1 (Bol028913, Bol028914) and CYP81F4 genes was associated with significantly higher GBS accumulation under MeJA treatment compared to controls in all three subspecies. CYP81F4 genes, trans-activated by MYB34 genes, were expressed at remarkably high levels in all three subspecies under MeJA treatment, which also induced in higher indolic NGBS accumulation in all three subspecies. Remarkably higher expression of MYB28 (Bol036286), ST5b , ST5c , AOP2 , FMOGS-OX5 (Bol031350) and GSL-OH (Bol033373) was associated with much higher contents of aliphatic glucosinolates in kale leaves compared to the other two subspecies. The genes expressed highly could be utilized in strategies to selectively increase glucosinolate compounds in B. oleracea

  20. Gene Therapy

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    Gene therapy Overview Gene therapy involves altering the genes inside your body's cells in an effort to treat or stop disease. Genes contain your ... that don't work properly can cause disease. Gene therapy replaces a faulty gene or adds a new ...

  1. A Malus crabapple chalcone synthase gene, McCHS, regulates red petal color and flavonoid biosynthesis.

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    Deqiang Tai

    Full Text Available Chalcone synthase is a key and often rate-limiting enzyme in the biosynthesis of anthocyanin pigments that accumulate in plant organs such as flowers and fruits, but the relationship between CHS expression and the petal coloration level in different cultivars is still unclear. In this study, three typical crabapple cultivars were chosen based on different petal colors and coloration patterns. The two extreme color cultivars, 'Royalty' and 'Flame', have dark red and white petals respectively, while the intermediate cultivar 'Radiant' has pink petals. We detected the flavoniods accumulation and the expression levels of McCHS during petals expansion process in different cultivars. The results showed McCHS have their special expression patterns in each tested cultivars, and is responsible for the red coloration and color variation in crabapple petals, especially for color fade process in 'Radiant'. Furthermore, tobacco plants constitutively expressing McCHS displayed a higher anthocyanins accumulation and a deeper red petal color compared with control untransformed lines. Moreover, the expression levels of several anthocyanin biosynthetic genes were higher in the transgenic McCHS overexpressing tobacco lines than in the control plants. A close relationship was observed between the expression of McCHS and the transcription factors McMYB4 and McMYB5 during petals development in different crabapple cultivars, suggesting that the expression of McCHS was regulated by these transcription factors. We conclude that the endogenous McCHS gene is a critical factor in the regulation of anthocyanin biosynthesis during petal coloration in Malus crabapple.

  2. Transcriptome Analysis of Early Responsive Genes in Rice during Magnaporthe oryzae Infection

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    Yiming Wang

    2014-12-01

    Full Text Available Rice blast disease caused by Magnaporthe oryzae is one of the most serious diseases of cultivated rice (Oryza sativa L. in most rice-growing regions of the world. In order to investigate early response genes in rice, we utilized the transcriptome analysis approach using a 300 K tilling microarray to rice leaves infected with compatible and incompatible M. oryzae strains. Prior to the microarray experiment, total RNA was validated by measuring the differential expression of rice defense-related marker genes (chitinase 2, barwin, PBZ1, and PR-10 by RT-PCR, and phytoalexins (sakuranetin and momilactone A with HPLC. Microarray analysis revealed that 231 genes were up-regulated (>2 fold change, p < 0.05 in the incompatible interaction compared to the compatible one. Highly expressed genes were functionally characterized into metabolic processes and oxidation-reduction categories. The oxidative stress response was induced in both early and later infection stages. Biotic stress overview from MapMan analysis revealed that the phytohormone ethylene as well as signaling molecules jasmonic acid and salicylic acid is important for defense gene regulation. WRKY and Myb transcription factors were also involved in signal transduction processes. Additionally, receptor-like kinases were more likely associated with the defense response, and their expression patterns were validated by RT-PCR. Our results suggest that candidate genes, including receptor-like protein kinases, may play a key role in disease resistance against M. oryzae attack.

  3. A chalcone isomerase-like protein enhances flavonoid production and flower pigmentation.

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    Morita, Yasumasa; Takagi, Kyoko; Fukuchi-Mizutani, Masako; Ishiguro, Kanako; Tanaka, Yoshikazu; Nitasaka, Eiji; Nakayama, Masayoshi; Saito, Norio; Kagami, Takashi; Hoshino, Atsushi; Iida, Shigeru

    2014-04-01

    Flavonoids are major pigments in plants, and their biosynthetic pathway is one of the best-studied metabolic pathways. Here we have identified three mutations within a gene that result in pale-colored flowers in the Japanese morning glory (Ipomoea nil). As the mutations lead to a reduction of the colorless flavonoid compound flavonol as well as of anthocyanins in the flower petal, the identified gene was designated enhancer of flavonoid production (EFP). EFP encodes a chalcone isomerase (CHI)-related protein classified as a type IV CHI protein. CHI is the second committed enzyme of the flavonoid biosynthetic pathway, but type IV CHI proteins are thought to lack CHI enzymatic activity, and their functions remain unknown. The spatio-temporal expression of EFP and structural genes encoding enzymes that produce flavonoids is very similar. Expression of both EFP and the structural genes is coordinately promoted by genes encoding R2R3-MYB and WD40 family proteins. The EFP gene is widely distributed in land plants, and RNAi knockdown mutants of the EFP homologs in petunia (Petunia hybrida) and torenia (Torenia hybrida) had pale-colored flowers and low amounts of anthocyanins. The flavonol and flavone contents in the knockdown petunia and torenia flowers, respectively, were also significantly decreased, suggesting that the EFP protein contributes in early step(s) of the flavonoid biosynthetic pathway to ensure production of flavonoid compounds. From these results, we conclude that EFP is an enhancer of flavonoid production and flower pigmentation, and its function is conserved among diverse land plant species. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

  4. Characterization of the human gene (TBXAS1) encoding thromboxane synthase.

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    Miyata, A; Yokoyama, C; Ihara, H; Bandoh, S; Takeda, O; Takahashi, E; Tanabe, T

    1994-09-01

    The gene encoding human thromboxane synthase (TBXAS1) was isolated from a human EMBL3 genomic library using human platelet thromboxane synthase cDNA as a probe. Nucleotide sequencing revealed that the human thromboxane synthase gene spans more than 75 kb and consists of 13 exons and 12 introns, of which the splice donor and acceptor sites conform to the GT/AG rule. The exon-intron boundaries of the thromboxane synthase gene were similar to those of the human cytochrome P450 nifedipine oxidase gene (CYP3A4) except for introns 9 and 10, although the primary sequences of these enzymes exhibited 35.8% identity each other. The 1.2-kb of the 5'-flanking region sequence contained potential binding sites for several transcription factors (AP-1, AP-2, GATA-1, CCAAT box, xenobiotic-response element, PEA-3, LF-A1, myb, basic transcription element and cAMP-response element). Primer-extension analysis indicated the multiple transcription-start sites, and the major start site was identified as an adenine residue located 142 bases upstream of the translation-initiation site. However, neither a typical TATA box nor a typical CAAT box is found within the 100-b upstream of the translation-initiation site. Southern-blot analysis revealed the presence of one copy of the thromboxane synthase gene per haploid genome. Furthermore, a fluorescence in situ hybridization study revealed that the human gene for thromboxane synthase is localized to band q33-q34 of the long arm of chromosome 7. A tissue-distribution study demonstrated that thromboxane synthase mRNA is widely expressed in human tissues and is particularly abundant in peripheral blood leukocyte, spleen, lung and liver. The low but significant levels of mRNA were observed in kidney, placenta and thymus.

  5. Population genomics of the Arabidopsis thaliana flowering time gene network.

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    Flowers, Jonathan M; Hanzawa, Yoshie; Hall, Megan C; Moore, Richard C; Purugganan, Michael D

    2009-11-01

    The time to flowering is a key component of the life-history strategy of the model plant Arabidopsis thaliana that varies quantitatively among genotypes. A significant problem for evolutionary and ecological genetics is to understand how natural selection may operate on this ecologically significant trait. Here, we conduct a population genomic study of resequencing data from 52 genes in the flowering time network. McDonald-Kreitman tests of neutrality suggested a strong excess of amino acid polymorphism when pooling across loci. This excess of replacement polymorphism across the flowering time network and a skewed derived frequency spectrum toward rare alleles for both replacement and noncoding polymorphisms relative to synonymous changes is consistent with a large class of deleterious polymorphisms segregating in these genes. Assuming selective neutrality of synonymous changes, we estimate that approximately 30% of amino acid polymorphisms are deleterious. Evidence of adaptive substitution is less prominent in our analysis. The photoperiod regulatory gene, CO, and a gibberellic acid transcription factor, AtMYB33, show evidence of adaptive fixation of amino acid mutations. A test for extended haplotypes revealed no examples of flowering time alleles with haplotypes comparable in length to those associated with the null fri(Col) allele reported previously. This suggests that the FRI gene likely has a uniquely intense or recent history of selection among the flowering time genes considered here. Although there is some evidence for adaptive evolution in these life-history genes, it appears that slightly deleterious polymorphisms are a major component of natural molecular variation in the flowering time network of A. thaliana.

  6. Global Gene-Expression Analysis to Identify Differentially Expressed Genes Critical for the Heat Stress Response in Brassica rapa.

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    Xiangshu Dong

    Full Text Available Genome-wide dissection of the heat stress response (HSR is necessary to overcome problems in crop production caused by global warming. To identify HSR genes, we profiled gene expression in two Chinese cabbage inbred lines with different thermotolerances, Chiifu and Kenshin. Many genes exhibited >2-fold changes in expression upon exposure to 0.5- 4 h at 45°C (high temperature, HT: 5.2% (2,142 genes in Chiifu and 3.7% (1,535 genes in Kenshin. The most enriched GO (Gene Ontology items included 'response to heat', 'response to reactive oxygen species (ROS', 'response to temperature stimulus', 'response to abiotic stimulus', and 'MAPKKK cascade'. In both lines, the genes most highly induced by HT encoded small heat shock proteins (Hsps and heat shock factor (Hsf-like proteins such as HsfB2A (Bra029292, whereas high-molecular weight Hsps were constitutively expressed. Other upstream HSR components were also up-regulated: ROS-scavenging genes like glutathione peroxidase 2 (BrGPX2, Bra022853, protein kinases, and phosphatases. Among heat stress (HS marker genes in Arabidopsis, only exportin 1A (XPO1A (Bra008580, Bra006382 can be applied to B. rapa for basal thermotolerance (BT and short-term acquired thermotolerance (SAT gene. CYP707A3 (Bra025083, Bra021965, which is involved in the dehydration response in Arabidopsis, was associated with membrane leakage in both lines following HS. Although many transcription factors (TF genes, including DREB2A (Bra005852, were involved in HS tolerance in both lines, Bra024224 (MYB41 and Bra021735 (a bZIP/AIR1 [Anthocyanin-Impaired-Response-1] were specific to Kenshin. Several candidate TFs involved in thermotolerance were confirmed as HSR genes by real-time PCR, and these assignments were further supported by promoter analysis. Although some of our findings are similar to those obtained using other plant species, clear differences in Brassica rapa reveal a distinct HSR in this species. Our data could also provide a

  7. Identification of Putative Genes Involved in Limonoids Biosynthesis in Citrus by Comparative Transcriptomic Analysis

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    Fusheng Wang

    2017-05-01

    Full Text Available Limonoids produced by citrus are a group of highly bioactive secondary metabolites which provide health benefits for humans. Currently there is a lack of information derived from research on the genetic mechanisms controlling the biosynthesis of limonoids, which has limited the improvement of citrus for high production of limonoids. In this study, the transcriptome sequences of leaves, phloems and seeds of pummelo (Citrus grandis (L. Osbeck at different development stages with variances in limonoids contents were used for digital gene expression profiling analysis in order to identify the genes corresponding to the biosynthesis of limonoids. Pair-wise comparison of transcriptional profiles between different tissues identified 924 differentially expressed genes commonly shared between them. Expression pattern analysis suggested that 382 genes from three conjunctive groups of K-means clustering could be possibly related to the biosynthesis of limonoids. Correlation analysis with the samples from different genotypes, and different developing tissues of the citrus revealed that the expression of 15 candidate genes were highly correlated with the contents of limonoids. Among them, the cytochrome P450s (CYP450s and transcriptional factor MYB demonstrated significantly high correlation coefficients, which indicated the importance of those genes on the biosynthesis of limonoids. CiOSC gene encoding the critical enzyme oxidosqualene cyclase (OSC for biosynthesis of the precursor of triterpene scaffolds was found positively corresponding to the accumulation of limonoids during the development of seeds. Suppressing the expression of CiOSC with VIGS (Virus-induced gene silencing demonstrated that the level of gene silencing was significantly correlated to the reduction of limonoids contents. The results indicated that the CiOSC gene plays a pivotal role in biosynthesis of limonoids.

  8. Identification of fasciclin-like arabinogalactan proteins in textile hemp (Cannabis sativa L.): in silico analyses and gene expression patterns in different tissues.

    Science.gov (United States)

    Guerriero, Gea; Mangeot-Peter, Lauralie; Legay, Sylvain; Behr, Marc; Lutts, Stanley; Siddiqui, Khawar Sohail; Hausman, Jean-Francois

    2017-09-20

    The fasciclin-like arabinogalactan proteins (FLAs) belong to the arabinogalactan protein (AGP) superfamily and are known to play different physiological roles in plants. This class of proteins was shown to participate in plant growth, development, defense against abiotic stresses and, notably, cell wall biosynthesis. Although some studies are available on the characterization of FLA genes from different species, both woody and herbaceous, no detailed information is available on the FLA family of textile hemp (Cannabis sativa L.), an economically important fibre crop. By searching the Cannabis genome and EST databases, 23 CsaFLAs have been here identified which are divided into four phylogenetic groups. A real-time qPCR analysis performed on stem tissues (isolated bast fibres and shivs sampled at three heights), hypocotyls (6-9-12-15-17-20 days-old), whole seedlings, roots, leaves and female/male flowers of the monoecious fibre variety Santhica 27, indicates that the identified FLA genes are differentially expressed. Interestingly, some hemp FLAs are expressed during early phases of fibre growth (elongation), while others are more expressed in the middle and base of the stem and thus potentially involved in secondary cell wall formation (fibre thickening). The bioinformatic analysis of the promoter regions shows that the FLAs upregulated in the younger regions of the stem share a conserved motif related to flowering control and regulation of photoperiod perception. The promoters of the FLA genes expressed at higher levels in the older stem regions, instead, share a motif putatively recognized by MYB3, a transcriptional repressor belonging to the MYB family subgroup S4. These results point to the existence of a transcriptional network fine-tuning the expression of FLA genes in the older and younger regions of the stem, as well as in the bast fibres/shivs of textile hemp. In summary, our study paves the way for future analyses on the biological functions of FLAs in

  9. Identification of unique cis-element pattern on simulated microgravity treated Arabidopsis by in silico and gene expression

    Science.gov (United States)

    Soh, Hyuncheol; Choi, Yongsang; Lee, Taek-Kyun; Yeo, Up-Dong; Han, Kyeongsik; Auh, Chungkyun; Lee, Sukchan

    2012-08-01

    Arabidopsis gene expression microarray (44 K) was used to detect genes highly induced under simulated microgravity stress (SMS). Ten SMS-inducible genes were selected from the microarray data and these 10 genes were found to be abundantly expressed in 3-week-old plants. Nine out of the 10 SMS-inducible genes were also expressed in response to the three abiotic stresses of drought, touch, and wounding in 3-week-old Arabidopsis plants respectively. However, WRKY46 was elevated only in response to SMS. Six other WRKY genes did not respond to SMS. To clarify the characteristics of the genes expressed at high levels in response to SMS, 20 cis-elements in the promoters of the 40 selected genes including the 10 SMS-inducible genes, the 6 WRKY genes, and abiotic stress-inducible genes were analyzed and their spatial positions on each promoter were determined. Four cis-elements (M/T-G-T-P from MYB1AT or TATABOX5, GT1CONSENSUS, TATABOX5, and POLASIG1) showed a unique spatial arrangement in most SMS-inducible genes including WRKY46. Therefore the M/T-G-T-P cis-element patterns identified in the promoter of WRKY46 may play important roles in regulating gene expression in response to SMS. The presences of the cis-element patterns suggest that the order or spatial positioning of certain groups of cis-elements is more important than the existence or numbers of specific cis-elements. Taken together, our data indicate that WRKY46 is a novel SMS inducible transcription factor and the unique spatial arrangement of cis-elements shown in WRKY46 promoter may play an important role for its response to SMS.

  10. The +37 kb Cebpa Enhancer Is Critical for Cebpa Myeloid Gene Expression and Contains Functional Sites that Bind SCL, GATA2, C/EBPα, PU.1, and Additional Ets Factors

    Science.gov (United States)

    Cooper, Stacy; Guo, Hong; Friedman, Alan D.

    2015-01-01

    The murine Cebpa gene contains an evolutionarily conserved 453 bp enhancer located at +37 kb that, together with its promoter, directs expression to myeloid progenitors and to long-term hematopoietic stem cells in transgenic mice. In human acute myeloid leukemia cases, the enhancer lacks point mutations but binds the RUNX1-ETO oncoprotein. The enhancer contains the H3K4me1 and H3K27Ac histone modifications, denoting an active enhancer, at progressively increasing levels as long-term hematopoietic stem cells transition to granulocyte-monocyte progenitors. We previously identified four enhancer sites that bind RUNX1 and demonstrated that their integrity is required for maximal enhancer activity in 32Dcl3 myeloid cells. The +37 kb Cebpa enhancer also contains C/EBP, Ets factor, Myb, GATA, and E-box consensus sites conserved in the human +42 kb CEBPA enhancer. Mutation of the two C/EBP, seven Ets, one Myb, two GATA, or two E-box sites reduces activity of an enhancer-promoter reporter in 32Dcl3 cells. In 293T gel shift assays, exogenous C/EBPα binds both C/EBP sites, c-Myb binds the Myb site, PU.1 binds the second Ets site, PU.1, Fli-1, ERG, and Ets1 bind the sixth Ets site, GATA2 binds both GATA sites, and SCL binds the second E-box. Endogenous hematopoietic RUNX1, PU.1, Fli-1, ERG, C/EBPα, GATA2, and SCL were previously shown to bind the enhancer, and we find that endogenous PU.1 binds the second Ets site in 32Dcl3 cells. Using CRISPR/Cas9, we developed 32Dcl3 lines in which the wild-type enhancer alleles are replaced with a variant mutant in the seven Ets sites. These lines have 20-fold reduced Cebpa mRNA when cultured in IL-3 or G-CSF, demonstrating a critical requirement for enhancer integrity for optimal Cebpa expression. In addition, these results indicate that the +37 kb Cebpa enhancer is the focus of multiple regulatory transcriptional pathways that impact its expression during normal hematopoiesis and potentially during myeloid transformation. PMID:25938608

  11. An apple B-box protein, MdCOL11, is involved in UV-B- and temperature-induced anthocyanin biosynthesis.

    Science.gov (United States)

    Bai, Songling; Saito, Takanori; Honda, Chikako; Hatsuyama, Yoshimichi; Ito, Akiko; Moriguchi, Takaya

    2014-11-01

    Our studies showed that an apple B-box protein, MdCOL11, the homolog of AtBBX22, is involved in UV-B- and temperature-induced anthocyanin biosynthesis in apple peel. Anthocyanin is responsible for the red pigmentation in apple peel and a R2R3 MYB gene, MdMYBA/1/10, a homolog of MdMYBA, controls its accumulation. Arabidopsis PAP1 is under the control of a series of upstream factors involved in light signal transduction and photomorphogenesis, such as ELONGATED HYPOCOTYL 5 (HY5) and B-box family (BBX) proteins. In this study, we identified and characterized the homolog of Arabidopsis BBX22 in apple, designated as MdCOL11. Overexpression of MdCOL11 in Arabidopsis enhanced the accumulation of anthocyanin. In apples, MdCOL11 was differentially expressed in all tissues, with the highest expression in petals and the lowest expression in the xylem. Transcripts of MdCOL11 noticeably accumulated at the ripening stage, concomitant with increases in the expressions of anthocyanin biosynthesis-related genes. In an in vitro treatment experiment, MdCOL11 was upregulated in an ultra-violet (UV)-B- and temperature-dependent manner, together with the inductions of anthocyanin biosynthesis-related genes and anthocyanin accumulation in apple peel. Furthermore, a dual-luciferase assay indicated that (1) MdCOL11 regulated the expression of MdMYBA and (2) MdCOL11 was a target of MdHY5. Taken together, our results suggest that MdCOL11 is involved in MdHY5-mediated signal transduction and regulates anthocyanin accumulation in apple peel, which sheds new light on anthocyanin accumulation in apples.

  12. A pomegranate (Punica granatum L.) WD40-repeat gene is a functional homologue of Arabidopsis TTG1 and is involved in the regulation of anthocyanin biosynthesis during pomegranate fruit development.

    Science.gov (United States)

    Ben-Simhon, Zohar; Judeinstein, Sylvie; Nadler-Hassar, Talia; Trainin, Taly; Bar-Ya'akov, Irit; Borochov-Neori, Hamutal; Holland, Doron

    2011-11-01

    Anthocyanins are the major pigments responsible for the pomegranate (Punica granatum L.) fruit skin color. The high variability in fruit external color in pomegranate cultivars reflects variations in anthocyanin composition. To identify genes involved in the regulation of anthocyanin biosynthesis pathway in the pomegranate fruit skin we have isolated, expressed and characterized the pomegranate homologue of the Arabidopsis thaliana TRANSPARENT TESTA GLABRA1 (TTG1), encoding a WD40-repeat protein. The TTG1 protein is a regulator of anthocyanins and proanthocyanidins (PAs) biosynthesis in Arabidopsis, and acts by the formation of a transcriptional regulatory complex with two other regulatory proteins: bHLH and MYB. Our results reveal that the pomegranate gene, designated PgWD40, recovered the anthocyanin, PAs, trichome and seed coat mucilage phenotype in Arabidopsis ttg1 mutant. PgWD40 expression and anthocyanin composition in the skin were analyzed during pomegranate fruit development, in two accessions that differ in skin color intensity and timing of appearance. The results indicate high positive correlation between the total cyanidin derivatives quantity (red pigments) and the expression level of PgWD40. Furthermore, strong correlation was found between the steady state levels of PgWD40 transcripts and the transcripts of pomegranate homologues of the structural genes PgDFR and PgLDOX. PgWD40, PgDFR and PgLDOX expression also correlated with the expression of pomegranate homologues of the regulatory genes PgAn1 (bHLH) and PgAn2 (MYB). On the basis of our results we propose that PgWD40 is involved in the regulation of anthocyanin biosynthesis during pomegranate fruit development and that expression of PgWD40, PgAn1 and PgAn2 in the pomegranate fruit skin is required to regulate the expression of downstream structural genes involved in the anthocyanin biosynthesis.

  13. MicroRNA-15a and -16-1 act via MYB to elevate fetal hemoglobin expression in human trisomy 13

    OpenAIRE

    Sankaran, Vijay G.; Menne, Tobias F.; Šćepanović, Danilo; Vergilio, Jo-Anne; Ji, Peng; Kim, Jinkuk; Thiru, Prathapan; Orkin, Stuart H.; Lander, Eric S.; Lodish, Harvey F.

    2011-01-01

    Many human aneuploidy syndromes have unique phenotypic consequences, but in most instances it is unclear whether these phenotypes are attributable to alterations in the dosage of specific genes. In human trisomy 13, there is delayed switching and persistence of fetal hemoglobin (HbF) and elevation of embryonic hemoglobin in newborns. Using partial trisomy cases, we mapped this trait to chromosomal band 13q14; by examining the genes in this region, two microRNAs, miR-15a and -16-1, appear as t...

  14. Identification of candidate genes associated with leaf senescence in cultivated sunflower (Helianthus annuus L..

    Directory of Open Access Journals (Sweden)

    Sebastian Moschen

    Full Text Available Cultivated sunflower (Helianthus annuus L., an important source of edible vegetable oil, shows rapid onset of senescence, which limits production by reducing photosynthetic capacity under specific growing conditions. Carbon for grain filling depends strongly on light interception by green leaf area, which diminishes during grain filling due to leaf senescence. Transcription factors (TFs regulate the progression of leaf senescence in plants and have been well explored in model systems, but information for many agronomic crops remains limited. Here, we characterize the expression profiles of a set of putative senescence associated genes (SAGs identified by a candidate gene approach and sunflower microarray expression studies. We examined a time course of sunflower leaves undergoing natural senescence and used quantitative PCR (qPCR to measure the expression of 11 candidate genes representing the NAC, WRKY, MYB and NF-Y TF families. In addition, we measured physiological parameters such as chlorophyll, total soluble sugars and nitrogen content. The expression of Ha-NAC01, Ha-NAC03, Ha-NAC04, Ha-NAC05 and Ha-MYB01 TFs increased before the remobilization rate increased and therefore, before the appearance of the first physiological symptoms of senescence, whereas Ha-NAC02 expression decreased. In addition, we also examined the trifurcate feed-forward pathway (involving ORE1, miR164, and ethylene insensitive 2 previously reported for Arabidopsis. We measured transcription of Ha-NAC01 (the sunflower homolog of ORE1 and Ha-EIN2, along with the levels of miR164, in two leaves from different stem positions, and identified differences in transcription between basal and upper leaves. Interestingly, Ha-NAC01 and Ha-EIN2 transcription profiles showed an earlier up-regulation in upper leaves of plants close to maturity, compared with basal leaves of plants at pre-anthesis stages. These results suggest that the H. annuus TFs characterized in this work could

  15. Identification of candidate genes associated with leaf senescence in cultivated sunflower (Helianthus annuus L.).

    Science.gov (United States)

    Moschen, Sebastian; Bengoa Luoni, Sofia; Paniego, Norma B; Hopp, H Esteban; Dosio, Guillermo A A; Fernandez, Paula; Heinz, Ruth A

    2014-01-01

    Cultivated sunflower (Helianthus annuus L.), an important source of edible vegetable oil, shows rapid onset of senescence, which limits production by reducing photosynthetic capacity under specific growing conditions. Carbon for grain filling depends strongly on light interception by green leaf area, which diminishes during grain filling due to leaf senescence. Transcription factors (TFs) regulate the progression of leaf senescence in plants and have been well explored in model systems, but information for many agronomic crops remains limited. Here, we characterize the expression profiles of a set of putative senescence associated genes (SAGs) identified by a candidate gene approach and sunflower microarray expression studies. We examined a time course of sunflower leaves undergoing natural senescence and used quantitative PCR (qPCR) to measure the expression of 11 candidate genes representing the NAC, WRKY, MYB and NF-Y TF families. In addition, we measured physiological parameters such as chlorophyll, total soluble sugars and nitrogen content. The expression of Ha-NAC01, Ha-NAC03, Ha-NAC04, Ha-NAC05 and Ha-MYB01 TFs increased before the remobilization rate increased and therefore, before the appearance of the first physiological symptoms of senescence, whereas Ha-NAC02 expression decreased. In addition, we also examined the trifurcate feed-forward pathway (involving ORE1, miR164, and ethylene insensitive 2) previously reported for Arabidopsis. We measured transcription of Ha-NAC01 (the sunflower homolog of ORE1) and Ha-EIN2, along with the levels of miR164, in two leaves from different stem positions, and identified differences in transcription between basal and upper leaves. Interestingly, Ha-NAC01 and Ha-EIN2 transcription profiles showed an earlier up-regulation in upper leaves of plants close to maturity, compared with basal leaves of plants at pre-anthesis stages. These results suggest that the H. annuus TFs characterized in this work could play important

  16. Gene expression

    International Nuclear Information System (INIS)

    Hildebrand, C.E.; Crawford, B.D.; Walters, R.A.; Enger, M.D.

    1983-01-01

    We prepared probes for isolating functional pieces of the metallothionein locus. The probes enabled a variety of experiments, eventually revealing two mechanisms for metallothionein gene expression, the order of the DNA coding units at the locus, and the location of the gene site in its chromosome. Once the switch regulating metallothionein synthesis was located, it could be joined by recombinant DNA methods to other, unrelated genes, then reintroduced into cells by gene-transfer techniques. The expression of these recombinant genes could then be induced by exposing the cells to Zn 2+ or Cd 2+ . We would thus take advantage of the clearly defined switching properties of the metallothionein gene to manipulate the expression of other, perhaps normally constitutive, genes. Already, despite an incomplete understanding of how the regulatory switch of the metallothionein locus operates, such experiments have been performed successfully

  17. Characterization of carotenoid hydroxylase gene promoter in Haematococcus pluvialis.

    Science.gov (United States)

    Meng, C X; Wei, W; Su, Z- L; Qin, S

    2006-10-01

    Astaxanthin, a high-value ketocarotenoid is mainly used in fish aquaculture. It also has potential in human health due to its higher antioxidant capacity than beta-carotene and vitamin E. The unicellular green alga Haematococcus pluvialis is known to accumulate astaxanthin in response to environmental stresses, such as high light intensity and salt stress. Carotenoid hydroxylase plays a key role in astaxanthin biosynthesis in H. pluvialis. In this paper, we report the characterization of a promoter-like region (-378 to -22 bp) of carotenoid hydroxylase gene by cloning, sequence analysis and functional verification of its 919 bp 5'-flanking region in H. pluvialis. The 5'-flanking region was characterized using micro-particle bombardment method and transient expression of LacZ reporter gene. Results of sequence analysis showed that the 5'-flanking region might have putative cis-acting elements, such as ABA (abscisic acid)-responsive element (ABRE), C-repeat/dehydration responsive element (C-repeat/DRE), ethylene-responsive element (ERE), heat-shock element (HSE), wound-responsive element (WUN-motif), gibberellin-responsive element (P-box), MYB-binding site (MBS) etc., except for typical TATA and CCAAT boxes. Results of 5' deletions construct and beta-galactosidase assays revealed that a highest promoter-like region might exist from -378 to -22 bp and some negative regulatory elements might lie in the region from -919 to -378 bp. Results of site-directed mutagenesis of a putative C-repeat/DRE and an ABRE-like motif in the promoter-like region (-378 to -22 bp) indicated that the putative C-repeat/DRE and ABRE-like motif might be important for expression of carotenoid hydroxylase gene.

  18. Downregulation of RWA genes in hybrid aspen affects xylan acetylation and wood saccharification.

    Science.gov (United States)

    Pawar, Prashant Mohan-Anupama; Ratke, Christine; Balasubramanian, Vimal K; Chong, Sun-Li; Gandla, Madhavi Latha; Adriasola, Mathilda; Sparrman, Tobias; Hedenström, Mattias; Szwaj, Klaudia; Derba-Maceluch, Marta; Gaertner, Cyril; Mouille, Gregory; Ezcurra, Ines; Tenkanen, Maija; Jönsson, Leif J; Mellerowicz, Ewa J

    2017-06-01

    High acetylation of angiosperm wood hinders its conversion to sugars by glycoside hydrolases, subsequent ethanol fermentation and (hence) its use for biofuel production. We studied the REDUCED WALL ACETYLATION (RWA) gene family of the hardwood model Populus to evaluate its potential for improving saccharification. The family has two clades, AB and CD, containing two genes each. All four genes are expressed in developing wood but only RWA-A and -B are activated by master switches of the secondary cell wall PtNST1 and PtMYB21. Histochemical analysis of promoter::GUS lines in hybrid aspen (Populus tremula × tremuloides) showed activation of RWA-A and -B promoters in the secondary wall formation zone, while RWA-C and -D promoter activity was diffuse. Ectopic downregulation of either clade reduced wood xylan and xyloglucan acetylation. Suppressing both clades simultaneously using the wood-specific promoter reduced wood acetylation by 25% and decreased acetylation at position 2 of Xylp in the dimethyl sulfoxide-extracted xylan. This did not affect plant growth but decreased xylose and increased glucose contents in the noncellulosic monosaccharide fraction, and increased glucose and xylose yields of wood enzymatic hydrolysis without pretreatment. Both RWA clades regulate wood xylan acetylation in aspen and are promising targets to improve wood saccharification. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  19. Endogenous and ectopic expression of telomere regulating genes in chicken embryonic fibroblasts

    International Nuclear Information System (INIS)

    Michailidis, Georgios; Saretzki, Gabriele; Hall, Judith

    2005-01-01

    In this study, we compared the endogenous expression of genes encoding telomere regulating proteins in cultured chicken embryonic fibroblasts (CEFs) and 10-day-old chicken embryos. CEFs maintained in vitro senesced and senescence was accompanied by reduced telomere length, telomerase activity, and expression of the chicken (c) TRF1 gene. There was no change in TRF2 gene expression although the major TRF2 transcript identified in 10-day-old chicken embryos encoded a truncated TRF2 protein (TRF2'), containing an N-terminal dimerisation domain but lacking a myb-related DNA binding domain and nuclear localisation signal. Senescence of the CEFs in vitro was associated with the loss of the TRF2' transcript, indicative of a novel function for the encoded protein. Senescence was also coupled with decreased expression of RAD51, but increased RAD52 expression. These data support that RAD51 independent recombination mechanisms do not function in vitro to maintain chicken telomeres. To attempt to rescue the CEFs from replicative senescence, we stably transfected passage 3 CEFs with the human telomerase reverse transcriptase (hTERT) catalytic subunit. While hTERT expression was detected in the stable transfectants neither telomerase activity nor the stabilisation of telomere length was observed, and the transfectant cells senesced at the same passage number as the untransfected cells. These data indicate that the human TERT is incompatible with the avian telomere maintenance apparatus and suggest the functioning of a species specific telomere system in the avian

  20. Isolation, characterization and expression analysis of the BABY BOOM (BBM) gene from Larix kaempferi × L. olgensis during adventitious rooting.

    Science.gov (United States)

    Li, Kui-Peng; Sun, Xiao-Mei; Han, Hua; Zhang, Shou-Gong

    2014-11-10

    The full-length cDNA and genomic sequences of the BABY BOOM (BBM) gene, designated LkBBM, were isolated from Larix kaempferi × Larix olgensis. The 3324 bp cDNA was cloned and its open reading frame (ORF) consists of 2370 nucleotides. The deduced 789 amino acid protein contains two AP2 domains and a BBM specific motif. Four conserved motifs between BBM and PLT were identified, which may be conducive to the similar function of BBM and PLT. The three dimensional (3D) structure of LkBBM was predicted and β-sheets in the AP2-R2 domain of LkBBM might recognize the specific base pairs in the major groove. Analysis of the LkBBM gene structure indicates that the gene has eight introns and nine exons. In the 5'-flanking promoter region of LkBBM, many important potential cis-acting elements were identified, such as the TATABOX5 element (a functional TATA element), ROOTMOTIFTAPOX1 element (element of root specificity), AUXREPSIAA4 element (element involved in auxin responsiveness and gene expression in root meristem), MYB1AT element (element involved in MYB recognition), ARR1AT element (element involved in cytokinin responsiveness), GARE1OSREP1 element (element involved in gibberellin responsiveness) and PYRIMIDINEBOXHVEPB1 element (element involved in abscisic acid responsiveness), which all suggested that the expression of LkBBM is highly regulated. Compared with gene expression levels in the stem, stem tip and leaf, LkBBM shows a specific expression in the root, which indicates that LkBBM plays a key role in regulating the development and growth of root in larch. In the processing of larch adventitious root formation, LkBBM started to express on the eighth day after rooting treatment and its transcript level increased continuously afterwards. According to the gene characteristics, LkBBM is proposed as a molecular marker for root primordia of larch, and the initial period of LkBBM expression may be the formation period of root primordia in the processing of adventitious

  1. Drought response in wheat: key genes and regulatory mechanisms controlling root system architecture and transpiration efficiency

    Science.gov (United States)

    Kulkarni, Manoj; Soolanayakanahally, Raju; Ogawa, Satoshi; Uga, Yusaku; Selvaraj, Michael G.; Kagale, Sateesh

    2017-12-01

    Abiotic stresses such as drought, heat, salinity and flooding threaten global food security. Crop genetic improvement with increased resilience to abiotic stresses is a critical component of crop breeding strategies. Wheat is an important cereal crop and a staple food source globally. Enhanced drought tolerance in wheat is critical for sustainable food production and global food security. Recent advances in drought tolerance research have uncovered many key genes and transcription regulators governing morpho-physiological traits. Genes controlling root architecture and stomatal development play an important role in soil moisture extraction and its retention, and therefore have been targets of molecular breeding strategies for improving drought tolerance. In this systematic review, we have summarized evidence of beneficial contributions of root and stomatal traits to plant adaptation to drought stress. Specifically, we discuss a few key genes such as DRO1 in rice and ERECTA in Arabidopsis and rice that were identified to be the enhancers of drought tolerance via regulation of root traits and transpiration efficiency. Additionally, we highlight several transcription factor families, such as ERF (ethylene response factors), DREB (dehydration responsive element binding), ZFP (zinc finger proteins), WRKY and MYB that were identified to be both positive and negative regulators of drought responses in wheat, rice, maize and/or Arabidopsis. The overall aim of this review was to provide an overview of candidate genes that have been tested as regulators of drought response in plants. The lack of a reference genome sequence for wheat and nontransgenic approaches for manipulation of gene functions in the past had impeded high-resolution interrogation of functional elements, including genes and QTLs, and their application in cultivar improvement. The recent developments in wheat genomics and reverse genetics, including the availability of a gold-standard reference genome

  2. Transcriptome analysis and anthocyanin-related genes in red leaf lettuce.

    Science.gov (United States)

    Zhang, Y Z; Xu, S Z; Cheng, Y W; Ya, H Y; Han, J M

    2016-01-29

    This study aimed to analyze the transcriptome profile of red lettuce and identify the genes involved in anthocyanin accumulation. Red leaf lettuce is a popular vegetable and popular due to its high anthocyanin content. However, there is limited information available about the genes involved in anthocyanin biosynthesis in this species. In this study, transcriptomes of 15-day-old seedlings and 40-day-old red lettuce leaves were analyzed using an Illuminia HiseqTM 2500 platform. A total of 10.6 GB clean data were obtained and de novo assembled into 83,333 unigenes with an N50 of 1067. After annotation against public databases, 51,850 unigene sequences were identified, among which 46,087 were annotated in the NCBI non-redundant protein database, and 41,752 were annotated in the Swiss-Prot database. A total of 9125 unigenes were mapped into 163 pathways using the Kyoto Encyclopedia of Genes and Genomes database. Thirty-four structural genes were found to cover the main steps of the anthocyanin pathway, including chalcone synthase, chalcone isomerase, flavanone 3-hydroxylase, flavonoid 3'-hydroxylase, flavonoid 3',5'-hydroxylase, dihydroflavonol 4-reductase, and anthocyanidin synthase. Seven MYB, three bHLH, and two WD40 genes, considered anthocyanin regulatory genes, were also identified. In addition, 3607 simple sequence repeat (SSR) markers were identified from 2916 unigenes. This research uncovered the transcriptomic characteristics of red leaf lettuce seedlings and mature plants. The identified candidate genes related to anthocyanin biosynthesis and the detected SSRs provide useful tools for future molecular breeding studies.

  3. Regulation of trichome development in tobacco by JcZFP8, a C2H2 zinc finger protein gene from Jatropha curcas L.

    Science.gov (United States)

    Shi, Xiaodong; Gu, Yuxi; Dai, Tingwei; Wu, Yang; Wu, Peng; Xu, Ying; Chen, Fang

    2018-06-05

    Trichomes are epidermal outgrowths of plant tissues that can secrete or store large quantities of secondary metabolites, which contribute to plant defense responses against stress. The use of bioengineering methods for regulating the development of trichomes and metabolism is a widely researched topic. In the present study, we demonstrate that JcZFP8, a C2H2 zinc finger protein gene from Jatropha curcas L., can regulate trichome development in transgenic tobacco. To understand the underlying mechanisms, we performed transcriptome profiling of overexpression JcZFP8 transgenic plants and wild-type tobacco. Based on the analysis of differentially expressed genes, we determined that genes of the plant hormone signal transduction pathway was significantly enriched, suggesting that these pathways were modulated in the transgenic plants. In addition, the transcript levels of the known trichome-related genes in Arabidopsis were not significantly changed, whereas CycB2 and MYB genes were differentially expressed in the transgenic plants. Despite tobacco and Arabidopsis have different types of trichomes, all the pathways were associated with C2H2 zinc finger protein genes. Our findings help us to understand the regulation of multicellular trichome formation and suggest a new metabolic engineering method for the improvement of plants. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. ThMYC4E, candidate Blue aleurone 1 gene controlling the associated trait in Triticum aestivum.

    Directory of Open Access Journals (Sweden)

    Na Li

    Full Text Available Blue aleurone is a useful and interesting trait in common wheat that was derived from related species. Here, transcriptomes of blue and white aleurone were compared for isolating Blue aleurone 1 (Ba1 transferred from Thinopyrum ponticum. In the genes involved in anthocyanin biosynthesis, only a basic helix-loop-helix (bHLH transcription factor, ThMYC4E, had a higher transcript level in blue aleurone phenotype, and was homologous to the genes on chromosome 4 of Triticum aestivum. ThMYC4E carried the characteristic domains (bHLH-MYC_N, HLH and ACT-like of a bHLH transcription factor, and clustered with genes regulating anthocyanin biosynthesis upon phylogenetic analysis. The over-expression of ThMYC4E regulated anthocyanin biosynthesis with the coexpression of the MYB transcription factor ZmC1 from maize. ThMYC4E existed in the genomes of the addition, substitution and near isogenic lines with the blue aleurone trait derived from Th. ponticum, and could not be detected in any germplasm of T. urartu, T. monococcum, T. turgidum, Aegilops tauschii or T. aestivum, with white aleurone. These results suggested that ThMYC4E was candidate Ba1 gene controlling the blue aleurone trait in T. aestivum genotypes carrying Th. ponticum introgression. The ThMYC4E isolation aids in better understanding the genetic mechanisms of the blue aleurone trait and in its more effective use during wheat breeding.

  5. Transcriptional profiles of hybrid Eucalyptus genotypes with contrasting lignin content reveal that monolignol biosynthesis-related genes regulate wood composition

    Directory of Open Access Journals (Sweden)

    Tomotaka eShinya

    2016-04-01

    Full Text Available Eucalyptus species constitutes the most widely planted hardwood trees in temperate and subtropical regions. In this study, we compared the transcript levels of genes involved in lignocellulose formation such as cellulose, hemicellulose and lignin biosynthesis in two selected three-year old hybrid Eucalyptus (Eucalyptus urophylla x E. grandis genotypes (AM063 and AM380 that have different lignin content. AM063 and AM380 had 20.2 and 35.5% of Klason lignin content and 59.0% and 48.2%, -cellulose contents, respectively. We investigated the correlation between wood properties and transcript levels of wood formation-related genes using RNA-seq with total RNAs extracted from developing xylem tissues at a breast height. Transcript levels of cell wall construction genes such as cellulose synthase (CesA and sucrose synthase (SUSY were almost the same in both genotypes. However, AM063 exhibited higher transcript levels of UDP-glucose pyrophosphorylase (UGP and xyloglucan endotransglucoxylase (XTH than those in AM380. Most monolignol biosynthesis- related isozyme genes showed higher transcript levels in AM380. These results indicate monolignol biosynthesis-related genes may regulate wood composition in Eucalyptus. Flavonoids contents were also observed at much higher levels in AM380 as a result of the elevated transcript levels of common phenylpropanoid pathway genes, phenylalanine ammonium lyase (PAL, cinnamate-4-hydroxylase (C4H and 4-coumarate-CoA ligase (4CL. Secondary plant cell wall formation is regulated by many transcription factors. We analyzed genes encoding NAC, WRKY, AP2/ERF and KNOX transcription factors and found higher transcript levels of these genes in AM380. We also observed increased transcription of some MYB and LIM domain transcription factors in AM380 compared to AM063. All these results show that genes related to monolignol biosynthesis may regulate the wood composition and help maintain the ratio of cellulose and lignin contents

  6. Identification of Gene Modules Associated with Low Temperatures Response in Bambara Groundnut by Network-Based Analysis.

    Directory of Open Access Journals (Sweden)

    Venkata Suresh Bonthala

    Full Text Available Bambara groundnut (Vigna subterranea (L. Verdc. is an African legume and is a promising underutilized crop with good seed nutritional values. Low temperature stress in a number of African countries at night, such as Botswana, can effect the growth and development of bambara groundnut, leading to losses in potential crop yield. Therefore, in this study we developed a computational pipeline to identify and analyze the genes and gene modules associated with low temperature stress responses in bambara groundnut using the cross-species microarray technique (as bambara groundnut has no microarray chip coupled with network-based analysis. Analyses of the bambara groundnut transcriptome using cross-species gene expression data resulted in the identification of 375 and 659 differentially expressed genes (p<0.01 under the sub-optimal (23°C and very sub-optimal (18°C temperatures, respectively, of which 110 genes are commonly shared between the two stress conditions. The construction of a Highest Reciprocal Rank-based gene co-expression network, followed by its partition using a Heuristic Cluster Chiseling Algorithm resulted in 6 and 7 gene modules in sub-optimal and very sub-optimal temperature stresses being identified, respectively. Modules of sub-optimal temperature stress are principally enriched with carbohydrate and lipid metabolic processes, while most of the modules of very sub-optimal temperature stress are significantly enriched with responses to stimuli and various metabolic processes. Several transcription factors (from MYB, NAC, WRKY, WHIRLY & GATA classes that may regulate the downstream genes involved in response to stimulus in order for the plant to withstand very sub-optimal temperature stress were highlighted. The identified gene modules could be useful in breeding for low-temperature stress tolerant bambara groundnut varieties.

  7. Identification of a cis-regulatory element by transient analysis of co-ordinately regulated genes

    Directory of Open Access Journals (Sweden)

    Allan Andrew C

    2008-07-01

    Full Text Available Abstract Background Transcription factors (TFs co-ordinately regulate target genes that are dispersed throughout the genome. This co-ordinate regulation is achieved, in part, through the interaction of transcription factors with conserved cis-regulatory motifs that are in close proximity to the target genes. While much is known about the families of transcription factors that regulate gene expression in plants, there are few well characterised cis-regulatory motifs. In Arabidopsis, over-expression of the MYB transcription factor PAP1 (PRODUCTION OF ANTHOCYANIN PIGMENT 1 leads to transgenic plants with elevated anthocyanin levels due to the co-ordinated up-regulation of genes in the anthocyanin biosynthetic pathway. In addition to the anthocyanin biosynthetic genes, there are a number of un-associated genes that also change in expression level. This may be a direct or indirect consequence of the over-expression of PAP1. Results Oligo array analysis of PAP1 over-expression Arabidopsis plants identified genes co-ordinately up-regulated in response to the elevated expression of this transcription factor. Transient assays on the promoter regions of 33 of these up-regulated genes identified eight promoter fragments that were transactivated by PAP1. Bioinformatic analysis on these promoters revealed a common cis-regulatory motif that we showed is required for PAP1 dependent transactivation. Conclusion Co-ordinated gene regulation by individual transcription factors is a complex collection of both direct and indirect effects. Transient transactivation assays provide a rapid method to identify direct target genes from indirect target genes. Bioinformatic analysis of the promoters of these direct target genes is able to locate motifs that are common to this sub-set of promoters, which is impossible to identify with the larger set of direct and indirect target genes. While this type of analysis does not prove a direct interaction between protein and DNA

  8. Trichoderma genes

    Science.gov (United States)

    Foreman, Pamela [Los Altos, CA; Goedegebuur, Frits [Vlaardingen, NL; Van Solingen, Pieter [Naaldwijk, NL; Ward, Michael [San Francisco, CA

    2012-06-19

    Described herein are novel gene sequences isolated from Trichoderma reesei. Two genes encoding proteins comprising a cellulose binding domain, one encoding an arabionfuranosidase and one encoding an acetylxylanesterase are described. The sequences, CIP1 and CIP2, contain a cellulose binding domain. These proteins are especially useful in the textile and detergent industry and in pulp and paper industry.

  9. Transcriptome and proteome data reveal candidate genes for pollinator attraction in sexually deceptive orchids.

    Science.gov (United States)

    Sedeek, Khalid E M; Qi, Weihong; Schauer, Monica A; Gupta, Alok K; Poveda, Lucy; Xu, Shuqing; Liu, Zhong-Jian; Grossniklaus, Ueli; Schiestl, Florian P; Schlüter, Philipp M

    2013-01-01

    Sexually deceptive orchids of the genus Ophrys mimic the mating signals of their pollinator females to attract males as pollinators. This mode of pollination is highly specific and leads to strong reproductive isolation between species. This study aims to identify candidate genes responsible for pollinator attraction and reproductive isolation between three closely related species, O. exaltata, O. sphegodes and O. garganica. Floral traits such as odour, colour and morphology are necessary for successful pollinator attraction. In particular, different odour hydrocarbon profiles have been linked to differences in specific pollinator attraction among these species. Therefore, the identification of genes involved in these traits is important for understanding the molecular basis of pollinator attraction by sexually deceptive orchids. We have created floral reference transcriptomes and proteomes for these three Ophrys species using a combination of next-generation sequencing (454 and Solexa), Sanger sequencing, and shotgun proteomics (tandem mass spectrometry). In total, 121 917 unique transcripts and 3531 proteins were identified. This represents the first orchid proteome and transcriptome from the orchid subfamily Orchidoideae. Proteome data revealed proteins corresponding to 2644 transcripts and 887 proteins not observed in the transcriptome. Candidate genes for hydrocarbon and anthocyanin biosynthesis were represented by 156 and 61 unique transcripts in 20 and 7 genes classes, respectively. Moreover, transcription factors putatively involved in the regulation of flower odour, colour and morphology were annotated, including Myb, MADS and TCP factors. Our comprehensive data set generated by combining transcriptome and proteome technologies allowed identification of candidate genes for pollinator attraction and reproductive isolation among sexually deceptive orchids. This includes genes for hydrocarbon and anthocyanin biosynthesis and regulation, and the development of

  10. Gene expression signature analysis identifies vorinostat as a candidate therapy for gastric cancer.

    Directory of Open Access Journals (Sweden)

    Sofie Claerhout

    Full Text Available Gastric cancer continues to be one of the deadliest cancers in the world and therefore identification of new drugs targeting this type of cancer is thus of significant importance. The purpose of this study was to identify and validate a therapeutic agent which might improve the outcomes for gastric cancer patients in the future.Using microarray technology, we generated a gene expression profile of human gastric cancer-specific genes from human gastric cancer tissue samples. We used this profile in the Broad Institute's Connectivity Map analysis to identify candidate therapeutic compounds for gastric cancer. We found the histone deacetylase inhibitor vorinostat as the lead compound and thus a potential therapeutic drug for gastric cancer. Vorinostat induced both apoptosis and autophagy in gastric cancer cell lines. Pharmacological and genetic inhibition of autophagy however, increased the therapeutic efficacy of vorinostat, indicating that a combination of vorinostat with autophagy inhibitors may therapeutically be more beneficial. Moreover, gene expression analysis of gastric cancer identified a collection of genes (ITGB5, TYMS, MYB, APOC1, CBX5, PLA2G2A, and KIF20A whose expression was elevated in gastric tumor tissue and downregulated more than 2-fold by vorinostat treatment in gastric cancer cell lines. In contrast, SCGB2A1, TCN1, CFD, APLP1, and NQO1 manifested a reversed pattern.We showed that analysis of gene expression signature may represent an emerging approach to discover therapeutic agents for gastric cancer, such as vorinostat. The observation of altered gene expression after vorinostat treatment may provide the clue to identify the molecular mechanism of vorinostat and those patients likely to benefit from vorinostat treatment.

  11. Gene Expression Signature Analysis Identifies Vorinostat as a Candidate Therapy for Gastric Cancer

    Science.gov (United States)

    Choi, Woonyoung; Park, Yun-Yong; Kim, KyoungHyun; Kim, Sang-Bae; Lee, Ju-Seog; Mills, Gordon B.; Cho, Jae Yong

    2011-01-01

    Background Gastric cancer continues to be one of the deadliest cancers in the world and therefore identification of new drugs targeting this type of cancer is thus of significant importance. The purpose of this study was to identify and validate a therapeutic agent which might improve the outcomes for gastric cancer patients in the future. Methodology/Principal Findings Using microarray technology, we generated a gene expression profile of human gastric cancer–specific genes from human gastric cancer tissue samples. We used this profile in the Broad Institute's Connectivity Map analysis to identify candidate therapeutic compounds for gastric cancer. We found the histone deacetylase inhibitor vorinostat as the lead compound and thus a potential therapeutic drug for gastric cancer. Vorinostat induced both apoptosis and autophagy in gastric cancer cell lines. Pharmacological and genetic inhibition of autophagy however, increased the therapeutic efficacy of vorinostat, indicating that a combination of vorinostat with autophagy inhibitors may therapeutically be more beneficial. Moreover, gene expression analysis of gastric cancer identified a collection of genes (ITGB5, TYMS, MYB, APOC1, CBX5, PLA2G2A, and KIF20A) whose expression was elevated in gastric tumor tissue and downregulated more than 2-fold by vorinostat treatment in gastric cancer cell lines. In contrast, SCGB2A1, TCN1, CFD, APLP1, and NQO1 manifested a reversed pattern. Conclusions/Significance We showed that analysis of gene expression signature may represent an emerging approach to discover therapeutic agents for gastric cancer, such as vorinostat. The observation of altered gene expression after vorinostat treatment may provide the clue to identify the molecular mechanism of vorinostat and those patients likely to benefit from vorinostat treatment. PMID:21931799

  12. P1 epigenetic regulation in leaves of high altitude maize landraces: effect of UV-B radiation

    Directory of Open Access Journals (Sweden)

    Sebastian Pablo Rius

    2016-04-01

    Full Text Available P1 is a R2R3-MYB transcription factor that regulates the accumulation of a specific group of flavonoids in maize floral tissues, such as flavones and phlobaphenes. P1 is also highly expressed in leaves of maize landraces adapted to high altitudes and higher levels of UV-B radiation. In this work, we analyzed the epigenetic regulation of the P1 gene by UV-B in leaves of different maize landraces. Our results demonstrate that DNA methylation in the P1 proximal promoter, intron1 and intron2 is decreased by UV-B in all lines analyzed; however, the basal DNA methylation levels are lower in the landraces than in B73, a low altitude inbred line. DNA demethylation by UV-B is accompanied by a decrease in H3 methylation at Lys 9 and 27, and by an increase in H3 acetylation. smRNAs complementary to specific regions of the proximal promoter and of intron 2 3' end are also decreased by UV-B; interestingly, P1 smRNA levels are lower in the landraces than in B73 both under control conditions and after UV-B exposure, suggesting that smRNAs regulate P1 expression by UV-B in maize leaves. Finally, we investigated if different P1 targets in flower tissues are also regulated by this transcription factor in response to UV-B. Some targets analyzed show an induction in maize landraces in response to UV-B, with higher basal expression levels in the landraces than in B73; however, not all the transcripts analyzed were found to be regulated by UV-B in leaves.

  13. Regulation of gene expression by manipulating transcriptional repressor activity using a novel CoSRI technology.

    Science.gov (United States)

    Xu, Yue; Li, Song Feng; Parish, Roger W

    2017-07-01

    Targeted gene manipulation is a central strategy for studying gene function and identifying related biological processes. However, a methodology for manipulating the regulatory motifs of transcription factors is lacking as these factors commonly possess multiple motifs (e.g. repression and activation motifs) which collaborate with each other to regulate multiple biological processes. We describe a novel approach designated conserved sequence-guided repressor inhibition (CoSRI) that can specifically reduce or abolish the repressive activities of transcription factors in vivo. The technology was evaluated using the chimeric MYB80-EAR transcription factor and subsequently the endogenous WUS transcription factor. The technology was employed to develop a reversible male sterility system applicable to hybrid seed production. In order to determine the capacity of the technology to regulate the activity of endogenous transcription factors, the WUS repressor was chosen. The WUS repression motif could be inhibited in vivo and the transformed plants exhibited the wus-1 phenotype. Consequently, the technology can be used to manipulate the activities of transcriptional repressor motifs regulating beneficial traits in crop plants and other eukaryotic organisms. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  14. Identification of a cis-regulatory region of a gene in Arabidopsis thaliana whose induction by dehydration is mediated by abscisic acid and requires protein synthesis.

    Science.gov (United States)

    Iwasaki, T; Yamaguchi-Shinozaki, K; Shinozaki, K

    1995-05-20

    In Arabidopsis thaliana, the induction of a dehydration-responsive gene, rd22, is mediated by abscisic acid (ABA) but the gene does not include any sequence corresponding to the consensus ABA-responsive element (ABRE), RYACGTGGYR, in its promoter region. The cis-regulatory region of the rd22 promoter was identified by monitoring the expression of beta-glucuronidase (GUS) activity in leaves of transgenic tobacco plants transformed with chimeric gene fusions constructed between 5'-deleted promoters of rd22 and the coding region of the GUS reporter gene. A 67-bp nucleotide fragment corresponding to positions -207 to -141 of the rd22 promoter conferred responsiveness to dehydration and ABA on a non-responsive promoter. The 67-bp fragment contains the sequences of the recognition sites for some transcription factors, such as MYC, MYB, and GT-1. The fact that accumulation of rd22 mRNA requires protein synthesis raises the possibility that the expression of rd22 might be regulated by one of these trans-acting protein factors whose de novo synthesis is induced by dehydration or ABA. Although the structure of the RD22 protein is very similar to that of a non-storage seed protein, USP, of Vicia faba, the expression of the GUS gene driven by the rd22 promoter in non-stressed transgenic Arabidopsis plants was found mainly in flowers and bolted stems rather than in seeds.

  15. Ageing genes

    DEFF Research Database (Denmark)

    Rattan, Suresh

    2018-01-01

    The idea of gerontogenes is in line with the evolutionary explanation of ageing as being an emergent phenomenon as a result of the imperfect maintenance and repair systems. Although evolutionary processes did not select for any specific ageing genes that restrict and determine the lifespan...... of an individual, the term ‘gerontogenes’ primarily refers to any genes that may seem to influence ageing and longevity, without being specifically selected for that role. Such genes can also be called ‘virtual gerontogenes’ by virtue of their indirect influence on the rate and process of ageing. More than 1000...... virtual gerontogenes have been associated with ageing and longevity in model organisms and humans. The ‘real’ genes, which do influence the essential lifespan of a species, and have been selected for in accordance with the evolutionary life history of the species, are known as the longevity assurance...

  16. De novo transcriptome assembly and quantification reveal differentially expressed genes between soft-seed and hard-seed pomegranate (Punica granatum L..

    Directory of Open Access Journals (Sweden)

    Hui Xue

    Full Text Available Pomegranate (Punica granatum L. belongs to Punicaceae, and is valued for its social, ecological, economic, and aesthetic values, as well as more recently for its health benefits. The 'Tunisia' variety has softer seeds and big arils that are easily swallowed. It is a widely popular fruit; however, the molecular mechanisms of the formation of hard and soft seeds is not yet clear. We conducted a de novo assembly of the seed transcriptome in P. granatum L. and revealed differential gene expression between the soft-seed and hard-seed pomegranate varieties. A total of 35.1 Gb of data were acquired in this study, including 280,881,106 raw reads. Additionally, de novo transcriptome assembly generated 132,287 transcripts and 105,743 representative unigenes; approximately 13,805 unigenes (37.7% were longer than 1,000 bp. Using bioinformatics annotation libraries, a total of 76,806 unigenes were annotated and, among the high-quality reads, 72.63% had at least one significant match to an existing gene model. Gene expression and differentially expressed genes were analyzed. The seed formation of the two pomegranate cultivars involves lignin biosynthesis and metabolism, including some genes encoding laccase and peroxidase, WRKY, MYB, and NAC transcription factors. In the hard-seed pomegranate, lignin-related genes and cellulose synthesis-related genes were highly expressed; in soft-seed pomegranates, expression of genes related to flavonoids and programmed cell death was slightly higher. We validated selection of the identified genes using qRT-PCR. This is the first transcriptome analysis of P. granatum L. This transcription sequencing greatly enriched the pomegranate molecular database, and the high-quality SSRs generated in this study will aid the gene cloning from pomegranate in the future. It provides important insights into the molecular mechanisms underlying the formation of soft seeds in pomegranate.

  17. De novo transcriptome assembly and quantification reveal differentially expressed genes between soft-seed and hard-seed pomegranate (Punica granatum L.).

    Science.gov (United States)

    Xue, Hui; Cao, Shangyin; Li, Haoxian; Zhang, Jie; Niu, Juan; Chen, Lina; Zhang, Fuhong; Zhao, Diguang

    2017-01-01

    Pomegranate (Punica granatum L.) belongs to Punicaceae, and is valued for its social, ecological, economic, and aesthetic values, as well as more recently for its health benefits. The 'Tunisia' variety has softer seeds and big arils that are easily swallowed. It is a widely popular fruit; however, the molecular mechanisms of the formation of hard and soft seeds is not yet clear. We conducted a de novo assembly of the seed transcriptome in P. granatum L. and revealed differential gene expression between the soft-seed and hard-seed pomegranate varieties. A total of 35.1 Gb of data were acquired in this study, including 280,881,106 raw reads. Additionally, de novo transcriptome assembly generated 132,287 transcripts and 105,743 representative unigenes; approximately 13,805 unigenes (37.7%) were longer than 1,000 bp. Using bioinformatics annotation libraries, a total of 76,806 unigenes were annotated and, among the high-quality reads, 72.63% had at least one significant match to an existing gene model. Gene expression and differentially expressed genes were analyzed. The seed formation of the two pomegranate cultivars involves lignin biosynthesis and metabolism, including some genes encoding laccase and peroxidase, WRKY, MYB, and NAC transcription factors. In the hard-seed pomegranate, lignin-related genes and cellulose synthesis-related genes were highly expressed; in soft-seed pomegranates, expression of genes related to flavonoids and programmed cell death was slightly higher. We validated selection of the identified genes using qRT-PCR. This is the first transcriptome analysis of P. granatum L. This transcription sequencing greatly enriched the pomegranate molecular database, and the high-quality SSRs generated in this study will aid the gene cloning from pomegranate in the future. It provides important insights into the molecular mechanisms underlying the formation of soft seeds in pomegranate.

  18. Gene doping.

    Science.gov (United States)

    Haisma, H J; de Hon, O

    2006-04-01

    Together with the rapidly increasing knowledge on genetic therapies as a promising new branch of regular medicine, the issue has arisen whether these techniques might be abused in the field of sports. Previous experiences have shown that drugs that are still in the experimental phases of research may find their way into the athletic world. Both the World Anti-Doping Agency (WADA) and the International Olympic Committee (IOC) have expressed concerns about this possibility. As a result, the method of gene doping has been included in the list of prohibited classes of substances and prohibited methods. This review addresses the possible ways in which knowledge gained in the field of genetic therapies may be misused in elite sports. Many genes are readily available which may potentially have an effect on athletic performance. The sporting world will eventually be faced with the phenomena of gene doping to improve athletic performance. A combination of developing detection methods based on gene arrays or proteomics and a clear education program on the associated risks seems to be the most promising preventive method to counteract the possible application of gene doping.

  19. Gene Locater

    DEFF Research Database (Denmark)

    Anwar, Muhammad Zohaib; Sehar, Anoosha; Rehman, Inayat-Ur

    2012-01-01

    software's for calculating recombination frequency is mostly limited to the range and flexibility of this type of analysis. GENE LOCATER is a fully customizable program for calculating recombination frequency, written in JAVA. Through an easy-to-use interface, GENE LOCATOR allows users a high degree...... of flexibility in calculating genetic linkage and displaying linkage group. Among other features, this software enables user to identify linkage groups with output visualized graphically. The program calculates interference and coefficient of coincidence with elevated accuracy in sample datasets. AVAILABILITY...

  20. Integrative analysis of copy number and gene expression in breast cancer using formalin-fixed paraffin-embedded core biopsy tissue: a feasibility study.

    Science.gov (United States)

    Iddawela, Mahesh; Rueda, Oscar; Eremin, Jenny; Eremin, Oleg; Cowley, Jed; Earl, Helena M; Caldas, Carlos

    2017-07-11

    An absence of reliable molecular markers has hampered individualised breast cancer treatments, and a major limitation for translational research is the lack of fresh tissue. There are, however, abundant banks of formalin-fixed paraffin-embedded (FFPE) tissue. This study evaluated two platforms available for the analysis of DNA copy number and gene expression using FFPE samples. The cDNA-mediated annealing, selection, extension, and ligation assay (DASL™) has been developed for gene expression analysis and the Molecular Inversion Probes assay (Oncoscan™), were used for copy number analysis using FFPE tissues. Gene expression and copy number were evaluated in core-biopsy samples from patients with breast cancer undergoing neoadjuvant chemotherapy (NAC). Forty-three core-biopsies were evaluated and characteristic copy number changes in breast cancers, gains in 1q, 8q, 11q, 17q and 20q and losses in 6q, 8p, 13q and 16q, were confirmed. Regions that frequently exhibited gains in tumours showing a pathological complete response (pCR) to NAC were 1q (55%), 8q (40%) and 17q (40%), whereas 11q11 (37%) gain was the most frequent change in non-pCR tumours. Gains associated with poor survival were 11q13 (62%), 8q24 (54%) and 20q (47%). Gene expression assessed by DASL correlated with immunohistochemistry (IHC) analysis for oestrogen receptor (ER) [area under the curve (AUC) = 0.95], progesterone receptor (PR)(AUC = 0.90) and human epidermal growth factor type-2 receptor (HER-2) (AUC = 0.96). Differential expression analysis between ER+ and ER- cancers identified over-expression of TTF1, LAF-4 and C-MYB (p ≤ 0.05), and between pCR vs non-pCRs, over-expression of CXCL9, AREG, B-MYB and under-expression of ABCG2. This study was an integrative analysis of copy number and gene expression using FFPE core biopsies and showed that molecular marker data from FFPE tissues were consistent with those in previous studies using fresh-frozen samples. FFPE tissue can provide

  1. Temporal dynamics and transcriptional control using single-cell gene expression analysis.

    Science.gov (United States)

    Kouno, Tsukasa; de Hoon, Michiel; Mar, Jessica C; Tomaru, Yasuhiro; Kawano, Mitsuoki; Carninci, Piero; Suzuki, Harukazu; Hayashizaki, Yoshihide; Shin, Jay W

    2013-01-01

    Changes in environmental conditions lead to expression variation that manifest at the level of gene regulatory networks. Despite a strong understanding of the role noise plays in synthetic biological systems, it remains unclear how propagation of expression heterogeneity in an endogenous regulatory network is distributed and utilized by cells transitioning through a key developmental event. Here we investigate the temporal dynamics of a single-cell transcriptional network of 45 transcription factors in THP-1 human myeloid monocytic leukemia cells undergoing differentiation to macrophages. We systematically measure temporal regulation of expression and variation by profiling 120 single cells at eight distinct time points, and infer highly controlled regulatory modules through which signaling operates with stochastic effects. This reveals dynamic and specific rewiring as a cellular strategy for differentiation. The integration of both positive and negative co-expression networks further identifies the proto-oncogene MYB as a network hinge to modulate both the pro- and anti-differentiation pathways. Compared to averaged cell populations, temporal single-cell expression profiling provides a much more powerful technique to probe for mechanistic insights underlying cellular differentiation. We believe that our approach will form the basis of novel strategies to study the regulation of transcription at a single-cell level.

  2. Vanillylacetone up-regulates anthocyanin accumulation and expression of anthocyanin biosynthetic genes by inducing endogenous abscisic acid in grapevine tissues.

    Science.gov (United States)

    Enoki, Shinichi; Hattori, Tomoki; Ishiai, Shiho; Tanaka, Sayumi; Mikami, Masachika; Arita, Kayo; Nagasaka, Shu; Suzuki, Shunji

    2017-12-01

    We investigated the effect of vanillylacetone (VA) on anthocyanin accumulation with aim of improving grape berry coloration. Spraying Vitis vinifera cv. Muscat Bailey A berries with VA at veraison increased sugar/acid ratio, an indicator of maturation and total anthocyanin accumulation. To elucidate the molecular mechanism underlying the effect of VA on anthocyanin accumulation, in vitro VA treatment of a grapevine cell culture was carried out. Endogenous abscisic acid (ABA) content was higher in the VA-treated cell cultures than in control at 3h after treatment. Consistent with this, the relative expression levels of anthocyanin-synthesis-related genes, including DFR, LDOX, MybA1 and UFGT, in VA-treated cell cultures were much higher than those in control, and high total anthocyanin accumulation was noted in the VA-treated cell cultures as well. These results suggest that VA up-regulates the expression of genes leading to anthocyanin accumulation by inducing endogenous ABA. In addition, VA increased total anthocyanin content in a dose-dependent manner. Although VA treatment in combination with exogenous ABA did not exhibit any synergistic effect, treatment with VA alone showed an equivalent effect to that with exogenous ABA alone on total anthocyanin accumulation. These findings point to the possibility of using VA for improving grape berry coloration. Copyright © 2017 Elsevier GmbH. All rights reserved.

  3. CmWRKY1 Enhances the Dehydration Tolerance of Chrysanthemum through the Regulation of ABA-Associated Genes.

    Directory of Open Access Journals (Sweden)

    Qingqing Fan

    Full Text Available WRKY transcription factors serve as antagonistic or synergistic regulators in a variety of abiotic stress responses in plants. Here, we show that CmWRKY1, a member of the group IIb WRKY family isolated from Chrysanthemum morifolium, exhibits no transcriptional activation in yeast cells. The subcellular localization examination showed that CmWRKY1 localizes to the nucleus in vivo. Furthermore, CmWRKY1-overexpressing transgenic lines exhibit enhanced dehydration tolerance in response to polyethylene glycol (PEG treatment compared with wild-type plants. We further confirmed that the transgenic plants exhibit suppressed expression levels of genes negatively regulated by ABA, such as PP2C, ABI1 and ABI2, and activated expression levels of genes positively regulated by ABA, such as PYL2, SnRK2.2, ABF4, MYB2, RAB18, and DREB1A. Taken together, our results indicate that CmWRKY1 plays an important role in the response to drought in chrysanthemum through an ABA-mediated pathway.

  4. Exogenous GA3 Application Enhances Xylem Development and Induces the Expression of Secondary Wall Biosynthesis Related Genes in Betula platyphylla

    Directory of Open Access Journals (Sweden)

    Huiyan Guo

    2015-09-01

    Full Text Available Gibberellin (GA is a key signal molecule inducing differentiation of tracheary elements, fibers, and xylogenesis. However the molecular mechanisms underlying the effect of GA on xylem elongation and secondary wall development in tree species remain to be determined. In this study, Betula platyphylla (birch seeds were treated with 300 ppm GA3 and/or 300 ppm paclobutrazol (PAC, seed germination was recorded, and transverse sections of hypocotyls were stained with toluidine blue; the two-month-old seedlings were treated with 50 μM GA3 and/or 50 μM PAC, transverse sections of seedling stems were stained using phloroglucinol–HCl, and secondary wall biosynthesis related genes expression was analyzed by real-time quantitative PCR. Results indicated that germination percentage, energy and time of seeds, hypocotyl height and seedling fresh weight were enhanced by GA3, and reduced by PAC; the xylem development was wider in GA3-treated plants than in the control; the expression of NAC and MYB transcription factors, CESA, PAL, and GA oxidase was up-regulated during GA3 treatment, suggesting their role in GA3-induced xylem development in the birch. Our results suggest that GA3 induces the expression of secondary wall biosynthesis related genes to trigger xylogenesis in the birch plants.

  5. Preharvest Ultraviolet C Irradiation Increased the Level of Polyphenol Accumulation and Flavonoid Pathway Gene Expression in Strawberry Fruit.

    Science.gov (United States)

    Xu, Yanqun; Charles, Marie Thérèse; Luo, Zisheng; Mimee, Benjamin; Veronneau, Pierre-Yves; Rolland, Daniel; Roussel, Dominique

    2017-11-22

    Preharvest ultraviolet C (UV-C) irradiation is an innovative approach for increasing the bioactive phytochemical content of strawberries to increase the disease resistance and nutritional value. This study investigated the changes in individual flavonoids in strawberry developed with three different cumulative doses of preharvest UV-C treatment (low, 9.6 kJ m -2 ; middle, 15 kJ m -2 ; and high , 29.4 kJ m -2 ). Significant accumulation (p radiation. The expression of the flavonoid pathway structural genes, i.e., FaCHS1, FaCHI, FaFHT, FaDFR, FaFLS, and FaFGT, was upregulated in the low- and middle-dose groups, while the early stage genes were not affected by the high dose. FaMYB1 was also relatively enhanced in the low- and middle-dose groups, while FaASR was upregulated in only the low-dose group. Hormetic preharvest UV-C dose ranges for enhancing the polyphenol content of strawberries were established for the first time.

  6. Gene Ontology

    Directory of Open Access Journals (Sweden)

    Gaston K. Mazandu

    2012-01-01

    Full Text Available The wide coverage and biological relevance of the Gene Ontology (GO, confirmed through its successful use in protein function prediction, have led to the growth in its popularity. In order to exploit the extent of biological knowledge that GO offers in describing genes or groups of genes, there is a need for an efficient, scalable similarity measure for GO terms and GO-annotated proteins. While several GO similarity measures exist, none adequately addresses all issues surrounding the design and usage of the ontology. We introduce a new metric for measuring the distance between two GO terms using the intrinsic topology of the GO-DAG, thus enabling the measurement of functional similarities between proteins based on their GO annotations. We assess the performance of this metric using a ROC analysis on human protein-protein interaction datasets and correlation coefficient analysis on the selected set of protein pairs from the CESSM online tool. This metric achieves good performance compared to the existing annotation-based GO measures. We used this new metric to assess functional similarity between orthologues, and show that it is effective at determining whether orthologues are annotated with similar functions and identifying cases where annotation is inconsistent between orthologues.

  7. Identification and characterization of cis-acting elements involved in the regulation of ABA- and/or GA-mediated LuPLR1 gene expression and lignan biosynthesis in flax (Linum usitatissimum L.) cell cultures.

    Science.gov (United States)

    Corbin, Cyrielle; Renouard, Sullivan; Lopez, Tatiana; Lamblin, Frédéric; Lainé, Eric; Hano, Christophe

    2013-03-15

    Pinoresinol lariciresinol reductase 1, encoded by the LuPLR1 gene in flax (Linum usitatissimum L.), is responsible for the biosynthesis of (+)-secoisolariciresinol, a cancer chemopreventive phytoestrogenic lignan accumulated in high amount in the hull of flaxseed. Our recent studies have demonstrated a key role of abscisic acid (ABA) in the regulation of LuPLR1 gene expression and thus of the (+)-secoisolariciresinol synthesis during the flax seedcoat development. It is well accepted that gibberellins (GA) and ABA play antagonistic roles in the regulation of numerous developmental processes; therefore it is of interest to clarify their respective effects on lignan biosynthesis. Herein, using flax cell suspension cultures, we demonstrate that LuPLR1 gene expression and (+)-secoisolariciresinol synthesis are up-regulated by ABA and down-regulated by GA. The LuPLR1 gene promoter analysis and mutation experiments allow us to identify and characterize two important cis-acting sequences (ABRE and MYB2) required for these regulations. These results imply that a cross-talk between ABA and GA signaling orchestrated by transcription factors is involved in the regulation of lignan biosynthesis. This is particularly evidenced in the case of the ABRE cis-regulatory sequence of LuPLR1 gene promoter that appears to be a common target sequence of GA and ABA signals. Copyright © 2012 Elsevier GmbH. All rights reserved.

  8. Gene doping: gene delivery for olympic victory

    OpenAIRE

    Gould, David

    2012-01-01

    With one recently recommended gene therapy in Europe and a number of other gene therapy treatments now proving effective in clinical trials it is feasible that the same technologies will soon be adopted in the world of sport by unscrupulous athletes and their trainers in so called ‘gene doping’. In this article an overview of the successful gene therapy clinical trials is provided and the potential targets for gene doping are highlighted. Depending on whether a doping gene product is secreted...

  9. Exome sequencing of oral squamous cell carcinoma in users of Arabian snuff reveals novel candidates for driver genes.

    Science.gov (United States)

    Al-Hebshi, Nezar Noor; Li, Shiyong; Nasher, Akram Thabet; El-Setouhy, Maged; Alsanosi, Rashad; Blancato, Jan; Loffredo, Christopher

    2016-07-15

    The study sought to identify genetic aberrations driving oral squamous cell carcinoma (OSCC) development among users of shammah, an Arabian preparation of smokeless tobacco. Twenty archival OSCC samples, 15 of which with a history of shammah exposure, were whole-exome sequenced at an average depth of 127×. Somatic mutations were identified using a novel, matched controls-independent filtration algorithm. CODEX and Exomedepth coupled with a novel, Database of Genomic Variant-based filter were employed to call somatic gene-copy number variations. Significantly mutated genes were identified with Oncodrive FM and the Youn and Simon's method. Candidate driver genes were nominated based on Gene Set Enrichment Analysis. The observed mutational spectrum was similar to that reported by the TCGA project. In addition to confirming known genes of OSCC (TP53, CDKNA2, CASP8, PIK3CA, HRAS, FAT1, TP63, CCND1 and FADD) the analysis identified several candidate novel driver events including mutations of NOTCH3, CSMD3, CRB1, CLTCL1, OSMR and TRPM2, amplification of the proto-oncogenes FOSL1, RELA, TRAF6, MDM2, FRS2 and BAG1, and deletion of the recently described tumor suppressor SMARCC1. Analysis also revealed significantly altered pathways not previously implicated in OSCC including Oncostatin-M signalling pathway, AP-1 and C-MYB transcription networks and endocytosis. There was a trend for higher number of mutations, amplifications and driver events in samples with history of shammah exposure particularly those that tested EBV positive, suggesting an interaction between tobacco exposure and EBV. The work provides further evidence for the genetic heterogeneity of oral cancer and suggests shammah-associated OSCC is characterized by extensive amplification of oncogenes. © 2016 UICC.

  10. Combined Analysis of the Fruit Metabolome and Transcriptome Reveals Candidate Genes Involved in Flavonoid Biosynthesis in Actinidia arguta.

    Science.gov (United States)

    Li, Yukuo; Fang, Jinbao; Qi, Xiujuan; Lin, Miaomiao; Zhong, Yunpeng; Sun, Leiming; Cui, Wen

    2018-05-15

    To assess the interrelation between the change of metabolites and the change of fruit color, we performed a combined metabolome and transcriptome analysis of the flesh in two different Actinidia arguta cultivars: "HB" ("Hongbaoshixing") and "YF" ("Yongfengyihao") at two different fruit developmental stages: 70d (days after full bloom) and 100d (days after full bloom). Metabolite and transcript profiling was obtained by ultra-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometer and high-throughput RNA sequencing, respectively. The identification and quantification results of metabolites showed that a total of 28,837 metabolites had been obtained, of which 13,715 were annotated. In comparison of HB100 vs. HB70, 41 metabolites were identified as being flavonoids, 7 of which, with significant difference, were identified as bracteatin, luteolin, dihydromyricetin, cyanidin, pelargonidin, delphinidin and (-)-epigallocatechin. Association analysis between metabolome and transcriptome revealed that there were two metabolic pathways presenting significant differences during fruit development, one of which was flavonoid biosynthesis, in which 14 structural genes were selected to conduct expression analysis, as well as 5 transcription factor genes obtained by transcriptome analysis. RT-qPCR results and cluster analysis revealed that AaF3H , AaLDOX , AaUFGT , AaMYB , AabHLH , and AaHB2 showed the best possibility of being candidate genes. A regulatory network of flavonoid biosynthesis was established to illustrate differentially expressed candidate genes involved in accumulation of metabolites with significant differences, inducing red coloring during fruit development. Such a regulatory network linking genes and flavonoids revealed a system involved in the pigmentation of all-red-fleshed and all-green-fleshed A. arguta , suggesting this conjunct analysis approach is not only useful in understanding the relationship between genotype and phenotype

  11. Light response and potential interacting proteins of a grape flavonoid 3'-hydroxylase gene promoter.

    Science.gov (United States)

    Sun, Run-Ze; Pan, Qiu-Hong; Duan, Chang-Qing; Wang, Jun

    2015-12-01

    Flavonoid 3'-hydroxylase (F3'H), a member of cytochrome P450 protein family, introduces B-ring hydroxyl group in the 3' position of the flavonoid. In this study, the cDNA sequence of a F3'H gene (VviF3'H), which contains an open reading frame of 1530 bp encoding a polypeptide of 509 amino acids, was cloned and characterized from Vitis vinifera L. cv. Cabernet Sauvignon. VviF3'H showed high homology to known F3'H genes, especially F3'Hs from the V. vinifera reference genome (Pinot Noir) and lotus. Expression profiling analysis using real-time PCR revealed that VviF3'H was ubiquitously expressed in all tested tissues including berries, leaves, flowers, roots, stems and tendrils, suggesting its important physiological role in plant growth and development. Moreover, the transcript level of VviF3'H gene in grape berries was relatively higher at early developmental stages and gradually decreased during véraison, and then increased in the mature phase. In addition, the promoter of VviF3'H was isolated by using TAIL-PCR. Yeast one-hybrid screening of the Cabernet Sauvignon cDNA library and subsequent in vivo/vitro validations revealed the interaction between VviF3'H promoter and several transcription factors, including members of HD-Zip, NAC, MYB and EIN families. A transcriptional regulation mechanism of VviF3'H expression is proposed for the first time. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  12. Differential gene expression and alternative splicing between diploid and tetraploid watermelon.

    Science.gov (United States)

    Saminathan, Thangasamy; Nimmakayala, Padma; Manohar, Sumanth; Malkaram, Sridhar; Almeida, Aldo; Cantrell, Robert; Tomason, Yan; Abburi, Lavanya; Rahman, Mohammad A; Vajja, Venkata G; Khachane, Amit; Kumar, Brajendra; Rajasimha, Harsha K; Levi, Amnon; Wehner, Todd; Reddy, Umesh K

    2015-03-01

    The exploitation of synthetic polyploids for producing seedless fruits is well known in watermelon. Tetraploid progenitors of triploid watermelon plants, compared with their diploid counterparts, exhibit wide phenotypic differences. Although many factors modulate alternative splicing (AS) in plants, the effects of autopolyploidization on AS are still unknown. In this study, we used tissues of leaf, stem, and fruit of diploid and tetraploid sweet watermelon to understand changes in gene expression and the occurrence of AS. RNA-sequencing analysis was performed along with reverse transcription quantitative PCR and rapid amplification of cDNA ends (RACE)-PCR to demonstrate changes in expression and splicing. All vegetative tissues except fruit showed an increased level of AS in the tetraploid watermelon throughout the growth period. The ploidy levels of diploids and the tetraploid were confirmed using a ploidy analyser. We identified 5362 and 1288 genes that were up- and downregulated, respectively, in tetraploid as compared with diploid plants. We further confirmed that 22 genes underwent AS events across tissues, indicating possibilities of generating different protein isoforms with altered functions of important transcription factors and transporters. Arginine biosynthesis, chlorophyllide synthesis, GDP mannose biosynthesis, trehalose biosynthesis, and starch and sucrose degradation pathways were upregulated in autotetraploids. Phloem protein 2, chloroplastic PGR5-like protein, zinc-finger protein, fructokinase-like 2, MYB transcription factor, and nodulin MtN21 showed AS in fruit tissues. These results should help in developing high-quality seedless watermelon and provide additional transcriptomic information related to other cucurbits. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  13. Profile of differentially expressed genes mediated by the type III epidermal growth factor receptor mutation expressed in a small-cell lung cancer cell line

    DEFF Research Database (Denmark)

    Pedersen, M.W.; Andersen, Thomas Thykjær; Ørntoft, Torben Falck

    2001-01-01

    Previous studies have shown a correlation between expression of the EGF receptor type III mutation (EGFRvIII) and a more malignant phenotype of various cancers including: non-small-cell lung cancer, glioblastoma multiforme, prostate cancer and breast cancer. Thus, a detailed molecular genetic...... understanding of how the EGFRvIII contributes to the malignant phenotype is of major importance for future therapy. The GeneChip Hu6800Set developed by Affymetrix was used to identify changes in gene expression caused by the expression of EGFRvIII. The cell line selected for the study was an EGF receptor...... negative small-cell-lung cancer cell line, GLC3, stably transfected with the EGFRvIII gene in a Tet-On system. By comparison of mRNA levels in EGFRvIII-GLC3 with those of Tet-On-GLC3, it was found that the levels of mRNAs encoding several transcription factors (ATF-3, JunD, and c-Myb), cell adhesion...

  14. Genes and Hearing Loss

    Science.gov (United States)

    ... ENTCareers Marketplace Find an ENT Doctor Near You Genes and Hearing Loss Genes and Hearing Loss Patient ... mutation may only have dystopia canthorum. How Do Genes Work? Genes are a road map for the ...

  15. De novo transcriptome sequencing of Acer palmatum and comprehensive analysis of differentially expressed genes under salt stress in two contrasting genotypes.

    Science.gov (United States)

    Rong, Liping; Li, Qianzhong; Li, Shushun; Tang, Ling; Wen, Jing

    2016-04-01

    Maple (Acer palmatum) is an important species for landscape planting worldwide. Salt stress affects the normal growth of the Maple leaf directly, leading to loss of esthetic value. However, the limited availability of Maple genomic information has hindered research on the mechanisms underlying this tolerance. In this study, we performed comprehensive analyses of the salt tolerance in two genotypes of Maple using RNA-seq. Approximately 146.4 million paired-end reads, representing 181,769 unigenes, were obtained. The N50 length of the unigenes was 738 bp, and their total length over 102.66 Mb. 14,090 simple sequence repeats and over 500,000 single nucleotide polymorphisms were identified, which represent useful resources for marker development. Importantly, 181,769 genes were detected in at least one library, and 303 differentially expressed genes (DEGs) were identified between salt-sensitive and salt-tolerant genotypes. Among these DEGs, 125 were upregulated and 178 were downregulated genes. Two MYB-related proteins and one LEA protein were detected among the first 10 most downregulated genes. Moreover, a methyltransferase-related gene was detected among the first 10 most upregulated genes. The three most significantly enriched pathways were plant hormone signal transduction, arginine and proline metabolism, and photosynthesis. The transcriptome analysis provided a rich genetic resource for gene discovery related to salt tolerance in Maple, and in closely related species. The data will serve as an important public information platform to further our understanding of the molecular mechanisms involved in salt tolerance in Maple.

  16. In silico analysis of cis-acting regulatory elements in 5' regulatory regions of sucrose transporter gene families in rice (Oryza sativa Japonica) and Arabidopsis thaliana.

    Science.gov (United States)

    Ibraheem, Omodele; Botha, Christiaan E J; Bradley, Graeme

    2010-12-01

    The regulation of gene expression involves a multifarious regulatory system. Each gene contains a unique combination of cis-acting regulatory sequence elements in the 5' regulatory region that determines its temporal and spatial expression. Cis-acting regulatory elements are essential transcriptional gene regulatory units; they control many biological processes and stress responses. Thus a full understanding of the transcriptional gene regulation system will depend on successful functional analyses of cis-acting elements. Cis-acting regulatory elements present within the 5' regulatory region of the sucrose transporter gene families in rice (Oryza sativa Japonica cultivar-group) and Arabidopsis thaliana, were identified using a bioinformatics approach. The possible cis-acting regulatory elements were predicted by scanning 1.5kbp of 5' regulatory regions of the sucrose transporter genes translational start sites, using Plant CARE, PLACE and Genomatix Matinspector professional databases. Several cis-acting regulatory elements that are associated with plant development, plant hormonal regulation and stress response were identified, and were present in varying frequencies within the 1.5kbp of 5' regulatory region, among which are; A-box, RY, CAT, Pyrimidine-box, Sucrose-box, ABRE, ARF, ERE, GARE, Me-JA, ARE, DRE, GA-motif, GATA, GT-1, MYC, MYB, W-box, and I-box. This result reveals the probable cis-acting regulatory elements that possibly are involved in the expression and regulation of sucrose transporter gene families in rice and Arabidopsis thaliana during cellular development or environmental stress conditions. Copyright © 2010 Elsevier Ltd. All rights reserved.

  17. Molecular cloning and characterization of a novel salt-inducible gene encoding an acidic isoform of PR-5 protein in soybean (Glycine max [L.] Merr.).

    Science.gov (United States)

    Onishi, M; Tachi, H; Kojima, T; Shiraiwa, M; Takahara, H

    2006-10-01

    We identified a novel salt-inducible soybean gene encoding an acidic-isoform of pathogenesis-related protein group 5 (PR-5 protein). The soybean PR-5-homologous gene, designated as Glycine max osmotin-like protein, acidic isoform (GmOLPa)), encodes a putative polypeptide having an N-terminal signal peptide. The mature GmOLPa protein without the signal peptide has a calculated molecular mass of 21.5 kDa and a pI value of 4.4, and was distinguishable from a known PR-5-homologous gene of soybean (namely P21 protein) through examination of the structural features. A comparison with two intracellular salt-inducible PR-5 proteins, tobacco osmotin and tomato NP24, revealed that GmOLPa did not have a C-terminal extension sequence functioning as a vacuole-targeting motif. The GmOLPa gene was transcribed constitutively in the soybean root and was induced almost exclusively in the root during 24 h of high-salt stress (300 mM NaCl). Interestingly, GmOLPa gene expression in the stem and leaf, not observed until 24 h, was markedly induced at 48 and 72 h after commencement of the high-salt stress. Abscisic acid (ABA) and dehydration also induced expression of the GmOLPa gene in the root; additionally, dehydration slightly induced expression in the stem and leaf. In fact, the 5'-upstream sequence of the GmOLPa gene contained several putative cis-elements known to be involved in responsiveness to ABA and dehydration, e.g. ABA-responsive element (ABRE), MYB/MYC, and low temperature-responsive element (LTRE). These results suggested that GmOLPa may function as a protective PR-5 protein in the extracellular space of the soybean root in response to high-salt stress and dehydration.

  18. Role of c-Myb in chondrogenesis

    Czech Academy of Sciences Publication Activity Database

    Oralová, Veronika; Matalová, Eva; Janečková, Eva; Drobná Krejčí, E.; Knopfová, L.; Šnajdr, P.; Tucker, A. S.; Veselá, I.; Šmarda, J.; Buchtová, Marcela

    2015-01-01

    Roč. 76, č. 1 (2015), s. 97-106 ISSN 8756-3282 R&D Projects: GA ČR GCP302/12/J059; GA ČR GB14-37368G Institutional support: RVO:67985904 Keywords : micromass cultures * mouse limbs * endochondral bone Subject RIV: EA - Cell Biology Impact factor: 3.736, year: 2015

  19. Gene expression and gene therapy imaging

    International Nuclear Information System (INIS)

    Rome, Claire; Couillaud, Franck; Moonen, Chrit T.W.

    2007-01-01

    The fast growing field of molecular imaging has achieved major advances in imaging gene expression, an important element of gene therapy. Gene expression imaging is based on specific probes or contrast agents that allow either direct or indirect spatio-temporal evaluation of gene expression. Direct evaluation is possible with, for example, contrast agents that bind directly to a specific target (e.g., receptor). Indirect evaluation may be achieved by using specific substrate probes for a target enzyme. The use of marker genes, also called reporter genes, is an essential element of MI approaches for gene expression in gene therapy. The marker gene may not have a therapeutic role itself, but by coupling the marker gene to a therapeutic gene, expression of the marker gene reports on the expression of the therapeutic gene. Nuclear medicine and optical approaches are highly sensitive (detection of probes in the picomolar range), whereas MRI and ultrasound imaging are less sensitive and require amplification techniques and/or accumulation of contrast agents in enlarged contrast particles. Recently developed MI techniques are particularly relevant for gene therapy. Amongst these are the possibility to track gene therapy vectors such as stem cells, and the techniques that allow spatiotemporal control of gene expression by non-invasive heating (with MRI guided focused ultrasound) and the use of temperature sensitive promoters. (orig.)

  20. Imaging reporter gene for monitoring gene therapy

    International Nuclear Information System (INIS)

    Beco, V. de; Baillet, G.; Tamgac, F.; Tofighi, M.; Weinmann, P.; Vergote, J.; Moretti, J.L.; Tamgac, G.

    2002-01-01

    Scintigraphic images can be obtained to document gene function at cellular level. This approach is presented here and the use of a reporter gene to monitor gene therapy is described. Two main ways are presented: either the use of a reporter gene coding for an enzyme the action of which will be monitored by radiolabeled pro-drug, or a cellular receptor gene, the action of which is documented by a radio labeled cognate receptor ligand. (author)

  1. Drought Response in Wheat: Key Genes and Regulatory Mechanisms Controlling Root System Architecture and Transpiration Efficiency

    Directory of Open Access Journals (Sweden)

    Manoj Kulkarni

    2017-12-01

    Full Text Available Abiotic stresses such as, drought, heat, salinity, and flooding threaten global food security. Crop genetic improvement with increased resilience to abiotic stresses is a critical component of crop breeding strategies. Wheat is an important cereal crop and a staple food source globally. Enhanced drought tolerance in wheat is critical for sustainable food production and global food security. Recent advances in drought tolerance research have uncovered many key genes and transcription regulators governing morpho-physiological traits. Genes controlling root architecture and stomatal development play an important role in soil moisture extraction and its retention, and therefore have been targets of molecular breeding strategies for improving drought tolerance. In this systematic review, we have summarized evidence of beneficial contributions of root and stomatal traits to plant adaptation to drought stress. Specifically, we discuss a few key genes such as, DRO1 in rice and ERECTA in Arabidopsis and rice that were identified to be the enhancers of drought tolerance via regulation of root traits and transpiration efficiency. Additionally, we highlight several transcription factor families, such as, ERF (ethylene response factors, DREB (dehydration responsive element binding, ZFP (zinc finger proteins, WRKY, and MYB that were identified to be both positive and negative regulators of drought responses in wheat, rice, maize, and/or Arabidopsis. The overall aim of this review is to provide an overview of candidate genes that have been identified as regulators of drought response in plants. The lack of a reference genome sequence for wheat and non-transgenic approaches for manipulation of gene functions in wheat in the past had impeded high-resolution interrogation of functional elements, including genes and QTLs, and their application in cultivar improvement. The recent developments in wheat genomics and reverse genetics, including the availability of a

  2. Transcriptome Analysis of Flower Sex Differentiation in Jatropha curcas L. Using RNA Sequencing.

    Science.gov (United States)

    Xu, Gang; Huang, Jian; Yang, Yong; Yao, Yin-an

    2016-01-01

    Jatropha curcas is thought to be a promising biofuel material, but its yield is restricted by a low ratio of instaminate/staminate flowers (1/10-1/30). Furthermore, valuable information about flower sex differentiation in this plant is scarce. To explore the mechanism of this process in J. curcas, transcriptome profiling of flower development was carried out, and certain genes related with sex differentiation were obtained through digital gene expression analysis of flower buds from different phases of floral development. After Illumina sequencing and clustering, 57,962 unigenes were identified. A total of 47,423 unigenes were annotated, with 85 being related to carpel and stamen differentiation, 126 involved in carpel and stamen development, and 592 functioning in the later development stage for the maturation of staminate or instaminate flowers. Annotation of these genes provided comprehensive information regarding the sex differentiation of flowers, including the signaling system, hormone biosynthesis and regulation, transcription regulation and ubiquitin-mediated proteolysis. A further expression pattern analysis of 15 sex-related genes using quantitative real-time PCR revealed that gibberellin-regulated protein 4-like protein and AMP-activated protein kinase are associated with stamen differentiation, whereas auxin response factor 6-like protein, AGAMOUS-like 20 protein, CLAVATA1, RING-H2 finger protein ATL3J, auxin-induced protein 22D, and r2r3-myb transcription factor contribute to embryo sac development in the instaminate flower. Cytokinin oxidase, Unigene28, auxin repressed-like protein ARP1, gibberellin receptor protein GID1 and auxin-induced protein X10A are involved in both stages mentioned above. In addition to its function in the differentiation and development of the stamens, the gibberellin signaling pathway also functions in embryo sac development for the instaminate flower. The auxin signaling pathway also participates in both stamen development

  3. Genetic control of functional traits related to photosynthesis and water use efficiency in Pinus pinaster Ait. drought response: integration of genome annotation, allele association and QTL detection for candidate gene identification.

    Science.gov (United States)

    de Miguel, Marina; Cabezas, José-Antonio; de María, Nuria; Sánchez-Gómez, David; Guevara, María-Ángeles; Vélez, María-Dolores; Sáez-Laguna, Enrique; Díaz, Luis-Manuel; Mancha, Jose-Antonio; Barbero, María-Carmen; Collada, Carmen; Díaz-Sala, Carmen; Aranda, Ismael; Cervera, María-Teresa

    2014-06-12

    Understanding molecular mechanisms that control photosynthesis and water use efficiency in response to drought is crucial for plant species from dry areas. This study aimed to identify QTL for these traits in a Mediterranean conifer and tested their stability under drought. High density linkage maps for Pinus pinaster were used in the detection of QTL for photosynthesis and water use efficiency at three water irrigation regimes. A total of 28 significant and 27 suggestive QTL were found. QTL detected for photochemical traits accounted for the higher percentage of phenotypic variance. Functional annotation of genes within the QTL suggested 58 candidate genes for the analyzed traits. Allele association analysis in selected candidate genes showed three SNPs located in a MYB transcription factor that were significantly associated with efficiency of energy capture by open PSII reaction centers and specific leaf area. The integration of QTL mapping of functional traits, genome annotation and allele association yielded several candidate genes involved with molecular control of photosynthesis and water use efficiency in response to drought in a conifer species. The results obtained highlight the importance of maintaining the integrity of the photochemical machinery in P. pinaster drought response.

  4. Alteration of Transcripts of Stress-Protective Genes and Transcriptional Factors by γ-Aminobutyric Acid (GABA Associated with Improved Heat and Drought Tolerance in Creeping Bentgrass (Agrostis stolonifera

    Directory of Open Access Journals (Sweden)

    Zhou Li

    2018-05-01

    Full Text Available Gamma-aminobutyric acid (GABA may play a positive role in regulating plant tolerance to drought or heat stress. The objectives of this study were to investigate the physiological effects of GABA on tolerance of creeping bentgrass (Agrostis stolonifera to heat and drought stress and to determine whether enhanced heat and drought tolerance due to GABA treatment was associated with the up-regulation of selected genes and transcriptional factors involved in stress protection. Creeping bentgrass (cultivar “Penncross” plants were treated with 0.5 mM GABA or water (untreated control as a foliar spray and were subsequently exposed to heat stress (35/30 °C, day/night, drought stress by withholding irrigation, or non-stress conditions in controlled-environment growth chambers. Exogenous application of GABA significantly improved plant tolerance to heat and drought stress, as reflected by increased leaf water content, cell membrane stability, and chlorophyll content. The analysis of gene transcript level revealed that exogenous GABA up-regulated the expression of ABF3, POD, APX, HSP90, DHN3, and MT1 during heat stress and the expression of CDPK26, MAPK1, ABF3, WRKY75, MYB13, HSP70, MT1, 14-3-3, and genes (SOD, CAT, POD, APX, MDHAR, DHAR, and GR encoding antioxidant enzymes during drought stress. The up-regulation of the aforementioned stress-protective genes and transcriptional factors could contribute to improved heat and drought tolerance in creeping bentgrass.

  5. Alteration of Transcripts of Stress-Protective Genes and Transcriptional Factors by γ-Aminobutyric Acid (GABA) Associated with Improved Heat and Drought Tolerance in Creeping Bentgrass (Agrostis stolonifera).

    Science.gov (United States)

    Li, Zhou; Peng, Yan; Huang, Bingru

    2018-05-31

    Gamma-aminobutyric acid (GABA) may play a positive role in regulating plant tolerance to drought or heat stress. The objectives of this study were to investigate the physiological effects of GABA on tolerance of creeping bentgrass ( Agrostis stolonifera ) to heat and drought stress and to determine whether enhanced heat and drought tolerance due to GABA treatment was associated with the up-regulation of selected genes and transcriptional factors involved in stress protection. Creeping bentgrass (cultivar "Penncross") plants were treated with 0.5 mM GABA or water (untreated control) as a foliar spray and were subsequently exposed to heat stress (35/30 °C, day/night), drought stress by withholding irrigation, or non-stress conditions in controlled-environment growth chambers. Exogenous application of GABA significantly improved plant tolerance to heat and drought stress, as reflected by increased leaf water content, cell membrane stability, and chlorophyll content. The analysis of gene transcript level revealed that exogenous GABA up-regulated the expression of ABF3 , POD , APX , HSP90 , DHN3 , and MT1 during heat stress and the expression of CDPK26 , MAPK1 , ABF3 , WRKY75 , MYB13 , HSP70 , MT1 , 14-3-3 , and genes ( SOD , CAT , POD , APX , MDHAR , DHAR , and GR ) encoding antioxidant enzymes during drought stress. The up-regulation of the aforementioned stress-protective genes and transcriptional factors could contribute to improved heat and drought tolerance in creeping bentgrass.

  6. Genome-Wide Identification and Analysis of Drought-Responsive Genes and MicroRNAs in Tobacco

    Directory of Open Access Journals (Sweden)

    Fuqiang Yin

    2015-03-01

    Full Text Available Drought stress response is a complex trait regulated at transcriptional and post-transcriptional levels in tobacco. Since the 1990s, many studies have shown that miRNAs act in many ways to regulate target expression in plant growth, development and stress response. The recent draft genome sequence of Nicotiana benthamiana has provided a framework for Digital Gene Expression (DGE and small RNA sequencing to understand patterns of transcription in the context of plant response to environmental stress. We sequenced and analyzed three Digital Gene Expression (DGE libraries from roots of normal and drought-stressed tobacco plants, and four small RNA populations from roots, stems and leaves of control or drought-treated tobacco plants, respectively. We identified 276 candidate drought responsive genes (DRGs with sequence similarities to 64 known DRGs from other model plant crops, 82 were transcription factors (TFs including WRKY, NAC, ERF and bZIP families. Of these tobacco DRGs, 54 differentially expressed DRGs included 21 TFs, which belonged to 4 TF families such as NAC (6, MYB (4, ERF (10, and bZIP (1. Additionally, we confirmed expression of 39 known miRNA families (122 members and five conserved miRNA families, which showed differential regulation under drought stress. Targets of miRNAs were further surveyed based on a recently published study, of which ten targets were DRGs. An integrated gene regulatory network is proposed for the molecular mechanisms of tobacco root response to drought stress using differentially expressed DRGs, the changed expression profiles of miRNAs and their target transcripts. This network analysis serves as a reference for future studies on tobacco response stresses such as drought, cold and heavy metals.

  7. Methylation effect on chalcone synthase gene expression determines anthocyanin pigmentation in floral tissues of two Oncidium orchid cultivars.

    Science.gov (United States)

    Liu, Xiao-Jing; Chuang, Yao-Nung; Chiou, Chung-Yi; Chin, Dan-Chu; Shen, Fu-Quan; Yeh, Kai-Wun

    2012-08-01

    The anthocyanin-biosynthetic pathway was studied in flowers of Oncidium Gower Ramsey with yellow floral color and mosaic red anthocyanin in lip crests, sepals and petals, and compared with the anthocyanin biosynthesis in flowers of Oncidium Honey Dollp, a natural somatoclone derived from tissue culture of Gower Ramsey, with a yellow perianth without red anthocyanins in floral tissues. HPLC analysis revealed that the red anthocyanin in lip crests of the Gower Ramsey cultivar comprised peonidin-3-O-glucoside, delphinidin-3-O-glucoside and cyanidin-3-O-glucoside, whereas Honey Dollp was devoid of anthocyanin compounds. Among the five anthocyanin-biosynthetic genes, OgCHS was actively expressed in lip crests of Gower Ramsey flowers, but no transcripts of OgCHS were detected in Honey Dollp floral tissues. Transient expression of OgCHS by bombardment confirmed that recovery of the OgCHS gene expression completed the anthocyanin pathway and produced anthocyanin compounds in lip crests of Honey Dollp flowers. Transcription factor genes regulating anthocyanin biosynthesis showed no distinctive differences in the expression level of OgMYB1, OgbHLH and OgWD40 between the two cultivars. A methylation assay revealed that the promoter of OgCHS was not methylated in Gower Ramsey, while a positive methylation effect was present in the upstream promoter region of OgCHS in Honey Dollp. Overall, our results suggest that the failure of anthocyanin accumulation in Honey Dollp floral tissues may be attributed to inactivation of the OgCHS gene resulting from the epigenetic methylation of 5'-upstream promoter region.

  8. Expression Profiling of Glucosinolate Biosynthetic Genes in Brassica oleracea L. var. capitata Inbred Lines Reveals Their Association with Glucosinolate Content

    Directory of Open Access Journals (Sweden)

    Arif Hasan Khan Robin

    2016-06-01

    Full Text Available Glucosinolates are the biochemical compounds that provide defense to plants against pathogens and herbivores. In this study, the relative expression level of 48 glucosinolate biosynthesis genes was explored in four morphologically-different cabbage inbred lines by qPCR analysis. The content of aliphatic and indolic glucosinolate molecules present in those cabbage lines was also estimated by HPLC analysis. The possible association between glucosinolate accumulation and related gene expression level was explored by principal component analysis (PCA. The genotype-dependent variation in the relative expression level of different aliphatic and indolic glucosinolate biosynthesis genes is the novel result of this study. A total of eight different types of glucosinolates, including five aliphatic and three indolic glucosinolates, was detected in four cabbage lines. Three inbred lines BN3383, BN4059 and BN4072 had no glucoraphanin, sinigrin and gluconapin detected, but the inbred line BN3273 had these three aliphatic glucosinolate compounds. PCA revealed that a higher expression level of ST5b genes and lower expression of GSL-OH was associated with the accumulation of these three aliphatic glucosinolate compounds. PCA further revealed that comparatively higher accumulation of neoglucobrassicin in the inbred line, BN4072, was associated with a high level of expression of MYB34 (Bol017062 and CYP81F1 genes. The Dof1 and IQD1 genes probably trans-activated the genes related to biosynthesis of glucoerucin and methoxyglucobrassicin for their comparatively higher accumulation in the BN4059 and BN4072 lines compared to the other two lines, BN3273 and BN3383. A comparatively higher progoitrin level in BN3273 was probably associated with the higher expression level of the GSL-OH gene. The cabbage inbred line BN3383 accounted for the significantly higher relative expression level for the 12 genes out of 48, but this line had comparatively lower total

  9. Expression Profile of Stress-responsive Arabidopsis thaliana miRNAs and their Target Genes in Response to Inoculation with Pectobacterium carotovorum subsp. carotovorum.

    Science.gov (United States)

    Djami-Tchatchou, A T; Ntushelo, K

    2017-01-01

    Pectobacterium carotovorum subsp. carotovorum (Pcc) is a soft rot bacterium which upon entry into the plant macerates plant tissues by producing plant cell wall degrading enzymes. It has a wide host range which includes carrot, potato, tomato, leafy greens, squash and other cucurbits, onion, green peppers and cassava. During plant-microbe interactions, one of the ways of plant response to pathogen infection is through the small RNA silencing mechanism. Under pathogen attack the plant utilizes microRNAs to regulate gene expression by means of mediating gene silencing at transcriptional and post-transcriptional level. This study aims to assess for the first time, the expression profile of some stress-responsive miRNA and differential expression pattern of their target genes in Arabidopsis thaliana inoculated with Pcc. Leaves of five weeks old Arabidopsis thaliana plants were infected with Pcc and the quantitative real time-PCR, was used to investigate after 0, 24, 48 and 72 h post infection, the expression profiling of the stress-responsive miRNAs which include: miR156, miR159, miR169, miR393, miR396 miR398, miR399 and miR408 along with their target genes which include: Squamosa promoter-binding-like protein, myb domain protein 101, nuclear factor Y subunit A8, concanavalin A-like lectin protein kinase, growth regulating factor 4, copper superoxide dismutase, ubiquitin-protein ligase and plantacyanin respectively. The findings showed that the overexpression of 6 miRNAs at 24, 48 and 72 h after infection resulted in the repression of their target genes and the expression of 2 miRNAs didn't affect their target genes. These results provide the first indication of the miRNAs role in response to the infection of Pcc in A. thaliana and open new vistas for a better understanding of miRNA regulation of plant response to Pcc.

  10. The dynamic changes of DNA methylation and histone modifications of salt responsive transcription factor genes in soybean.

    Directory of Open Access Journals (Sweden)

    Yuguang Song

    Full Text Available Epigenetic modification contributes to the regulation of gene expression and plant development under salinity stress. Here we describe the identification of 49 soybean transcription factors by microarray analysis as being inducible by salinity stress. A semi-quantitative RT-PCR-based expression assay confirmed the salinity stress inducibility of 45 of these 49 transcription factors, and showed that ten of them were up-regulated when seedlings were exposed to the demethylation agent 5-aza-2-deoxycytidine. Salinity stress was shown to affect the methylation status of four of these ten transcription factors (one MYB, one b-ZIP and two AP2/DREB family members using a combination of bisulfite sequencing and DNA methylation-sensitive DNA gel blot analysis. ChIP analysis indicated that the activation of three of the four DNA methylated transcription factors was correlated with an increased level of histone H3K4 trimethylation and H3K9 acetylation, and/or a reduced level of H3K9 demethylation in various parts of the promoter or coding regions. Our results suggest a critical role for some transcription factors' activation/repression by DNA methylation and/or histone modifications in soybean tolerance to salinity stress.

  11. Modulation of flavonoid biosynthetic pathway genes and anthocyanins due to virus infection in grapevine (Vitis vinifera L. leaves

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    Gutha Linga R

    2010-08-01

    Full Text Available Abstract Background Symptoms of grapevine leafroll disease (GLRD in red-fruited wine grape (Vitis vinifera L. cultivars consist of green veins and red and reddish-purple discoloration of inter-veinal areas of leaves. The reddish-purple color of symptomatic leaves may be due to the accumulation of anthocyanins and could reflect an up-regulation of genes involved in their biosynthesis. Results We examined six putative constitutively expressed genes, Ubiquitin, Actin, GAPDH, EF1-a, SAND and NAD5, for their potential as references for normalization of gene expression in reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR. Using the geNorm program, a combination of two genes (Actin and NAD5 was identified as the stable set of reference genes for normalization of gene expression data obtained from grapevine leaves. By using gene-specific RT-qPCR in combination with a reliable normalization factor, we compared relative expression of the flavonoid biosynthetic pathway genes between leaves infected with Grapevine leafroll-associated virus 3 (GLRaV-3 and exhibiting GLRD symptoms and virus-free green leaves obtained from a red-fruited wine grape cultivar (cv. Merlot. The expression levels of these different genes ranged from two- to fifty-fold increase in virus-infected leaves. Among them, CHS3, F3'5'H, F3H1, LDOX, LAR1 and MybA1 showed greater than 10-fold increase suggesting that they were expressed at significantly higher levels in virus-infected symptomatic leaves. HPLC profiling of anthocyanins extracted from leaves indicated the presence of cyanidin-3-glucoside and malvidin-3-glucoside only in virus-infected symptomatic leaves. The results also showed 24% higher levels of flavonols in virus-infected symptomatic leaves than in virus-free green leaves, with quercetin followed by myricetin being the predominant compounds. Proanthocyanidins, estimated as total tannins by protein precipitation method, were 36% higher in virus

  12. The Journey of a Transcription Factor

    DEFF Research Database (Denmark)

    Pireyre, Marie

    Plants have developed astonishing networks regulating their metabolism to adapt to their environment. The complexity of these networks is illustrated by the expansion of families of regulators such as transcription factors in the plant kingdom. Transcription factors specifically impact...... transcriptional networks by integrating exogenous and endogenous stimuli and regulating gene expression accordingly. Regulation of transcription factors and their activation is thus highly important to modulate the transcriptional programs and increase fitness of the plant in a given environment. Plant metabolism....... The biosynthetic machinery of GLS is governed by interplay of six MYB and three bHLH transcription factors. MYB28, MYB29 and MYB76 regulate methionine-derived GLS, and MYB51, MYB34 and MYB122 regulate tryptophan-derived GLS. The three bHLH transcription factors MYC2, MYC3 and MYC4 physically interact with all six...

  13. Imaging gene expression in gene therapy

    International Nuclear Information System (INIS)

    Wiebe, Leonard I.

    1997-01-01

    Full text. Gene therapy can be used to introduce new genes, or to supplement the function of indigenous genes. At the present time, however, there is non-invasive test to demonstrate efficacy of the gene transfer and expression processes. It has been postulated that scintigraphic imaging can offer unique information on both the site at which the transferred gene is expressed, and the degree of expression, both of which are critical issue for safety and clinical efficacy. Many current studies are based on 'suicide gene therapy' of cancer. Cells modified to express these genes commit metabolic suicide in the presence of an enzyme encoded by the transferred gene and a specifically-convertible pro drug. Pro drug metabolism can lead to selective metabolic trapping, required for scintigraphy. Herpes simplex virus type-1 thymidine kinase (H S V-1 t k + ) has been use for 'suicide' in vivo tumor gene therapy. It has been proposed that radiolabelled nucleosides can be used as radiopharmaceuticals to detect H S V-1 t k + gene expression where the H S V-1 t k + gene serves a reporter or therapeutic function. Animal gene therapy models have been studied using purine-([ 18 F]F H P G; [ 18 F]-A C V), and pyrimidine- ([ 123 / 131 I]I V R F U; [ 124 / 131I ]) antiviral nucleosides. Principles of gene therapy and gene therapy imaging will be reviewed and experimental data for [ 123 / 131I ]I V R F U imaging with the H S V-1 t k + reporter gene will be presented

  14. Imaging gene expression in gene therapy

    Energy Technology Data Exchange (ETDEWEB)

    Wiebe, Leonard I. [Alberta Univ., Edmonton (Canada). Noujaim Institute for Pharmaceutical Oncology Research

    1997-12-31

    Full text. Gene therapy can be used to introduce new genes, or to supplement the function of indigenous genes. At the present time, however, there is non-invasive test to demonstrate efficacy of the gene transfer and expression processes. It has been postulated that scintigraphic imaging can offer unique information on both the site at which the transferred gene is expressed, and the degree of expression, both of which are critical issue for safety and clinical efficacy. Many current studies are based on `suicide gene therapy` of cancer. Cells modified to express these genes commit metabolic suicide in the presence of an enzyme encoded by the transferred gene and a specifically-convertible pro drug. Pro drug metabolism can lead to selective metabolic trapping, required for scintigraphy. Herpes simplex virus type-1 thymidine kinase (H S V-1 t k{sup +}) has been use for `suicide` in vivo tumor gene therapy. It has been proposed that radiolabelled nucleosides can be used as radiopharmaceuticals to detect H S V-1 t k{sup +} gene expression where the H S V-1 t k{sup +} gene serves a reporter or therapeutic function. Animal gene therapy models have been studied using purine-([{sup 18} F]F H P G; [{sup 18} F]-A C V), and pyrimidine- ([{sup 123}/{sup 131} I]I V R F U; [{sup 124}/{sup 131I}]) antiviral nucleosides. Principles of gene therapy and gene therapy imaging will be reviewed and experimental data for [{sup 123}/{sup 131I}]I V R F U imaging with the H S V-1 t k{sup +} reporter gene will be presented

  15. Involvement of co-repressor LUH and the adapter proteins SLK1 and SLK2 in the regulation of abiotic stress response genes in Arabidopsis.

    Science.gov (United States)

    Shrestha, Barsha; Guragain, Bhuwan; Sridhar, Vaniyambadi V

    2014-02-24

    During abiotic stress many genes that are important for growth and adaptation to stress are expressed at elevated levels. However, the mechanisms that keep the stress responsive genes from expressing under non stress conditions remain elusive. Recent genetic characterization of the co-repressor LEUNIG_HOMOLOG (LUH) and transcriptional adaptor proteins SEUSS-LIKE1 (SLK1) and SLK2 have been proposed to function redundantly in diverse developmental processes; however their function in the abiotic stress response is unknown. Moreover, the molecular functions of LUH, SLK1 and SLK2 remain obscure. Here, we show the molecular function of LUH, SLK1 and SLK2 and the role of this complex in the abiotic stress response. The luh, slk1 and slk2 mutant plants shows enhanced tolerance to salt and osmotic stress conditions. SLK1 and SLK2 interact physically with the LUFS domain in LUH forming SLK1-LUH and SLK2-LUH co-repressor complexes to inhibit the transcription. LUH has repressor activity, whereas SLK1 and SLK2 function as adaptors to recruit LUH, which in turn recruits histone deacetylase to the target sequences to repress transcription. The stress response genes RD20, MYB2 and NAC019 are expressed at elevated levels in the luh, slk1 and slk2 mutant plants. Furthermore, these stress response genes are associated with decreased nucleosome density and increased acetylation levels at H3K9 and H3K14 in the luh, slk1 and slk2 mutant plants. Our results indicate that SLK1, SLK2 and LUH form a co-repressor complex. LUH represses by means of an epigenetic process involving histone modification to facilitate the condensation of chromatin thus preventing transcription at the target genes.

  16. Gene doping: gene delivery for olympic victory.

    Science.gov (United States)

    Gould, David

    2013-08-01

    With one recently recommended gene therapy in Europe and a number of other gene therapy treatments now proving effective in clinical trials it is feasible that the same technologies will soon be adopted in the world of sport by unscrupulous athletes and their trainers in so called 'gene doping'. In this article an overview of the successful gene therapy clinical trials is provided and the potential targets for gene doping are highlighted. Depending on whether a doping gene product is secreted from the engineered cells or is retained locally to, or inside engineered cells will, to some extent, determine the likelihood of detection. It is clear that effective gene delivery technologies now exist and it is important that detection and prevention plans are in place. © 2012 The Author. British Journal of Clinical Pharmacology © 2012 The British Pharmacological Society.

  17. GmGBP1, a homolog of human ski interacting protein in soybean, regulates flowering and stress tolerance in Arabidopsis

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    Zhang Yanwei

    2013-02-01

    Full Text Available Abstract Background SKIP is a transcription cofactor in many eukaryotes. It can regulate plant stress tolerance in rice and Arabidopsis. But the homolog of SKIP protein in soybean has been not reported up to now. Results In this study, the expression patterns of soybean GAMYB binding protein gene (GmGBP1 encoding a homolog of SKIP protein were analyzed in soybean under abiotic stresses and different day lengths. The expression of GmGBP1 was induced by polyethyleneglycol 6000, NaCl, gibberellin, abscisic acid and heat stress. GmGBP1 had transcriptional activity in C-terminal. GmGBP1 could interact with R2R3 domain of GmGAMYB1 in SKIP domain to take part in gibberellin flowering pathway. In long-day (16 h-light condition, transgenic Arabidopsis with the ectopic overexpression of GmGBP1 exhibited earlier flowering and less number of rosette leaves; Suppression of AtSKIP in Arabidopsis resulted in growth arrest, flowering delay and down-regulation of many flowering-related genes (CONSTANS, FLOWERING LOCUS T, LEAFY; Arabidopsis myb33 mutant plants with ectopic overexpression of GmGBP1 showed the same flowering phenotype with wild type. In short-day (8 h-light condition, transgenic Arabidopsis plants with GmGBP1 flowered later and showed a higher level of FLOWERING LOCUS C compared with wild type. When treated with abiotic stresses, transgenic Arabidopsis with the ectopic overexpression of GmGBP1 enhanced the tolerances to heat and drought stresses but reduced the tolerance to high salinity, and affected the expressions of several stress-related genes. Conclusions In Arabidopsis, GmGBP1 might positively regulate the flowering time by affecting CONSTANS, FLOWERING LOCUS T, LEAFY and GAMYB directly or indirectly in photoperiodic and gibberellin pathways in LDs, but GmGBP1 might represse flowering by affecting FLOWERING LOCUS C and SHORT VEGETATIVE PHASE in autonomous pathway in SDs. GmGBP1 might regulate the activity of ROS-eliminating to improve the

  18. A Novel G-Protein-Coupled Receptors Gene from Upland Cotton Enhances Salt Stress Tolerance in Transgenic Arabidopsis.

    Science.gov (United States)

    Lu, Pu; Magwanga, Richard Odongo; Lu, Hejun; Kirungu, Joy Nyangasi; Wei, Yangyang; Dong, Qi; Wang, Xingxing; Cai, Xiaoyan; Zhou, Zhongli; Wang, Kunbo; Liu, Fang

    2018-04-12

    Plants have developed a number of survival strategies which are significant for enhancing their adaptation to various biotic and abiotic stress factors. At the transcriptome level, G-protein-coupled receptors (GPCRs) are of great significance, enabling the plants to detect a wide range of endogenous and exogenous signals which are employed by the plants in regulating various responses in development and adaptation. In this research work, we carried out genome-wide analysis of target of Myb1 ( TOM1 ), a member of the GPCR gene family. The functional role of TOM1 in salt stress tolerance was studied using a transgenic Arabidopsis plants over-expressing the gene. By the use of the functional domain PF06454, we obtained 16 TOM genes members in Gossypium hirsutum , 9 in Gossypium arboreum , and 11 in Gossypium raimondii . The genes had varying physiochemical properties, and it is significant to note that all the grand average of hydropathy (GRAVY) values were less than one, indicating that all are hydrophobic in nature. In all the genes analysed here, both the exonic and intronic regions were found. The expression level of Gh_A07G0747 (GhTOM) was significantly high in the transgenic lines as compared to the wild type; a similar trend in expression was observed in all the salt-related genes tested in this study. The study in epidermal cells confirmed the localization of the protein coded by the gene TOM1 in the plasma membrane. Analysis of anti-oxidant enzymes showed higher concentrations of antioxidants in transgenic lines and relatively lower levels of oxidant substances such as H₂O₂. The low malondialdehyde (MDA) level in transgenic lines indicated that the transgenic lines had relatively low level of oxidative damage compared to the wild types. The results obtained indicate that Gh_A07G0747 (GhTOM) can be a putative target gene for enhancing salt stress tolerance in plants and could be exploited in the future for the development of salt stress-tolerant cotton

  19. A Novel G-Protein-Coupled Receptors Gene from Upland Cotton Enhances Salt Stress Tolerance in Transgenic Arabidopsis

    Directory of Open Access Journals (Sweden)

    Pu Lu

    2018-04-01

    Full Text Available Plants have developed a number of survival strategies which are significant for enhancing their adaptation to various biotic and abiotic stress factors. At the transcriptome level, G-protein-coupled receptors (GPCRs are of great significance, enabling the plants to detect a wide range of endogenous and exogenous signals which are employed by the plants in regulating various responses in development and adaptation. In this research work, we carried out genome-wide analysis of target of Myb1 (TOM1, a member of the GPCR gene family. The functional role of TOM1 in salt stress tolerance was studied using a transgenic Arabidopsis plants over-expressing the gene. By the use of the functional domain PF06454, we obtained 16 TOM genes members in Gossypium hirsutum, 9 in Gossypium arboreum, and 11 in Gossypium raimondii. The genes had varying physiochemical properties, and it is significant to note that all the grand average of hydropathy (GRAVY values were less than one, indicating that all are hydrophobic in nature. In all the genes analysed here, both the exonic and intronic regions were found. The expression level of Gh_A07G0747 (GhTOM was significantly high in the transgenic lines as compared to the wild type; a similar trend in expression was observed in all the salt-related genes tested in this study. The study in epidermal cells confirmed the localization of the protein coded by the gene TOM1 in the plasma membrane. Analysis of anti-oxidant enzymes showed higher concentrations of antioxidants in transgenic lines and relatively lower levels of oxidant substances such as H2O2. The low malondialdehyde (MDA level in transgenic lines indicated that the transgenic lines had relatively low level of oxidative damage compared to the wild types. The results obtained indicate that Gh_A07G0747 (GhTOM can be a putative target gene for enhancing salt stress tolerance in plants and could be exploited in the future for the development of salt stress

  20. RNA Sequencing and Coexpression Analysis Reveal Key Genes Involved in α-Linolenic Acid Biosynthesis in Perilla frutescens Seed

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    Tianyuan Zhang

    2017-11-01

    Full Text Available Perilla frutescen is used as traditional food and medicine in East Asia. Its seeds contain high levels of α-linolenic acid (ALA, which is important for health, but is scarce in our daily meals. Previous reports on RNA-seq of perilla seed had identified fatty acid (FA and triacylglycerol (TAG synthesis genes, but the underlying mechanism of ALA biosynthesis and its regulation still need to be further explored. So we conducted Illumina RNA-sequencing in seven temporal developmental stages of perilla seeds. Sequencing generated a total of 127 million clean reads, containing 15.88 Gb of valid data. The de novo assembly of sequence reads yielded 64,156 unigenes with an average length of 777 bp. A total of 39,760 unigenes were annotated and 11,693 unigenes were found to be differentially expressed in all samples. According to Kyoto Encyclopedia of Genes and Genomes (KEGG pathway analysis, 486 unigenes were annotated in the “lipid metabolism” pathway. Of these, 150 unigenes were found to be involved in fatty acid (FA biosynthesis and triacylglycerol (TAG assembly in perilla seeds. A coexpression analysis showed that a total of 104 genes were highly coexpressed (r > 0.95. The coexpression network could be divided into two main subnetworks showing over expression in the medium or earlier and late phases, respectively. In order to identify the putative regulatory genes, a transcription factor (TF analysis was performed. This led to the identification of 45 gene families, mainly including the AP2-EREBP, bHLH, MYB, and NAC families, etc. After coexpression analysis of TFs with highly expression of FAD2 and FAD3 genes, 162 TFs were found to be significantly associated with two FAD genes (r > 0.95. Those TFs were predicted to be the key regulatory factors in ALA biosynthesis in perilla seed. The qRT-PCR analysis also verified the relevance of expression pattern between two FAD genes and partial candidate TFs. Although it has been reported that some TFs

  1. Evolution of homeobox genes.

    Science.gov (United States)

    Holland, Peter W H

    2013-01-01

    Many homeobox genes encode transcription factors with regulatory roles in animal and plant development. Homeobox genes are found in almost all eukaryotes, and have diversified into 11 gene classes and over 100 gene families in animal evolution, and 10 to 14 gene classes in plants. The largest group in animals is the ANTP class which includes the well-known Hox genes, plus other genes implicated in development including ParaHox (Cdx, Xlox, Gsx), Evx, Dlx, En, NK4, NK3, Msx, and Nanog. Genomic data suggest that the ANTP class diversified by extensive tandem duplication to generate a large array of genes, including an NK gene cluster and a hypothetical ProtoHox gene cluster that duplicated to generate Hox and ParaHox genes. Expression and functional data suggest that NK, Hox, and ParaHox gene clusters acquired distinct roles in patterning the mesoderm, nervous system, and gut. The PRD class is also diverse and includes Pax2/5/8, Pax3/7, Pax4/6, Gsc, Hesx, Otx, Otp, and Pitx genes. PRD genes are not generally arranged in ancient genomic clusters, although the Dux, Obox, and Rhox gene clusters arose in mammalian evolution as did several non-clustered PRD genes. Tandem duplication and genome duplication expanded the number of homeobox genes, possibly contributing to the evolution of developmental complexity, but homeobox gene loss must not be ignored. Evolutionary changes to homeobox gene expression have also been documented, including Hox gene expression patterns shifting in concert with segmental diversification in vertebrates and crustaceans, and deletion of a Pitx1 gene enhancer in pelvic-reduced sticklebacks. WIREs Dev Biol 2013, 2:31-45. doi: 10.1002/wdev.78 For further resources related to this article, please visit the WIREs website. The author declares that he has no conflicts of interest. Copyright © 2012 Wiley Periodicals, Inc.

  2. Gene cluster statistics with gene families.

    Science.gov (United States)

    Raghupathy, Narayanan; Durand, Dannie

    2009-05-01

    Identifying genomic regions that descended from a common ancestor is important for understanding the function and evolution of genomes. In distantly related genomes, clusters of homologous gene pairs are evidence of candidate homologous regions. Demonstrating the statistical significance of such "gene clusters" is an essential component of comparative genomic analyses. However, currently there are no practical statistical tests for gene clusters that model the influence of the number of homologs in each gene family on cluster significance. In this work, we demonstrate empirically that failure to incorporate gene family size in gene cluster statistics results in overestimation of significance, leading to incorrect conclusions. We further present novel analytical methods for estimating gene cluster significance that take gene family size into account. Our methods do not require complete genome data and are suitable for testing individual clusters found in local regions, such as contigs in an unfinished assembly. We consider pairs of regions drawn from the same genome (paralogous clusters), as well as regions drawn from two different genomes (orthologous clusters). Determining cluster significance under general models of gene family size is computationally intractable. By assuming that all gene families are of equal size, we obtain analytical expressions that allow fast approximation of cluster probabilities. We evaluate the accuracy of this approximation by comparing the resulting gene cluster probabilities with cluster probabilities obtained by simulating a realistic, power-law distributed model of gene family size, with parameters inferred from genomic data. Surprisingly, despite the simplicity of the underlying assumption, our method accurately approximates the true cluster probabilities. It slightly overestimates these probabilities, yielding a conservative test. We present additional simulation results indicating the best choice of parameter values for data

  3. Carboxylesterase 1 genes

    DEFF Research Database (Denmark)

    Rasmussen, Henrik Berg; Madsen, Majbritt Busk

    2018-01-01

    The carboxylesterase 1 gene (CES1) encodes a hydrolase that metabolizes commonly used drugs. The CES1-related pseudogene, carboxylesterase 1 pseudogene 1 (CES1P1), has been implicated in gene exchange with CES1 and in the formation of hybrid genes including the carboxylesterase 1A2 gene (CES1A2...

  4. Transcriptomic events involved in melon mature-fruit abscission comprise the sequential induction of cell-wall degrading genes coupled to a stimulation of endo and exocytosis.

    Directory of Open Access Journals (Sweden)

    Jorge Corbacho

    Full Text Available Mature-fruit abscission (MFA in fleshy-fruit is a genetically controlled process with mechanisms that, contrary to immature-fruit abscission, has not been fully characterized. Here, we use pyrosequencing to characterize the transcriptomes of melon abscission zone (AZ at three stages during AZ-cell separation in order to understand MFA control at an early stage of AZ-activation.The results show that by early induction of MFA, the melon AZ exhibits major gene induction, while by late induction of MFA, melon AZ shows major gene repression. Although some genes displayed similar regulation in both early and late induction of abscission, such as EXT1-EXT4, EGase1, IAA2, ERF1, AP2D15, FLC, MADS2, ERAF17, SAP5 and SCL13 genes, the majority had different expression patterns. This implies that time-specific events occur during MFA, and emphasizes the value of characterizing multiple time-specific abscission transcriptomes. Analysis of gene-expression from these AZs reveal that a sequential induction of cell-wall-degrading genes is associated with the upregulation of genes involved in endo and exocytosis, and a shift in plant-hormone metabolism and signaling genes during MFA. This is accompanied by transcriptional activity of small-GTPases and synthaxins together with tubulins, dynamins, V-type ATPases and kinesin-like proteins potentially involved in MFA signaling. Early events are potentially controlled by down-regulation of MADS-box, AP2/ERF and Aux/IAA transcription-factors, and up-regulation of homeobox, zinc finger, bZIP, and WRKY transcription-factors, while late events may be controlled by up-regulation of MYB transcription-factors.Overall, the data provide a comprehensive view on MFA in fleshy-fruit, identifying candidate genes and pathways associated with early induction of MFA. Our comprehensive gene-expression profile will be very useful for elucidating gene regulatory networks of the MFA in fleshy-fruit.

  5. Allelic variants of OsSUB1A cause differential expression of transcription factor genes in response to submergence in rice.

    Science.gov (United States)

    Sharma, Niharika; Dang, Trang Minh; Singh, Namrata; Ruzicic, Slobodan; Mueller-Roeber, Bernd; Baumann, Ute; Heuer, Sigrid

    2018-01-08

    Flooding during seasonal monsoons affects millions of hectares of rice-cultivated areas across Asia. Submerged rice plants die within a week due to lack of oxygen, light and excessive elongation growth to escape the water. Submergence tolerance was first reported in an aus-type rice landrace, FR13A, and the ethylene-responsive transcription factor (TF) gene SUB1A-1 was identified as the major tolerance gene. Intolerant rice varieties generally lack the SUB1A gene but some intermediate tolerant varieties, such as IR64, carry the allelic variant SUB1A-2. Differential effects of the two alleles have so far not been addressed. As a first step, we have therefore quantified and compared the expression of nearly 2500 rice TF genes between IR64 and its derived tolerant near isogenic line IR64-Sub1, which carries the SUB1A-1 allele. Gene expression was studied in internodes, where the main difference in expression between the two alleles was previously shown. Nineteen and twenty-six TF genes were identified that responded to submergence in IR64 and IR64-Sub1, respectively. Only one gene was found to be submergence-responsive in both, suggesting different regulatory pathways under submergence in the two genotypes. These differentially expressed genes (DEGs) mainly included MYB, NAC, TIFY and Zn-finger TFs, and most genes were downregulated upon submergence. In IR64, but not in IR64-Sub1, SUB1B and SUB1C, which are also present in the Sub1 locus, were identified as submergence responsive. Four TFs were not submergence responsive but exhibited constitutive, genotype-specific differential expression. Most of the identified submergence responsive DEGs are associated with regulatory hormonal pathways, i.e. gibberellins (GA), abscisic acid (ABA), and jasmonic acid (JA), apart from ethylene. An in-silico promoter analysis of the two genotypes revealed the presence of allele-specific single nucleotide polymorphisms, giving rise to ABRE, DRE/CRT, CARE and Site II cis-elements, which

  6. CCoAOMT Down-Regulation Activates Anthocyanin Biosynthesis in Petunia1

    Science.gov (United States)

    Shaipulah, Nur Fariza M.; Muhlemann, Joëlle K.; Woodworth, Benjamin D.; Van Moerkercke, Alex; Ramirez, Aldana A.; Haring, Michel A.; Schuurink, Robert C.

    2016-01-01

    Anthocyanins and volatile phenylpropenes (isoeugenol and eugenol) in petunia (Petunia hybrida) flowers have the precursor 4-coumaryl coenzyme A (CoA) in common. These phenolics are produced at different stages during flower development. Anthocyanins are synthesized during early stages of flower development and sequestered in vacuoles during the lifespan of the flowers. The production of isoeugenol and eugenol starts when flowers open and peaks after anthesis. To elucidate additional biochemical steps toward (iso)eugenol production, we cloned and characterized a caffeoyl-coenzyme A O-methyltransferase (PhCCoAOMT1) from the petals of the fragrant petunia ‘Mitchell’. Recombinant PhCCoAOMT1 indeed catalyzed the methylation of caffeoyl-CoA to produce feruloyl CoA. Silencing of PhCCoAOMT1 resulted in a reduction of eugenol production but not of isoeugenol. Unexpectedly, the transgenic plants had purple-colored leaves and pink flowers, despite the fact that cv Mitchell lacks the functional R2R3-MYB master regulator ANTHOCYANIN2 and has normally white flowers. Our results indicate that down-regulation of PhCCoAOMT1 activated the anthocyanin pathway through the R2R3-MYBs PURPLE HAZE (PHZ) and DEEP PURPLE, with predominantly petunidin accumulating. Feeding cv Mitchell flowers with caffeic acid induced PHZ expression, suggesting that the metabolic perturbation of the phenylpropanoid pathway underlies the activation of the anthocyanin pathway. Our results demonstrate a role for PhCCoAOMT1 in phenylpropene production and reveal a link between PhCCoAOMT1 and anthocyanin production. PMID:26620524

  7. CCoAOMT Down-Regulation Activates Anthocyanin Biosynthesis in Petunia.

    Science.gov (United States)

    Shaipulah, Nur Fariza M; Muhlemann, Joëlle K; Woodworth, Benjamin D; Van Moerkercke, Alex; Verdonk, Julian C; Ramirez, Aldana A; Haring, Michel A; Dudareva, Natalia; Schuurink, Robert C

    2016-02-01

    Anthocyanins and volatile phenylpropenes (isoeugenol and eugenol) in petunia (Petunia hybrida) flowers have the precursor 4-coumaryl coenzyme A (CoA) in common. These phenolics are produced at different stages during flower development. Anthocyanins are synthesized during early stages of flower development and sequestered in vacuoles during the lifespan of the flowers. The production of isoeugenol and eugenol starts when flowers open and peaks after anthesis. To elucidate additional biochemical steps toward (iso)eugenol production, we cloned and characterized a caffeoyl-coenzyme A O-methyltransferase (PhCCoAOMT1) from the petals of the fragrant petunia 'Mitchell'. Recombinant PhCCoAOMT1 indeed catalyzed the methylation of caffeoyl-CoA to produce feruloyl CoA. Silencing of PhCCoAOMT1 resulted in a reduction of eugenol production but not of isoeugenol. Unexpectedly, the transgenic plants had purple-colored leaves and pink flowers, despite the fact that cv Mitchell lacks the functional R2R3-MYB master regulator ANTHOCYANIN2 and has normally white flowers. Our results indicate that down-regulation of PhCCoAOMT1 activated the anthocyanin pathway through the R2R3-MYBs PURPLE HAZE (PHZ) and DEEP PURPLE, with predominantly petunidin accumulating. Feeding cv Mitchell flowers with caffeic acid induced PHZ expression, suggesting that the metabolic perturbation of the phenylpropanoid pathway underlies the activation of the anthocyanin pathway. Our results demonstrate a role for PhCCoAOMT1 in phenylpropene production and reveal a link between PhCCoAOMT1 and anthocyanin production. © 2016 American Society of Plant Biologists. All Rights Reserved.

  8. Overexpression of the OsIMP Gene Increases the Accumulation of Inositol and Confers Enhanced Cold Tolerance in Tobacco through Modulation of the Antioxidant Enzymes’ Activities

    Directory of Open Access Journals (Sweden)

    Rong-Xiang Zhang

    2017-07-01

    Full Text Available Inositol is a cyclic polyol that is involved in various physiological processes, including signal transduction and stress adaptation in plants. l-myo-inositol monophosphatase (IMPase is one of the metal-dependent phosphatase family members and catalyzes the last reaction step of biosynthesis of inositol. Although increased IMPase activity induced by abiotic stress has been reported in chickpea plants, the role and regulation of the IMP gene in rice (Oryza sativa L. remains poorly understood. In the present work, we obtained a full-length cDNA sequence coding IMPase in the cold tolerant rice landraces in Gaogonggui, which is named as OsIMP. Multiple alignment results have displayed that this sequence has characteristic signature motifs and conserved enzyme active sites of the phosphatase super family. Phylogenetic analysis showed that IMPase is most closely related to that of the wild rice Oryza brachyantha, while transcript analysis revealed that the expression of the OsIMP is significantly induced by cold stress and exogenous abscisic acid (ABA treatment. Meanwhile, we cloned the 5’ flanking promoter sequence of the OsIMP gene and identified several important cis-acting elements, such as LTR (low-temperature responsiveness, TCA-element (salicylic acid responsiveness, ABRE-element (abscisic acid responsiveness, GARE-motif (gibberellin responsive, MBS (MYB Binding Site and other cis-acting elements related to defense and stress responsiveness. To further investigate the potential function of the OsIMP gene, we generated transgenic tobacco plants overexpressing the OsIMP gene and the cold tolerance test indicated that these transgenic tobacco plants exhibit improved cold tolerance. Furthermore, transgenic tobacco plants have a lower level of hydrogen peroxide (H2O2 and malondialdehyde (MDA, and a higher content of total chlorophyll as well as increased antioxidant enzyme activities of superoxide dismutase (SOD, catalase (CAT and peroxidase (POD

  9. Comparative transcriptome analysis of isonuclear-alloplasmic lines unmask key transcription factor genes and metabolic pathways involved in sterility of maize CMS-C.

    Science.gov (United States)

    Li, Chuan; Zhao, Zhuofan; Liu, Yongming; Liang, Bing; Guan, Shuxian; Lan, Hai; Wang, Jing; Lu, Yanli; Cao, Moju

    2017-01-01

    Although C-type cytoplasmic male sterility (CMS-C) is one of the most attractive tools for maize hybrid seed production, the detailed regulation network of the male sterility remains unclear. In order to identify the CMS-C sterility associated genes and/or pathways, the comparison of the transcriptomes between the CMS-C line C48-2 and its isonuclear-alloplasmic maintainer line N48-2 at pollen mother cell stage (PS), an early development stage of microspore, and mononuclear stage (MS), an abortive stage of microspore, were analyzed. 2,069 differentially expressed genes (DEGs) between the two stages were detected and thought to be essential for the spikelet development of N48-2. 453 of the 2,069 DEGs were differentially expressed at MS stage between the two lines and thought to be participated in the process or the causes of microspore abortion. Among the 453 DEGs, 385 (84.99%) genes were down-regulated and only 68 (15.01%) genes were up-regulated in C48-2 at MS stage. The dramatic decreased expression of the four DEGs encoding MYB transcription factors and the DEGs involved in "polyamine metabolic process", "Cutin, suberine and wax biosynthesis", "Fatty acid elongation", "Biosynthesis of unsaturated fatty acids" and "Proline metabolism" might play an important role in the sterility of C48-2. This study will point out some directions for detailed molecular analysis and better understanding of sterility of CMS-C in maize.

  10. Comparative transcriptome analysis of isonuclear-alloplasmic lines unmask key transcription factor genes and metabolic pathways involved in sterility of maize CMS-C

    Directory of Open Access Journals (Sweden)

    Chuan Li

    2017-05-01

    Full Text Available Although C-type cytoplasmic male sterility (CMS-C is one of the most attractive tools for maize hybrid seed production, the detailed regulation network of the male sterility remains unclear. In order to identify the CMS-C sterility associated genes and/or pathways, the comparison of the transcriptomes between the CMS-C line C48-2 and its isonuclear-alloplasmic maintainer line N48-2 at pollen mother cell stage (PS, an early development stage of microspore, and mononuclear stage (MS, an abortive stage of microspore, were analyzed. 2,069 differentially expressed genes (DEGs between the two stages were detected and thought to be essential for the spikelet development of N48-2. 453 of the 2,069 DEGs were differentially expressed at MS stage between the two lines and thought to be participated in the process or the causes of microspore abortion. Among the 453 DEGs, 385 (84.99% genes were down-regulated and only 68 (15.01% genes were up-regulated in C48-2 at MS stage. The dramatic decreased expression of the four DEGs encoding MYB transcription factors and the DEGs involved in “polyamine metabolic process”, “Cutin, suberine and wax biosynthesis”, “Fatty acid elongation”, “Biosynthesis of unsaturated fatty acids” and “Proline metabolism” might play an important role in the sterility of C48-2. This study will point out some directions for detailed molecular analysis and better understanding of sterility of CMS-C in maize.

  11. Overexpression of the OsIMP Gene Increases the Accumulation of Inositol and Confers Enhanced Cold Tolerance in Tobacco through Modulation of the Antioxidant Enzymes' Activities.

    Science.gov (United States)

    Zhang, Rong-Xiang; Qin, Li-Jun; Zhao, De-Gang

    2017-07-20

    Inositol is a cyclic polyol that is involved in various physiological processes, including signal transduction and stress adaptation in plants. l- myo -inositol monophosphatase (IMPase) is one of the metal-dependent phosphatase family members and catalyzes the last reaction step of biosynthesis of inositol. Although increased IMPase activity induced by abiotic stress has been reported in chickpea plants, the role and regulation of the IMP gene in rice ( Oryza sativa L.) remains poorly understood. In the present work, we obtained a full-length cDNA sequence coding IMPase in the cold tolerant rice landraces in Gaogonggui, which is named as OsIMP . Multiple alignment results have displayed that this sequence has characteristic signature motifs and conserved enzyme active sites of the phosphatase super family. Phylogenetic analysis showed that IMPase is most closely related to that of the wild rice Oryza brachyantha , while transcript analysis revealed that the expression of the OsIMP is significantly induced by cold stress and exogenous abscisic acid (ABA) treatment. Meanwhile, we cloned the 5' flanking promoter sequence of the OsIMP gene and identified several important cis -acting elements, such as LTR (low-temperature responsiveness), TCA-element (salicylic acid responsiveness), ABRE-element (abscisic acid responsiveness), GARE-motif (gibberellin responsive), MBS (MYB Binding Site) and other cis -acting elements related to defense and stress responsiveness. To further investigate the potential function of the OsIMP gene, we generated transgenic tobacco plants overexpressing the OsIMP gene and the cold tolerance test indicated that these transgenic tobacco plants exhibit improved cold tolerance. Furthermore, transgenic tobacco plants have a lower level of hydrogen peroxide (H₂O₂) and malondialdehyde (MDA), and a higher content of total chlorophyll as well as increased antioxidant enzyme activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD

  12. Gene doping in sports.

    Science.gov (United States)

    Unal, Mehmet; Ozer Unal, Durisehvar

    2004-01-01

    Gene or cell doping is defined by the World Anti-Doping Agency (WADA) as "the non-therapeutic use of genes, genetic elements and/or cells that have the capacity to enhance athletic performance". New research in genetics and genomics will be used not only to diagnose and treat disease, but also to attempt to enhance human performance. In recent years, gene therapy has shown progress and positive results that have highlighted the potential misuse of this technology and the debate of 'gene doping'. Gene therapies developed for the treatment of diseases such as anaemia (the gene for erythropoietin), muscular dystrophy (the gene for insulin-like growth factor-1) and peripheral vascular diseases (the gene for vascular endothelial growth factor) are potential doping methods. With progress in gene technology, many other genes with this potential will be discovered. For this reason, it is important to develop timely legal regulations and to research the field of gene doping in order to develop methods of detection. To protect the health of athletes and to ensure equal competitive conditions, the International Olympic Committee, WADA and International Sports Federations have accepted performance-enhancing substances and methods as being doping, and have forbidden them. Nevertheless, the desire to win causes athletes to misuse these drugs and methods. This paper reviews the current status of gene doping and candidate performance enhancement genes, and also the use of gene therapy in sports medicine and ethics of genetic enhancement. Copyright 2004 Adis Data Information BV