Science.gov

Sample records for grapevine r2r3-myb transcription

  1. New member of the R2R3-MYB transcription factors family in grapevine suppresses the anthocyanin accumulation in the flowers of transgenic tobacco.

    PubMed

    Pérez-Díaz, J Ricardo; Pérez-Díaz, Jorge; Madrid-Espinoza, José; González-Villanueva, Enrique; Moreno, Yerko; Ruiz-Lara, Simón

    2016-01-01

    In grapevine, anthocyanins and proanthocyanidins are the main flavonoids in berries, which are associated to organoleptic properties in red wine such as color and astringency. Flavonoid pathway is specifically regulated at transcriptional level and several R2R3-MYB proteins have shown to act as positive regulators. However, some members of this family have shown to repress the flavonoid biosynthesis. In this work, we present the characterization of VvMYB4-like gene, which encodes a putative transcriptional factor highly expressed in the skin of berries at the pre veraison stage in grapevine. Its over-expression in tobacco resulted in the loss of pigmentation in flowers due a decrease in anthocyanin accumulation. Severity in anthocyanin suppression observed in petals could be associated with the expression level of the VvMYB4-like transgene. Expression analysis of flavonoid structural genes revealed the strong down-regulation of the flavonoid-related genes anthocyanidin synthase (ANS) and dihydroflavonol reductase (DFR) genes and also the reduction of the anthocyanin-related gene UDP glucose:flavonoid 3-O-glucosyl transferase (UFGT), which was dependent of the transgene expression. In addition, expression of VvMYB4-like in the model plant Arabidopsis showed similar results, with the higher down-regulation observed in the AtDFR and AtLDOX genes. These results suggest that VvMYB4-like may play an important role in regulation of anthocyanin biosynthesis in grapevine acting as a transcriptional repressor of flavonoid structural genes. PMID:26497001

  2. Expansion and diversification of the Populus R2R3-MYB family of transcription factors.

    PubMed

    Wilkins, Olivia; Nahal, Hardeep; Foong, Justin; Provart, Nicholas J; Campbell, Malcolm M

    2009-02-01

    The R2R3-MYB proteins comprise one of the largest families of transcription factors in plants. R2R3-MYB family members regulate plant-specific processes, such as the elaboration of specialized cell types, including xylem, guard cells, trichomes, and root hairs, and the biosynthesis of specialized branches of metabolism, including phenylpropanoid biosynthesis. As such, R2R3-MYB family members are hypothesized to contribute to the emergence of evolutionary innovations that have arisen in specific plant lineages. As a first step in determining the role played by R2R3-MYB family members in the emergence of lineage-specific innovations in the genus Populus, the entire Populus trichocarpa R2R3-MYB family was characterized. The Populus R2R3-MYB complement is much larger than that found in other angiosperms with fully sequenced genomes. Phylogenetic analyses, together with chromosome placement, showed that the expansion of the Populus R2R3-MYB family was not only attributable to whole genome duplication but also involved selective expansion of specific R2R3-MYB clades. Expansion of the Populus R2R3-MYB family prominently involved members with expression patterns that suggested a role in specific components of Populus life history, including wood formation and reproductive development. An expandable compendium of microarray-based expression data (PopGenExpress) and associated Web-based tools were developed to better enable within- and between-species comparisons of Populus R2R3-MYB gene expression. This resource, which includes intuitive graphic visualization of gene expression data across multiple tissues, organs, and treatments, is freely available to, and expandable by, scientists wishing to better understand the genome biology of Populus, an ecologically dominant and economically important forest tree genus. PMID:19091872

  3. The R2R3-Myb transcription fators of cotton: SNP characterization, chromosomal assignment, and phylogenetic analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The R2R3-Myb transcription factors are involved in many plant physiological and biochemical processes including regulation of trichome length and density in Arabidopsis. In cotton, Gossypium spp.,the developmental regulation of some R2R3-Myb transcription factors are related to fiber differentiatio...

  4. A R2R3-MYB Transcription Factor from Epimedium sagittatum Regulates the Flavonoid Biosynthetic Pathway

    PubMed Central

    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. PMID:23936468

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

    PubMed

    Medina-Puche, Laura; Molina-Hidalgo, Francisco Javier; Boersma, Maaike; Schuurink, Robert C; López-Vidriero, Irene; Solano, Roberto; Franco-Zorrilla, José-Manuel; Caballero, José Luis; Blanco-Portales, Rosario; Muñoz-Blanco, Juan

    2015-06-01

    Eugenol is a volatile phenylpropanoid that contributes to flower and ripe fruit scent. In ripe strawberry (Fragaria × ananassa) fruit receptacles, eugenol is biosynthesized by eugenol synthase (FaEGS2). However, the transcriptional regulation of this process is still unknown. We have identified and functionally characterized an R2R3 MYB transcription factor (emission of benzenoid II [FaEOBII]) that seems to be the orthologous gene of PhEOBII from Petunia hybrida, which contributes to the regulation of eugenol biosynthesis in petals. The expression of FaEOBII was ripening related and fruit receptacle specific, although high expression values were also found in petals. This expression pattern of FaEOBII correlated with eugenol content in both fruit receptacle and petals. The expression of FaEOBII was repressed by auxins and activated by abscisic acid, in parallel to the ripening process. In ripe strawberry receptacles, where the expression of FaEOBII was silenced, the expression of cinnamyl alcohol dehydrogenase1 and FaEGS2, two structural genes involved in eugenol production, was down-regulated. A subsequent decrease in eugenol content in ripe receptacles was also observed, confirming the involvement of FaEOBII in eugenol metabolism. Additionally, the expression of FaEOBII was under the control of FaMYB10, another R2R3 MYB transcription factor that regulates the early and late biosynthetic genes from the flavonoid/phenylpropanoid pathway. In parallel, the amount of eugenol in FaMYB10-silenced receptacles was also diminished. Taken together, these data indicate that FaEOBII plays a regulating role in the volatile phenylpropanoid pathway gene expression that gives rise to eugenol production in ripe strawberry receptacles. PMID:25931522

  6. The R2R3-MYB transcription factors MYB14 and MYB15 regulate stilbene biosynthesis in Vitis vinifera.

    PubMed

    Höll, Janine; Vannozzi, Alessandro; Czemmel, Stefan; D'Onofrio, Claudio; Walker, Amanda R; Rausch, Thomas; Lucchin, Margherita; Boss, Paul K; Dry, Ian B; Bogs, Jochen

    2013-10-01

    Plant stilbenes are phytoalexins that accumulate in a small number of plant species, including grapevine (Vitis vinifera), in response to biotic and abiotic stresses and have been implicated in many beneficial effects on human health. In particular, resveratrol, the basic unit of all other complex stilbenes, has received widespread attention because of its cardio-protective, anticarcinogenic, and antioxidant properties. Although stilbene synthases (STSs), the key enzymes responsible for resveratrol biosynthesis, have been isolated and characterized from several plant species, the transcriptional regulation underlying stilbene biosynthesis is unknown. Here, we report the identification and functional characterization of two R2R3-MYB-type transcription factors (TFs) from grapevine, which regulate the stilbene biosynthetic pathway. These TFs, designated MYB14 and MYB15, strongly coexpress with STS genes, both in leaf tissues under biotic and abiotic stress and in the skin and seed of healthy developing berries during maturation. In transient gene reporter assays, MYB14 and MYB15 were demonstrated to specifically activate the promoters of STS genes, and the ectopic expression of MYB15 in grapevine hairy roots resulted in increased STS expression and in the accumulation of glycosylated stilbenes in planta. These results demonstrate the involvement of MYB14 and MYB15 in the transcriptional regulation of stilbene biosynthesis in grapevine. PMID:24151295

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

    PubMed

    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. PMID:26377817

  8. Characterization of a citrus R2R3-MYB transcription factor that regulates the flavonol and hydroxycinnamic acid biosynthesis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flavonols and hydroxycinnamic acids are important phenylpropanoid metabolites in plants. In this study, we isolated and characterized a citrus R2R3-MYB transcription factor CsMYBF1, encoding a protein belonging to the flavonol-specific MYB subgroup. Ectopic expression of CsMYBF1 in tomato led to an ...

  9. Three R2R3-MYB transcription factors regulate distinct floral pigmentation patterning in Phalaenopsis spp.

    PubMed

    Hsu, Chia-Chi; Chen, You-Yi; Tsai, Wen-Chieh; Chen, Wen-Huei; Chen, Hong-Hwa

    2015-05-01

    Orchidaceae are well known for their fascinating floral morphologic features, specialized pollination, and distinctive ecological strategies. With their long-lasting flowers of various colors and pigmentation patterning, Phalaenopsis spp. have become important ornamental plants worldwide. In this study, we identified three R2R3-MYB transcription factors PeMYB2, PeMYB11, and PeMYB12. Their expression profiles were concomitant with red color formation in Phalaenopsis spp. flowers. Transient assay of overexpression of three PeMYBs verified that PeMYB2 resulted in anthocyanin accumulation, and these PeMYBs could activate the expression of three downstream structural genes Phalaenopsis spp. Flavanone 3-hydroxylase5, Phalaenopsis spp. Dihydroflavonol 4-reductase1, and Phalaenopsis spp. Anthocyanidin synthase3. In addition, these three PeMYBs participated in the distinct pigmentation patterning in a single flower, which was revealed by virus-induced gene silencing. In the sepals/petals, silencing of PeMYB2, PeMYB11, and PeMYB12 resulted in the loss of the full-red pigmentation, red spots, and venation patterns, respectively. Moreover, different pigmentation patterning was regulated by PeMYBs in the sepals/petals and lip. PeMYB11 was responsive to the red spots in the callus of the lip, and PeMYB12 participated in the full pigmentation in the central lobe of the lip. The differential pigmentation patterning was validated by RNA in situ hybridization. Additional assessment was performed in six Phalaenopsis spp. cultivars with different color patterns. The combined expression of these three PeMYBs in different ratios leads to a wealth of complicated floral pigmentation patterning in Phalaenopsis spp. PMID:25739699

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

    PubMed Central

    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 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. PMID:20302676

  11. An R2R3-MYB Transcription Factor Regulates Eugenol Production in Ripe Strawberry Fruit Receptacles1

    PubMed Central

    Medina-Puche, Laura; Molina-Hidalgo, Francisco Javier; Boersma, Maaike; Schuurink, Robert C.; López-Vidriero, Irene; Solano, Roberto; Franco-Zorrilla, José-Manuel; Caballero, José Luis; Blanco-Portales, Rosario; Muñoz-Blanco, Juan

    2015-01-01

    Eugenol is a volatile phenylpropanoid that contributes to flower and ripe fruit scent. In ripe strawberry (Fragaria × ananassa) fruit receptacles, eugenol is biosynthesized by eugenol synthase (FaEGS2). However, the transcriptional regulation of this process is still unknown. We have identified and functionally characterized an R2R3 MYB transcription factor (EMISSION OF BENZENOID II [FaEOBII]) that seems to be the orthologous gene of PhEOBII from Petunia hybrida, which contributes to the regulation of eugenol biosynthesis in petals. The expression of FaEOBII was ripening related and fruit receptacle specific, although high expression values were also found in petals. This expression pattern of FaEOBII correlated with eugenol content in both fruit receptacle and petals. The expression of FaEOBII was repressed by auxins and activated by abscisic acid, in parallel to the ripening process. In ripe strawberry receptacles, where the expression of FaEOBII was silenced, the expression of CINNAMYL ALCOHOL DEHYDROGENASE1 and FaEGS2, two structural genes involved in eugenol production, was down-regulated. A subsequent decrease in eugenol content in ripe receptacles was also observed, confirming the involvement of FaEOBII in eugenol metabolism. Additionally, the expression of FaEOBII was under the control of FaMYB10, another R2R3 MYB transcription factor that regulates the early and late biosynthetic genes from the flavonoid/phenylpropanoid pathway. In parallel, the amount of eugenol in FaMYB10-silenced receptacles was also diminished. Taken together, these data indicate that FaEOBII plays a regulating role in the volatile phenylpropanoid pathway gene expression that gives rise to eugenol production in ripe strawberry receptacles. PMID:25931522

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

    PubMed Central

    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

  13. The soybean R2R3 MYB transcription factor GmMYB100 negatively regulates plant flavonoid biosynthesis.

    PubMed

    Yan, Junhui; Wang, Biao; Zhong, Yunpeng; Yao, Luming; Cheng, Linjing; Wu, Tianlong

    2015-09-01

    Soybean flavonoids, a group of important signaling molecules in plant-environment interaction, ubiquitously exist in soybean and are tightly regulated by many genes. Here we reported that GmMYB100, a gene encoding a R2R3 MYB transcription factor, is involved in soybean flavonoid biosynthesis. GmMYB100 is mainly expressed in flowers, leaves and immature embryo, and its level is decreased after pod ripening. Subcellular localization assay indicates that GmMYB100 is a nuclear protein. GmMYB100 has transactivation ability revealed by a yeast functional assay; whereas bioinformatic analysis suggests that GmMYB100 has a negative function in flavonoid biosynthesis. GmMYB100-overexpression represses the transcript levels of flavonoid-related genes in transgenic soybean hairy roots and Arabidopsis, and inhibits isoflavonoid (soybean) and flavonol (Arabidopsis) production in transgenic plants. Furthermore, the transcript levels of six flavonoid-related genes and flavonoid (isoflavonoid and flavone aglycones) accumulation are elevated in the GmMYB100-RNAi transgenic hairy roots. We also demonstrate that GmMYB100 protein depresses the promoter activities of soybean chalcone synthase and chalcone isomerase. These findings indicate that GmMYB100 is a negative regulator in soybean flavonoid biosynthesis pathway. PMID:26231207

  14. Characterization of two tartary buckwheat R2R3-MYB transcription factors and their regulation of proanthocyanidin biosynthesis.

    PubMed

    Bai, Yue-Chen; Li, Cheng-Lei; Zhang, Jin-Wen; Li, Shuang-Jiang; Luo, Xiao-Peng; Yao, Hui-Peng; Chen, Hui; Zhao, Hai-Xia; Park, Sang-Un; Wu, Qi

    2014-11-01

    Tartary buckwheat (Fagopyrum tataricum Gaertn.) contains high concentrations of flavonoids. The flavonoids are mainly represented by rutin, anthocyanins and proanthocyanins in tartary buckwheat. R2R3-type MYB transcription factors (TFs) play key roles in the transcriptional regulation of the flavonoid biosynthetic pathway. In this study, two TF genes, FtMYB1 and FtMYB2, were isolated from F. tataricum and characterized. The results of bioinformatic analysis indicated that the putative FtMYB1 and FtMYB2 proteins belonged to the R2R3-MYB family and displayed a high degree of similarity with TaMYB14 and AtMYB123/TT2. In vitro and in vivo evidence both showed the two proteins were located in the nucleus and exhibited transcriptional activation activities. During florescence, both FtMYB1 and FtMYB2 were more highly expressed in the flowers than any other organ. The overexpression of FtMYB1 and FtMYB2 significantly enhanced the accumulation of proanthocyanidins (PAs) and showed a strong effect on the target genes' expression in Nicotiana tabacum. The expression of dihydroflavonol-4-reductase (DFR) was upregulated to 5.6-fold higher than that of control, and the expression level was lower for flavonol synthase (FLS). To our knowledge, this is the first functional characterization of two MYB TFs from F. tataricum that control the PA pathway. PMID:24730512

  15. Cotton (Gossypium spp.) R2R3-MYB transcription factors SNP identification, phylo-genomic characterization, chromosome localization and linkage mapping

    Technology Transfer Automated Retrieval System (TEKTRAN)

    R2R3-MYB transcription factors of plants are involved in the regulation of trichome length and density. Several of them are differentially expressed with initiation and expansion of cotton fibers. We report sequence phylo-genomic characterization of the six MYB genes, their chromosomal localizatio...

  16. Characterization of a Citrus R2R3-MYB Transcription Factor that Regulates the Flavonol and Hydroxycinnamic Acid Biosynthesis.

    PubMed

    Liu, Chaoyang; Long, Jianmei; Zhu, Kaijie; Liu, Linlin; Yang, Wei; Zhang, Hongyan; Li, Li; Xu, Qiang; Deng, Xiuxin

    2016-01-01

    Flavonols and hydroxycinnamic acids are important phenylpropanoid metabolites in plants. In this study, we isolated and characterized a citrus R2R3-MYB transcription factor CsMYBF1, encoding a protein belonging to the flavonol-specific MYB subgroup. Ectopic expression of CsMYBF1 in tomato led to an up-regulation of a series of genes involved in primary metabolism and the phenylpropanoid pathway, and induced a strong accumulation of hydroxycinnamic acid compounds but not the flavonols. The RNAi suppression of CsMYBF1 in citrus callus caused a down-regulation of many phenylpropanoid pathway genes and reduced the contents of hydroxycinnamic acids and flavonols. Transactivation assays indicated that CsMYBF1 activated several promoters of phenylpropanoid pathway genes in tomato and citrus. Interestingly, CsMYBF1 could activate the CHS gene promoter in citrus, but not in tomato. Further examinations revealed that the MYBPLANT cis-elements were essential for CsMYBF1 in activating phenylpropanoid pathway genes. In summary, our data indicated that CsMYBF1 possessed the function in controlling the flavonol and hydroxycinnamic acid biosynthesis, and the regulatory differences in the target metabolite accumulation between two species may be due to the differential activation of CHS promoters by CsMYBF1. Therefore, CsMYBF1 constitutes an important gene source for the engineering of specific phenylpropanoid components. PMID:27162196

  17. Characterization of a Citrus R2R3-MYB Transcription Factor that Regulates the Flavonol and Hydroxycinnamic Acid Biosynthesis

    PubMed Central

    Liu, Chaoyang; Long, Jianmei; Zhu, Kaijie; Liu, Linlin; Yang, Wei; Zhang, Hongyan; Li, Li; Xu, Qiang; Deng, Xiuxin

    2016-01-01

    Flavonols and hydroxycinnamic acids are important phenylpropanoid metabolites in plants. In this study, we isolated and characterized a citrus R2R3-MYB transcription factor CsMYBF1, encoding a protein belonging to the flavonol-specific MYB subgroup. Ectopic expression of CsMYBF1 in tomato led to an up-regulation of a series of genes involved in primary metabolism and the phenylpropanoid pathway, and induced a strong accumulation of hydroxycinnamic acid compounds but not the flavonols. The RNAi suppression of CsMYBF1 in citrus callus caused a down-regulation of many phenylpropanoid pathway genes and reduced the contents of hydroxycinnamic acids and flavonols. Transactivation assays indicated that CsMYBF1 activated several promoters of phenylpropanoid pathway genes in tomato and citrus. Interestingly, CsMYBF1 could activate the CHS gene promoter in citrus, but not in tomato. Further examinations revealed that the MYBPLANT cis-elements were essential for CsMYBF1 in activating phenylpropanoid pathway genes. In summary, our data indicated that CsMYBF1 possessed the function in controlling the flavonol and hydroxycinnamic acid biosynthesis, and the regulatory differences in the target metabolite accumulation between two species may be due to the differential activation of CHS promoters by CsMYBF1. Therefore, CsMYBF1 constitutes an important gene source for the engineering of specific phenylpropanoid components. PMID:27162196

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

    PubMed Central

    Kelemen, Zsolt; Sebastian, Alvaro; Xu, Wenjia; Grain, Damaris; Salsac, Fabien; Avon, Alexandra; Berger, Nathalie; Tran, Joseph; Dubreucq, Bertrand; Lurin, Claire; Lepiniec, Loïc; Contreras-Moreira, Bruno; Dubos, Christian

    2015-01-01

    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. PMID:26484765

  19. Three R2R3-MYB Transcription Factors Regulate Distinct Floral Pigmentation Patterning in Phalaenopsis spp.1[OPEN

    PubMed Central

    Hsu, Chia-Chi; Chen, You-Yi; Tsai, Wen-Chieh; Chen, Wen-Huei; Chen, Hong-Hwa

    2015-01-01

    Orchidaceae are well known for their fascinating floral morphologic features, specialized pollination, and distinctive ecological strategies. With their long-lasting flowers of various colors and pigmentation patterning, Phalaenopsis spp. have become important ornamental plants worldwide. In this study, we identified three R2R3-MYB transcription factors PeMYB2, PeMYB11, and PeMYB12. Their expression profiles were concomitant with red color formation in Phalaenopsis spp. flowers. Transient assay of overexpression of three PeMYBs verified that PeMYB2 resulted in anthocyanin accumulation, and these PeMYBs could activate the expression of three downstream structural genes Phalaenopsis spp. Flavanone 3-hydroxylase5, Phalaenopsis spp. Dihydroflavonol 4-reductase1, and Phalaenopsis spp. Anthocyanidin synthase3. In addition, these three PeMYBs participated in the distinct pigmentation patterning in a single flower, which was revealed by virus-induced gene silencing. In the sepals/petals, silencing of PeMYB2, PeMYB11, and PeMYB12 resulted in the loss of the full-red pigmentation, red spots, and venation patterns, respectively. Moreover, different pigmentation patterning was regulated by PeMYBs in the sepals/petals and lip. PeMYB11 was responsive to the red spots in the callus of the lip, and PeMYB12 participated in the full pigmentation in the central lobe of the lip. The differential pigmentation patterning was validated by RNA in situ hybridization. Additional assessment was performed in six Phalaenopsis spp. cultivars with different color patterns. The combined expression of these three PeMYBs in different ratios leads to a wealth of complicated floral pigmentation patterning in Phalaenopsis spp. PMID:25739699

  20. The Scutellaria baicalensis R2R3-MYB Transcription Factors Modulates Flavonoid Biosynthesis by Regulating GA Metabolism in Transgenic Tobacco Plants

    PubMed Central

    Liu, Yunjun; Yang, Jian; Huang, Luqi

    2013-01-01

    R2R3-MYB proteins play role in plant development, response to biotic and abiotic stress, and regulation of primary and secondary metabolism. Little is known about the R2R3-MYB proteins in Scutellaria baicalensis which is an important Chinese medical plant. In this paper, nineteen putative SbMYB genes were identified from a S. baicalensis cDNA library, and eleven R2R3-MYBs were clustered into 5 subgroups according to phylogenetic reconstruction. In the S. baicalensis leaves which were sprayed with GA3, SbMYB2 and SbMYB7 had similar expression pattern with SbPALs, indicating that SbMYB2 and SbMYB7 might be involved in the flavonoid metabolism. Transactivation assay results showed that SbMYB2 and SbMYB7 can function as transcriptional activator. The expression of several flavonoid biosynthesis-related genes were induced or suppressed by overexpression of SbMYB2 or SbMYB7 in transgenic tobacco plants. Consistent with the change of the expression of NtDH29 and NtCHI, the contents of dicaffeoylspermidine and quercetin-3,7-O-diglucoside in SbMYB2-overexpressing or SbMYB7-overexpressing transgenic tobacco plants were decreased. The transcriptional level of NtUFGT in transgenic tobacco overexpressing SbMYB7 and the transcriptional level of NtHCT in SbMYB2-overexpressing tobacco plants were increased; however the application of GA3 inhibited the transcriptional level of these two genes. These results suggest that SbMYB2 and SbMYB7 might regulate the flavonoid biosynthesis through GA metabolism. PMID:24143216

  1. A R2R3-MYB Transcription Factor Regulates the Flavonol Biosynthetic Pathway in a Traditional Chinese Medicinal Plant, Epimedium sagittatum.

    PubMed

    Huang, Wenjun; Khaldun, A B M; Chen, Jianjun; Zhang, Chanjuan; Lv, Haiyan; Yuan, Ling; Wang, Ying

    2016-01-01

    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 (BCs) 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 Epimedium 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 BCs in E. sagittatum. Thus

  2. A R2R3-MYB Transcription Factor Regulates the Flavonol Biosynthetic Pathway in a Traditional Chinese Medicinal Plant, Epimedium sagittatum

    PubMed Central

    Huang, Wenjun; Khaldun, A. B. M.; Chen, Jianjun; Zhang, Chanjuan; Lv, Haiyan; Yuan, Ling; Wang, Ying

    2016-01-01

    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 (BCs) 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 Epimedium 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 BCs in E. sagittatum. Thus

  3. The wheat R2R3-MYB transcription factor TaRIM1 participates in resistance response against the pathogen Rhizoctonia cerealis infection through regulating defense genes.

    PubMed

    Shan, Tianlei; Rong, Wei; Xu, Huijun; Du, Lipu; Liu, Xin; Zhang, Zengyan

    2016-01-01

    The necrotrophic fungus Rhizoctonia cerealis is a major pathogen of sharp eyespot that is a devastating disease of wheat (Triticum aestivum). Little is known about roles of MYB genes in wheat defense response to R. cerealis. In this study, TaRIM1, a R. cerealis-induced wheat MYB gene, was identified by transcriptome analysis, then cloned from resistant wheat CI12633, and its function and preliminary mechanism were studied. Sequence analysis showed that TaRIM1 encodes a R2R3-MYB transcription factor with transcription-activation activity. The molecular-biological assays revealed that the TaRIM1 protein localizes to nuclear and can bind to five MYB-binding site cis-elements. Functional dissection results showed that following R. cerealis inoculation, TaRIM1 silencing impaired the resistance of wheat CI12633, whereas TaRIM1 overexpression significantly increased resistance of transgenic wheat compared with susceptible recipient. TaRIM1 positively regulated the expression of five defense genes (Defensin, PR10, PR17c, nsLTP1, and chitinase1) possibly through binding to MYB-binding sites in their promoters. These results suggest that the R2R3-MYB transcription factor TaRIM1 positively regulates resistance response to R. cerealis infection through modulating the expression of a range of defense genes, and that TaRIM1 is a candidate gene to improve sharp eyespot resistance in wheat. PMID:27364458

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

    PubMed

    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. PMID:21235651

  5. The Heterologous Expression of the Chrysanthemum R2R3-MYB Transcription Factor CmMYB1 Alters Lignin Composition and Represses Flavonoid Synthesis in Arabidopsis thaliana

    PubMed Central

    Chen, Sumei; Jiang, Jiafu; Gu, Chunsun; Zhou, Guoqin; Chen, Yu; Song, Aiping; Chen, Fadi

    2013-01-01

    Plant R2R3-MYB transcription factor genes are widely distributed in higher plants and play important roles in the regulation of many secondary metabolites at the transcriptional level. In this study, a chrysanthemum subgroup 4 R2R3-MYB transcription factor gene, designated CmMYB1, was isolated through screening chrysanthemum EST (expressed sequence tag) libraries and using rapid application of cDNA ends (RACE) methods and functionally characterized. CmMYB1 is expressed in the root, stem, leaf and flowers, but most strongly in the stem and most weakly in the root. Its heterologous expression in Arabidopsis thaliana reduced the lignin content and altered the lignin composition. The heterologous expression also repressed the flavonoids content in A. thaliana. Together, these results suggested that CmMYB1 is a negative regulator of genes involved in the lignin pathway and flavonoid pathway, it may be a promising gene for controlling lignin and flavonoids profiles in plants. PMID:23840353

  6. The wheat R2R3-MYB transcription factor TaRIM1 participates in resistance response against the pathogen Rhizoctonia cerealis infection through regulating defense genes

    PubMed Central

    Shan, Tianlei; Rong, Wei; Xu, Huijun; Du, Lipu; Liu, Xin; Zhang, Zengyan

    2016-01-01

    The necrotrophic fungus Rhizoctonia cerealis is a major pathogen of sharp eyespot that is a devastating disease of wheat (Triticum aestivum). Little is known about roles of MYB genes in wheat defense response to R. cerealis. In this study, TaRIM1, a R. cerealis-induced wheat MYB gene, was identified by transcriptome analysis, then cloned from resistant wheat CI12633, and its function and preliminary mechanism were studied. Sequence analysis showed that TaRIM1 encodes a R2R3-MYB transcription factor with transcription-activation activity. The molecular-biological assays revealed that the TaRIM1 protein localizes to nuclear and can bind to five MYB-binding site cis-elements. Functional dissection results showed that following R. cerealis inoculation, TaRIM1 silencing impaired the resistance of wheat CI12633, whereas TaRIM1 overexpression significantly increased resistance of transgenic wheat compared with susceptible recipient. TaRIM1 positively regulated the expression of five defense genes (Defensin, PR10, PR17c, nsLTP1, and chitinase1) possibly through binding to MYB-binding sites in their promoters. These results suggest that the R2R3-MYB transcription factor TaRIM1 positively regulates resistance response to R. cerealis infection through modulating the expression of a range of defense genes, and that TaRIM1 is a candidate gene to improve sharp eyespot resistance in wheat. PMID:27364458

  7. Function search in a large transcription factor gene family in Arabidopsis: assessing the potential of reverse genetics to identify insertional mutations in R2R3 MYB genes.

    PubMed Central

    Meissner, R C; Jin, H; Cominelli, E; Denekamp, M; Fuertes, A; Greco, R; Kranz, H D; Penfield, S; Petroni, K; Urzainqui, A; Martin, C; Paz-Ares, J; Smeekens, S; Tonelli, C; Weisshaar, B; Baumann, E; Klimyuk, V; Marillonnet, S; Patel, K; Speulman, E; Tissier, A F; Bouchez, D; Jones, J J; Pereira, A; Wisman, E

    1999-01-01

    More than 92 genes encoding MYB transcription factors of the R2R3 class have been described in Arabidopsis. The functions of a few members of this large gene family have been described, indicating important roles for R2R3 MYB transcription factors in the regulation of secondary metabolism, cell shape, and disease resistance, and in responses to growth regulators and stresses. For the majority of the genes in this family, however, little functional information is available. As the first step to characterizing these genes functionally, the sequences of >90 family members, and the map positions and expression profiles of >60 members, have been determined previously. An important second step in the functional analysis of the MYB family, through a process of reverse genetics that entails the isolation of insertion mutants, is described here. For this purpose, a variety of gene disruption resources has been used, including T-DNA-insertion populations and three distinct populations that harbor transposon insertions. We report the isolation of 47 insertions into 36 distinct MYB genes by screening a total of 73 genes. These defined insertion lines will provide the foundation for subsequent detailed functional analyses for the assignment of specific functions to individual members of the R2R3 MYB gene family. PMID:10521515

  8. Regulation of secondary cell wall biosynthesis by poplar R2R3 MYB transcription factor PtrMYB152 in Arabidopsis

    SciTech Connect

    Wang, Shucai; Li, Eryang; Porth, Ilga; Chen, Jin-Gui; Mansfield, Shawn D.; Douglas, Carl

    2014-05-23

    Poplar has 192 annotated R2R3 MYB genes, of which only three have been shown to play a role in the regulation of secondary cell wall formation. Here we report the characterization of PtrMYB152, a poplar homolog of the Arabidopsis R2R3 MYB transcription factor AtMYB43, in the regulation of secondary cell wall biosynthesis. The expression of PtrMYB152 in secondary xylem is about 18 times of that in phloem. When expressed in Arabidopsis under the control of either 35S or PtrCesA8 promoters, PtrMYB152 increased secondary cell wall thickness, which is likely caused by increased lignification. Accordingly, elevated expression of genes encoding sets of enzymes in secondary wall biosynthesis were observed in transgenic plants expressing PtrMYB152. Arabidopsis protoplast transfection assays suggested that PtrMYB152 functions as a transcriptional activator. Taken together, our results suggest that PtrMYB152 may be part of a regulatory network activating expression of discrete sets of secondary cell wall biosynthesis genes.

  9. Control of root hair development in Arabidopsis thaliana by an endoplasmic reticulum anchored member of the R2R3-MYB transcription factor family.

    PubMed

    Slabaugh, Erin; Held, Michael; Brandizzi, Federica

    2011-08-01

    The evolution of roots and root hairs was a crucial innovation that contributed to the adaptation of plants to a terrestrial environment. Initiation of root hairs involves transcriptional cues that in part determine cell patterning of the root epidermis. Once root hair initiation has occurred, elongation of the root hair takes place. Although many genes have been identified as being involved in root hair development, many contributors remain uncharacterized. In this study we report on the involvement of a member (here dubbed maMYB) of the plant-specific R2R3-MYB family of transcription factors in root hair elongation in Arabidopsis. We show that maMYB is associated with the endoplasmic reticulum membrane with the transcription factor domain exposed to the cytosol, suggesting that it may function as a membrane-tethered transcription factor. We demonstrate that a truncated form of maMYB (maMYB⁸⁴⁻³⁰⁹), which contains the R2R3-MYB transcription factor domain, is localized and retained in the nucleus, where it regulates gene expression. Silencing of maMyb resulted in plants with significantly shorter root hairs but similar root hair density compared with wild type, implying a role of the protein in root hair elongation. 2,4-D (2,4-dichlorophenoxyacetic acid), an exogenous auxin analog that promotes root hair elongation, rescued the short root hair phenotype and maMyb mRNA was induced in the presence of 2,4-D and IAA (indole-3-acetic acid). These results indicate a functional role of maMYB, which is integrated with auxin, in root hair elongation in Arabidopsis. PMID:21477080

  10. Isolation and characterization of GtMYBP3 and GtMYBP4, orthologues of R2R3-MYB transcription factors that regulate early flavonoid biosynthesis, in gentian flowers

    PubMed Central

    2012-01-01

    Flavonoids are one of the major plant pigments for flower colour. Not only coloured anthocyanins, but also co-pigment flavones or flavonols, accumulate in flowers. To study the regulation of early flavonoid biosynthesis, two R2R3-MYB transcription factors, GtMYBP3 and GtMYBP4, were identified from the petals of Japanese gentian (Gentiana triflora). Phylogenetic analysis showed that these two proteins belong to the subgroup 7 clade (flavonol-specific MYB), which includes Arabidopsis AtMYB12, grapevine VvMYBF1, and tomato SlMYB12. Gt MYBP3 and Gt MYBP4 transcripts were detected specifically in young petals and correlated with the profiles of flavone accumulation. Transient expression assays showed that GtMYBP3 and GtMYBP4 enhanced the promoter activities of early biosynthetic genes, including flavone synthase II (FNSII) and flavonoid 3′-hydroxylase (F3′H), but not the late biosynthetic gene, flavonoid 3′,5′-hydroxylase (F3′5′H). GtMYBP3 also enhanced the promoter activity of the chalcone synthase (CHS) gene. In transgenic Arabidopsis, overexpression of Gt MYBP3 and Gt MYBP4 activated the expression of endogenous flavonol biosynthesis genes and led to increased flavonol accumulation in seedlings. In transgenic tobacco petals, overexpression of Gt MYBP3 and Gt MYBP4 caused decreased anthocyanin levels, resulting in pale flower colours. Gt MYBP4-expressing transgenic tobacco flowers also showed increased flavonols. As far as is known, this is the first functional characterization of R2R3-MYB transcription factors regulating early flavonoid biosynthesis in petals. PMID:23125348

  11. Cloning and Characterization of a Putative R2R3 MYB Transcriptional Repressor of the Rosmarinic Acid Biosynthetic Pathway from Salvia miltiorrhiza

    PubMed Central

    Zhang, Shuncang; Ma, Pengda; Yang, Dongfeng; Li, Wenjing; Liang, Zongsuo; Liu, Yan; Liu, Fenghua

    2013-01-01

    Salvia miltiorrhiza Bunge is one of the most renowned traditional medicinal plants in China. Phenolic acids that are derived from the rosmarinic acid pathway, such as rosmarinic acid and salvianolic acid B, are important bioactive components in S. miltiorrhiza. Accumulations of these compounds have been reported to be induced by various elicitors, while little is known about transcription factors that function in their biosynthetic pathways. We cloned a subgroup 4 R2R3 MYB transcription factor gene (SmMYB39) from S. miltiorrhiza and characterized its roles through overexpression and RNAi-mediated silencing. As the results showed, the content of 4-coumaric acid, rosmarinic acid, salvianolic acid B, salvianolic acid A and total phenolics was dramatically decreased in SmMYB39-overexpressing S. miltiorrhiza lines while being enhanced by folds in SmMYB39-RNAi lines. Quantitative real-time PCR and enzyme activities analyses showed that SmMYB39 negatively regulated transcripts and enzyme activities of 4-hydroxylase (C4H) and tyrosine aminotransferase (TAT). These data suggest that SmMYB39 is involved in regulation of rosmarinic acid pathway and acts as a repressor through suppressing transcripts of key enzyme genes. PMID:24039895

  12. Purple foliage coloration in tea (Camellia sinensis L.) arises from activation of the R2R3-MYB transcription factor CsAN1

    PubMed Central

    Sun, Binmei; Zhu, Zhangsheng; Cao, Panrong; Chen, Hao; Chen, Changming; Zhou, Xin; Mao, Yanhui; Lei, Jianjun; Jiang, Yanpin; Meng, Wei; Wang, Yingxi; Liu, Shaoqun

    2016-01-01

    Purple foliage always appears in Camellia sinensis families; however, the transcriptional regulation of anthocyanin biosynthesis is unknown. The tea bud sport cultivar ‘Zijuan’ confers an abnormal pattern of anthocyanin accumulation, resulting in a mutant phenotype that has a striking purple color in young foliage and in the stem. In this study, we aimed to unravel the underlying molecular mechanism of anthocyanin biosynthetic regulation in C. sinensis. Our results revealed that activation of the R2R3-MYB transcription factor (TF) anthocyanin1 (CsAN1) specifically upregulated the bHLH TF CsGL3 and anthocyanin late biosynthetic genes (LBGs) to confer ectopic accumulation of pigment in purple tea. We found CsAN1 interacts with bHLH TFs (CsGL3 and CsEGL3) and recruits a WD-repeat protein CsTTG1 to form the MYB-bHLH-WDR (MBW) complex that regulates anthocyanin accumulation. We determined that the hypomethylation of a CpG island in the CsAN1 promoter is associated with the purple phenotype. Furthermore, we demonstrated that low temperature and long illumination induced CsAN1 promoter demethylation, resulting in upregulated expression to promote anthocyanin accumulation in the foliage. The successful isolation of CsAN1 provides important information on the regulatory control of anthocyanin biosynthesis in C. sinensis and offers a genetic resource for the development of new varieties with enhanced anthocyanin content. PMID:27581206

  13. Purple foliage coloration in tea (Camellia sinensis L.) arises from activation of the R2R3-MYB transcription factor CsAN1.

    PubMed

    Sun, Binmei; Zhu, Zhangsheng; Cao, Panrong; Chen, Hao; Chen, Changming; Zhou, Xin; Mao, Yanhui; Lei, Jianjun; Jiang, Yanpin; Meng, Wei; Wang, Yingxi; Liu, Shaoqun

    2016-01-01

    Purple foliage always appears in Camellia sinensis families; however, the transcriptional regulation of anthocyanin biosynthesis is unknown. The tea bud sport cultivar 'Zijuan' confers an abnormal pattern of anthocyanin accumulation, resulting in a mutant phenotype that has a striking purple color in young foliage and in the stem. In this study, we aimed to unravel the underlying molecular mechanism of anthocyanin biosynthetic regulation in C. sinensis. Our results revealed that activation of the R2R3-MYB transcription factor (TF) anthocyanin1 (CsAN1) specifically upregulated the bHLH TF CsGL3 and anthocyanin late biosynthetic genes (LBGs) to confer ectopic accumulation of pigment in purple tea. We found CsAN1 interacts with bHLH TFs (CsGL3 and CsEGL3) and recruits a WD-repeat protein CsTTG1 to form the MYB-bHLH-WDR (MBW) complex that regulates anthocyanin accumulation. We determined that the hypomethylation of a CpG island in the CsAN1 promoter is associated with the purple phenotype. Furthermore, we demonstrated that low temperature and long illumination induced CsAN1 promoter demethylation, resulting in upregulated expression to promote anthocyanin accumulation in the foliage. The successful isolation of CsAN1 provides important information on the regulatory control of anthocyanin biosynthesis in C. sinensis and offers a genetic resource for the development of new varieties with enhanced anthocyanin content. PMID:27581206

  14. Overexpression of soybean R2R3-MYB transcription factor, GmMYB12B2, and tolerance to UV radiation and salt stress in transgenic Arabidopsis.

    PubMed

    Li, X W; Wang, Y; Yan, F; Li, J W; Zhao, Y; Zhao, X; Zhai, Y; Wang, Q Y

    2016-01-01

    MYB, v-myb avian myeloblastosis viral oncogene homolog, proteins play central roles in plant stress response. Previously, we identified a novel R2R3-MYB transcription factor, GmMYB12B2, which affected the expression levels of some key enzyme genes involved in flavonoid biosynthesis in transgenic Arabidopsis. In the present study, we analyzed the expression levels of GmMYB12B2 under salt, low temperature, drought, abscisic acid (ABA), and ultraviolet (UV) radiation treatments in soybean using semi-quantitative reverse transcription polymerase chain reaction. The expression of GmMYB12B2 was drastically induced by UV irradiation and salt treatment, but no response was detected under low temperature, drought, and ABA stresses. A detailed characterization of the GmMYB12B2 overexpression lines revealed that GmMYB12B2 might be involved in response of plants to UV radiation and salt stresses. Transgenic Arabidopsis lines constitutively expressing GmMYB12B2 showed an increased tolerance to salt and UV radiation treatment compared with wild-type plants. The expression levels of certain salt stress-responsive genes, such as DREB2A and RD17, were found to be elevated in the transgenic plants. These results indicate that GmMYB12B2 acts as a regulator in the plant stress response. PMID:27323089

  15. OsMYB103L, an R2R3-MYB transcription factor, influences leaf rolling and mechanical strength in rice (Oryza sativa L.)

    PubMed Central

    2014-01-01

    Background The shape of grass leaves possesses great value in both agronomy and developmental biology research. Leaf rolling is one of the important traits in rice (Oryza sativa L.) breeding. MYB transcription factors are one of the largest gene families and have important roles in plant development, metabolism and stress responses. However, little is known about their functions in rice. Results In this study, we report the functional characterization of a rice gene, OsMYB103L, which encodes an R2R3-MYB transcription factor. OsMYB103L was localized in the nucleus with transactivation activity. Overexpression of OsMYB103L in rice resulted in a rolled leaf phenotype. Further analyses showed that expression levels of several cellulose synthase genes (CESAs) were significantly increased, as was the cellulose content in OsMYB103L overexpressing lines. Knockdown of OsMYB103L by RNA interference led to a decreased level of cellulose content and reduced mechanical strength in leaves. Meanwhile, the expression levels of several CESA genes were decreased in these knockdown lines. Conclusions These findings suggest that OsMYB103L may target CESA genes for regulation of cellulose synthesis and could potentially be engineered for desirable leaf shape and mechanical strength in rice. PMID:24906444

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

    PubMed

    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. PMID:25534543

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

    PubMed

    Kasajima, Ichiro; Sasaki, Katsutomo

    2016-05-01

    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. PMID:27089475

  18. Fine mapping of the pleiotropic locus B for black spine and orange mature fruit color in cucumber identifies a 50 kb region containing a R2R3-MYB transcription factor.

    PubMed

    Li, Yuhong; Wen, Changlong; Weng, Yiqun

    2013-08-01

    In cucumber, Cucumis sativus L., the spine and skin colors are two important fruit quality traits for variety improvement. In this study, we investigated the inheritance of spine and mature fruit skin colors in F2 and F3 populations derived from a cross between two inbred lines WI7200 (black spine and orange fruit skin colors) and WI7201 (white spine and creamy fruit skin colors). We confirmed that a single, dominant gene, B, controlled both black spine color and orange mature fruit color. Initial framework mapping with microsatellite markers located the B locus in the distal region of the short arm of cucumber chromosome 4. Fine mapping was conducted with draft genome scaffold-assisted chromosome walking and stepwise increase of mapping population sizes, which allowed for the assignment of the B locus to a 50 kb genomic DNA region with two flanking markers that were 0.06 and 0.09 cM, respectively, from the B locus in a mapping population of 2,001 F2 plants. Gene annotation of this 50 kb region identified six genes including one encoding for a R2R3-MYB transcription factor. Sequence alignment of the R2R3-MYB homologs between the two parent inbreds identified a 1 bp deletion in the third intron of this gene in WI 7201. A molecular marker based on this indel was co-segregating with the spine and fruit colors. Quantitative RT-PCR revealed higher level of expression of this R2R3-MYB gene in WI7200 than in WI7201 in both immature and mature fruits. This R2R3-MYB gene seems to be the best candidate gene for the B locus conditioning black spine and orange mature fruit colors of cultivated cucumber. PMID:23689749

  19. The R2R3-MYB Transcription Factors MYB14 and MYB15 Regulate Stilbene Biosynthesis in Vitis vinifera[W

    PubMed Central

    Höll, Janine; Vannozzi, Alessandro; Czemmel, Stefan; D'Onofrio, Claudio; Walker, Amanda R.; Rausch, Thomas; Lucchin, Margherita; Boss, Paul K.; Dry, Ian B.; Bogs, Jochen

    2013-01-01

    Plant stilbenes are phytoalexins that accumulate in a small number of plant species, including grapevine (Vitis vinifera), in response to biotic and abiotic stresses and have been implicated in many beneficial effects on human health. In particular, resveratrol, the basic unit of all other complex stilbenes, has received widespread attention because of its cardio-protective, anticarcinogenic, and antioxidant properties. Although stilbene synthases (STSs), the key enzymes responsible for resveratrol biosynthesis, have been isolated and characterized from several plant species, the transcriptional regulation underlying stilbene biosynthesis is unknown. Here, we report the identification and functional characterization of two R2R3-MYB–type transcription factors (TFs) from grapevine, which regulate the stilbene biosynthetic pathway. These TFs, designated MYB14 and MYB15, strongly coexpress with STS genes, both in leaf tissues under biotic and abiotic stress and in the skin and seed of healthy developing berries during maturation. In transient gene reporter assays, MYB14 and MYB15 were demonstrated to specifically activate the promoters of STS genes, and the ectopic expression of MYB15 in grapevine hairy roots resulted in increased STS expression and in the accumulation of glycosylated stilbenes in planta. These results demonstrate the involvement of MYB14 and MYB15 in the transcriptional regulation of stilbene biosynthesis in grapevine. PMID:24151295

  20. Genome-Wide Identification and Characterization of R2R3MYB Family in Cucumis sativus

    PubMed Central

    Li, Qiang; Zhang, Cunjia; Li, Jing; Wang, Lina; Ren, Zhonghai

    2012-01-01

    Background The R2R3MYB proteins comprise one of the largest families of transcription factors in plants. Although genome-wide analysis of this family has been carried out in some species, little is known about R2R3MYB genes in cucumber (Cucumis sativus L.). Principal Findings This study has identified 55 R2R3MYB genes in the latest cucumber genome and the CsR2R3MYB family contained the smallest number of identified genes compared to other species that have been studied due to the absence of recent gene duplication events. These results were also supported by genome distribution and gene duplication analysis. Phylogenetic analysis showed that they could be classified into 11 subgroups. The evolutionary relationships and the intron - exon organizations that showed similarities with Arabidopsis, Vitis and Glycine R2R3MYB proteins were also analyzed and suggested strong gene conservation but also the expansions of particular functional genes during the evolution of the plant species. In addition, we found that 8 out of 55 (∼14.54%) cucumber R2R3MYB genes underwent alternative splicing events, producing a variety of transcripts from a single gene, which illustrated the extremely high complexity of transcriptome regulation. Tissue-specific expression profiles showed that 50 cucumber R2R3MYB genes were expressed in at least one of the tissues and the other 5 genes showed very low expression in all tissues tested, which suggested that cucumber R2R3MYB genes took part in many cellular processes. The transcript abundance level analysis during abiotic conditions (NaCl, ABA and low temperature treatments) identified a group of R2R3MYB genes that responded to one or more treatments. Conclusions This study has produced a comparative genomics analysis of the cucumber R2R3MYB gene family and has provided the first steps towards the selection of CsR2R3MYB genes for cloning and functional dissection that can be used in further studies to uncover their roles in cucumber growth and

  1. A Novel R2R3-MYB Transcription Factor BpMYB106 of Birch (Betula platyphylla) Confers Increased Photosynthesis and Growth Rate through Up-regulating Photosynthetic Gene Expression

    PubMed Central

    Zhou, Chenguang; Li, Chenghao

    2016-01-01

    We isolated a R2R3-MYB transcription factor BpMYB106, which regulates photosynthesis in birch (Betula platyphylla Suk.). BpMYB106 mainly expresses in the leaf and shoot tip of birch, and its protein is localized in the nucleus. We further fused isolated a 1588 bp promoter of BpMYB106 and analyzed it by PLACE, which showed some cis-acting elements related to photosynthesis. BpMYB106 promoter β-glucuronidase (GUS) reporter fusion studies gene, the result, showed the GUS reporter gene in transgenic birch with BpMYB106 promoter showed strong activities in shoot tip, cotyledon margins, and mature leaf trichomes. The overexpression of BpMYB106 in birch resulted in significantly increased trichome density, net photosynthetic rate, and growth rate as compared with the wild-type birch. RNA-Seq profiling revealed the upregulation of several photosynthesis-related genes in the photosynthesis and oxidative phosphorylation pathways in the leaves of transgenic plants. Yeast one-hybrid analysis, coupled with transient assay in tobacco, revealed that BpMYB106 binds a MYB binding site MYB2 in differentially expressed gene promoters. Thus, BpMYB106 may directly activate the expression of a range of photosynthesis related genes through interacting with the MYB2 element in their promoters. Our study demonstrating the overexpression of BpMYB106—a R2R3-MYB transcription factor—upregulates the genes of the photosynthesis and oxidative phosphorylation pathways to improve photosynthesis. PMID:27047502

  2. Expression of the R2R3-MYB Transcription Factor TaMYB14 from Trifolium arvense Activates Proanthocyanidin Biosynthesis in the Legumes Trifolium repens and Medicago sativa1[W][OA

    PubMed Central

    Hancock, Kerry R.; Collette, Vern; Fraser, Karl; Greig, Margaret; Xue, Hong; Richardson, Kim; Jones, Chris; Rasmussen, Susanne

    2012-01-01

    Proanthocyanidins (PAs) are oligomeric flavonoids and one group of end products of the phenylpropanoid pathway. PAs have been reported to be beneficial for human and animal health and are particularly important in pastoral agricultural systems for improved animal production and reduced greenhouse gas emissions. However, the main forage legumes grown in these systems, such as Trifolium repens and Medicago sativa, do not contain any substantial amounts of PAs in leaves. We have identified from the foliar PA-accumulating legume Trifolium arvense an R2R3-MYB transcription factor, TaMYB14, and provide evidence that this transcription factor is involved in the regulation of PA biosynthesis in legumes. TaMYB14 expression is necessary and sufficient to up-regulate late steps of the phenylpropanoid pathway and to induce PA biosynthesis. RNA interference silencing of TaMYB14 resulted in almost complete cessation of PA biosynthesis in T. arvense, whereas Nicotiana tabacum, M. sativa, and T. repens plants constitutively expressing TaMYB14 synthesized and accumulated PAs in leaves up to 1.8% dry matter. Targeted liquid chromatography-multistage tandem mass spectrometry analysis identified foliar PAs up to degree of polymerization 6 in leaf extracts. Hence, genetically modified M. sativa and T. repens plants expressing TaMYB14 provide a viable option for improving animal health and mitigating the negative environmental impacts of pastoral animal production systems. PMID:22566493

  3. Changing a conserved amino acid in R2R3-MYB transcription repressors results in cytoplasmic accumulation and abolishes their repressive activity in Arabidopsis.

    PubMed

    Zhou, Meiliang; Sun, Zhanmin; Wang, Chenglong; Zhang, Xinquan; Tang, Yixiong; Zhu, Xuemei; Shao, Jirong; Wu, Yanmin

    2015-10-01

    Sub-group 4 R2R3-type MYB transcription factors, including MYB3, MYB4, MYB7 and MYB32, act as repressors in phenylpropanoid metabolism. These proteins contain the conserved MYB domain and the ethylene-responsive element binding factor-associated amphiphilic repression (EAR) repression domain. Additionally, MYB4, MYB7 and MYB32 possess a putative zinc-finger domain and a conserved GY/FDFLGL motif in their C-termini. The protein 'sensitive to ABA and drought 2' (SAD2) recognizes the nuclear pore complex, which then transports the SAD2-MYB4 complex into the nucleus. Here, we show that the conserved GY/FDFLGL motif contributes to the interaction between MYB factors and SAD2. The Asp → Asn mutation in the GY/FDFLGL motif abolishes the interaction between MYB transcription factors and SAD2, and therefore they cannot be transported into the nucleus and cannot repress their target genes. We found that MYB4(D261N) loses the capacity to repress expression of the cinnamate 4-hydroxylase (C4H) gene and biosynthesis of sinapoyl malate. Our results indicate conservation among MYB transcription factors in terms of their interaction with SAD2. Therefore, the Asp → Asn mutation may be used to engineer transcription factors. PMID:26332741

  4. The Rice R2R3-MYB Transcription Factor OsMYB55 Is Involved in the Tolerance to High Temperature and Modulates Amino Acid Metabolism

    PubMed Central

    El-kereamy, Ashraf; Bi, Yong-Mei; Ranathunge, Kosala; Beatty, Perrin H.; Good, Allen G.; Rothstein, Steven J.

    2012-01-01

    Temperatures higher than the optimum negatively affects plant growth and development. Tolerance to high temperature is a complex process that involves several pathways. Understanding this process, especially in crops such as rice, is essential to prepare for predicted climate changes due to global warming. Here, we show that OsMYB55 is induced by high temperature and overexpression of OsMYB55 resulted in improved plant growth under high temperature and decreased the negative effect of high temperature on grain yield. Transcriptome analysis revealed an increase in expression of several genes involved in amino acids metabolism. We demonstrate that OsMYB55 binds to the promoter regions of target genes and directly activates expression of some of those genes including glutamine synthetase (OsGS1;2) glutamine amidotransferase (GAT1) and glutamate decarboxylase 3 (GAD3). OsMYB55 overexpression resulted in an increase in total amino acid content and of the individual amino acids produced by the activation of the above mentioned genes and known for their roles in stress tolerance, namely L-glutamic acid, GABA and arginine especially under high temperature condition. In conclusion, overexpression of OsMYB55 improves rice plant tolerance to high temperature, and this high tolerance is associated with enhanced amino acid metabolism through transcription activation. PMID:23251677

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

    PubMed

    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. PMID:27408811

  6. Subspecialization of R2R3-MYB Repressors for Anthocyanin and Proanthocyanidin Regulation in Forage Legumes

    PubMed Central

    Albert, Nick W.

    2015-01-01

    The synthesis of anthocyanin pigments and proanthocyanidins (condensed tannins) is regulated by MYB-bHLH-WDR (MBW) transcription factor complexes in all angiosperms studied to date. Tr-MYB133 and Tr-MYB134 were isolated from Trifolium repens and encode R2R3-MYBs that antagonize the activity of MBW activation complexes. These two genes are conserved in other legume species, and form two sub-clades within the larger anthocyanin/proanthocyanidin clade of MYB repressors. However, unlike petunia and Arabidopsis, these R2R3-MYB repressors do not prevent ectopic accumulation of anthocyanins or proanthocyanidins. Instead, they are expressed when anthocyanins or proanthocyanidins are being synthesized, and provide feedback regulation to MBW complexes. This feedback occurs because Tr-MYB133 and Tr-MYB134 are themselves regulated by MBW complexes. Tr-MYB133 is regulated by MBW complexes containing anthocyanin-related R2R3-MYB proteins (Tr-RED LEAF), while Tr-MYB134 is regulated by complexes containing the proanthocyanidin R2R3-MYBs (Tr-MYB14). Other features of the MBW gene regulation networks are also conserved within legumes, including the ability for the anthocyanin MBW complexes to activate the expression of the AN1/TT8 clade bHLH factor. The regulation of Tr-MYB133 and Tr-MYB134 by distinct, pathway-specific MBW complexes has resulted in subspecialization for controlling anthocyanin or proanthocyanidin synthesis. PMID:26779194

  7. 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.)

    PubMed Central

    2012-01-01

    depends on variable activation by combinations of R2R3Myb, bHLH and WDR TF homologues and inhibition by a Myb repressor. PMID:22340661

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

    PubMed Central

    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

  9. Genome-Wide Analysis of Citrus R2R3MYB Genes and Their Spatiotemporal Expression under Stresses and Hormone Treatments

    PubMed Central

    He, Shaolan; Zheng, Yongqiang; Yi, Shilai; Lv, Qiang; Deng, Lie

    2014-01-01

    The R2R3MYB proteins represent one of the largest families of transcription factors, which play important roles in plant growth and development. Although genome-wide analysis of this family has been conducted in many species, little is known about R2R3MYB genes in citrus, In this study, 101 R2R3MYB genes has been identified in the citrus (Citrus sinesis and Citrus clementina) genomes, which are almost equal to the number of rice. Phylogenetic analysis revealed that they could be subdivided into 21 subgroups. The evolutionary relationships and the intro-exon organizations were also analyzed, revealing strong gene conservation but also the expansions of particular functional genes during the plant evolution. Tissue-specific expression profiles showed that 95 citrus R2R3MYB genes were expressed in at least one tissue and the other 6 genes showed very low expression in all tissues tested, suggesting that citrus R2R3MYB genes play important roles in the development of all citrus organs. The transcript abundance level analysis during abiotic conditions (NaCl, abscisic acid, jasmonic acid, drought and low temperature) identified a group of R2R3MYB genes that responded to one or multiple treatments, which showed a promising for improving citrus adaptation to stresses. Our results provided an essential foundation for the future selection of the citrus R2R3MYB genes for cloning and functional dissection with an aim of uncovering their roles in citrus growth and development. PMID:25473954

  10. Genome-wide analysis of citrus R2R3MYB genes and their spatiotemporal expression under stresses and hormone treatments.

    PubMed

    Xie, Rangjin; Li, Yongjie; He, Shaolan; Zheng, Yongqiang; Yi, Shilai; Lv, Qiang; Deng, Lie

    2014-01-01

    The R2R3MYB proteins represent one of the largest families of transcription factors, which play important roles in plant growth and development. Although genome-wide analysis of this family has been conducted in many species, little is known about R2R3MYB genes in citrus, In this study, 101 R2R3MYB genes has been identified in the citrus (Citrus sinesis and Citrus clementina) genomes, which are almost equal to the number of rice. Phylogenetic analysis revealed that they could be subdivided into 21 subgroups. The evolutionary relationships and the intro-exon organizations were also analyzed, revealing strong gene conservation but also the expansions of particular functional genes during the plant evolution. Tissue-specific expression profiles showed that 95 citrus R2R3MYB genes were expressed in at least one tissue and the other 6 genes showed very low expression in all tissues tested, suggesting that citrus R2R3MYB genes play important roles in the development of all citrus organs. The transcript abundance level analysis during abiotic conditions (NaCl, abscisic acid, jasmonic acid, drought and low temperature) identified a group of R2R3MYB genes that responded to one or multiple treatments, which showed a promising for improving citrus adaptation to stresses. Our results provided an essential foundation for the future selection of the citrus R2R3MYB genes for cloning and functional dissection with an aim of uncovering their roles in citrus growth and development. PMID:25473954

  11. Opposite action of R2R3-MYBs from different subgroups on key genes of the shikimate and monolignol pathways in spruce.

    PubMed

    Bomal, Claude; Duval, Isabelle; Giguère, Isabelle; Fortin, Élise; Caron, Sébastien; Stewart, Don; Boyle, Brian; Séguin, Armand; MacKay, John J

    2014-02-01

    Redundancy and competition between R2R3-MYB activators and repressors on common target genes has been proposed as a fine-tuning mechanism for the regulation of plant secondary metabolism. This hypothesis was tested in white spruce [Picea glauca (Moench) Voss] by investigating the effects of R2R3-MYBs from different subgroups on common targets from distinct metabolic pathways. Comparative analysis of transcript profiling data in spruces overexpressing R2R3-MYBs from loblolly pine (Pinus taeda L.), PtMYB1, PtMYB8, and PtMYB14, defined a set of common genes that display opposite regulation effects. The relationship between the closest MYB homologues and 33 putative target genes was explored by quantitative PCR expression profiling in wild-type P. glauca plants during the diurnal cycle. Significant Spearman's correlation estimates were consistent with the proposed opposite effect of different R2R3-MYBs on several putative target genes in a time-related and tissue-preferential manner. Expression of sequences coding for 4CL, DHS2, COMT1, SHM4, and a lipase thio/esterase positively correlated with that of PgMYB1 and PgMYB8, but negatively with that of PgMYB14 and PgMYB15. Complementary electrophoretic mobility shift assay (EMSA) and transactivation assay provided experimental evidence that these different R2R3-MYBs are able to bind similar AC cis-elements in the promoter region of Pg4CL and PgDHS2 genes but have opposite effects on their expression. Competitive binding EMSA experiments showed that PgMYB8 competes more strongly than PgMYB15 for the AC-I MYB binding site in the Pg4CL promoter. Together, the results bring a new perspective to the action of R2R3-MYB proteins in the regulation of distinct but interconnecting metabolism pathways. PMID:24336492

  12. Comparative genomic analysis of the R2R3 MYB secondary cell wall regulators of Arabidopsis, poplar, rice, maize, and switchgrass

    PubMed Central

    2014-01-01

    Background R2R3 MYB proteins constitute one of the largest plant transcription factor clades and regulate diverse plant-specific processes. Several R2R3 MYB proteins act as regulators of secondary cell wall (SCW) biosynthesis in Arabidopsis thaliana (At), a dicotyledenous plant. Relatively few studies have examined SCW R2R3 MYB function in grasses, which may have diverged from dicots in terms of SCW regulatory mechanisms, as they have in cell wall composition and patterning. Understanding cell wall regulation is especially important for improving lignocellulosic bioenergy crops, such as switchgrass. Results Here, we describe the results of applying phylogenic, OrthoMCL, and sequence identity analyses to classify the R2R3 MYB family proteins from the annotated proteomes of Arabidposis, poplar, rice, maize and the initial genome (v0.0) and translated transcriptome of switchgrass (Panicum virgatum). We find that the R2R3 MYB proteins of the five species fall into 48 subgroups, including three dicot-specific, six grass-specific, and two panicoid grass-expanded subgroups. We observe four classes of phylogenetic relationships within the subgroups of known SCW-regulating MYB proteins between Arabidopsis and rice, ranging from likely one-to-one orthology (for AtMYB26, AtMYB103, AtMYB69) to no homologs identifiable (for AtMYB75). Microarray data for putative switchgrass SCW MYBs indicate that many maintain similar expression patterns with the Arabidopsis SCW regulators. However, some of the switchgrass-expanded candidate SCW MYBs exhibit differences in gene expression patterns among paralogs, consistent with subfunctionalization. Furthermore, some switchgrass representatives of grass-expanded clades have gene expression patterns consistent with regulating SCW development. Conclusions Our analysis suggests that no single comparative genomics tool is able to provide a complete picture of the R2R3 MYB protein family without leaving ambiguities, and establishing likely false

  13. Positive selection and functional divergence of R2R3-MYB paralogous genes expressed in inflorescence buds of Scutellaria species (Labiatae).

    PubMed

    Huang, Bing-Hong; Pang, Erli; Chen, Yi-Wen; Cao, Huifen; Ruan, Yu; Liao, Pei-Chun

    2015-01-01

    Anthocyanin is the main pigment forming floral diversity. Several transcription factors that regulate the expression of anthocyanin biosynthetic genes belong to the R2R3-MYB family. Here we examined the transcriptomes of inflorescence buds of Scutellaria species (skullcaps), identified the expression R2R3-MYBs, and detected the genetic signatures of positive selection for adaptive divergence across the rapidly evolving skullcaps. In the inflorescence buds, seven R2R3-MYBs were identified. MYB11 and MYB16 were detected to be positively selected. The signature of positive selection on MYB genes indicated that species diversification could be affected by transcriptional regulation, rather than at the translational level. When comparing among the background lineages of Arabidopsis, tomato, rice, and Amborella, heterogeneous evolutionary rates were detected among MYB paralogs, especially between MYB13 and MYB19. Significantly different evolutionary rates were also evidenced by type-I functional divergence between MYB13 and MYB19, and the accelerated evolutionary rates in MYB19, implied the acquisition of novel functions. Another paralogous pair, MYB2/7 and MYB11, revealed significant radical amino acid changes, indicating divergence in the regulation of different anthocyanin-biosynthetic enzymes. Our findings not only showed that Scutellaria R2R3-MYBs are functionally divergent and positively selected, but also indicated the adaptive relevance of regulatory genes in floral diversification. PMID:25782156

  14. Positive Selection and Functional Divergence of R2R3-MYB Paralogous Genes Expressed in Inflorescence Buds of Scutellaria Species (Labiatae)

    PubMed Central

    Huang, Bing-Hong; Pang, Erli; Chen, Yi-Wen; Cao, Huifen; Ruan, Yu; Liao, Pei-Chun

    2015-01-01

    Anthocyanin is the main pigment forming floral diversity. Several transcription factors that regulate the expression of anthocyanin biosynthetic genes belong to the R2R3-MYB family. Here we examined the transcriptomes of inflorescence buds of Scutellaria species (skullcaps), identified the expression R2R3-MYBs, and detected the genetic signatures of positive selection for adaptive divergence across the rapidly evolving skullcaps. In the inflorescence buds, seven R2R3-MYBs were identified. MYB11 and MYB16 were detected to be positively selected. The signature of positive selection on MYB genes indicated that species diversification could be affected by transcriptional regulation, rather than at the translational level. When comparing among the background lineages of Arabidopsis, tomato, rice, and Amborella, heterogeneous evolutionary rates were detected among MYB paralogs, especially between MYB13 and MYB19. Significantly different evolutionary rates were also evidenced by type-I functional divergence between MYB13 and MYB19, and the accelerated evolutionary rates in MYB19, implied the acquisition of novel functions. Another paralogous pair, MYB2/7 and MYB11, revealed significant radical amino acid changes, indicating divergence in the regulation of different anthocyanin-biosynthetic enzymes. Our findings not only showed that Scutellaria R2R3-MYBs are functionally divergent and positively selected, but also indicated the adaptive relevance of regulatory genes in floral diversification. PMID:25782156

  15. Identification, cloning and characterization of R2R3-MYB gene family in canola (Brassica napus L.) identify a novel member modulating ROS accumulation and hypersensitive-like cell death.

    PubMed

    Chen, Bisi; Niu, Fangfang; Liu, Wu-Zhen; Yang, Bo; Zhang, Jingxiao; Ma, Jieyu; Cheng, Hao; Han, Feng; Jiang, Yuan-Qing

    2016-04-01

    The R2R3-MYB proteins comprise one of the largest families of transcription factors in plants. Although genome-wide analysis of this family has been carried out in some plant species, little is known about R2R3-MYB genes in canola (Brassica napus L.). In this study, we have identified 76 R2R3-MYB genes in the canola genome through mining of expressed sequence tags (ESTs). The cDNA sequences of 44 MYB genes were successfully cloned. The transcriptional activities of BnaMYB proteins encoded by these genes were assayed in yeast. The subcellular localizations of representative R2R3-MYB proteins were investigated through GFP fusion. Besides, the transcript abundance level analysis during abiotic conditions and ABA treatment identified a group of R2R3-MYB genes that responded to one or more treatments. Furthermore, we identified a previously functionally unknown MYB gene-BnaMYB78, which modulates reactive oxygen species (ROS)-dependent cell death in Nicotiana benthamiana, through regulating the transcription of a few ROS- and defence-related genes. Taken together, this study has provided a solid foundation for understanding the roles and regulatory mechanism of canola R2R3-MYB genes. PMID:26800702

  16. Identification, cloning and characterization of R2R3-MYB gene family in canola (Brassica napus L.) identify a novel member modulating ROS accumulation and hypersensitive-like cell death

    PubMed Central

    Chen, Bisi; Niu, Fangfang; Liu, Wu-Zhen; Yang, Bo; Zhang, Jingxiao; Ma, Jieyu; Cheng, Hao; Han, Feng; Jiang, Yuan-Qing

    2016-01-01

    The R2R3-MYB proteins comprise one of the largest families of transcription factors in plants. Although genome-wide analysis of this family has been carried out in some plant species, little is known about R2R3-MYB genes in canola (Brassica napus L.). In this study, we have identified 76 R2R3-MYB genes in the canola genome through mining of expressed sequence tags (ESTs). The cDNA sequences of 44 MYB genes were successfully cloned. The transcriptional activities of BnaMYB proteins encoded by these genes were assayed in yeast. The subcellular localizations of representative R2R3-MYB proteins were investigated through GFP fusion. Besides, the transcript abundance level analysis during abiotic conditions and ABA treatment identified a group of R2R3-MYB genes that responded to one or more treatments. Furthermore, we identified a previously functionally unknown MYB gene-BnaMYB78, which modulates reactive oxygen species (ROS)-dependent cell death in Nicotiana benthamiana, through regulating the transcription of a few ROS- and defence-related genes. Taken together, this study has provided a solid foundation for understanding the roles and regulatory mechanism of canola R2R3-MYB genes. PMID:26800702

  17. TCP3 interacts with R2R3-MYB proteins, promotes flavonoid biosynthesis and negatively regulates the auxin response in Arabidopsis thaliana.

    PubMed

    Li, Shutian; Zachgo, Sabine

    2013-12-01

    TCP proteins belong to the plant-specific bHLH transcription factor family, and function as key regulators of diverse developmental processes. Functional redundancy amongst family members and post-transcriptional down-regulation by miRJAW of several TCP genes complicate their functional characterization. Here, we explore the role of TCP3 by analyzing transgenic plants expressing miRJAW-resistant mTCP3 and dominant-negative TCP3SRDX. Seedlings and seeds of mTCP3 plants were found to hyper-accumulate flavonols, anthocyanins and proanthocyanidins, whereas levels of proanthocyanidins were slightly reduced in TCP3SRDX plants. R2R3-MYB proteins control not only early flavonoid biosynthetic steps but also activate late flavonoid biosynthetic genes by forming ternary R2R3-MYB/bHLH/WD40 (MBW) complexes. TCP3 interacted in yeast with R2R3-MYB proteins, which was further confirmed in planta using BiFC experiments. Yeast three-hybrid assays revealed that TCP3 significantly strengthened the transcriptional activation capacity of R2R3-MYBs bound by the bHLH protein TT8. Transcriptome analysis of mTCP3 and TCP3SRDX plants supported a role for TCP3 in enhancing flavonoid biosynthesis. Moreover, several auxin-related developmental abnormalities were observed in mTCP3 plants. Transcriptome data coupled with studies of an auxin response reporter and auxin efflux carriers showed that TCP3 negatively modulates the auxin response, probably by compromising auxin transport capacity. Genetic experiments revealed that the chalcone synthase mutant tt4-11 lacking flavonoid biosynthesis abrogated the auxin-related defects caused by mTCP3. Together, these data suggest that TCP3 interactions with R2R3-MYBs lead to enhanced flavonoid production, which further negatively modulates the auxin response. PMID:24118612

  18. The oil palm VIRESCENS gene controls fruit colour and encodes a R2R3-MYB

    PubMed Central

    Singh, Rajinder; Low, Eng-Ti Leslie; Ooi, Leslie Cheng-Li; Ong-Abdullah, Meilina; Nookiah, Rajanaidu; Ting, Ngoot-Chin; Marjuni, Marhalil; Chan, Pek-Lan; Ithnin, Maizura; Manaf, Mohd Arif Abdul; Nagappan, Jayanthi; Chan, Kuang-Lim; Rosli, Rozana; Halim, Mohd Amin; Azizi, Norazah; Budiman, Muhammad A.; Lakey, Nathan; Bacher, Blaire; Van Brunt, Andrew; Wang, Chunyan; Hogan, Michael; He, Dong; MacDonald, Jill D.; Smith, Steven W.; Ordway, Jared M.; Martienssen, Robert A.; Sambanthamurthi, Ravigadevi

    2014-01-01

    Oil palm, a plantation crop of major economic importance in Southeast Asia, is the predominant source of edible oil worldwide. We report the identification of the VIRESCENS (VIR) gene, which controls fruit exocarp colour and is an indicator of ripeness. VIR is a R2R3-MYB transcription factor with homology to Lilium LhMYB12 and similarity to Arabidopsis PRODUCTION OF ANTHOCYANIN PIGMENT1 (PAP1). We identify five independent mutant alleles of VIR in over 400 accessions from sub-Saharan Africa that account for the dominant-negative virescens phenotype. Each mutation results in premature termination of the carboxy-terminal domain of VIR, resembling McClintock’s C1-I allele in maize. The abundance of alleles likely reflects cultural practices, by which fruits were venerated for magical and medicinal properties. The identification of VIR will allow selection of the trait at the seed or early-nursery stage, 3-6 years before fruits are produced, greatly advancing introgression into elite breeding material. PMID:24978855

  19. The oil palm VIRESCENS gene controls fruit colour and encodes a R2R3-MYB.

    PubMed

    Singh, Rajinder; Low, Eng-Ti Leslie; Ooi, Leslie Cheng-Li; Ong-Abdullah, Meilina; Nookiah, Rajanaidu; Ting, Ngoot-Chin; Marjuni, Marhalil; Chan, Pek-Lan; Ithnin, Maizura; Manaf, Mohd Arif Abdul; Nagappan, Jayanthi; Chan, Kuang-Lim; Rosli, Rozana; Halim, Mohd Amin; Azizi, Norazah; Budiman, Muhammad A; Lakey, Nathan; Bacher, Blaire; Van Brunt, Andrew; Wang, Chunyan; Hogan, Michael; He, Dong; MacDonald, Jill D; Smith, Steven W; Ordway, Jared M; Martienssen, Robert A; Sambanthamurthi, Ravigadevi

    2014-01-01

    Oil palm, a plantation crop of major economic importance in Southeast Asia, is the predominant source of edible oil worldwide. We report the identification of the virescens (VIR) gene, which controls fruit exocarp colour and is an indicator of ripeness. VIR is a R2R3-MYB transcription factor with homology to Lilium LhMYB12 and similarity to Arabidopsis production of anthocyanin pigment1 (PAP1). We identify five independent mutant alleles of VIR in over 400 accessions from sub-Saharan Africa that account for the dominant-negative virescens phenotype. Each mutation results in premature termination of the carboxy-terminal domain of VIR, resembling McClintock's C1-I allele in maize. The abundance of alleles likely reflects cultural practices, by which fruits were venerated for magical and medicinal properties. The identification of VIR will allow selection of the trait at the seed or early-nursery stage, 3-6 years before fruits are produced, greatly advancing introgression into elite breeding material. PMID:24978855

  20. The Evolutionary History of R2R3-MYB Proteins Across 50 Eukaryotes: New Insights Into Subfamily Classification and Expansion.

    PubMed

    Du, Hai; Liang, Zhe; Zhao, Sen; Nan, Ming-Ge; Tran, Lam-Son Phan; Lu, Kun; Huang, Yu-Bi; Li, Jia-Na

    2015-01-01

    R2R3-MYB proteins (2R-MYBs) are one of the main transcription factor families in higher plants. Since the evolutionary history of this gene family across the eukaryotic kingdom remains unknown, we performed a comparative analysis of 2R-MYBs from 50 major eukaryotic lineages, with particular emphasis on land plants. A total of 1548 candidates were identified among diverse taxonomic groups, which allowed for an updated classification of 73 highly conserved subfamilies, including many newly identified subfamilies. Our results revealed that the protein architectures, intron patterns, and sequence characteristics were remarkably conserved in each subfamily. At least four subfamilies were derived from early land plants, 10 evolved from spermatophytes, and 19 from angiosperms, demonstrating the diversity and preferential expansion of this gene family in land plants. Moreover, we determined that their remarkable expansion was mainly attributed to whole genome and segmental duplication, where duplicates were preferentially retained within certain subfamilies that shared three homologous intron patterns (a, b, and c) even though up to 12 types of patterns existed. Through our integrated distributions, sequence characteristics, and phylogenetic tree analyses, we confirm that 2R-MYBs are old and postulate that 3R-MYBs may be evolutionarily derived from 2R-MYBs via intragenic domain duplication. PMID:26047035

  1. The Evolutionary History of R2R3-MYB Proteins Across 50 Eukaryotes: New Insights Into Subfamily Classification and Expansion

    PubMed Central

    Du, Hai; Liang, Zhe; Zhao, Sen; Nan, Ming-Ge; Phan Tran, Lam-Son; Lu, Kun; Huang, Yu-Bi; Li, Jia-Na

    2015-01-01

    R2R3-MYB proteins (2R-MYBs) are one of the main transcription factor families in higher plants. Since the evolutionary history of this gene family across the eukaryotic kingdom remains unknown, we performed a comparative analysis of 2R-MYBs from 50 major eukaryotic lineages, with particular emphasis on land plants. A total of 1548 candidates were identified among diverse taxonomic groups, which allowed for an updated classification of 73 highly conserved subfamilies, including many newly identified subfamilies. Our results revealed that the protein architectures, intron patterns, and sequence characteristics were remarkably conserved in each subfamily. At least four subfamilies were derived from early land plants, 10 evolved from spermatophytes, and 19 from angiosperms, demonstrating the diversity and preferential expansion of this gene family in land plants. Moreover, we determined that their remarkable expansion was mainly attributed to whole genome and segmental duplication, where duplicates were preferentially retained within certain subfamilies that shared three homologous intron patterns (a, b, and c) even though up to 12 types of patterns existed. Through our integrated distributions, sequence characteristics, and phylogenetic tree analyses, we confirm that 2R-MYBs are old and postulate that 3R-MYBs may be evolutionarily derived from 2R-MYBs via intragenic domain duplication. PMID:26047035

  2. Genome-wide identification of cassava R2R3 MYB family genes related to abscission zone separation after environmental-stress-induced abscission

    PubMed Central

    Liao, Wenbin; Yang, Yiling; Li, Yayun; Wang, Gan; Peng, Ming

    2016-01-01

    Cassava plants (Manihot esculenta Crantz) resist environmental stresses by shedding leaves in leaf pulvinus abscission zones (AZs), thus leading to adaptation to new environmental conditions. Little is known about the roles of cassava R2R3 MYB factors in regulating AZ separation. Herein, 166 cassava R2R3 MYB genes were identified. Evolutionary analysis indicated that the 166 R2R3 MYB genes could be divided into 11 subfamilies. Transcriptome analysis indicated that 26 R2R3 MYB genes were expressed in AZs across six time points during both ethylene- and water-deficit stress-induced leaf abscission. Comparative expression profile analysis of similar SOTA (Self Organizing Tree Algorithm) clusters demonstrated that 10 R2R3 MYB genes had similar expression patterns at six time points in response to both treatments. GO (Gene Ontology) annotation confirmed that all 10 R2R3 MYB genes participated in the responses to stress and ethylene and auxin stimuli. Analysis of the putative 10 R2R3 MYB promoter regions showed that those genes primarily contained ethylene- and stress-related cis-elements. The expression profiles of the genes acting downstream of the selected MYBs were confirmed to be involved in cassava abscission zone separation. All these results indicated that R2R3 MYB plays an important regulatory role in AZ separation. PMID:27573926

  3. Genome-wide identification of cassava R2R3 MYB family genes related to abscission zone separation after environmental-stress-induced abscission.

    PubMed

    Liao, Wenbin; Yang, Yiling; Li, Yayun; Wang, Gan; Peng, Ming

    2016-01-01

    Cassava plants (Manihot esculenta Crantz) resist environmental stresses by shedding leaves in leaf pulvinus abscission zones (AZs), thus leading to adaptation to new environmental conditions. Little is known about the roles of cassava R2R3 MYB factors in regulating AZ separation. Herein, 166 cassava R2R3 MYB genes were identified. Evolutionary analysis indicated that the 166 R2R3 MYB genes could be divided into 11 subfamilies. Transcriptome analysis indicated that 26 R2R3 MYB genes were expressed in AZs across six time points during both ethylene- and water-deficit stress-induced leaf abscission. Comparative expression profile analysis of similar SOTA (Self Organizing Tree Algorithm) clusters demonstrated that 10 R2R3 MYB genes had similar expression patterns at six time points in response to both treatments. GO (Gene Ontology) annotation confirmed that all 10 R2R3 MYB genes participated in the responses to stress and ethylene and auxin stimuli. Analysis of the putative 10 R2R3 MYB promoter regions showed that those genes primarily contained ethylene- and stress-related cis-elements. The expression profiles of the genes acting downstream of the selected MYBs were confirmed to be involved in cassava abscission zone separation. All these results indicated that R2R3 MYB plays an important regulatory role in AZ separation. PMID:27573926

  4. Tomato R2R3-MYB Proteins SlANT1 and SlAN2: Same Protein Activity, Different Roles

    PubMed Central

    Bassolino, Laura; Povero, Giovanni; Spelt, Cornelis; Buti, Sara; Giuliano, Giovanni; Quattrocchio, Francesca; Koes, Ronald; Perata, Pierdomenico; Gonzali, Silvia

    2015-01-01

    Anthocyanins are water-soluble polyphenolic compounds with a high nutraceutical value. Despite the fact that cultivated tomato varieties do not accumulate anthocyanins in the fruit, the biosynthetic pathway can be activated in the vegetative organs by several environmental stimuli. Little is known about the molecular mechanisms regulating anthocyanin synthesis in tomato. Here, we carried out a molecular and functional characterization of two genes, SlAN2 and SlANT1, encoding two R2R3-MYB transcription factors. We show that both can induce ectopic anthocyanin synthesis in transgenic tomato lines, including the fruit. However, only SlAN2 acts as a positive regulator of anthocyanin synthesis in vegetative tissues under high light or low temperature conditions. PMID:26308527

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

    PubMed Central

    Zhu, Qinlong; Sui, Shunzhao; Lei, Xinghua; Yang, Zhongfang; Lu, Kun; Liu, Guangde; Liu, Yao-Guang; Li, Mingyang

    2015-01-01

    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. PMID:26448466

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

    PubMed

    Zhu, Qinlong; Sui, Shunzhao; Lei, Xinghua; Yang, Zhongfang; Lu, Kun; Liu, Guangde; Liu, Yao-Guang; Li, Mingyang

    2015-01-01

    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. PMID:26448466

  7. Functional diversification of the potato R2R3 MYB anthocyanin activators AN1, MYBA1, and MYB113 and their interaction with basic helix-loop-helix cofactors.

    PubMed

    Liu, Yuhui; Lin-Wang, Kui; Espley, Richard V; Wang, Li; Yang, Hongyu; Yu, Bin; Dare, Andrew; Varkonyi-Gasic, Erika; Wang, Jing; Zhang, Junlian; Wang, Di; Allan, Andrew C

    2016-04-01

    In potato (Solanum tuberosumL.), R2R3 MYBs are involved in the regulation of anthocyanin biosynthesis. We examined sequences of these MYBs in cultivated potatoes, which are more complex than diploid potato due to ploidy and heterozygosity. We found amino acid variants in the C-terminus of the MYB StAN1, termed R0, R1, and R3, due to the presence of a repeated 10-amino acid motif. These variant MYBs showed some expression in both white and pigmented tubers. We found several new alleles or gene family members of R2R3 MYBs,StMYBA1andStMYB113, which were also expressed in white potato tubers. From functional analysis in tobacco, we showed that the presence of a C-terminal 10-amino acid motif is optimal for activating anthocyanin accumulation. Engineering a motif back into a MYB lacking this sequence enhanced its activating ability. Versions ofStMYBA1andStMYB113can also activate anthocyanin accumulation in tobacco leaves, with the exception ofStMYB113-3, which has a partial R2R3 domain. We isolated five family members of potatoStbHLH1, and oneStJAF13, to test their ability to interact with MYB variants. The results showed that two alleles ofStbHLH1from white skin and red skin are non-functional, while three otherStbHLH1s have different co-regulating abilities, and need to be activated by StJAF13. Combined with expression analysis in potato tuber, results suggest thatStbHLH1andStJAF13are key co-regulators of anthocyanin biosynthesis, while the transcripts of MYB variantsStAN1,StMYBA1, andStMYB113are well expressed, even in the absence of pigmentation. PMID:26884602

  8. Functional diversification of the potato R2R3 MYB anthocyanin activators AN1, MYBA1, and MYB113 and their interaction with basic helix-loop-helix cofactors

    PubMed Central

    Liu, Yuhui; Lin-Wang, Kui; Espley, Richard V.; Wang, Li; Yang, Hongyu; Yu, Bin; Dare, Andrew; Varkonyi-Gasic, Erika; Wang, Jing; Zhang, Junlian; Wang, Di; Allan, Andrew C.

    2016-01-01

    In potato (Solanum tuberosum L.), R2R3 MYBs are involved in the regulation of anthocyanin biosynthesis. We examined sequences of these MYBs in cultivated potatoes, which are more complex than diploid potato due to ploidy and heterozygosity. We found amino acid variants in the C-terminus of the MYB StAN1, termed R0, R1, and R3, due to the presence of a repeated 10-amino acid motif. These variant MYBs showed some expression in both white and pigmented tubers. We found several new alleles or gene family members of R2R3 MYBs, StMYBA1 and StMYB113, which were also expressed in white potato tubers. From functional analysis in tobacco, we showed that the presence of a C-terminal 10-amino acid motif is optimal for activating anthocyanin accumulation. Engineering a motif back into a MYB lacking this sequence enhanced its activating ability. Versions of StMYBA1 and StMYB113 can also activate anthocyanin accumulation in tobacco leaves, with the exception of StMYB113-3, which has a partial R2R3 domain. We isolated five family members of potato StbHLH1, and one StJAF13, to test their ability to interact with MYB variants. The results showed that two alleles of StbHLH1 from white skin and red skin are non-functional, while three other StbHLH1s have different co-regulating abilities, and need to be activated by StJAF13. Combined with expression analysis in potato tuber, results suggest that StbHLH1 and StJAF13 are key co-regulators of anthocyanin biosynthesis, while the transcripts of MYB variants StAN1, StMYBA1, and StMYB113 are well expressed, even in the absence of pigmentation. PMID:26884602

  9. Loss-of-function mutations affecting a specific Glycine max R2R3 MYB transcription factor result in brown hilum and brown seed coats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although modern soybean cultivars feature yellow seed coats, with the only color variation found at the hila, the ancestral condition is black seed coats. Both seed coat and hila coloration are due to the presence of phenylpropanoid pathway derivatives, principally anthocyanins. The genetics of soyb...

  10. A wheat R2R3-MYB protein PURPLE PLANT1 (TaPL1) functions as a positive regulator of anthocyanin biosynthesis.

    PubMed

    Shin, Dong Ho; Choi, Myoung-Goo; Kang, Chon-Sik; Park, Chul-Soo; Choi, Sang-Bong; Park, Youn-Il

    2016-01-15

    Transcriptional activation of anthocyanin biosynthesis genes in vegetative tissues of monocotyledonous plants is mediated by cooperative activity of one component from each of the following two transcription factor families: MYB encoded by PURPLE PLANT1/COLORED ALEURONE1 (PL1/C1), and basic helix-loop-helix (bHLH) encoded by RED/BOOSTER (R1/B1). In the present study, putative PL cDNA was cloned from the wheat (Triticum aestivum) cultivar Iksan370, which preferentially expresses anthocyanins in coleoptiles. Phylogenetic tree analysis of deduced amino acid sequences showed that a putative TaPL1 is highly homologous to barley (Hordeum vulgare) HvPL1, but is distinct from wheat TaC1. Transgenic Arabidopsis thaliana stably expressing putative TaPL1 accumulated anthocyanin pigments in leaves and up-regulated structural genes involved in both early and late anthocyanin biosynthesis steps. TaPL1 transcript levels in Iksan370 were more prominent in vegetative tissues such as young coleoptiles than in reproductive tissues such as spikelets. TaPL1 expression was significantly up-regulated by environmental stresses including cold, salt, and light, which are known to induce anthocyanin accumulation. These combined results suggest that TaPL1 is an active positive regulator of anthocyanin biosynthesis in wheat coleoptiles. PMID:26692488

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

    PubMed Central

    Sun, Shan-Shan

    2016-01-01

    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.

  12. The grapevine guard cell-related VvMYB60 transcription factor is involved in the regulation of stomatal activity and is differentially expressed in response to ABA and osmotic stress

    PubMed Central

    2011-01-01

    Background Under drought, plants accumulate the signaling hormone abscisic acid (ABA), which induces the rapid closure of stomatal pores to prevent water loss. This event is trigged by a series of signals produced inside guard cells which finally reduce their turgor. Many of these events are tightly regulated at the transcriptional level, including the control exerted by MYB proteins. In a previous study, while identifying the grapevine R2R3 MYB family, two closely related genes, VvMYB30 and VvMYB60 were found with high similarity to AtMYB60, an Arabidopsis guard cell-related drought responsive gene. Results Promoter-GUS transcriptional fusion assays showed that expression of VvMYB60 was restricted to stomatal guard cells and was attenuated in response to ABA. Unlike VvMYB30, VvMYB60 was able to complement the loss-of-function atmyb60-1 mutant, indicating that VvMYB60 is the only true ortholog of AtMYB60 in the grape genome. In addition, VvMYB60 was differentially regulated during development of grape organs and in response to ABA and drought-related stress conditions. Conclusions These results show that VvMYB60 modulates physiological responses in guard cells, leading to the possibility of engineering stomatal conductance in grapevine, reducing water loss and helping this species to tolerate drought under extreme climatic conditions. PMID:22018045

  13. Fine mapping of the pleiotropic locus B for black spine and orange mature fruit color in cucumber identifies a 50 kb region containing a R2R3-MYB transcription factor

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The spine and skin colors on fruits are two important fruit quality traits in cucumber for variety improvement. In this study, we investigated the inheritance of spine and mature fruit colors with segregation populations developed from the cross between two inbred lines WI7200 (black spine and orang...

  14. Characterization and expression profiling of MYB transcription factors against stresses and during male organ development in Chinese cabbage (Brassica rapa ssp. pekinensis).

    PubMed

    Saha, Gopal; Park, Jong-In; Ahmed, Nasar Uddin; Kayum, Md Abdul; Kang, Kwon-Kyoo; Nou, Ill-Sup

    2016-07-01

    MYB proteins comprise a large family of plant transcription factors that play regulatory roles in different biological processes such as plant development, metabolism, and defense responses. To gain insight into this gene superfamily and to elucidate its roles in stress resistance, we performed a comprehensive genome-wide identification, characterization, and expression analysis of MYB genes in Chinese cabbage (Brassica rapa ssp. pekinensis). We identified 475 Chinese cabbage MYB genes, among which most were from R2R3-MYB (256 genes) and MYB-related (202) subfamilies. Analysis of sequence characteristics, phylogenetic classification, and protein motif structures confirmed the existence of several categories (1R, 2R, 3R, 4R, and 5R) of Chinese cabbage MYB genes, which is comparable with MYB genes of other crops. An extensive in silico functional analysis, based on established functional properties of MYB genes from different crop species, revealed 11 and four functional clades within the Chinese cabbage R2R3-MYB and MYB-related subfamilies, respectively. In this study, we reported a MYB-like group within the MYB-related subfamily contains 77 MYB genes. Expression analysis using low temperature-treated whole-genome microarray data revealed variable transcript abundance of 1R/2R/3R/4R/5R-MYB genes in 11 clusters between two inbred lines of Chinese cabbage, Chiifu and Kenshin, which differ in cold tolerance. In further validation tests, we used qRT-PCR to examine the cold-responsive expression patterns of 27 BrMYB genes; surprisingly, the MYB-related genes were induced more highly than the R2R3-MYB genes. In addition, we identified 10 genes with corresponsive expression patterns from a set of salt-, drought-, ABA-, JA-, and SA-induced R2R3-MYB genes. We identified 11 R2R3-MYBs functioning in resistance against biotic stress, including 10 against Fusarium oxysporum f.sp. conglutinans and one against Pectobacterium carotovoram subsp. caratovorum. Furthermore, based on

  15. Peach MYB7 activates transcription of the proanthocyanidin pathway gene encoding leucoanthocyanidin reductase, but not anthocyanidin reductase

    PubMed Central

    Zhou, Hui; Lin-Wang, Kui; Liao, Liao; Gu, Chao; Lu, Ziqi; Allan, Andrew C.; Han, Yuepeng

    2015-01-01

    Proanthocyanidins (PAs) are a group of natural phenolic compounds that have a great effect on both flavor and nutritious value of fruit. It has been shown that PA synthesis is regulated by R2R3-MYB transcription factors (TFs) via activation of PA-specific pathway genes encoding leucoanthocyanidin reductase and anthocyanidin reductase. Here, we report the isolation and characterization of a MYB gene designated PpMYB7 in peach. The peach PpMYB7 represents a new group of R2R3-MYB genes regulating PA synthesis in plants. It is able to activate transcription of PpLAR1 but not PpANR, and has a broader selection of potential bHLH partners compared with PpMYBPA1. Transcription of PpMYB7 can be activated by the peach basic leucine-zipper 5 TF (PpbZIP5) via response to ABA. Our study suggests a transcriptional network regulating PA synthesis in peach, with the results aiding the understanding of the functional divergence between R2R3-MYB TFs in plants. PMID:26579158

  16. Identification of Transcription Factors ZmMYB111 and ZmMYB148 Involved in Phenylpropanoid Metabolism

    PubMed Central

    Zhang, Junjie; Zhang, Shuangshuang; Li, Hui; Du, Hai; Huang, Huanhuan; Li, Yangping; Hu, Yufeng; Liu, Hanmei; Liu, Yinghong; Yu, Guowu; Huang, Yubi

    2016-01-01

    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 ZmMYB111 and 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. PMID:26913047

  17. The Transcription Factor VvMYB5b Contributes to the Regulation of Anthocyanin and Proanthocyanidin Biosynthesis in Developing Grape Berries12[W

    PubMed Central

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

    2008-01-01

    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. PMID:18539781

  18. Engineering phenolics metabolism in the grasses using transcription factors

    SciTech Connect

    Grotewold, Erich

    2013-07-26

    The economical competitiveness of agriculture-derived biofuels can be significantly enhanced by increasing biomass/acre yields and by furnishing the desired carbon balance for facilitating liquid fuel production (e.g., ethanol) or for high-energy solid waste availability to be used as biopower (e.g., for electricity production). Biomass production and carbon balance are tightly linked to the biosynthesis of phenolic compounds, which are found in crops and in agricultural residues either as lignins, as part of the cell wall, or as soluble phenolics which play a variety of functions in the biology of plants. The grasses, in particular maize, provide the single major source of agricultural biomass, offering significant opportunities for increasing renewable fuel production. Our laboratory has pioneered the use of transcription factors for manipulating plant metabolic pathways, an approach that will be applied here towards altering the composition of phenolic compounds in maize. Previously, we identified a small group of ten maize R2R3-MYB transcription factors with all the characteristics of regulators of different aspects of phenolic biosynthesis. Here, we propose to investigate the participation of these R2R3-MYB factors in the regulation of soluble and insoluble maize phenolics, using a combination of over-expression and down-regulation of these transcription factors in transgenic maize cultured cells and in maize plants. Maize cells and plants altered in the activity of these regulatory proteins will be analyzed for phenolic composition by targeted metabolic profiling. Specifically, we will I) Investigate the effect of gain- and loss-of-function of a select group of R2R3-MYB transcription factors on the phenolic composition of maize plants and II) Identify the biosynthetic genes regulated by each of the selected R2R3-MYB factors. While a likely outcome of these studies are transgenic maize plants with altered phenolic composition, this research will significantly

  19. Transcription factors of Lotus: regulation of isoflavonoid biosynthesis requires coordinated changes in transcription factor activity.

    PubMed

    Shelton, Dale; Stranne, Maria; Mikkelsen, Lisbeth; Pakseresht, Nima; Welham, Tracey; Hiraka, Hideki; Tabata, Satoshi; Sato, Shusei; Paquette, Suzanne; Wang, Trevor L; Martin, Cathie; Bailey, Paul

    2012-06-01

    Isoflavonoids are a class of phenylpropanoids made by legumes, and consumption of dietary isoflavonoids confers benefits to human health. Our aim is to understand the regulation of isoflavonoid biosynthesis. Many studies have shown the importance of transcription factors in regulating the transcription of one or more genes encoding enzymes in phenylpropanoid metabolism. In this study, we coupled bioinformatics and coexpression analysis to identify candidate genes encoding transcription factors involved in regulating isoflavonoid biosynthesis in Lotus (Lotus japonicus). Genes encoding proteins belonging to 39 of the main transcription factor families were examined by microarray analysis of RNA from leaf tissue that had been elicited with glutathione. Phylogenetic analyses of each transcription factor family were used to identify subgroups of proteins that were specific to L. japonicus or closely related to known regulators of the phenylpropanoid pathway in other species. R2R3MYB subgroup 2 genes showed increased expression after treatment with glutathione. One member of this subgroup, LjMYB14, was constitutively overexpressed in L. japonicus and induced the expression of at least 12 genes that encoded enzymes in the general phenylpropanoid and isoflavonoid pathways. A distinct set of six R2R3MYB subgroup 2-like genes was identified. We suggest that these subgroup 2 sister group proteins and those belonging to the main subgroup 2 have roles in inducing isoflavonoid biosynthesis. The induction of isoflavonoid production in L. japonicus also involves the coordinated down-regulation of competing biosynthetic pathways by changing the expression of other transcription factors. PMID:22529285

  20. Circadian oscillatory transcriptional programs in grapevine ripening fruits

    PubMed Central

    2014-01-01

    Background Temperature and solar radiation influence Vitis vinifera L. berry ripening. Both environmental conditions fluctuate cyclically on a daily period basis and the strength of this fluctuation affects grape ripening too. Additionally, a molecular circadian clock regulates daily cyclic expression in a large proportion of the plant transcriptome modulating multiple developmental processes in diverse plant organs and developmental phases. Circadian cycling of fruit transcriptomes has not been characterized in detail despite their putative relevance in the final composition of the fruit. Thus, in this study, gene expression throughout 24 h periods in pre-ripe berries of Tempranillo and Verdejo grapevine cultivars was followed to determine whether different ripening transcriptional programs are activated during certain times of day in different grape tissues and genotypes. Results Microarray analyses identified oscillatory transcriptional profiles following circadian variations in the photocycle and the thermocycle. A higher number of expression oscillating transcripts were detected in samples carrying exocarp tissue including biotic stress-responsive transcripts activated around dawn. Thermotolerance-like responses and regulation of circadian clock-related genes were observed in all studied samples. Indeed, homologs of core clock genes were identified in the grapevine genome and, among them, VvREVEILLE1 (VvRVE1), showed a consistent circadian expression rhythm in every grape berry tissue analysed. Light signalling components and terpenoid biosynthetic transcripts were specifically induced during the daytime in Verdejo, a cultivar bearing white-skinned and aromatic berries, whereas transcripts involved in phenylpropanoid biosynthesis were more prominently regulated in Tempranillo, a cultivar bearing black-skinned berries. Conclusions The transcriptome of ripening fruits varies in response to daily environmental changes, which might partially be under the control

  1. Ectopic expression of R3 MYB transcription factor gene OsTCL1 in Arabidopsis, but not rice, affects trichome and root hair formation

    PubMed Central

    Zheng, Kaijie; Tian, Hainan; Hu, Qingnan; Guo, Hongyan; Yang, Li; Cai, Ling; Wang, Xutong; Liu, Bao; Wang, Shucai

    2016-01-01

    In Arabidopsis, a MYB-bHLH-WD40 (MBW) transcriptional activator complex activates the homeodomain protein gene GLABRA2 (GL2), leading to the promotion of trichome formation and inhibition of root hair formation. The same MBW complex also activates single-repeat R3 MYB genes. R3 MYBs in turn, play a negative feedback role by competing with R2R3 MYB proteins for binding bHLH proteins, thus blocking the formation of the MBW complex. By BLASTing the rice (Oryza sativa) protein database using the entire amino acid sequence of Arabidopsis R3 MYB transcription factor TRICHOMELESS1 (TCL1), we found that there are two genes in rice genome encoding R3 MYB transcription factors, namely Oryza sativa TRICHOMELESS1 (OsTCL1) and OsTCL2. Expressing OsTCL1 in Arabidopsis inhibited trichome formation and promoted root hair formation, and OsTCL1 interacted with GL3 when tested in Arabidopsis protoplasts. Consistent with these observations, expression levels of GL2, R2R3 MYB transcription factor gene GLABRA1 (GL1) and several R3 MYB genes were greatly reduced, indicating that OsTCL1 is functional R3 MYB. However, trichome and root hair formation in transgenic rice plants overexpressing OsTCL1 remained largely unchanged, and elevated expression of OsGL2 was observed in the transgenic rice plants, indicating that rice may use different mechanisms to regulate trichome formation. PMID:26758286

  2. Ectopic expression of R3 MYB transcription factor gene OsTCL1 in Arabidopsis, but not rice, affects trichome and root hair formation.

    PubMed

    Zheng, Kaijie; Tian, Hainan; Hu, Qingnan; Guo, Hongyan; Yang, Li; Cai, Ling; Wang, Xutong; Liu, Bao; Wang, Shucai

    2016-01-01

    In Arabidopsis, a MYB-bHLH-WD40 (MBW) transcriptional activator complex activates the homeodomain protein gene GLABRA2 (GL2), leading to the promotion of trichome formation and inhibition of root hair formation. The same MBW complex also activates single-repeat R3 MYB genes. R3 MYBs in turn, play a negative feedback role by competing with R2R3 MYB proteins for binding bHLH proteins, thus blocking the formation of the MBW complex. By BLASTing the rice (Oryza sativa) protein database using the entire amino acid sequence of Arabidopsis R3 MYB transcription factor TRICHOMELESS1 (TCL1), we found that there are two genes in rice genome encoding R3 MYB transcription factors, namely Oryza sativa TRICHOMELESS1 (OsTCL1) and OsTCL2. Expressing OsTCL1 in Arabidopsis inhibited trichome formation and promoted root hair formation, and OsTCL1 interacted with GL3 when tested in Arabidopsis protoplasts. Consistent with these observations, expression levels of GL2, R2R3 MYB transcription factor gene GLABRA1 (GL1) and several R3 MYB genes were greatly reduced, indicating that OsTCL1 is functional R3 MYB. However, trichome and root hair formation in transgenic rice plants overexpressing OsTCL1 remained largely unchanged, and elevated expression of OsGL2 was observed in the transgenic rice plants, indicating that rice may use different mechanisms to regulate trichome formation. PMID:26758286

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

    PubMed Central

    2011-01-01

    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 of protein

  4. A comprehensive survey of the grapevine VQ gene family and its transcriptional correlation with WRKY proteins

    PubMed Central

    Wang, Min; Vannozzi, Alessandro; Wang, Gang; Zhong, Yan; Corso, Massimiliano; Cavallini, Erika; Cheng, Zong-Ming (Max)

    2015-01-01

    WRKY proteins are a class of transcription factors (TFs) involved in the regulation of various physiological processes, including the plant response to biotic and abiotic stresses. Recent studies in Arabidopsis have revealed that some WRKY TFs interact with a class of proteins designed as VQ proteins because of their typical conserved motif (FxxxVQxLTG). So far, no information is available about the genomic organization and the function of VQ motif-containing protein in grapevine (Vitis vinifera L). In the current study, we analyzed the 12X V1 prediction of the nearly homozygous PN40024 genotype identifying up to 18 predicted VQ genes (VvVQ). VvVQs phylogenetic and bioinformatic analyses indicated that the intron-exon structures and motif distribution are highly divergent between different members of the grapevine VQ family. Moreover, the analysis of the V. vinifera cv. Corvina expression atlas revealed a tissue- and stage-specific expression of several members of the family which also showed a significant correlation with WRKY TFs. Grapevine VQ genes also exhibited altered expression in response to drought, powdery mildew infection, salicylic acid (SA) and ethylene (ETH) treatments. The present study represents the first characterization of VQ genes in a grapevine genotype and it is a pivotal foundation for further studies aimed at functionally characterizing this mostly unknown grapevine multigenic family. PMID:26124765

  5. Genome-wide analysis of the MYB transcription factor superfamily in soybean

    PubMed Central

    2012-01-01

    Background The MYB superfamily constitutes one of the most abundant groups of transcription factors described in plants. Nevertheless, their functions appear to be highly diverse and remain rather unclear. To date, no genome-wide characterization of this gene family has been conducted in a legume species. Here we report the first genome-wide analysis of the whole MYB superfamily in a legume species, soybean (Glycine max), including the gene structures, phylogeny, chromosome locations, conserved motifs, and expression patterns, as well as a comparative genomic analysis with Arabidopsis. Results A total of 244 R2R3-MYB genes were identified and further classified into 48 subfamilies based on a phylogenetic comparative analysis with their putative orthologs, showed both gene loss and duplication events. The phylogenetic analysis showed that most characterized MYB genes with similar functions are clustered in the same subfamily, together with the identification of orthologs by synteny analysis, functional conservation among subgroups of MYB genes was strongly indicated. The phylogenetic relationships of each subgroup of MYB genes were well supported by the highly conserved intron/exon structures and motifs outside the MYB domain. Synonymous nucleotide substitution (dN/dS) analysis showed that the soybean MYB DNA-binding domain is under strong negative selection. The chromosome distribution pattern strongly indicated that genome-wide segmental and tandem duplication contribute to the expansion of soybean MYB genes. In addition, we found that ~ 4% of soybean R2R3-MYB genes had undergone alternative splicing events, producing a variety of transcripts from a single gene, which illustrated the extremely high complexity of transcriptome regulation. Comparative expression profile analysis of R2R3-MYB genes in soybean and Arabidopsis revealed that MYB genes play conserved and various roles in plants, which is indicative of a divergence in function. Conclusions In this

  6. A subgroup of MYB transcription factor genes undergoes highly conserved alternative splicing in Arabidopsis and rice.

    PubMed

    Li, Jigang; Li, Xiaojuan; Guo, Lei; Lu, Feng; Feng, Xiaojie; He, Kun; Wei, Liping; Chen, Zhangliang; Qu, Li-Jia; Gu, Hongya

    2006-01-01

    MYB transcription factor genes play important roles in many developmental processes and in various defence responses of plants. Two Arabidopsis R2R3-type MYB genes, AtMYB59 and AtMYB48, were found to undergo similar alternative splicing. Both genes have four distinctively spliced transcripts that encode either MYB-related proteins or R2R3-MYB proteins. An extensive BLAST search of the GenBank database resulted in finding and cloning two rice homologues, both of which were also found to share a similar alternative splicing pattern. In a semi-quantitative study, the expression of one splice variant of AtMYB59 was found to be differentially regulated in treatments with different phytohormones and stresses. GFP fusion protein analysis revealed that both of the two predicted nuclear localization signals (NLSs) in the R3 domain are required for localizing to the nucleus. Promoter-GUS analysis in transgenic plants showed that 5'-UTR is sufficient for the translation initiation of type 3 transcripts (encoding R2R3-MYB proteins), but not for type 2 transcripts (encoding MYB-related proteins). Moreover, a new type of non-canonical intron, with the same nucleotide repeats at the 5' and 3' splice sites, was identified. Thirty-eight Arabidopsis and rice genes were found to have this type of non-canonical intron, most of which undergo alternative splicing. These data suggest that this subgroup of transcription factor genes may be involved in multiple biological processes and may be transcriptionally regulated by alternative splicing. PMID:16531467

  7. Modified bimolecular fluorescence complementation assay to study the inhibition of transcription complex formation by JAZ proteins.

    PubMed

    Qi, Tiancong; Song, Susheng; Xie, Daoxin

    2013-01-01

    The jasmonate (JA) ZIM-domain (JAZ) proteins of Arabidopsis thaliana repress JA signaling and negatively regulate the JA responses. Recently, JAZ proteins have been found to inhibit the transcriptional function of several transcription factors, among which the basic helix-loop-helix (bHLH) (GLABRA3 [GL3], ENHANCER OF GLABRA3 [EGL3], and TRANSPARENT TESTA8 [TT8]) and R2R3-MYB (GL1 and MYB75) that can interact with each other to form bHLH-MYB complexes and further control gene expression. The bimolecular fluorescence complementation (BiFC) assay is a widely used technique to study protein-protein interactions in living cells. Here we describe a modified BiFC experimental procedure to study the inhibition of the formation of the bHLH (GL3)-MYB (GL1) complex by JAZ proteins. PMID:23615997

  8. Laser Microdissection of Grapevine Leaves Reveals Site-Specific Regulation of Transcriptional Response to Plasmopara viticola.

    PubMed

    Lenzi, Luisa; Caruso, Carla; Bianchedi, Pier Luigi; Pertot, Ilaria; Perazzolli, Michele

    2016-01-01

    Grapevine is one of the most important fruit crops in the world, and it is highly susceptible to downy mildew caused by the biotrophic oomycete Plasmopara viticola. Gene expression profiling has been used extensively to investigate the regulation processes of grapevine-P. viticola interaction, but all studies to date have involved the use of whole leaves. However, only a small fraction of host cells is in contact with the pathogen, so highly localized transcriptional changes of infected cells may be masked by the large portion of non-infected cells when analyzing the whole leaf. In order to understand the transcriptional regulation of the plant reaction at the sites of pathogen infection, we optimized a laser microdissection protocol and analyzed the transcriptional changes in stomata cells and surrounding areas of grapevine leaves at early stages of P. viticola infection. The results indicate that the expression levels of seven P. viticola-responsive genes were greater in microdissected cells than in whole leaves, highlighting the site-specific transcriptional regulation of the host response. The gene modulation was restricted to the stomata cells and to the surrounding areas of infected tissues, indicating that the host response is mainly located at the infection sites and that short-distance signals are implicated. In addition, due to the high sensitivity of the laser microdissection technique, significant modulations of three genes that were completely masked in the whole tissue analysis were detected. The protocol validated in this study could greatly increase the sensitivity of further transcriptomic studies of the grapevine-P. viticola interaction. PMID:26546320

  9. Transcriptional analysis of late ripening stages of grapevine berry

    PubMed Central

    2011-01-01

    Background The composition of grapevine berry at harvest is a major determinant of wine quality. Optimal oenological maturity of berries is characterized by a high sugar/acidity ratio, high anthocyanin content in the skin, and low astringency. However, harvest time is still mostly determined empirically, based on crude biochemical composition and berry tasting. In this context, it is interesting to identify genes that are expressed/repressed specifically at the late stages of ripening and which may be used as indicators of maturity. Results Whole bunches and berries sorted by density were collected in vineyard on Chardonnay (white cultivar) grapevines for two consecutive years at three stages of ripening (7-days before harvest (TH-7), harvest (TH), and 10-days after harvest (TH+10)). Microvinification and sensory analysis indicate that the quality of the wines made from the whole bunches collected at TH-7, TH and TH+10 differed, TH providing the highest quality wines. In parallel, gene expression was studied with Qiagen/Operon microarrays using two types of samples, i.e. whole bunches and berries sorted by density. Only 12 genes were consistently up- or down-regulated in whole bunches and density sorted berries for the two years studied in Chardonnay. 52 genes were differentially expressed between the TH-7 and TH samples. In order to determine whether these genes followed a similar pattern of expression during the late stages of berry ripening in a red cultivar, nine genes were selected for RT-PCR analysis with Cabernet Sauvignon grown under two different temperature regimes affecting the precocity of ripening. The expression profiles and their relationship to ripening were confirmed in Cabernet Sauvignon for seven genes, encoding a carotenoid cleavage dioxygenase, a galactinol synthase, a late embryogenesis abundant protein, a dirigent-like protein, a histidine kinase receptor, a valencene synthase and a putative S-adenosyl-L-methionine:salicylic acid carboxyl

  10. A characterization of grapevine of GRAS domain transcription factor gene family.

    PubMed

    Sun, Xin; Xie, Zhengqiang; Zhang, Cheng; Mu, Qian; Wu, Weimin; Wang, Baoju; Fang, Jinggui

    2016-07-01

    GRAS domain genes are a group of important plant-specific transcription factors that have been reported to be involved in plant development. In order to know the roles of GRAS genes in grapevine, a widely cultivated fruit crop, the study on grapevine GRAS (VvGRAS) was carried out, and from which, 43 were identified from 12× assemble grapevine genomic sequences. Further, the genomic structures, synteny, phylogeny, expression profiles in different tissues of these genes, and their roles in response to stress were investigated. Among the genes, two potential target genes (VvSCL15 and VvSCL22) for VvmiR171 were experimentally verified by PPM-RACE and RLM-RACE, in that not only the cleavage sites of miR171 on the target mRNA were mapped but also the cleaved fragments and their expressing patterns were detected. Transgenic Arabidopsis plants over expression VvSCL15 showed lower tolerance to drought and salt treatments. PMID:26842940

  11. Phosphatidic Acid Interacts with a MYB Transcription Factor and Regulates Its Nuclear Localization and Function in Arabidopsis[C][W

    PubMed Central

    Yao, Hongyan; Wang, Geliang; Guo, Liang; Wang, Xuemin

    2013-01-01

    Phosphatidic acid (PA) has emerged as a class of cellular mediators involved in various cellular and physiological processes, but little is known about its mechanism of action. Here we show that PA interacts with WEREWOLF (WER), a R2R3 MYB transcription factor involved in root hair formation. The PA-interacting region is confined to the end of the R2 subdomain. The ablation of the PA binding motif has no effect on WER binding to DNA, but abolishes its nuclear localization and its function in regulating epidermal cell fate. Inhibition of PA production by phospholipase Dζ also suppresses WER’s nuclear localization, root hair formation, and elongation. These results suggest a role for PA in promoting protein nuclear localization. PMID:24368785

  12. The grapevine VvibZIPC22 transcription factor is involved in the regulation of flavonoid biosynthesis

    PubMed Central

    Malacarne, Giulia; Coller, Emanuela; Czemmel, Stefan; Vrhovsek, Urska; Engelen, Kristof; Goremykin, Vadim; Bogs, Jochen; Moser, Claudio

    2016-01-01

    In grapevine, flavonoids constitute one of the most abundant subgroups of secondary metabolites, influencing the quality, health value, and typicity of wines. Their synthesis in many plant species is mainly regulated at the transcriptional level by modulation of flavonoid pathway genes either by single regulators or by complexes of different regulators. In particular, bZIP and MYB factors interact synergistically in the recognition of light response units present in the promoter of some genes of the pathway, thus mediating light-dependent flavonoid biosynthesis. We recently identified VvibZIPC22, a member of clade C of the grapevine bZIP family, in a quantitative trait locus (QTL) specifically associated with kaemperol content in mature berries. Here, to validate the involvement of this candidate gene in the fine regulation of flavonol biosynthesis, we characterized its function by in vitro and in vivo experiments. A role for this gene in the control of flavonol biosynthesis was indeed confirmed by its highest expression at flowering and during UV light-mediated induction, paralleled by accumulation of the flavonol synthase 1 transcript and flavonol compounds. The overexpression of VvibZIPC22 in tobacco caused a significant increase in several flavonoids in the flower, via induction of general and specific genes of the pathway. In agreement with this evidence, VvibZIPC22 was able to activate the promoters of specific genes of the flavonoid pathway, alone or together with other factors, as revealed by transient reporter assays. These findings, supported by in silico indications, allowed us to propose VvibZIPC22 as a new regulator of flavonoid biosynthesis in grapevine. PMID:27194742

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  14. Transcript abundance profiles reveal larger and more complex responses of grapevine to chilling compared to osmotic and salinity stress

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this study, iso-osmotic salinity (120 mM NaCl, 12mM CaCl2) and osmotic (PEG) stresses, along with chilling (5oC) stress, were applied to the cold-sensitive grapevine species V. vinifera cv. Cabernet Sauvignon. Microarray analysis of transcript abundance in shoot tips revealed that 43% of gene exp...

  15. Transcriptional changes of gibberellin oxidase genes in grapevines with or without gibberellin application during inflorescence development.

    PubMed

    Jung, Chan Jin; Hur, Youn Young; Jung, Sung-Min; Noh, Jung-Ho; Do, Gyung-Ran; Park, Seo-June; Nam, Jong-Chul; Park, Kyo-Sun; Hwang, Hae-Sung; Choi, Doil; Lee, Hee Jae

    2014-03-01

    The concept that gibberellin (GA) application on seeded grapevines induces seedlessness has been known for decades in viticulture. GA was applied to inflorescence clusters of seeded diploid grapevine cultivar 'Tamnara' (Vitis spp.) at 14 days before full bloom (DBF). Morphological and molecular effects of GA application were examined on the induction of parthenocarpic fruit development. With GA application, ovaries were enlarged and pollen tube growth was completely inhibited. Vitis GA oxidase enzymes, key determinants for GA level, were characterized through phylogenetic analysis with Arabidopsis GA oxidase enzymes. Five VvGA 20-oxidase (VvGA20ox), three VvGA 3-oxidase (VvGA3ox), and nine VvGA 2-oxidase (VvGA2ox) family proteins, and one VvGA methyltransferase (VvGAMT) and one Vitis cytochrome P450 714A1 proteins were identified, and their expression patterns were analyzed during inflorescence development from 14 DBF to 5 days after full bloom (DAF). VvGA2ox1, VvGA20ox3, and VvGA3ox2 were the most abundantly expressed genes in each gene family at 7, 5, and 2 DBF, respectively. Following GA application at 14 DBF inducing seedlessness, GA catabolic genes such as VvGAMT2, VvGA2ox3, and VvGA2ox4 were up-regulated at 12 DBF, full bloom, and 5 DAF, respectively. Conversely, most GA biosynthetic genes, VvGA20oxs and VvGA3oxs, were down-regulated at near full bloom, and the timing of their peak expression was changed. These results suggest that GA application at pre-bloom changes the GA biosynthesis into GA catabolic pathway at near full bloom by altering the transcription level and timing of GA oxidase genes during grapevine inflorescence development. PMID:24374939

  16. Development of duplex SYBR Green I-based real-time quantitative reverse-transcription PCR for detection and discrimination of grapevine viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A SYBR® Green-based real-time quantitative reverse transcription PCR (qRT-PCR) assay in combination with melt curve analysis (MCA) was developed for the detection of nine grapevine viruses. The detection limits for singleplex qRT-PCR for all nine grapevine viruses were determined to be in the range ...

  17. An ancestral allele of grapevine transcription factor MYB14 promotes plant defence.

    PubMed

    Duan, Dong; Fischer, Sabine; Merz, Patrick; Bogs, Jochen; Riemann, Michael; Nick, Peter

    2016-04-01

    Stilbene synthase is a key enzyme for the production of the phytoalexin resveratrol. Some clones of Vitis sylvestris, a wild European grapevine species which is almost extinct, have been shown to accumulate more resveratrol in response to different forms of stress. In the current study, we asked whether the induction of stilbene synthase transcripts in Hoe29, one of the V. sylvestris clones with elevated stilbene inducibility, might result from the elevated induction of the transcription factor MYB14. The MYB14 promoter of Hoe29 and of Ke83 (a second stilbene-inducible genotype) harboured distinct regions and were applied to a promoter-reporter system. We show that stilbene synthase inducibility correlates with differences in the induction of MYB14 transcripts for these two genotypes. Both alleles were induced by UV in a promoter-reporter assay, but only the MYB14 promoter from Hoe29 was induced by flg22, consistent with the stilbene synthase expression of the donor genotypes, where both respond to UV but only Hoe29 is responsive to Plasmopara viticola during defence. We mapped upstream signals and found that a RboH-dependent oxidative burst, calcium influx, a MAPK cascade, and jasmonate activated the MYB14 promoter, whereas salicylic acid was ineffective. Our data suggest that the Hoe29 allele of the MYB14 promoter has potential as a candidate target for resistance breeding. PMID:26842984

  18. An ancestral allele of grapevine transcription factor MYB14 promotes plant defence

    PubMed Central

    Duan, Dong; Fischer, Sabine; Merz, Patrick; Bogs, Jochen; Riemann, Michael; Nick, Peter

    2016-01-01

    Stilbene synthase is a key enzyme for the production of the phytoalexin resveratrol. Some clones of Vitis sylvestris, a wild European grapevine species which is almost extinct, have been shown to accumulate more resveratrol in response to different forms of stress. In the current study, we asked whether the induction of stilbene synthase transcripts in Hoe29, one of the V. sylvestris clones with elevated stilbene inducibility, might result from the elevated induction of the transcription factor MYB14. The MYB14 promoter of Hoe29 and of Ke83 (a second stilbene-inducible genotype) harboured distinct regions and were applied to a promoter–reporter system. We show that stilbene synthase inducibility correlates with differences in the induction of MYB14 transcripts for these two genotypes. Both alleles were induced by UV in a promoter–reporter assay, but only the MYB14 promoter from Hoe29 was induced by flg22, consistent with the stilbene synthase expression of the donor genotypes, where both respond to UV but only Hoe29 is responsive to Plasmopara viticola during defence. We mapped upstream signals and found that a RboH-dependent oxidative burst, calcium influx, a MAPK cascade, and jasmonate activated the MYB14 promoter, whereas salicylic acid was ineffective. Our data suggest that the Hoe29 allele of the MYB14 promoter has potential as a candidate target for resistance breeding. PMID:26842984

  19. Solar ultraviolet radiation is necessary to enhance grapevine fruit ripening transcriptional and phenolic responses

    PubMed Central

    2014-01-01

    Background Ultraviolet (UV) radiation modulates secondary metabolism in the skin of Vitis vinifera L. berries, which affects the final composition of both grapes and wines. The expression of several phenylpropanoid biosynthesis-related genes is regulated by UV radiation in grape berries. However, the complete portion of transcriptome and ripening processes influenced by solar UV radiation in grapes remains unknown. Results Whole genome arrays were used to identify the berry skin transcriptome modulated by the UV radiation received naturally in a mid-altitude Tempranillo vineyard. UV radiation-blocking and transmitting filters were used to generate the experimental conditions. The expression of 121 genes was significantly altered by solar UV radiation. Functional enrichment analysis of altered transcripts mainly pointed out that secondary metabolism-related transcripts were induced by UV radiation including VvFLS1, VvGT5 and VvGT6 flavonol biosynthetic genes and monoterpenoid biosynthetic genes. Berry skin phenolic composition was also analysed to search for correlation with gene expression changes and UV-increased flavonols accumulation was the most evident impact. Among regulatory genes, novel UV radiation-responsive transcription factors including VvMYB24 and three bHLH, together with known grapevine UV-responsive genes such as VvMYBF1, were identified. A transcriptomic meta-analysis revealed that genes up-regulated by UV radiation in the berry skin were also enriched in homologs of Arabidopsis UVR8 UV-B photoreceptor-dependent UV-B -responsive genes. Indeed, a search of the grapevine reference genomic sequence identified UV-B signalling pathway homologs and among them, VvHY5-1, VvHY5-2 and VvRUP were up-regulated by UV radiation in the berry skin. Conclusions Results suggest that the UV-B radiation-specific signalling pathway is activated in the skin of grapes grown at mid-altitudes. The biosynthesis and accumulation of secondary metabolites, which are

  20. Identification and expression analysis of heat shock transcription factors in the wild Chinese grapevine (Vitis pseudoreticulata).

    PubMed

    Hu, Yang; Han, Yong-Tao; Zhang, Kai; Zhao, Feng-Li; Li, Ya-Juan; Zheng, Yi; Wang, Yue-Jin; Wen, Ying-Qiang

    2016-02-01

    Heat shock transcription factors (Hsfs) are known to play pivotal roles in the adaptation of plants to heat stress and other stress stimuli. While grapevine (Vitis vinifera L.) is one of the most important fruit crops worldwide, little is known about the Hsf family in Vitis spp. Here, we identified nineteen putative Hsf genes (VviHsfs) in Vitis spp based on the 12 × grape genome (V. vinifera L.). Phylogenetic analysis revealed three classes of grape Hsf genes (classes A, B, and C). Additional comparisons between grape and Arabidopsis thaliana demonstrated that several VviHsfs genes occurred in corresponding syntenic blocks of Arabidopsis. Moreover, we examined the expression profiles of the homologs of the VviHsfs genes (VpHsfs) in the wild Chinese Vitis pseudoreticulata accession Baihe-35-1, which is tolerant to various environmental stresses. Among the nineteen VpHsfs, ten VpHsfs displayed lower transcript levels under non-stress conditions and marked up-regulation during heat stress treatment; several VpHsfs also displayed altered expression levels in response to cold, salt, and hormone treatments, suggesting their versatile roles in response to stress stimuli. In addition, eight VpHsf-GFP fusion proteins showed differential subcellular localization in V. pseudoreticulata mesophyll protoplasts. Taken together, our data may provide an important reference for further studies of Hsf genes in Vitis spp. PMID:26689772

  1. Molecular and SNP characterization of two genome specific transcription factor genes GhMyb8 and GhMyb10 in cotton species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two R2R3-Myb cDNAs (GhMyb8 and GhMyb10) and their corresponding genes were isolated and characterized from allotetraploid cotton (Gossypium hirsutum L. cv. DES119) fiber cells. Both GhMyb8 and GhMyb10 exhibit some conserved features shared in subgroup 4 of plant R2R3-MYB proteins, including the GIDx...

  2. Resistance to Plasmopara viticola in a grapevine segregating population is associated with stilbenoid accumulation and with specific host transcriptional responses

    PubMed Central

    2011-01-01

    Background Downy mildew, caused by the oomycete Plasmopara viticola, is a serious disease in Vitis vinifera, the most commonly cultivated grapevine species. Several wild Vitis species have instead been found to be resistant to this pathogen and have been used as a source to introgress resistance into a V. vinifera background. Stilbenoids represent the major phytoalexins in grapevine, and their toxicity is closely related to the specific compound. The aim of this study was to assess the resistance response to P. viticola of the Merzling × Teroldego cross by profiling the stilbenoid content of the leaves of an entire population and the transcriptome of resistant and susceptible individuals following infection. Results A three-year analysis of the population's response to artificial inoculation showed that individuals were distributed in nine classes ranging from total resistance to total susceptibility. In addition, quantitative metabolite profiling of stilbenoids in the population, carried out using HPLC-DAD-MS, identified three distinct groups differing according to the concentrations present and the complexity of their profiles. The high producers were characterized by the presence of trans-resveratrol, trans-piceid, trans-pterostilbene and up to thirteen different viniferins, nine of them new in grapevine. Accumulation of these compounds is consistent with a resistant phenotype and suggests that they may contribute to the resistance response. A preliminary transcriptional study using cDNA-AFLP selected a set of genes modulated by the oomycete in a resistant genotype. The expression of this set of genes in resistant and susceptible genotypes of the progeny population was then assessed by comparative microarray analysis. A group of 57 genes was found to be exclusively modulated in the resistant genotype suggesting that they are involved in the grapevine-P. viticola incompatible interaction. Functional annotation of these transcripts revealed that they belong to

  3. Transcriptional control of anthocyanin biosynthetic genes in extreme phenotypes for berry pigmentation of naturally occurring grapevines

    PubMed Central

    Castellarin, Simone D; Di Gaspero, Gabriele

    2007-01-01

    Background Fruit coloration of red-skinned grapevines is mainly due to anthocyanin pigments. We analysed a panel of nine cultivars that included extreme phenotypes for berry colour, ranging from green (absence of anthocyanins) to red, purple, violet and blue. Expression of six genes of the anthocyanin pathway coding for flavanone-hydroxylase (F3H), flavonoid 3'-hydroxylase (F3'H), flavonoid 3',5'-hydroxylase (F3'5'H), UDP-glucose:flavonoid-3-O-glucosyltransferase (UFGT), glutathione-S-transferase (GST), O-methyltransferase (OMT) and four transcription factors (MybA, MybB, MybC, MybD) was analysed by quantitative RT-PCR at four developmental stages from before the onset of ripening until full maturity and compared to anthocyanin metabolites. Results Total anthocyanin content at full maturity correlated well with the cumulative expression of F3H, UFGT and GST throughout ripening. Transcripts of the last two genes were absent in the green-skinned cultivar 'Sauvignonasse', also known as 'Tocai friulano', and were at least 10-fold less abundant in pale red cultivars, such as 'Pinot gris' and 'Gewürztraminer', compared to fully coloured cultivars. Predominance of tri-hydroxylated anthocyanins (delphinidin, petunidin and malvidin) in cultivars bearing dark berries with violet and blue hue was associated with higher ratios of F3'5'H/F3'H transcription, compared to red-skinned cultivars. Higher levels of OMT transcripts were observed in berries of cultivars that accumulated methoxylated forms of anthocyanins more abundantly than non-methoxylated forms. Conclusion Colour variation of the grape berry conforms to a peculiar pattern of genotype-specific expression of the whole set of anthocyanin genes in a direct transcript-metabolite-phenotype relationship. Cumulative mRNA levels of the structural genes and their relative abundance throughout ripening explained per se the final phenotype for anthocyanin content, anthocyanin composition, colour intensity and colour hue of

  4. SYBR(®) Green-based real-time quantitative reverse-transcription PCR for detection and discrimination of grapevine viruses.

    PubMed

    Poojari, Sudarsana; Alabi, Olufemi J; Okubara, Patricia A; Naidu, Rayapati A

    2016-09-01

    A SYBR(®) Green-based real-time quantitative reverse transcription PCR (qRT-PCR) assay in combination with melt-curve analysis (MCA) was optimized for the detection of nine grapevine viruses. The detection limits for simplex qRT-PCR for all nine grapevine viruses were estimated to be in the range of 214-1112 copies of the virus genome. Amplicons with melting temperatures (Tm) separated by at least 2°C in the MCA could differentiate two viruses in the same reaction. Therefore, eight of the nine viruses could be co-diagnosed in five different combinations of duplex assays. Of 305 grape leaf samples from the field or greenhouse, 162 were positive for at least one of the nine grapevine viruses using the duplex qRT-PCR assays. In contrast, only 127 samples were positive using endpoint RT-PCR and PCR assays, indicating the enhanced sensitivity of duplex real-time PCR. In addition, the duplex qRT-PCR assays were be used to detect Grapevine leafroll associated virus 3 (GLRaV-3) in its vector, the grape mealybug (Pseudococcus maritimus Ehrhorn), and Grapevine red blotch-associated virus (GRBaV) in Virginia creeper leafhopper (Erythroneura ziczac Walsh). The simplex and duplex real-time PCR assays developed in this study can be used to examine transmission of co-occruing viruses by insect vectors as well as for rapid and sensitive detection of viruses in infected grapevines. PMID:27246908

  5. Rapid detection of Grapevine leafroll-associated virus type 3 using a reverse transcription loop-mediated amplification method.

    PubMed

    Walsh, Helen Ann; Pietersen, Gerhard

    2013-12-01

    Grapevine leafroll disease (GLD) is the most important disease of Grapevines in South Africa. Grapevine leafroll-associated virus type 3 (GLRaV-3) has a close association with the disease and is prevalent in South African vineyards. GLD can be controlled using a combination of virus-free planting material, systemic insecticides to control vector populations and removal of infected vines by roguing. Infected vines are identified each autumn using either symptom display (in red cultivars) or ELISA (in white cultivars). While ELISA is a simple, reliable means of testing for GLRaV-3, it is time consuming, laborious and insensitive and a quicker, more sensitive method of detecting GLRaV-3 in the field is needed. A single-tube one-step reverse transcription (RT) loop-mediated isothermal amplification (LAMP) assay combined with a simple RNA extraction protocol was developed for the rapid and easy detection of GLRaV-3. Hydroxy napthol blue was included as an indicator and under isothermal conditions at 60 °C the target viral gene could be amplified in under 2h and positive results could be easily seen by examining the colour change from violet to sky blue. Using this method, 50 samples could be also pooled together with a single positive sample still being detected. A direct comparison of ELISA, nested PCR and RT-LAMP showed that RT-LAMP is as sensitive as nested PCR and could be performed in a much shorter time with less equipment. This assay is may be a possible alternative to ELISA for the detection of GLRaV-3 in the field. PMID:24025344

  6. The Arabidopsis Transcription Factor MYB77 Modulates Auxin Signal Transduction[W

    PubMed Central

    Shin, Ryoung; Burch, Adrien Y.; Huppert, Kari A.; Tiwari, Shiv B.; Murphy, Angus S.; Guilfoyle, Tom J.; Schachtman, Daniel P.

    2007-01-01

    Auxin is a key plant hormone that regulates plant development, apical dominance, and growth-related tropisms, such as phototropism and gravitropism. In this study, we report a new Arabidopsis thaliana transcription factor, MYB77, that is involved in auxin response. In MYB77 knockout plants, we found that auxin-responsive gene expression was greatly attenuated. Lateral root density in the MYB77 knockout was lower than the wild type at low concentrations of indole-3-acetic acid (IAA) and also under low nutrient conditions. MYB77 interacts with auxin response factors (ARFs) in vitro through the C terminus (domains III and IV) of ARFs and the activation domain of MYB77. A synergistic genetic interaction was demonstrated between MYB77 and ARF7 that resulted in a strong reduction in lateral root numbers. Experiments with protoplasts confirmed that the coexpression of MYB77 and an ARF C terminus enhance reporter gene expression. R2R3 MYB transcription factors have not been previously implicated in regulating the expression of auxin-inducible genes. Also it was previously unknown that ARFs interact with proteins other than those in the Aux/IAA family via conserved domains. The interaction between MYB77 and ARFs defines a new type of combinatorial transcriptional control in plants. This newly defined transcription factor interaction is part of the plant cells' repertoire for modulating response to auxin, thereby controlling lateral root growth and development under changing environmental conditions. PMID:17675404

  7. Salt-induced transcription factor MYB74 is regulated by the RNA-directed DNA methylation pathway in Arabidopsis

    PubMed Central

    Xu, Rui; Wang, Yuhan; Zheng, Hao; Lu, Wei; Wu, Changai; Huang, Jinguang; Yan, Kang; Yang, Guodong; Zheng, Chengchao

    2015-01-01

    Salt stress is one of the major abiotic stresses in agriculture worldwide that causes crop failure by interfering with the profile of gene expression and cell metabolism. Transcription factors and RNA-directed DNA methylation (RdDM) play an important role in the regulation of gene activation under abiotic stress in plants. This work characterized AtMYB74, a member of the R2R3-MYB gene family, which is transcriptionally regulated mainly by RdDM as a response in salt stress in Arabidopsis. Bisulphite sequencing indicated that 24-nt siRNAs target a region approximately 500bp upstream of the transcription initiation site of AtMYB74, which is heavily methylated. Levels of DNA methylation in this region were significantly reduced in wild type plants under salt stress, whereas no changes were found in RdDM mutants. Northern blot and quantitative real-time reverse transcription PCR analysis showed that the accumulation of 24-nt siRNAs was decreased in WT plants under salt stress. Further promoter deletion analysis revealed that the siRNA target region is essential for maintaining AtMYB74 expression patterns. In addition, transgenic plants overexpressing AtMYB74 displayed hypersensitivity to NaCl during seed germination. These results suggest that changes in the levels of the five 24-nt siRNAs regulate the AtMYB74 transcription factor via RdDM in response to salt stress. PMID:26139822

  8. Transcriptional regulation of PIN genes by FOUR LIPS and MYB88 during Arabidopsis root gravitropism

    PubMed Central

    Wang, Hong-Zhe; Yang, Ke-Zhen; Zou, Jun-Jie; Zhu, Ling-Ling; Xie, Zi Dian; Morita, Miyo Terao; Tasaka, Masao; Friml, Jiří; Grotewold, Erich; Beeckman, Tom; Vanneste, Steffen; Sack, Fred; Le, Jie

    2015-01-01

    PIN proteins are auxin export carriers that direct intercellular auxin flow and in turn regulate many aspects of plant growth and development including responses to environmental changes. The Arabidopsis R2R3-MYB transcription factor FOUR LIPS (FLP) and its paralogue MYB88 regulate terminal divisions during stomatal development, as well as female reproductive development and stress responses. Here we show that FLP and MYB88 act redundantly but differentially in regulating the transcription of PIN3 and PIN7 in gravity-sensing cells of primary and lateral roots. On the one hand, FLP is involved in responses to gravity stimulation in primary roots, whereas on the other, FLP and MYB88 function complementarily in establishing the gravitropic set-point angles of lateral roots. Our results support a model in which FLP and MYB88 expression specifically determines the temporal-spatial patterns of PIN3 and PIN7 transcription that are closely associated with their preferential functions during root responses to gravity. PMID:26578169

  9. Transcriptional regulation of PIN genes by FOUR LIPS and MYB88 during Arabidopsis root gravitropism.

    PubMed

    Wang, Hong-Zhe; Yang, Ke-Zhen; Zou, Jun-Jie; Zhu, Ling-Ling; Xie, Zi Dian; Morita, Miyo Terao; Tasaka, Masao; Friml, Jiří; Grotewold, Erich; Beeckman, Tom; Vanneste, Steffen; Sack, Fred; Le, Jie

    2015-01-01

    PIN proteins are auxin export carriers that direct intercellular auxin flow and in turn regulate many aspects of plant growth and development including responses to environmental changes. The Arabidopsis R2R3-MYB transcription factor FOUR LIPS (FLP) and its paralogue MYB88 regulate terminal divisions during stomatal development, as well as female reproductive development and stress responses. Here we show that FLP and MYB88 act redundantly but differentially in regulating the transcription of PIN3 and PIN7 in gravity-sensing cells of primary and lateral roots. On the one hand, FLP is involved in responses to gravity stimulation in primary roots, whereas on the other, FLP and MYB88 function complementarily in establishing the gravitropic set-point angles of lateral roots. Our results support a model in which FLP and MYB88 expression specifically determines the temporal-spatial patterns of PIN3 and PIN7 transcription that are closely associated with their preferential functions during root responses to gravity. PMID:26578169

  10. Ectopic expression of a grapevine transcription factor VvWRKY11 contributes to osmotic stress tolerance in Arabidopsis.

    PubMed

    Liu, Huaying; Yang, Wenlong; Liu, Dongcheng; Han, Yuepeng; Zhang, Aimin; Li, Shaohua

    2011-01-01

    Plant WRKY transcriptional factors play an important role in response to biotic and abiotic stresses. In this study, a WRKY transcription factor was isolated from grapevine. This transcription factor showed 66% and 58% identity at the DNA and amino acid sequence levels, respectively, with Arabidopsis AtWRKY11 genes, and was therefore designated VvWRKY11. Phylogenetic analysis and structure comparison indicated that VvWRKY11 protein belongs to group IIc. The VvWRKY11 protein was shown to be located in the nucleus based on green fluorescent protein analysis. Yeast one-hybrid analysis further indicated that VvWRKY11 protein binds specifically to the W-box element. The expression profile of VvWRKY11 in response to treatment with phytohormone salicylic acid or pathogen Plasmopara viticola is rapid and transient. Transgenic Arabidopsis seedlings overexpressing VvWRKY11 showed higher tolerance to water stress induced by mannitol than wild-type plants. These results clearly demonstrated that the VvWRKY11 gene is involved in the response to dehydration stress. In addition, the role of VvWRKY11 protein in regulating the expression of two stress response genes, AtRD29A and AtRD29B, is also discussed. PMID:20354906

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

    PubMed

    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. PMID:26600674

  12. A Conserved Network of Transcriptional Activators and Repressors Regulates Anthocyanin Pigmentation in Eudicots[C][W][OPEN

    PubMed Central

    Albert, Nick W.; Davies, Kevin M.; Lewis, David H.; Zhang, Huaibi; Montefiori, Mirco; Brendolise, Cyril; Boase, Murray R.; Ngo, Hanh; Jameson, Paula E.; Schwinn, Kathy E.

    2014-01-01

    Plants require sophisticated regulatory mechanisms to ensure the degree of anthocyanin pigmentation is appropriate to myriad developmental and environmental signals. Central to this process are the activity of MYB-bHLH-WD repeat (MBW) complexes that regulate the transcription of anthocyanin genes. In this study, the gene regulatory network that regulates anthocyanin synthesis in petunia (Petunia hybrida) has been characterized. Genetic and molecular evidence show that the R2R3-MYB, MYB27, is an anthocyanin repressor that functions as part of the MBW complex and represses transcription through its C-terminal EAR motif. MYB27 targets both the anthocyanin pathway genes and basic-helix-loop-helix (bHLH) ANTHOCYANIN1 (AN1), itself an essential component of the MBW activation complex for pigmentation. Other features of the regulatory network identified include inhibition of AN1 activity by the competitive R3-MYB repressor MYBx and the activation of AN1, MYB27, and MYBx by the MBW activation complex, providing for both reinforcement and feedback regulation. We also demonstrate the intercellular movement of the WDR protein (AN11) and R3-repressor (MYBx), which may facilitate anthocyanin pigment pattern formation. The fundamental features of this regulatory network in the Asterid model of petunia are similar to those in the Rosid model of Arabidopsis thaliana and are thus likely to be widespread in the Eudicots. PMID:24642943

  13. Grafting with rootstocks induces extensive transcriptional re-programming in the shoot apical meristem of grapevine

    PubMed Central

    2013-01-01

    Background Grafting is widely used in the agriculture of fruit-bearing crops; rootstocks are known to confer differences in scion biomass in addition to improving other traits of agricultural interest. However, little is known about the effect of rootstocks on scion gene expression. The objective of this study was to determine whether hetero-grafting the grapevine variety Vitis vinifera cv. 'Cabernet Sauvignon N’ with two different rootstocks alters gene expression in the shoot apex in comparison to the auto-grafted control. Cabernet Sauvignon was hetero-grafted with two commercial rootstock genotypes and auto-grafted with itself. Vigor was quantified by measurements of root, stem, leaf and trunk biomass. Gene expression profiling was done using a whole genome grapevine microarray; four pools of five shoot apex samples were harvested 4 months after grafting for each scion/rootstock combination. Results The rootstocks increased stem biomass or conferred increased vigor by the end of the first growth cycle. Globally hetero-grafting two different genotypes together triggered an increase in shoot apex gene expression; however no genes were differentially expressed between the two hetero-grafts. The functional categories related to DNA, chromatin structure, histones, flavonoids and leucine rich repeat containing receptor kinases were the most enriched in the up-regulated genes in the shoot apex of hetero-grafted plants. Conclusions The choice of rootstock genotype had little effect on the gene expression in the shoot apex; this could suggest that auto- and hetero-grafting was the major factor regulating gene expression. PMID:24083813

  14. An Ancient Duplication of Apple MYB Transcription Factors Is Responsible for Novel Red Fruit-Flesh Phenotypes1[C][W

    PubMed Central

    Chagné, David; Lin-Wang, Kui; Espley, Richard V.; Volz, Richard K.; How, Natalie M.; Rouse, Simon; Brendolise, Cyril; Carlisle, Charmaine M.; Kumar, Satish; De Silva, Nihal; Micheletti, Diego; McGhie, Tony; Crowhurst, Ross N.; Storey, Roy D.; Velasco, Riccardo; Hellens, Roger P.; Gardiner, Susan E.; Allan, Andrew C.

    2013-01-01

    Anthocyanin accumulation is coordinated in plants by a number of conserved transcription factors. In apple (Malus × domestica), an R2R3 MYB transcription factor has been shown to control fruit flesh and foliage anthocyanin pigmentation (MYB10) and fruit skin color (MYB1). However, the pattern of expression and allelic variation at these loci does not explain all anthocyanin-related apple phenotypes. One such example is an open-pollinated seedling of cv Sangrado that has green foliage and develops red flesh in the fruit cortex late in maturity. We used methods that combine plant breeding, molecular biology, and genomics to identify duplicated MYB transcription factors that could control this phenotype. We then demonstrated that the red-flesh cortex phenotype is associated with enhanced expression of MYB110a, a paralog of MYB10. Functional characterization of MYB110a showed that it was able to up-regulate anthocyanin biosynthesis in tobacco (Nicotiana tabacum). The chromosomal location of MYB110a is consistent with a whole-genome duplication event that occurred during the evolution of apple within the Maloideae family. Both MYB10 and MYB110a have conserved function in some cultivars, but they differ in their expression pattern and response to fruit maturity. PMID:23096157

  15. Overexpression of the MYB37 transcription factor enhances abscisic acid sensitivity, and improves both drought tolerance and seed productivity in Arabidopsis thaliana.

    PubMed

    Yu, Yong-Tao; Wu, Zhen; Lu, Kai; Bi, Chao; Liang, Shan; Wang, Xiao-Fang; Zhang, Da-Peng

    2016-02-01

    Although a lot of genes have been revealed to participate in abscisic acid (ABA) signaling, many of the additional components involved in ABA signaling remain to be discovered. Here we report that overexpression of MYB37, a R2R3 MYB subgroup 14 transcription factor in Arabidopsis thaliana, confers hypersensitive phenotypes to exogenous ABA in all the major ABA responses, including ABA-induced inhibition of seed germination, cotyledon greening and early seedling growth, and ABA-induced stomatal closure and inhibition of stomatal opening. Interestingly and importantly, MYB37-overexpression improves plant tolerance to drought, enhances growth of mature plants and seed productivity, thought it delays flowering, which suggests that this gene may be used for improving crop adaptability to drought environment and productivity. However, a myb37-1 knockout mutant displays wild-type ABA responses most likely due to a functional redundancy of the multiple MYB members. Real-time PCR analysis shows that upregulation of the MYB37 expression changes expression of a subset of ABA-responsive genes. Together, these findings suggest that the MYB37 transcription factor plays an important, positive role in plant response to ABA and drought stress, and meanwhile, it plays a positive role in the regulation of seed production. PMID:26646286

  16. The transcription factor VvWRKY33 is involved in the regulation of grapevine (Vitis vinifera) defense against the oomycete pathogen Plasmopara viticola.

    PubMed

    Merz, Patrick R; Moser, Tina; Höll, Janine; Kortekamp, Andreas; Buchholz, Günther; Zyprian, Eva; Bogs, Jochen

    2015-03-01

    Grapevine (Vitis vinifera ssp. vinifera) is one of the most important fruit species; however, it is highly susceptible to various pathogens, which can cause severe crop losses in viticulture. It has been shown that several WRKY class transcription factors (TFs) are part of the signal transduction cascade, which leads to the activation of plant defense reactions against various pathogens. In the present investigation, a full-length cDNA was isolated from V. vinifera leaf tissue encoding a predicted protein, designated VvWRKY33, which shows the characteristics of group I WRKY protein family. VvWRKY33 induction correlates with the expression of VvPR10.1 (pathogenesis-related 10.1) gene in the leaves of the resistant cultivar 'Regent' after infection with Plasmopara viticola, whereas in the susceptible cultivar 'Lemberger' VvWRKY33 and VvPR10.1 are not induced. Corresponding expression of the TF and VvPR10.1 was even obtained in uninfected ripening berries. In planta, analysis of VvWRKY33 has been performed by ectopic expression of VvWRKY33 in grapevine leaves of greenhouse plants mediated via Agrobacterium tumefaciens transformation. In consequence, VvWRKY33 strongly increases resistance to P. viticola in the susceptible cultivar 'Shiraz' and reduces pathogen sporulation of about 50-70%, indicating a functional role for resistance in grapevine. Complementation of the resistance-deficient Arabidopsis thaliana Columbia-0 (Col-0) mutant line wrky33-1 by constitutive expression of VvWRKY33 restores resistance against Botrytis cinerea to wild-type level and in some complemented mutant lines even exceeds the resistance level of the parental line Col-0. Our results support the involvement of VvWRKY33 in the defense reaction of grapevine against different pathogens. PMID:25132131

  17. Development of three different cell types is associated with the activity of a specific MYB transcription factor in the ventral petal of Antirrhinum majus flowers.

    PubMed

    Perez-Rodriguez, Maria; Jaffe, Felix W; Butelli, Eugenio; Glover, Beverley J; Martin, Cathie

    2005-01-01

    Petal tissue comprises several different cell types, which have specialised functions in pollination in different flowering plant species. In Antirrhinum majus, the MIXTA protein directs the formation of conical epidermal cells in petals. Transgenic experiments have indicated that MIXTA activity can also initiate trichome development, dependent on the developmental timing of its expression. MIXTA is normally expressed late in petal development and functions only in conical cell differentiation. However, an R2R3 MYB transcription factor very similar to MIXTA (AmMYBML1), which induces both trichome and conical cell formation in transgenic plants, is expressed very early during the development of the ventral petal. Its cellular expression pattern suggests that it fulfils three functions: trichome production in the corolla tube, conical cell development in the petal hinge epidermis and reinforcement of the hinge through differential mesophyll cell expansion. The DIVARICATA (DIV) gene is required for ventral petal identity. In div mutants, the ventral petal assumes the identity of lateral petals lacking these three specialised cell types, and expression of AmMYBML1 is significantly reduced compared with wild type, supporting the proposed role of AmMYBML1 in petal cell specification. We suggest that AmMYBML1 is regulated by DIV in association with the B-function proteins DEFICIENS and GLOBOSA, and, consequently, controls specification of particular cells within the ventral petal which adapt the corolla to specialised functions in pollination. PMID:15604096

  18. Molecular genetics of blood-fleshed peach reveals activation of anthocyanin biosynthesis by NAC transcription factors.

    PubMed

    Zhou, Hui; Lin-Wang, Kui; Wang, Huiliang; Gu, Chao; Dare, Andrew P; Espley, Richard V; He, Huaping; Allan, Andrew C; Han, Yuepeng

    2015-04-01

    Anthocyanin pigmentation is an important consumer trait in peach (Prunus persica). In this study, the genetic basis of the blood-flesh trait was investigated using the cultivar Dahongpao, which shows high levels of cyanidin-3-glucoside in the mesocarp. Elevation of anthocyanin levels in the flesh was correlated with the expression of an R2R3 MYB transcription factor, PpMYB10.1. However, PpMYB10.1 did not co-segregate with the blood-flesh trait. The blood-flesh trait was mapped to a 200-kb interval on peach linkage group (LG) 5. Within this interval, a gene encoding a NAC domain transcription factor (TF) was found to be highly up-regulated in blood-fleshed peaches when compared with non-red-fleshed peaches. This NAC TF, designated blood (BL), acts as a heterodimer with PpNAC1 which shows high levels of expression in fruit at late developmental stages. We show that the heterodimer of BL and PpNAC1 can activate the transcription of PpMYB10.1, resulting in anthocyanin pigmentation in tobacco. Furthermore, silencing the BL gene reduces anthocyanin pigmentation in blood-fleshed peaches. The transactivation activity of the BL-PpNAC1 heterodimer is repressed by a SQUAMOSA promoter-binding protein-like TF, PpSPL1. Low levels of PpMYB10.1 expression in fruit at early developmental stages is probably attributable to lower levels of expression of PpNAC1 plus the presence of high levels of repressors such as PpSPL1. We present a mechanism whereby BL is the key gene for the blood-flesh trait in peach via its activation of PpMYB10.1 in maturing fruit. Partner TFs such as basic helix-loop-helix proteins and NAC1 are required, as is the removal of transcriptional repressors. PMID:25688923

  19. Gene expression and metabolite profiling of developing highbush blueberry fruit indicates transcriptional regulation of flavonoid metabolism and activation of abscisic acid metabolism.

    PubMed

    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 of

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

    PubMed Central

    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

  1. Glutathione-mediated regulation of nitric oxide, S-nitrosothiol and redox homeostasis confers cadmium tolerance by inducing transcription factors and stress response genes in tomato.

    PubMed

    Hasan, Md Kamrul; Liu, Congcong; Wang, Fanan; Ahammed, Golam Jalal; Zhou, Jie; Xu, Ming-Xing; Yu, Jing-Quan; Xia, Xiao-Jian

    2016-10-01

    Glutathione (GSH) plays a critical role in plant growth, development and responses to stress. However, the mechanism by which GSH regulates tolerance to cadmium (Cd) stress still remains unclear. Here we show that inhibition of GSH biosynthesis by buthionine sulfoximine (BSO) aggravated Cd toxicity by increasing accumulation of reactive oxygen species (ROS) and reducing contents of nitric oxide (NO) and S-nitrosothiol (SNO) in tomato roots. In contrast, exogenous GSH alleviated Cd toxicity by substantially minimizing ROS accumulation and increasing contents of NO and SNO, and activities of antioxidant enzymes that eventually reduced oxidative stress. GSH-induced enhancement in Cd tolerance was closely associated with the upregulation of transcripts of several transcription factors such as ETHYLENE RESPONSIVE TRANSCRIPTION FACTOR 1 (ERF1), ERF2, MYB1 TRANSCRIPTION FACTOR- AIM1 and R2R3-MYB TRANSCRIPTION FACTOR- AN2, and some stress response genes. In addition, GSH modulated the cellular redox balance through maintaining increased GSH: GSSG and AsA: DHA ratios, and also increased phytochelatins contents. Nonetheless, GSH-induced alleviation of Cd phytotoxicity was also associated with increased sequestration of Cd into cell walls and vacuoles but not with Cd accumulation. Under Cd stress, while treatment with BSO slightly decreased vacuolar fraction of Cd, combined treatment with BSO and GSH noticeably increased that fraction. Our results suggest that GSH increases tomato tolerance to Cd stress not only by promoting the chelation and sequestration of Cd but also by stimulating NO, SNO and the antioxidant system through a redox-dependent mechanism. PMID:27472435

  2. Graft union formation in grapevine induces transcriptional changes related to cell wall modification, wounding, hormone signalling, and secondary metabolism

    PubMed Central

    Cookson, Sarah Jane; Clemente Moreno, Maria José; Hevin, Cyril; Nyamba Mendome, Larissa Zita; Delrot, Serge; Trossat-Magnin, Claudine; Ollat, Nathalie

    2013-01-01

    Grafting is particularly important to the cultivation of perennial crops such as grapevine (Vitis vinifera) because rootstocks can provide resistance to soil-borne pests and diseases as well as improve tolerance to some abiotic stresses. Successful grafting is a complex biochemical and structural process beginning with the adhesion of the two grafted partners, followed by callus formation and the establishment of a functional vascular system. At the molecular level, the sequence of events underlying graft union formation remains largely uncharacterized. The present study investigates the transcriptome of grapevine rootstock and graft interface tissues sampled 3 d and 28 d after grafting of over-wintering stems in the spring. Many genes were differentially expressed over time, from 3 d to 28 d after grafting, which could be related to the activation of stem growth and metabolic activity in the spring. This hypothesis is supported by the up-regulation of many genes associated with cell wall synthesis, and phloem and xylem development. Generally, there was an up-regulation of gene expression in the graft interface tissue compared with the rootstock, particularly genes involved in cell wall synthesis, secondary metabolism, and signalling. Although there was overlap between the genes differentially expressed over time (from 3 d to 28 d after grafting) with the gene differentially expressed between the rootstock and the graft interface, numerous graft interface-specific genes were identified. PMID:23698628

  3. Targeted silencing of BjMYB28 transcription factor gene directs development of low glucosinolate lines in oilseed Brassica juncea.

    PubMed

    Augustine, Rehna; Mukhopadhyay, Arundhati; Bisht, Naveen C

    2013-09-01

    Brassica juncea (Indian mustard), a globally important oilseed crop, contains relatively high amount of seed glucosinolates ranging from 80 to 120 μmol/g dry weight (DW). One of the major breeding objectives in oilseed Brassicas is to improve the seed-meal quality through the development of low-seed-glucosinolate lines (<30 μmol/g DW), as high amounts of certain seed glucosinolates are known to be anti-nutritional and reduce the meal palatability. Here, we report the development of transgenic B. juncea lines having seed glucosinolates as low as 11.26 μmol/g DW, through RNAi-based targeted suppression of BjMYB28, a R2R3-MYB transcription factor family gene involved in aliphatic glucosinolate biosynthesis. Targeted silencing of BjMYB28 homologs provided significant reduction in the anti-nutritional aliphatic glucosinolates fractions, without altering the desirable nonaliphatic glucosinolate pool, both in leaves and seeds of transgenic plants. Molecular characterization of single-copy, low glucosinolate homozygous lines confirmed significant down-regulation of BjMYB28 homologs vis-à-vis enhanced accumulation of BjMYB28-specific siRNA pool. Consequently, these low glucosinolate lines also showed significant suppression of genes involved in aliphatic glucosinolate biosynthesis. The low glucosinolate trait was stable in subsequent generations of the transgenic lines with no visible off-target effects on plant growth and development. Various seed quality parameters including fatty acid composition, oil content, protein content and seed weight of the low glucosinolate lines also remained unaltered, when tested under containment conditions in the field. Our results indicate that targeted silencing of a key glucosinolate transcriptional regulator MYB28 has huge potential for reducing the glucosinolates content and improving the seed-meal quality of oilseed Brassica crops. PMID:23721233

  4. BjMYB1, a transcription factor implicated in plant defence through activating BjCHI1 chitinase expression by binding to a W-box-like element.

    PubMed

    Gao, Ying; Jia, Shuangwei; Wang, Chunlian; Wang, Fujun; Wang, Fajun; Zhao, Kaijun

    2016-08-01

    We previously identified the W-box-like-4 (Wbl-4) element (GTAGTGACTCAT), one of six Wbl elements in the BjC-P promoter of the unusual chitinase gene BjCHI1 from Brassica juncea, as the core element responsive to fungal infection. Here, we report the isolation and characterization of the cognate transcription factor interacting with the Wbl-4 element. Using Wbl-4 as a target, we performed yeast one-hybrid screening of a B. juncea cDNA library and isolated an R2R3-MYB transcription factor designated as BjMYB1. BjMYB1 was localized in the nucleus of plant cells. EMSA assays confirmed that BjMYB1 binds to the Wbl-4 element. Transiently expressed BjMYB1 up-regulated the activity of the BjC-P promoter through its binding to the Wbl-4 element in tobacco (Nicotiana benthamiana) leaves. In B. juncea, BjMYB1 displayed a similar induced expression pattern as that of BjCHI1 upon infection by the fungus Botrytis cinerea Moreover, heterogeneous overexpression of BjMYB1 significantly elevated the resistance of transgenic Arabidopsis thaliana to the fungus B. cinerea These results suggest that BjMYB1 is potentially involved in host defence against fungal attack through activating the expression of BjCHI1 by binding to the Wbl-4 element in the BjC-P promoter. This finding demonstrates a novel DNA target of plant MYB transcription factors. PMID:27353280

  5. BjMYB1, a transcription factor implicated in plant defence through activating BjCHI1 chitinase expression by binding to a W-box-like element

    PubMed Central

    Gao, Ying; Jia, Shuangwei; Wang, Chunlian; Wang, Fujun; Wang, Fajun; Zhao, Kaijun

    2016-01-01

    We previously identified the W-box-like-4 (Wbl-4) element (GTAGTGACTCAT), one of six Wbl elements in the BjC-P promoter of the unusual chitinase gene BjCHI1 from Brassica juncea, as the core element responsive to fungal infection. Here, we report the isolation and characterization of the cognate transcription factor interacting with the Wbl-4 element. Using Wbl-4 as a target, we performed yeast one-hybrid screening of a B. juncea cDNA library and isolated an R2R3-MYB transcription factor designated as BjMYB1. BjMYB1 was localized in the nucleus of plant cells. EMSA assays confirmed that BjMYB1 binds to the Wbl-4 element. Transiently expressed BjMYB1 up-regulated the activity of the BjC-P promoter through its binding to the Wbl-4 element in tobacco (Nicotiana benthamiana) leaves. In B. juncea, BjMYB1 displayed a similar induced expression pattern as that of BjCHI1 upon infection by the fungus Botrytis cinerea. Moreover, heterogeneous overexpression of BjMYB1 significantly elevated the resistance of transgenic Arabidopsis thaliana to the fungus B. cinerea. These results suggest that BjMYB1 is potentially involved in host defence against fungal attack through activating the expression of BjCHI1 by binding to the Wbl-4 element in the BjC-P promoter. This finding demonstrates a novel DNA target of plant MYB transcription factors. PMID:27353280

  6. Expression of a Grapevine NAC Transcription Factor Gene Is Induced in Response to Powdery Mildew Colonization in Salicylic Acid-Independent Manner.

    PubMed

    Toth, Zsofia; Winterhagen, Patrick; Kalapos, Balazs; Su, Yingcai; Kovacs, Laszlo; Kiss, Erzsebet

    2016-01-01

    Tissue colonization by grape powdery mildew (PM) pathogen Erysiphe necator (Schw.) Burr triggers a major remodeling of the transcriptome in the susceptible grapevine Vitis vinifera L. While changes in the expression of many genes bear the signature of salicylic acid (SA) mediated regulation, the breadth of PM-induced changes suggests the involvement of additional regulatory networks. To explore PM-associated gene regulation mediated by other SA-independent systems, we designed a microarray experiment to distinguish between transcriptome changes induced by E. necator colonization and those triggered by elevated SA levels. We found that the majority of genes responded to both SA and PM, but certain genes were responsive to PM infection alone. Among them, we identified genes of stilbene synthases, PR-10 proteins, and several transcription factors. The microarray results demonstrated that the regulation of these genes is either independent of SA, or dependent, but SA alone is insufficient to bring about their regulation. We inserted the promoter-reporter fusion of a PM-responsive transcription factor gene into a wild-type and two SA-signaling deficient Arabidopsis lines and challenged the resulting transgenic plants with an Arabidopsis-adapted PM pathogen. Our results provide experimental evidence that this grape gene promoter is activated by the pathogen in a SA-independent manner. PMID:27488171

  7. Expression of a Grapevine NAC Transcription Factor Gene Is Induced in Response to Powdery Mildew Colonization in Salicylic Acid-Independent Manner

    PubMed Central

    Toth, Zsofia; Winterhagen, Patrick; Kalapos, Balazs; Su, Yingcai; Kovacs, Laszlo; Kiss, Erzsebet

    2016-01-01

    Tissue colonization by grape powdery mildew (PM) pathogen Erysiphe necator (Schw.) Burr triggers a major remodeling of the transcriptome in the susceptible grapevine Vitis vinifera L. While changes in the expression of many genes bear the signature of salicylic acid (SA) mediated regulation, the breadth of PM-induced changes suggests the involvement of additional regulatory networks. To explore PM-associated gene regulation mediated by other SA-independent systems, we designed a microarray experiment to distinguish between transcriptome changes induced by E. necator colonization and those triggered by elevated SA levels. We found that the majority of genes responded to both SA and PM, but certain genes were responsive to PM infection alone. Among them, we identified genes of stilbene synthases, PR-10 proteins, and several transcription factors. The microarray results demonstrated that the regulation of these genes is either independent of SA, or dependent, but SA alone is insufficient to bring about their regulation. We inserted the promoter-reporter fusion of a PM-responsive transcription factor gene into a wild-type and two SA-signaling deficient Arabidopsis lines and challenged the resulting transgenic plants with an Arabidopsis-adapted PM pathogen. Our results provide experimental evidence that this grape gene promoter is activated by the pathogen in a SA-independent manner. PMID:27488171

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

    PubMed Central

    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

  9. The DOF protein, SAD, interacts with GAMYB in plant nuclei and activates transcription of endosperm-specific genes during barley seed development.

    PubMed

    Diaz, Isabel; Martinez, Manuel; Isabel-LaMoneda, Ines; Rubio-Somoza, Ignacio; Carbonero, Pilar

    2005-06-01

    The DOF protein, SAD, previously shown to be a transcriptional activator in barley aleurone cells upon seed germination, also has an important role in gene regulation during endosperm development. mRNA was detected in early (10 days after flowering) developing barley seeds where it accumulated in the starchy endosperm, aleurone cells, nucellar projection, vascular tissues and the immature embryo, as shown by RT-PCR and in situ hybridization analyses. The SAD protein, expressed in bacteria, binds to oligonucleotides containing the prolamine box, 5'-A/TAAAG-3'sequence, derived from the promoter regions of the endosperm-specific genes Hor2 and Itr1, encoding a B-hordein and trypsin-inhibitor BTI-CMe, respectively. SAD competed for the same binding sites with another endosperm-expressed DOF protein, BPBF. Transient expression experiments in co-bombarded developing endosperms demonstrated that SAD trans-activated transcription from Hor2 and Itr1 promoters through binding to the intact DOF motifs. When the two DOF factors are co-bombarded together an additive effect was observed upon the expression of the Itr1 gene. In-frame fusion of the Sad ORF to the reporter green fluorescent protein gene directs the fluorescence expression to the nucleus in transiently transformed onion epidermal layers. The visualization of fluorescence in the nucleus of onion cells, using the bimolecular fluorescent complex (BiFC) approach, has shown the in vivo interaction between SAD and the R2R3MYB protein GAMYB. The interaction in plant cells has also been documented for the DOF protein BPBF and GAMYB, but nuclear interaction could not be detected between BPBF and SAD by this procedure. PMID:15918880

  10. A genome-wide regulatory framework identifies maize Pericarp Color1 (P1) controlled genes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    P1 encodes an R2R3-MYB transcription factor responsible for the accumulation of insecticidal flavones in maize silks and red phlobaphene pigments in pericarps and other floral tissues. Using genome-wide expression analyses (RNA-Seq) in pericarps and silks of plants with contrasting P1 alleles combin...

  11. Genome-wide transcriptional analysis of grapevine berry ripening reveals a set of genes similarly modulated during three seasons and the occurrence of an oxidative burst at vèraison

    PubMed Central

    Pilati, Stefania; Perazzolli, Michele; Malossini, Andrea; Cestaro, Alessandro; Demattè, Lorenzo; Fontana, Paolo; Dal Ri, Antonio; Viola, Roberto; Velasco, Riccardo; Moser, Claudio

    2007-01-01

    Background Grapevine (Vitis species) is among the most important fruit crops in terms of cultivated area and economic impact. Despite this relevance, little is known about the transcriptional changes and the regulatory circuits underlying the biochemical and physical changes occurring during berry development. Results Fruit ripening in the non-climacteric crop species Vitis vinifera L. has been investigated at the transcriptional level by the use of the Affymetrix Vitis GeneChip® which contains approximately 14,500 unigenes. Gene expression data obtained from berries sampled before and after véraison in three growing years, were analyzed to identify genes specifically involved in fruit ripening and to investigate seasonal influences on the process. From these analyses a core set of 1477 genes was found which was similarly modulated in all seasons. We were able to separate ripening specific isoforms within gene families and to identify ripening related genes which appeared strongly regulated also by the seasonal weather conditions. Transcripts annotation by Gene Ontology vocabulary revealed five overrepresented functional categories of which cell wall organization and biogenesis, carbohydrate and secondary metabolisms and stress response were specifically induced during the ripening phase, while photosynthesis was strongly repressed. About 19% of the core gene set was characterized by genes involved in regulatory processes, such as transcription factors and transcripts related to hormonal metabolism and signal transduction. Auxin, ethylene and light emerged as the main stimuli influencing berry development. In addition, an oxidative burst, previously not detected in grapevine, characterized by rapid accumulation of H2O2 starting from véraison and by the modulation of many ROS scavenging enzymes, was observed. Conclusion The time-course gene expression analysis of grapevine berry development has identified the occurrence of two well distinct phases along the

  12. Comprehensive transcript profiling of two grapevine rootstock genotypes contrasting in drought susceptibility links the phenylpropanoid pathway to enhanced tolerance

    PubMed Central

    Corso, Massimiliano; Vannozzi, Alessandro; Maza, Elie; Vitulo, Nicola; Meggio, Franco; Pitacco, Andrea; Telatin, Andrea; D’Angelo, Michela; Feltrin, Erika; Negri, Alfredo Simone; Prinsi, Bhakti; Valle, Giorgio; Ramina, Angelo; Bouzayen, Mondher; Bonghi, Claudio; Lucchin, Margherita

    2015-01-01

    In light of ongoing climate changes in wine-growing regions, the selection of drought-tolerant rootstocks is becoming a crucial factor for developing a sustainable viticulture. In this study, M4, a new rootstock genotype that shows tolerance to drought, was compared from a genomic and transcriptomic point of view with the less drought-tolerant genotype 101.14. The root and leaf transcriptome of both 101.14 and the M4 rootstock genotype was analysed, following exposure to progressive drought conditions. Multifactorial analyses indicated that stress treatment represents the main factor driving differential gene expression in roots, whereas in leaves the genotype is the prominent factor. Upon stress, M4 roots and leaves showed a higher induction of resveratrol and flavonoid biosynthetic genes, respectively. The higher expression of VvSTS genes in M4, confirmed by the accumulation of higher levels of resveratrol in M4 roots compared with 101.14, was coupled to an up-regulation of several VvWRKY transcription factors. Interestingly, VvSTS promoter analyses performed on both the resequenced genomes highlighted a significantly higher number of W-BOX elements in the tolerant genotype. It is proposed that the elevated synthesis of resveratrol in M4 roots upon water stress could enhance the plant’s ability to cope with the oxidative stress usually associated with water deficit. PMID:26038306

  13. School Administrator Grapevine Structure.

    ERIC Educational Resources Information Center

    Licata, Joseph W.; Hack, Walter G.

    1980-01-01

    A study reveals that principals' grapevine structure shows both "guild-like" and "clan-like" grouping and reflects the patterns of occupational socialization of school principals and informal boundary spanning processes. (Author/JM)

  14. Grapevine (Vitis vinifera L.).

    PubMed

    Bouquet, Alain; Torregrosa, Laurent; Iocco, Pat; Thomas, Mark R

    2006-01-01

    Grapevine (Vitis) is considered to be one of the major fruit crops in the world based on hectares cultivated and economic value. Grapes are used not only for wine but also for fresh fruit, dried fruit, and juice production. Wine is by far the major product of grapes and the focus of this chapter is on wine grape cultivars. Grapevine cultivars of Vitis vinifera L. have a reputation for producing premium quality wines. These premium quality wines are produced from a small number of cultivars that enjoy a high level of consumer acceptance and are firmly entrenched in the market place because of varietal name branding and the association of certain wine styles and regions with specific cultivars. In light of this situation, grapevine improvement by a transgenic approach is attractive when compared to a classical breeding approach. The transfer of individual traits as single genes with a minimum disruption to the original genome would leave the traditional characteristics of the cultivar intact. However, a reliable transformation system is required for a successful transgenic approach to grapevine improvement. There are three criteria for achieving an efficient Agrobacterium-mediated transformation system: (1) the production of highly regenerative transformable tissue, (2) optimal co-cultivation conditions for both grapevine tissue and Agrobacterium, and (3) an efficient selection regime for transgenic plant regeneration. In this chapter, we describe a grapevine transformation system which meets the above mentioned criteria. PMID:17033070

  15. The plasticity of the grapevine berry transcriptome

    PubMed Central

    2013-01-01

    Background Phenotypic plasticity refers to the range of phenotypes a single genotype can express as a function of its environment. These phenotypic variations are attributable to the effect of the environment on the expression and function of genes influencing plastic traits. We investigated phenotypic plasticity in grapevine by comparing the berry transcriptome in a single clone of the vegetatively-propagated common grapevine species Vitis vinifera cultivar Corvina through 3 consecutive growth years cultivated in 11 different vineyards in the Verona area of Italy. Results Most of the berry transcriptome clustered by year of growth rather than common environmental conditions or viticulture practices, and transcripts related to secondary metabolism showed high sensitivity towards different climates, as confirmed also by metabolomic data obtained from the same samples. When analyzed in 11 vineyards during 1 growth year, the environmentally-sensitive berry transcriptome comprised 5% of protein-coding genes and 18% of the transcripts modulated during berry development. Plastic genes were particularly enriched in ontology categories such as transcription factors, translation, transport, and secondary metabolism. Specific plastic transcripts were associated with groups of vineyards sharing common viticulture practices or environmental conditions, and plastic transcriptome reprogramming was more intense in the year characterized by extreme weather conditions. We also identified a set of genes that lacked plasticity, showing either constitutive expression or similar modulation in all berries. Conclusions Our data reveal candidate genes potentially responsible for the phenotypic plasticity of grapevine and provide the first step towards the characterization of grapevine transcriptome plasticity under different agricultural systems. PMID:23759170

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

    PubMed

    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

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

    PubMed Central

    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

  18. Grapevine (Vitis vinifera L.).

    PubMed

    Torregrosa, Laurent; Vialet, Sandrine; Adivèze, Angélique; Iocco-Corena, Pat; Thomas, Mark R

    2015-01-01

    Grapevine (Vitis) is considered to be one of the major fruit crops in the world based on hectares cultivated and economic value. Grapes are used not only for wine but also for fresh fruit, dried fruit, and juice production. Wine is by far the major product of grapes, and the focus of this chapter is on wine grape cultivars. Grapevine cultivars of Vitis vinifera L. have a reputation for producing premium quality wines. These premium quality wines are produced from a small number of cultivars that enjoy a high level of consumer acceptance and are firmly entrenched in the market place because of varietal name branding and the association of certain wine styles and regions with specific cultivars. In light of this situation, grapevine improvement by a transgenic approach is attractive when compared to a classical breeding approach. The transfer of individual traits as single genes with a minimum disruption to the original genome would leave the traditional characteristics of the cultivar intact. However, a reliable transformation system is required for a successful transgenic approach to grapevine improvement. There are three criteria for achieving an efficient Agrobacterium-mediated transformation system: (1) the production of highly regenerative transformable tissue, (2) optimal cocultivation conditions for both grapevine tissue and Agrobacterium, and (3) an efficient selection regime for transgenic plant regeneration. In this chapter, we describe a grapevine transformation system that meets these criteria. We also describe a protocol for the production of transformed roots suitable for functional gene studies and for the production of semi-transgenic grafted plants. PMID:25416258

  19. Respecting the Grapevine.

    ERIC Educational Resources Information Center

    Carroll, David J.

    2001-01-01

    Administrators can create word-of-mouth communication that dispels negative attitudes and build good school reputations by discovering what parents and students are saying, targeting employee satisfaction and retention, providing excellent customer service, actively seeking and handling complaints, nurturing champions, and integrating "grapevine"…

  20. In the Solanaceae, a hierarchy of bHLHs confer distinct target specificity to the anthocyanin regulatory complex.

    PubMed

    Montefiori, Mirco; Brendolise, Cyril; Dare, Andrew P; Lin-Wang, Kui; Davies, Kevin M; Hellens, Roger P; Allan, Andrew C

    2015-03-01

    The anthocyanin biosynthetic pathway is regulated by a transcription factor complex consisting of an R2R3 MYB, a bHLH, and a WD40. Although R2R3 MYBs belonging to the anthocyanin-activating class have been identified in many plants, and their role well elucidated, the subgroups of bHLH implicated in anthocyanin regulation seem to be more complex. It is not clear whether these potential bHLH partners are biologically interchangeable with redundant functions, or even if heterodimers are involved. In this study, AcMYB110, an R2R3 MYB isolated from kiwifruit (Actinidia sp.) showing a strong activation of the anthocyanin pathway in tobacco (Nicotiana tabacum) was used to examine the function of interacting endogenous bHLH partners. Constitutive expression of AcMYB110 in tobacco leaves revealed different roles for two bHLHs, NtAN1 and NtJAF13. A hierarchical mechanism is shown to control the regulation of transcription factors and consequently of the anthocyanin biosynthetic pathway. Here, a model is proposed for the regulation of the anthocyanin pathway in Solanaceous plants in which AN1 is directly involved in the activation of the biosynthetic genes, whereas JAF13 is involved in the regulation of AN1 transcription. PMID:25628328

  1. In the Solanaceae, a hierarchy of bHLHs confer distinct target specificity to the anthocyanin regulatory complex

    PubMed Central

    Montefiori, Mirco; Brendolise, Cyril; Dare, Andrew P.; Lin-Wang, Kui; Davies, Kevin M.; Hellens, Roger P.; Allan, Andrew C.

    2015-01-01

    The anthocyanin biosynthetic pathway is regulated by a transcription factor complex consisting of an R2R3 MYB, a bHLH, and a WD40. Although R2R3 MYBs belonging to the anthocyanin-activating class have been identified in many plants, and their role well elucidated, the subgroups of bHLH implicated in anthocyanin regulation seem to be more complex. It is not clear whether these potential bHLH partners are biologically interchangeable with redundant functions, or even if heterodimers are involved. In this study, AcMYB110, an R2R3 MYB isolated from kiwifruit (Actinidia sp.) showing a strong activation of the anthocyanin pathway in tobacco (Nicotiana tabacum) was used to examine the function of interacting endogenous bHLH partners. Constitutive expression of AcMYB110 in tobacco leaves revealed different roles for two bHLHs, NtAN1 and NtJAF13. A hierarchical mechanism is shown to control the regulation of transcription factors and consequently of the anthocyanin biosynthetic pathway. Here, a model is proposed for the regulation of the anthocyanin pathway in Solanaceous plants in which AN1 is directly involved in the activation of the biosynthetic genes, whereas JAF13 is involved in the regulation of AN1 transcription. PMID:25628328

  2. Recent amplification and impact of MITEs on the genome of grapevine (Vitis vinifera L.)

    PubMed Central

    Benjak, Andrej; Boué, Stéphanie; Forneck, Astrid

    2009-01-01

    Miniature inverted-repeat transposable elements (MITEs) are a particular type of defective class II transposons present in genomes as highly homogeneous populations of small elements. Their high copy number and close association to genes make their potential impact on gene evolution particularly relevant. Here, we present a detailed analysis of the MITE families directly related to grapevine “cut-and-paste” transposons. Our results show that grapevine MITEs have transduplicated and amplified genomic sequences, including gene sequences and fragments of other mobile elements. Our results also show that although some of the MITE families were already present in the ancestor of the European and American Vitis wild species, they have been amplified and have been actively transposing accompanying grapevine domestication and breeding. We show that MITEs are abundant in grapevine and some of them are frequently inserted within the untranslated regions of grapevine genes. MITE insertions are highly polymorphic among grapevine cultivars, which frequently generate transcript variability. The data presented here show that MITEs have greatly contributed to the grapevine genetic diversity which has been used for grapevine domestication and breeding. PMID:20333179

  3. Grapevine Fanleaf Disease in Washington State Vineyards

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wine grapes (Vitis vinifera L.) are susceptible to a wide range of viruses. Among them, grapevine degeneration caused by Grapevine fanleaf virus (GFLV) is considered as one of the most economically important virus diseases affecting grapevines worldwide. Infected grapevines show a range of foliar sy...

  4. Transcriptomic and Metabolomic Networks in the Grape Berry Illustrate That it Takes More Than Flavonoids to Fight Against Ultraviolet Radiation.

    PubMed

    Matus, José Tomás

    2016-01-01

    Plants are constantly challenged by environmental fluctuations. In response, they have developed a wide range of morphological and biochemical adaptations committed to ameliorate the effects of abiotic stress. When exposed to higher solar radiation levels, plants activate the synthesis of a large set of enzymes and secondary metabolites as part of a complex sunscreen and antioxidant defense mechanism. Grapevine (Vitis vinifera L.) has become a widely used system for studying adaptive responses to this type of stress since changes in berry composition, positively influenced by increased ultraviolet (UV) radiation levels, improve the quality of wines subsequently produced. Despite the fact that most of the attention has been directed toward the synthesis of flavonoids, recent transcriptomic and metabolomic studies have shown that stilbenoids and isoprenoids (e.g., terpenes and carotenoids) are also an important part of the grape UV-response machinery. This minireview focuses on the latest findings referring to the metabolic responses of grapes to UV radiation and proposes a model for its transcriptional control. Depending on the berry developmental stage and the type of radiation (i.e., irradiance level, exposure length), increased UV levels activate different metabolic pathways through the activity of master regulators belonging to the basic Leucine Zipper Domain (bZIP) and R2R3-MYB transcription factor families. This transcriptional control is influenced by the interaction of other environmental factors such as light, temperature or soil water availability. In grapevine, phenylpropanoids are part of, but are not the whole story, in the fight against radiation damage. PMID:27625679

  5. Transcriptomic and Metabolomic Networks in the Grape Berry Illustrate That it Takes More Than Flavonoids to Fight Against Ultraviolet Radiation

    PubMed Central

    Matus, José Tomás

    2016-01-01

    Plants are constantly challenged by environmental fluctuations. In response, they have developed a wide range of morphological and biochemical adaptations committed to ameliorate the effects of abiotic stress. When exposed to higher solar radiation levels, plants activate the synthesis of a large set of enzymes and secondary metabolites as part of a complex sunscreen and antioxidant defense mechanism. Grapevine (Vitis vinifera L.) has become a widely used system for studying adaptive responses to this type of stress since changes in berry composition, positively influenced by increased ultraviolet (UV) radiation levels, improve the quality of wines subsequently produced. Despite the fact that most of the attention has been directed toward the synthesis of flavonoids, recent transcriptomic and metabolomic studies have shown that stilbenoids and isoprenoids (e.g., terpenes and carotenoids) are also an important part of the grape UV-response machinery. This minireview focuses on the latest findings referring to the metabolic responses of grapes to UV radiation and proposes a model for its transcriptional control. Depending on the berry developmental stage and the type of radiation (i.e., irradiance level, exposure length), increased UV levels activate different metabolic pathways through the activity of master regulators belonging to the basic Leucine Zipper Domain (bZIP) and R2R3-MYB transcription factor families. This transcriptional control is influenced by the interaction of other environmental factors such as light, temperature or soil water availability. In grapevine, phenylpropanoids are part of, but are not the whole story, in the fight against radiation damage. PMID:27625679

  6. De Novo Genome Assembly of Grapevine Yellow Speckle Viroid 1 from a Grapevine Transcriptome

    PubMed Central

    Jo, Yeonhwa; Choi, Hoseong; Yoon, Ju-Yeon; Choi, Seung-Kook

    2015-01-01

    Grapevine yellow speckle viroid 1 (GYSVd1), which is a member of the genus Apscaviroid, causes yellow speckle disease in grapevines. Here, we report the complete de novo genome assembly of GYSVd1 from the grapevine transcriptome and identified 10 single nucleotide polymorphisms of GYSVd1 across the grapevine populations. PMID:25999581

  7. Short day transcriptomic programming during induction of dormancy in grapevine.

    PubMed

    Fennell, Anne Y; Schlauch, Karen A; Gouthu, Satyanarayana; Deluc, Laurent G; Khadka, Vedbar; Sreekantan, Lekha; Grimplet, Jerome; Cramer, Grant R; Mathiason, Katherine L

    2015-01-01

    Bud dormancy in grapevine is an adaptive strategy for the survival of drought, high and low temperatures and freeze dehydration stress that limit the range of cultivar adaptation. Therefore, development of a comprehensive understanding of the biological mechanisms involved in bud dormancy is needed to promote advances in selection and breeding, and to develop improved cultural practices for existing grape cultivars. The seasonally indeterminate grapevine, which continuously develops compound axillary buds during the growing season, provides an excellent system for dissecting dormancy, because the grapevine does not transition through terminal bud development prior to dormancy. This study used gene expression patterns and targeted metabolite analysis of two grapevine genotypes that are short photoperiod responsive (Vitis riparia) and non-responsive (V. hybrid, Seyval) for dormancy development to determine differences between bud maturation and dormancy commitment. Grapevine gene expression and metabolites were monitored at seven time points under long (LD, 15 h) and short (SD, 13 h) day treatments. The use of age-matched buds and a small (2 h) photoperiod difference minimized developmental differences and allowed us to separate general photoperiod from dormancy specific gene responses. Gene expression profiles indicated three distinct phases (perception, induction and dormancy) in SD-induced dormancy development in V. riparia. Different genes from the NAC DOMAIN CONTAINING PROTEIN 19 and WRKY families of transcription factors were differentially expressed in each phase of dormancy. Metabolite and transcriptome analyses indicated ABA, trehalose, raffinose and resveratrol compounds have a potential role in dormancy commitment. Finally, a comparison between V. riparia compound axillary bud dormancy and dormancy responses in other species emphasized the relationship between dormancy and the expression of RESVERATROL SYNTHASE and genes associated with C3HC4-TYPE RING

  8. Short day transcriptomic programming during induction of dormancy in grapevine

    PubMed Central

    Fennell, Anne Y.; Schlauch, Karen A.; Gouthu, Satyanarayana; Deluc, Laurent G.; Khadka, Vedbar; Sreekantan, Lekha; Grimplet, Jerome; Cramer, Grant R.; Mathiason, Katherine L.

    2015-01-01

    Bud dormancy in grapevine is an adaptive strategy for the survival of drought, high and low temperatures and freeze dehydration stress that limit the range of cultivar adaptation. Therefore, development of a comprehensive understanding of the biological mechanisms involved in bud dormancy is needed to promote advances in selection and breeding, and to develop improved cultural practices for existing grape cultivars. The seasonally indeterminate grapevine, which continuously develops compound axillary buds during the growing season, provides an excellent system for dissecting dormancy, because the grapevine does not transition through terminal bud development prior to dormancy. This study used gene expression patterns and targeted metabolite analysis of two grapevine genotypes that are short photoperiod responsive (Vitis riparia) and non-responsive (V. hybrid, Seyval) for dormancy development to determine differences between bud maturation and dormancy commitment. Grapevine gene expression and metabolites were monitored at seven time points under long (LD, 15 h) and short (SD, 13 h) day treatments. The use of age-matched buds and a small (2 h) photoperiod difference minimized developmental differences and allowed us to separate general photoperiod from dormancy specific gene responses. Gene expression profiles indicated three distinct phases (perception, induction and dormancy) in SD-induced dormancy development in V. riparia. Different genes from the NAC DOMAIN CONTAINING PROTEIN 19 and WRKY families of transcription factors were differentially expressed in each phase of dormancy. Metabolite and transcriptome analyses indicated ABA, trehalose, raffinose and resveratrol compounds have a potential role in dormancy commitment. Finally, a comparison between V. riparia compound axillary bud dormancy and dormancy responses in other species emphasized the relationship between dormancy and the expression of RESVERATROL SYNTHASE and genes associated with C3HC4-TYPE RING

  9. Foreword: Special issue on fungal grapevine diseases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An impressively large proportion of fungicides applied in European, North American and Australian agriculture has been used to manage grapevine powdery mildew (Erysiphe necator), grapevine downy mildew (Plasmopara viticola), and botrytis bunch rot (Botrytis cinerea). These fungal and oomycetous plan...

  10. Grape (Vitis spp.) - Grapevine Red Blotch Disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grapevine red blotch disease is caused by Grapevine red blotch-associated virus (GRBaV), which was first reported in 2012 from New York and subsequently in California, Washington, Oregon, Idaho and elsewhere in the U.S. The discovery occurred when grapevines with red leaf symptoms that tested negati...

  11. Genome and transcriptome analysis of the grapevine (Vitis vinifera L.) WRKY gene family

    PubMed Central

    Wang, Min; Vannozzi, Alessandro; Wang, Gang; Liang, Ying-Hai; Tornielli, Giovanni Battista; Zenoni, Sara; Cavallini, Erika; Pezzotti, Mario; Cheng, Zong-Ming (Max)

    2014-01-01

    The plant WRKY gene family represents an ancient and complex class of zinc-finger transcription factors (TFs) that are involved in the regulation of various physiological processes, such as development and senescence, and in plant response to many biotic and abiotic stresses. Despite the growing number of studies on the genomic organisation of WRKY gene family in different species, little information is available about this family in grapevine (Vitis vinifera L.). In the present study, a total number of 59 putative grapevine WRKY transcription factors (VvWRKYs) were identified based on the analysis of various genomic and proteomic grapevine databases. According to their structural and phylogentic features, the identified grapevine WRKY transcription factors were classified into three main groups. In order to shed light into their regulatory roles in growth and development as well as in response to biotic and abiotic stress in grapevine, the VvWRKYs expression profiles were examined in publicly available microarray data. Bioinformatics analysis of these data revealed distinct temporal and spatial expression patterns of VvWRKYs in various tissues, organs and developmental stages, as well as in response to biotic and abiotic stresses. To also extend our analysis to situations not covered by the arrays and to validate our results, the expression profiles of selected VvWRKYs in response to drought stress, Erysiphe necator (powdery mildew) infection, and hormone treatments (salicilic acid and ethylene), were investigated by quantitative real-time reverse transcription PCR (qRT-PCR). The present study provides a foundation for further comparative genomics and functional studies of this important class of transcriptional regulators in grapevine. PMID:26504535

  12. The accumulation and localization of chalcone synthase in grapevine (Vitis vinifera L.).

    PubMed

    Wang, Huiling; Wang, Wei; Zhan, JiCheng; Yan, Ailing; Sun, Lei; Zhang, Guojun; Wang, Xiaoyue; Ren, Jiancheng; Huang, Weidong; Xu, Haiying

    2016-09-01

    Chalcone synthase (CHS, E.C.2.3.1.74) is the first committed enzyme in the flavonoid pathway. Previous studies have primarily focused on the cloning, expression and regulation of the gene at the transcriptional level. Little is yet known about the enzyme accumulation, regulation at protein level, as well as its localization in grapevine. In present study, the accumulation, tissue and subcellular localization of CHS in different grapevine tissues (Vitis vinifera L. Cabernet Sauvignon) were investigated via the techniques of Western blotting, immunohistochemical localization, immunoelectron microscopy and confocal microscopy. The results showed that CHS were mainly accumulated in the grape berry skin, leaves, stem tips and stem phloem, correlated with flavonoids accumulation. The accumulation of CHS is developmental dependent in grape berry skin and flesh. Immunohistochemical analysis revealed that CHS were primarily localized in the exocarp and vascular bundles of the fruits during berry development; in palisade, spongy tissues and vascular bundles of the leaves; in the primary phloem and pith ray in the stems; in the growth point, leaf primordium, and young leaves of leaf buds; and in the endoderm and primary phloem of grapevine roots. Furthermore, at the subcellular level, the cell wall, cytoplasm and nucleus localized patterns of CHS were observed in the grapevine vegetative tissue cells. Results above indicated that distribution of CHS in grapevine was organ-specific and tissue-specific. This work will provide new insight for the biosynthesis and regulation of diverse flavonoid compounds in grapevine. PMID:27161583

  13. Comparative transcriptome analysis of grapevine in response to copper stress

    PubMed Central

    Leng, Xiangpeng; Jia, Haifeng; Sun, Xin; Shangguan, Lingfei; Mu, Qian; Wang, Baoju; Fang, Jinggui

    2015-01-01

    Grapevine is one of the most economically important and widely cultivated fruit crop worldwide. With the industrialization and the popular application of cupric fungicides in grape industry, copper stress and copper pollution are also the factors affecting grape production and berry and wine quality. Here, 3,843 transcripts were significantly differently expressed genes in response to Cu stress by RNA-seq, which included 1,892 up-regulated and 1,951 down-regulated transcripts. During this study we found many known and novel Cu-induced and -repressed genes. Biological analysis of grape samples were indicated that exogenous Cu can influence chlorophylls metabolism and photosynthetic activities of grapevine. Most ROS detoxification systems, including antioxidant enzyme, stress-related proteins and secondary metabolites were strongly induced. Concomitantly, abscisic acid functioned as a negative regulator in Cu stress, in opposite action to ethylene, auxin, jasmonic acid, and brassinolide. This study also identified a set of Cu stress specifically activated genes coding copper transporter, P1B-type ATPase, multidrug transporters. Overall, this work was carried out to gain insights into the copper-regulated and stress-responsive mechanisms in grapevine at transcriptome level. This research can also provide some genetic information that can help us in better vinery management and breeding Cu-resistant grape cultivars. PMID:26673527

  14. Comparative transcriptome analysis of grapevine in response to copper stress.

    PubMed

    Leng, Xiangpeng; Jia, Haifeng; Sun, Xin; Shangguan, Lingfei; Mu, Qian; Wang, Baoju; Fang, Jinggui

    2015-01-01

    Grapevine is one of the most economically important and widely cultivated fruit crop worldwide. With the industrialization and the popular application of cupric fungicides in grape industry, copper stress and copper pollution are also the factors affecting grape production and berry and wine quality. Here, 3,843 transcripts were significantly differently expressed genes in response to Cu stress by RNA-seq, which included 1,892 up-regulated and 1,951 down-regulated transcripts. During this study we found many known and novel Cu-induced and -repressed genes. Biological analysis of grape samples were indicated that exogenous Cu can influence chlorophylls metabolism and photosynthetic activities of grapevine. Most ROS detoxification systems, including antioxidant enzyme, stress-related proteins and secondary metabolites were strongly induced. Concomitantly, abscisic acid functioned as a negative regulator in Cu stress, in opposite action to ethylene, auxin, jasmonic acid, and brassinolide. This study also identified a set of Cu stress specifically activated genes coding copper transporter, P1B-type ATPase, multidrug transporters. Overall, this work was carried out to gain insights into the copper-regulated and stress-responsive mechanisms in grapevine at transcriptome level. This research can also provide some genetic information that can help us in better vinery management and breeding Cu-resistant grape cultivars. PMID:26673527

  15. Consequences of transferring three sorghum genes for secondary metabolite (cyanogenic glucoside) biosynthesis to grapevine hairy roots.

    PubMed

    Franks, T K; Powell, K S; Choimes, S; Marsh, E; Iocco, P; Sinclair, B J; Ford, C M; van Heeswijck, R

    2006-04-01

    A multigenic trait (biosynthesis of the secondary metabolite, dhurrin cyanogenic glucoside) was engineered de novo in grapevine (Vitis vinifera L.). This follows a recent report of transfer of the same trait to Arabidopsis (Arabidopsis thaliana) using three genetic sequences from sorghum (Sorghum bicolor): two cytochrome P450-encoding cDNAs (CYP79A1 and CYP71E1) and a UDPG-glucosyltransferase-encoding cDNA (sbHMNGT). Here we describe the two-step process involving whole plant transformation followed by hairy root transformation, which was used to transfer the same three sorghum sequences to grapevine. Transgenic grapevine hairy root lines that accumulated transcript from none, one (sbHMNGT), two (CYP79A1 and CYP71E1) or all three transgenes were recovered and characterisation of these lines provided information about the requirements for dhurrin biosynthesis in grapevine. Only lines that accumulated transcripts from all three transgenes had significantly elevated cyanide potential (up to the equivalent of about 100 mg HCN kg(-1) fresh weight), and levels were highly variable. One dhurrin-positive line was tested and found to release cyanide upon maceration and can therefore be considered 'cyanogenic'. In in vitro dual co-culture of this cyanogenic hairy root line or an acyanogenic line with the specialist root-sucking, gall-forming, aphid-like insect, grapevine phylloxera (Daktulosphaira vitifoliae, Fitch), there was no evidence for protection of the cyanogenic plant tissue from infestation by the insect. Consistently high levels of dhurrin accumulation may be required for this to occur. The possibility that endogenous grapevine gene expression is modulated in response to engineered dhurrin biosynthesis was investigated using microarray analysis of 1225 grapevine ESTs, but differences in patterns of gene expression associated with dhurrin-positive and dhurrin-negative phenotypes were not identified. PMID:16604459

  16. Control of viruses infecting grapevine.

    PubMed

    Maliogka, Varvara I; Martelli, Giovanni P; Fuchs, Marc; Katis, Nikolaos I

    2015-01-01

    Grapevine is a high value vegetatively propagated fruit crop that suffers from numerous viruses, including some that seriously affect the profitability of vineyards. Nowadays, 64 viruses belonging to different genera and families have been reported in grapevines and new virus species will likely be described in the future. Three viral diseases namely leafroll, rugose wood, and infectious degeneration are of major economic importance worldwide. The viruses associated with these diseases are transmitted by mealybugs, scale and soft scale insects, or dagger nematodes. Here, we review control measures of the major grapevine viral diseases. More specifically, emphasis is laid on (i) approaches for the production of clean stocks and propagative material through effective sanitation, robust diagnosis, as well as local and regional certification efforts, (ii) the management of vectors of viruses using cultural, biological, and chemical methods, and (iii) the production of resistant grapevines mainly through the application of genetic engineering. The benefits and limitations of the different control measures are discussed with regard to accomplishments and future research directions. PMID:25591880

  17. Association of a DNA virus with grapevines affected by red blotch disease in California.

    PubMed

    Al Rwahnih, Maher; Dave, Ashita; Anderson, Michael M; Rowhani, Adib; Uyemoto, Jerry K; Sudarshana, Mysore R

    2013-10-01

    In the Napa Valley of California, vineyards of 'Cabernet Franc' (CF) clone 214, 'Cabernet Sauvignon' clone 337, and 'Zinfandel' clone 1A (Z1A) with grapevines exhibiting foliar symptoms of red blotches, marginal reddening, and red veins that were accompanied by reduced sugar accumulation in fruit at harvest were initially suspected to be infected with leafroll-associated viruses. However, reverse-transcription polymerase chain reaction (PCR) tests were negative for all known leafroll-associated viruses, with the exception of Grapevine leafroll-associated virus 2 in Z1A. Metagenomic analysis of cDNA libraries obtained from double-stranded RNA enriched nucleic acid (NA) preparations from bark scrapings of dormant canes on an Illumina platform revealed sequences having a distant relationship with members of the family Geminiviridae. Sequencing of products obtained by PCR assays using overlapping primers and rolling circle amplification (RCA) confirmed the presence of a single circular genome of 3,206 nucleotides which was nearly identical to the genome of a recently reported Grapevine cabernet franc-associated virus found in declining grapevines in New York. We propose to call this virus "Grapevine red blotch-associated virus" (GRBaV) to describe its association with grapevine red blotch disease. Primers specific to GRBaV amplified a product of expected size (557 bp) from NA preparations obtained from petioles of several diseased source vines. Chip bud inoculations successfully transmitted GRBaV to test plants of CF, as confirmed by PCR analysis. This is the first report of a DNA virus associated with red blotch disease of grapevines in California. PMID:23656312

  18. More Than Rumors. Understanding the Organizational Grapevine.

    ERIC Educational Resources Information Center

    Zaremba, Alan

    Because the grapevine can precipitate managerial nightmares (employee resentment, distorted messages, instant diffusion of incendiary rumors), managers are well-advised to study this informal communications network and diffuse its organizational impact. This paper discusses the development, accuracy, resilience, and management of the grapevine.…

  19. Procedure for collecting and packaging grapevine samples

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grapevine yellows (GY) is a term that is used to refer to any of several diseases of grapevine (Vitis vinifera) that are caused by phytoplasmas. Around the globe, diverse ‘Candidatus Phytoplasma’ species cause indistinguishable disease symptoms in V. vinifera and are spread by different species of ...

  20. MybA1 gene diversity across the Vitis genus.

    PubMed

    Péros, Jean-Pierre; Launay, Amandine; Berger, Gilles; Lacombe, Thierry; This, Patrice

    2015-06-01

    The MybA1 gene in the genus Vitis encodes a transcription factor, belonging to the R2R3 Myb family, that controls the last steps in the anthocyanins biosynthesis pathway. Polymorphism within MybA1 has been associated with color variation in berries of V. vinifera and other Vitis species. In this work, we analyzed the sequence variation in MybA1 both in the subg. Muscadinia and in an extended set of Asian, American and European genotypes of subg. Vitis. Our aims were to infer the evolution of this gene during the speciation process and to identify polymorphisms that could potentially generate changes in gene regulation. The results show that MybA1 experienced many insertions and deletions in non-coding regions but also in the third exon sequence. Owing to the larger set of Vitis species compared here, new indels were identified and the origin of previously described indels was reconsidered. A large number of single nucleotide polymorphisms were found in non-coding regions but also in the sequence coding for the R2R3 domain and the C terminal part of the protein. Some of these changes led to amino acid substitutions and therefore could have modified MybA1 protein activity. Bayesian phylogenetic analysis of all polymorphisms did not provide a consensus tree depicting the geographical partitioning of the species but allowed highlighting several species relationships within subgenus Vitis. Finally, the evolutionary events described could be useful to gain more insight into the role of MybA1 for anthocyanin biosynthesis in grapevine. PMID:25896368

  1. Transcriptome analyses of the Dof-like gene family in grapevine reveal its involvement in berry, flower and seed development

    PubMed Central

    da Silva, Danielle Costenaro; da Silveira Falavigna, Vítor; Fasoli, Marianna; Buffon, Vanessa; Porto, Diogo Denardi; Pappas, Georgios Joannis; Pezzotti, Mario; Pasquali, Giancarlo; Revers, Luís Fernando

    2016-01-01

    The Dof (DNA-binding with one finger) protein family spans a group of plant transcription factors involved in the regulation of several functions, such as plant responses to stress, hormones and light, phytochrome signaling and seed germination. Here we describe the Dof-like gene family in grapevine (Vitis vinifera L.), which consists of 25 genes coding for Dof. An extensive in silico characterization of the VviDofL gene family was performed. Additionally, the expression of the entire gene family was assessed in 54 grapevine tissues and organs using an integrated approach with microarray (cv Corvina) and real-time PCR (cv Pinot Noir) analyses. The phylogenetic analysis comparing grapevine sequences with those of Arabidopsis, tomato, poplar and already described Dof genes in other species allowed us to identify several duplicated genes. The diversification of grapevine DofL genes during evolution likely resulted in a broader range of biological roles. Furthermore, distinct expression patterns were identified between samples analyzed, corroborating such hypothesis. Our expression results indicate that several VviDofL genes perform their functional roles mainly during flower, berry and seed development, highlighting their importance for grapevine growth and production. The identification of similar expression profiles between both approaches strongly suggests that these genes have important regulatory roles that are evolutionally conserved between grapevine cvs Corvina and Pinot Noir. PMID:27610237

  2. Transcriptome analyses of the Dof-like gene family in grapevine reveal its involvement in berry, flower and seed development.

    PubMed

    da Silva, Danielle Costenaro; da Silveira Falavigna, Vítor; Fasoli, Marianna; Buffon, Vanessa; Porto, Diogo Denardi; Pappas, Georgios Joannis; Pezzotti, Mario; Pasquali, Giancarlo; Revers, Luís Fernando

    2016-01-01

    The Dof (DNA-binding with one finger) protein family spans a group of plant transcription factors involved in the regulation of several functions, such as plant responses to stress, hormones and light, phytochrome signaling and seed germination. Here we describe the Dof-like gene family in grapevine (Vitis vinifera L.), which consists of 25 genes coding for Dof. An extensive in silico characterization of the VviDofL gene family was performed. Additionally, the expression of the entire gene family was assessed in 54 grapevine tissues and organs using an integrated approach with microarray (cv Corvina) and real-time PCR (cv Pinot Noir) analyses. The phylogenetic analysis comparing grapevine sequences with those of Arabidopsis, tomato, poplar and already described Dof genes in other species allowed us to identify several duplicated genes. The diversification of grapevine DofL genes during evolution likely resulted in a broader range of biological roles. Furthermore, distinct expression patterns were identified between samples analyzed, corroborating such hypothesis. Our expression results indicate that several VviDofL genes perform their functional roles mainly during flower, berry and seed development, highlighting their importance for grapevine growth and production. The identification of similar expression profiles between both approaches strongly suggests that these genes have important regulatory roles that are evolutionally conserved between grapevine cvs Corvina and Pinot Noir. PMID:27610237

  3. Metabolic constituents of grapevine and grape-derived products

    PubMed Central

    Ali, Kashif; Maltese, Federica; Verpoorte, Robert

    2009-01-01

    The numerous uses of the grapevine fruit, especially for wine and beverages, have made it one of the most important plants worldwide. The phytochemistry of grapevine is rich in a wide range of compounds. Many of them are renowned for their numerous medicinal uses. The production of grapevine metabolites is highly conditioned by many factors like environment or pathogen attack. Some grapevine phytoalexins have gained a great deal of attention due to their antimicrobial activities, being also involved in the induction of resistance in grapevine against those pathogens. Meanwhile grapevine biotechnology is still evolving, thanks to the technological advance of modern science, and biotechnologists are making huge efforts to produce grapevine cultivars of desired characteristics. In this paper, important metabolites from grapevine and grape derived products like wine will be reviewed with their health promoting effects and their role against certain stress factors in grapevine physiology. PMID:20835385

  4. Grapevine canopy reflectance and yield

    NASA Technical Reports Server (NTRS)

    Minden, K. A.; Philipson, W. R.

    1982-01-01

    Field spectroradiometric and airborne multispectral scanner data were applied in a study of Concord grapevines. Spectroradiometric measurements of 18 experimental vines were collected on three dates during one growing season. Spectral reflectance, determined at 30 intervals from 0.4 to 1.1 microns, was correlated with vine yield, pruning weight, clusters/vine, and nitrogen input. One date of airborne multispectral scanner data (11 channels) was collected over commercial vineyards, and the average radiance values for eight vineyard sections were correlated with the corresponding average yields. Although some correlations were significant, they were inadequate for developing a reliable yield prediction model.

  5. Arthropods vector grapevine trunk disease pathogens.

    PubMed

    Moyo, P; Allsopp, E; Roets, F; Mostert, L; Halleen, F

    2014-10-01

    Arthropod-mediated dispersal of pathogens is known in many cropping systems but has never been demonstrated for grapevine trunk disease pathogens. Arthropods from vineyards were screened for the presence of pathogens associated with Petri disease and esca using cultural and molecular techniques. The ability of the most abundant pathogen-carrying species to inoculate healthy grapevine vascular tissues was also determined. Millipedes and ants were allowed to associate with a DsRed- Express-transformed Phaeomoniella chlamydospora, after which they were exposed to freshly pruned healthy grapevines under controlled conditions and wounds were monitored for subsequent infection. In addition, the possibility of millipede excreta, commonly found on pruning wounds in the field, to act as inoculum source was determined. A diverse arthropod fauna was associated with declining grapevines and many of these carried trunk disease pathogens. However, spiders, the ant Crematogaster peringueyi, and the millipede Ommattoiulus moreleti were the most abundant pathogen carriers. The ant and millipede species fed on pruning wound sap and effectively transmitted trunk disease pathogens. Millipede excreta contained viable spores of Phaeomoniella chlamydospora and may serve as an inoculum source. Numerous arthropods, including beneficial predators, are potential vectors of grapevine trunk disease pathogens. Our results highlight the need for an integrated approach, including targeted management of ants and millipedes at the time of pruning, to limit the spread of grapevine trunk diseases. PMID:24624953

  6. Grapevine red blotch-associated virus, an emerging threat to the grapevine industry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grapevine red blotch-associated virus (GRBaV) is a newly identified virus of grapevines, and a putative member of a new genus within the family Geminiviridae. This virus is associated with red blotch disease that was first reported in California in 2008. It affects the profitability of vineyards by ...

  7. Grapevine red blotch-associated virus (GRBaV) infection effects on foliar metabolism of grapevines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Red blotch disease, caused by Grapevine red blotch-associated virus (GRBaV), is an emerging problem for grapevine production in the United States. However, very little is known about how viruses, such as GRBaV, affect host physiology even though it is crucial to understanding host-pathogen interacti...

  8. VTCdb: a gene co-expression database for the crop species Vitis vinifera (grapevine)

    PubMed Central

    2013-01-01

    Background Gene expression datasets in model plants such as Arabidopsis have contributed to our understanding of gene function and how a single underlying biological process can be governed by a diverse network of genes. The accumulation of publicly available microarray data encompassing a wide range of biological and environmental conditions has enabled the development of additional capabilities including gene co-expression analysis (GCA). GCA is based on the understanding that genes encoding proteins involved in similar and/or related biological processes may exhibit comparable expression patterns over a range of experimental conditions, developmental stages and tissues. We present an open access database for the investigation of gene co-expression networks within the cultivated grapevine, Vitis vinifera. Description The new gene co-expression database, VTCdb (http://vtcdb.adelaide.edu.au/Home.aspx), offers an online platform for transcriptional regulatory inference in the cultivated grapevine. Using condition-independent and condition-dependent approaches, grapevine co-expression networks were constructed using the latest publicly available microarray datasets from diverse experimental series, utilising the Affymetrix Vitis vinifera GeneChip (16 K) and the NimbleGen Grape Whole-genome microarray chip (29 K), thus making it possible to profile approximately 29,000 genes (95% of the predicted grapevine transcriptome). Applications available with the online platform include the use of gene names, probesets, modules or biological processes to query the co-expression networks, with the option to choose between Affymetrix or Nimblegen datasets and between multiple co-expression measures. Alternatively, the user can browse existing network modules using interactive network visualisation and analysis via CytoscapeWeb. To demonstrate the utility of the database, we present examples from three fundamental biological processes (berry development, photosynthesis and

  9. TRANSPARENT TESTA GLABRA1 and GLABRA1 Compete for Binding to GLABRA3 in Arabidopsis

    PubMed Central

    Pesch, Martina; Schultheiß, Ilka; Klopffleisch, Karsten; Clemen, Christoph S.; Hülskamp, Martin

    2015-01-01

    The MBW (for R2R3MYB, basic helix-loop-helix [bHLH], and WD40) genes comprise an evolutionarily conserved gene cassette that regulates several traits such as (pro)anthocyanin and anthocyanin biosynthesis and epidermal cell differentiation in plants. Trichome differentiation in Arabidopsis (Arabidopsis thaliana) is governed by GLABRA1 (GL1; R2R3MYB), GL3 (bHLH), and TRANSPARENT TESTA GLABRA1 (TTG1; WD40). They are thought to form a trimeric complex that acts as a transcriptional activation complex. We provide evidence that these three MBW proteins form either GL1 GL3 or GL3 TTG1 dimers. The formation of each dimer is counteracted by the respective third protein in yeast three-hybrid assays, pulldown experiments (luminescence-based mammalian interactome), and fluorescence lifetime imaging microscopy-fluorescence resonance energy transfer studies. We further show that two target promoters, TRIPTYCHON (TRY) and CAPRICE (CPC), are differentially regulated: GL1 represses the activation of the TRY promoter by GL3 and TTG1, and TTG1 suppresses the activation of the CPC promoter by GL1 and GL3. Our data suggest that the transcriptional activation by the MBW complex involves alternative complex formation and that the two dimers can differentially regulate downstream genes. PMID:25926482

  10. Transcriptional control of floral anthocyanin pigmentation in monkeyflowers (Mimulus)

    PubMed Central

    Yuan, Yao-Wu; Sagawa, Janelle M.; Frost, Laura; Vela, James P.; Bradshaw, Harvey D.

    2014-01-01

    Summary A molecular description of the control of floral pigmentation in a multi-species group displaying various flower color patterns is of great interest for understanding the molecular bases of phenotypic diversification and pollinator-mediated speciation. Through transcriptome profiling, mutant analyses, and transgenic experiments, we aim to establish a ‘baseline’ floral anthocyanin regulation model in Mimulus lewisii and to examine the different ways of tinkering with this model in generating the diversity of floral anthocyanin patterns in other Mimulus species. We find one WD40 and one bHLH gene controlling anthocyanin pigmentation in the entire corolla of M. lewisii, and two R2R3-MYB genes, PELAN and NEGAN, controlling anthocyanin production in the petal lobe and nectar guide, respectively. The autoregulation of NEGAN might be a critical property to generate anthocyanin spots. Independent losses of PELAN expression (via different mechanisms) explain two natural yellow-flowered populations of M. cardinalis (typically red-flowered). The NEGAN ortholog is the only anthocyanin-activating MYB expressed in the M. guttatus flowers. The mutant lines and transgenic tools available for M. lewisii will enable gene-by-gene replacement experiments to dissect the genetic and developmental bases of more complex floral color patterns, and to test hypotheses on phenotypic evolution in general. PMID:25103615

  11. Structural and Functional Analysis of the GRAS Gene Family in Grapevine Indicates a Role of GRAS Proteins in the Control of Development and Stress Responses.

    PubMed

    Grimplet, Jérôme; Agudelo-Romero, Patricia; Teixeira, Rita T; Martinez-Zapater, Jose M; Fortes, Ana M

    2016-01-01

    GRAS transcription factors are involved in many processes of plant growth and development (e.g., axillary shoot meristem formation, root radial patterning, nodule morphogenesis, arbuscular development) as well as in plant disease resistance and abiotic stress responses. However, little information is available concerning this gene family in grapevine (Vitis vinifera L.), an economically important woody crop. We performed a model curation of GRAS genes identified in the latest genome annotation leading to the identification of 52 genes. Gene models were improved and three new genes were identified that could be grapevine- or woody-plant specific. Phylogenetic analysis showed that GRAS genes could be classified into 13 groups that mapped on the 19 V. vinifera chromosomes. Five new subfamilies, previously not characterized in other species, were identified. Multiple sequence alignment showed typical GRAS domain in the proteins and new motifs were also described. As observed in other species, both segmental and tandem duplications contributed significantly to the expansion and evolution of the GRAS gene family in grapevine. Expression patterns across a variety of tissues and upon abiotic and biotic conditions revealed possible divergent functions of GRAS genes in grapevine development and stress responses. By comparing the information available for tomato and grapevine GRAS genes, we identified candidate genes that might constitute conserved transcriptional regulators of both climacteric and non-climacteric fruit ripening. Altogether this study provides valuable information and robust candidate genes for future functional analysis aiming at improving the quality of fleshy fruits. PMID:27065316

  12. Structural and Functional Analysis of the GRAS Gene Family in Grapevine Indicates a Role of GRAS Proteins in the Control of Development and Stress Responses

    PubMed Central

    Grimplet, Jérôme; Agudelo-Romero, Patricia; Teixeira, Rita T.; Martinez-Zapater, Jose M.; Fortes, Ana M.

    2016-01-01

    GRAS transcription factors are involved in many processes of plant growth and development (e.g., axillary shoot meristem formation, root radial patterning, nodule morphogenesis, arbuscular development) as well as in plant disease resistance and abiotic stress responses. However, little information is available concerning this gene family in grapevine (Vitis vinifera L.), an economically important woody crop. We performed a model curation of GRAS genes identified in the latest genome annotation leading to the identification of 52 genes. Gene models were improved and three new genes were identified that could be grapevine- or woody-plant specific. Phylogenetic analysis showed that GRAS genes could be classified into 13 groups that mapped on the 19 V. vinifera chromosomes. Five new subfamilies, previously not characterized in other species, were identified. Multiple sequence alignment showed typical GRAS domain in the proteins and new motifs were also described. As observed in other species, both segmental and tandem duplications contributed significantly to the expansion and evolution of the GRAS gene family in grapevine. Expression patterns across a variety of tissues and upon abiotic and biotic conditions revealed possible divergent functions of GRAS genes in grapevine development and stress responses. By comparing the information available for tomato and grapevine GRAS genes, we identified candidate genes that might constitute conserved transcriptional regulators of both climacteric and non-climacteric fruit ripening. Altogether this study provides valuable information and robust candidate genes for future functional analysis aiming at improving the quality of fleshy fruits. PMID:27065316

  13. Unravelling the diversity of grapevine microbiome.

    PubMed

    Pinto, Cátia; Pinho, Diogo; Sousa, Susana; Pinheiro, Miguel; Egas, Conceição; Gomes, Ana C

    2014-01-01

    Vitis vinifera is one of the most widely cultivated fruit crops with a great economic impact on the global industry. As a plant, it is naturally colonised by a wide variety of both prokaryotic and eukaryotic microorganisms that interact with grapevine, having either beneficial or phytopathogenic effects, who play a major role in fruit yield, grape quality and, ultimately, in the evolution of grape fermentation and wine production. Therefore, the objective of this study was to extensively characterize the natural microbiome of grapevine. Considering that the majority of microorganisms are uncultivable, we have deeply studied the microflora of grapevine leaves using massive parallel rDNA sequencing, along its vegetative cycle. Among eukaryotic population the most abundant microorganisms belonged to the early diverging fungi lineages and Ascomycota phylum, whereas the Basidiomycota were the least abundant. Regarding prokaryotes, a high diversity of Proteobacteria, Firmicutes and Actinobacteria was unveiled. Indeed, the microbial communities present in the vineyard during its vegetative cycle were shown to be highly structured and dynamic. In all cases, the major abundant microorganisms were the yeast-like fungus Aureobasidium and the prokaryotic Enterobacteriaceae. Herein, we report the first complete microbiome landscape of the vineyard, through a metagenomic approach, and highlight the analysis of the microbial interactions within the vineyard and its importance for the equilibrium of the microecosystem of grapevines. PMID:24454903

  14. Spring Temperatures Alter Reproductive Development in Grapevines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Climate variation contributes to fluctuations in reproductive output, and spring temperature is thought to influence flower production in grapevines. We studied the influence of temperature near budburst on reproductive development in field-grown Cabernet Sauvignon while minimizing the influence of ...

  15. Fungal trunk diseases: A problem beyond grapevines?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grapevine trunk diseases (GTDs) are caused by a range of taxonomically unrelated fungi, which occur wherever grapes are grown and are the main biotic factor limiting vineyard productivity and longevity. GTDs cause untenable economic losses. For example, they are considered a “national crisis” in Fra...

  16. Unravelling the Diversity of Grapevine Microbiome

    PubMed Central

    Pinto, Cátia; Pinho, Diogo; Sousa, Susana; Pinheiro, Miguel; Egas, Conceição; C. Gomes, Ana

    2014-01-01

    Vitis vinifera is one of the most widely cultivated fruit crops with a great economic impact on the global industry. As a plant, it is naturally colonised by a wide variety of both prokaryotic and eukaryotic microorganisms that interact with grapevine, having either beneficial or phytopathogenic effects, who play a major role in fruit yield, grape quality and, ultimately, in the evolution of grape fermentation and wine production. Therefore, the objective of this study was to extensively characterize the natural microbiome of grapevine. Considering that the majority of microorganisms are uncultivable, we have deeply studied the microflora of grapevine leaves using massive parallel rDNA sequencing, along its vegetative cycle. Among eukaryotic population the most abundant microorganisms belonged to the early diverging fungi lineages and Ascomycota phylum, whereas the Basidiomycota were the least abundant. Regarding prokaryotes, a high diversity of Proteobacteria, Firmicutes and Actinobacteria was unveiled. Indeed, the microbial communities present in the vineyard during its vegetative cycle were shown to be highly structured and dynamic. In all cases, the major abundant microorganisms were the yeast-like fungus Aureobasidium and the prokaryotic Enterobacteriaceae. Herein, we report the first complete microbiome landscape of the vineyard, through a metagenomic approach, and highlight the analysis of the microbial interactions within the vineyard and its importance for the equilibrium of the microecosystem of grapevines. PMID:24454903

  17. EFFECTS OF ACID RAIN ON GRAPEVINES

    EPA Science Inventory

    Mature vineyard-growing Concord grapevines were sprayed with simulated acid rain solutions ranging from pH 2.5 to 5.5 both as acute treatments at anthesis and chronically throughout the season in 1980 and 1981. In 1981, 8 additional varieties were also treated with simulated acid...

  18. Identification and Characterization of 40 Isolated Rehmannia glutinosa MYB Family Genes and Their Expression Profiles in Response to Shading and Continuous Cropping

    PubMed Central

    Wang, Fengqing; Suo, Yanfei; Wei, He; Li, Mingjie; Xie, Caixia; Wang, Lina; Chen, Xinjian; Zhang, Zhongyi

    2015-01-01

    The v-myb avian myeloblastosis viral oncogene homolog (MYB) superfamily constitutes one of the most abundant groups of transcription factors (TFs) described in plants. To date, little is known about the MYB genes in Rehmannia glutinosa. Forty unique MYB genes with full-length cDNA sequences were isolated. These 40 genes were grouped into five categories, one R1R2R3-MYB, four TRFL MYBs, four SMH MYBs, 25 R2R3-MYBs, and six MYB-related members. The MYB DNA-binding domain (DBD) sequence composition was conserved among proteins of the same subgroup. As expected, most of the closely related members in the phylogenetic tree exhibited common motifs. Additionally, the gene structure and motifs of the R. glutinosa MYB genes were analyzed. MYB gene expression was analyzed in the leaf and the tuberous root under two abiotic stress conditions. Expression profiles showed that most R. glutinosa MYB genes were expressed in the leaf and the tuberous root, suggesting that MYB genes are involved in various physiological and developmental processes in R. glutinosa. Seven MYB genes were up-regulated in response to shading in at least one tissue. Two MYB genes showed increased expression and 13 MYB genes showed decreased expression in the tuberous root under continuous cropping. This investigation is the first comprehensive study of the MYB gene family in R. glutinosa. PMID:26147429

  19. Grapevine leafroll-associated virus 3

    PubMed Central

    Maree, Hans J.; Almeida, Rodrigo P. P.; Bester, Rachelle; Chooi, Kar Mun; Cohen, Daniel; Dolja, Valerian V.; Fuchs, Marc F.; Golino, Deborah A.; Jooste, Anna E. C.; Martelli, Giovanni P.; Naidu, Rayapati A.; Rowhani, Adib; Saldarelli, Pasquale; Burger, Johan T.

    2013-01-01

    Grapevine leafroll disease (GLD) is one of the most important grapevine viral diseases affecting grapevines worldwide. The impact on vine health, crop yield, and quality is difficult to assess due to a high number of variables, but significant economic losses are consistently reported over the lifespan of a vineyard if intervention strategies are not implemented. Several viruses from the family Closteroviridae are associated with GLD. However, Grapevine leafroll-associated virus 3 (GLRaV-3), the type species for the genus Ampelovirus, is regarded as the most important causative agent. Here we provide a general overview on various aspects of GLRaV-3, with an emphasis on the latest advances in the characterization of the genome. The full genome of several isolates have recently been sequenced and annotated, revealing the existence of several genetic variants. The classification of these variants, based on their genome sequence, will be discussed and a guideline is presented to facilitate future comparative studies. The characterization of sgRNAs produced during the infection cycle of GLRaV-3 has given some insight into the replication strategy and the putative functionality of the ORFs. The latest nucleotide sequence based molecular diagnostic techniques were shown to be more sensitive than conventional serological assays and although ELISA is not as sensitive it remains valuable for high-throughput screening and complementary to molecular diagnostics. The application of next-generation sequencing is proving to be a valuable tool to study the complexity of viral infection as well as plant pathogen interaction. Next-generation sequencing data can provide information regarding disease complexes, variants of viral species, and abundance of particular viruses. This information can be used to develop more accurate diagnostic assays. Reliable virus screening in support of robust grapevine certification programs remains the cornerstone of GLD management. PMID:23596440

  20. Aberrant Processing of Polyphenol Oxidase in a Variegated Grapevine Mutant 1

    PubMed Central

    Rathjen, Anne H.; Robinson, Simon P.

    1992-01-01

    Bruce's Sport is a mutant grapevine (Vitis vinifera L.) with green and white variegated fruit derived from the Sultana variety. The white regions of tissue have decreased polyphenol oxidase (PPO) activity resulting in a reduced capacity for browning. Active PPO from Sultana grapes was purified and had an apparent molecular weight of 40,000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Western blots indicated that mature Sultana grapes contained a single 40-kilodalton PPO, and young Sultana berries also had small quantities of a 60-kilodalton protein. Bruce's Sport grapes had much less of the 40-kilodalton PPO and greater amounts of the 60-kilodalton band. Protease digestion of Bruce's Sport extracts decreased the proportion of the 60-kilodalton protein and increased the 40-kilodalton band. A cDNA clone of grape PPO was used to probe a northern blot of Sultana and Bruce's Sport RNA and hybridized to a 2.2-kilobase transcript in both grapevines. The level of PPO mRNA was high in the early stages of berry development but then declined. The results suggest that in grapevine the active 40-kilodalton form of PPO is synthesized as a precursor protein of at least 60 kilodaltons, and normal processing is interrupted in Bruce's Sport resulting in the accumulation of the 60-kilodalton inactive preform of PPO. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5Figure 6 PMID:16669082

  1. Metabolic Consequences of Infection of Grapevine (Vitis vinifera L.) cv. "Modra frankinja" with Flavescence Dorée Phytoplasma.

    PubMed

    Prezelj, Nina; Covington, Elizabeth; Roitsch, Thomas; Gruden, Kristina; Fragner, Lena; Weckwerth, Wolfram; Chersicola, Marko; Vodopivec, Maja; Dermastia, Marina

    2016-01-01

    Flavescence dorée, caused by the quarantine phytoplasma FDp, represents the most devastating of the grapevine yellows diseases in Europe. In an integrated study we have explored the FDp-grapevine interaction in infected grapevines of cv. "Modra frankinja" under natural conditions in the vineyard. In FDp-infected leaf vein-enriched tissues, the seasonal transcriptional profiles of 14 genes selected from various metabolic pathways showed an FDp-specific plant response compared to other grapevine yellows and uncovered a new association of the SWEET17a vacuolar transporter of fructose with pathogens. Non-targeted metabolome analysis from leaf vein-enriched tissues identified 22 significantly changed compounds with increased levels during infection. Several metabolites corroborated the gene expression study. Detailed investigation of the dynamics of carbohydrate metabolism revealed significant accumulation of sucrose and starch in the mesophyll of FDp-infected leaves, as well as significant up-regulation of genes involved in their biosynthesis. In addition, infected leaves had high activities of ADP-glucose pyrophosphorylase and, more significantly, sucrose synthase. The data support the conclusion that FDp infection inhibits phloem transport, resulting in accumulation of carbohydrates and secondary metabolites that provoke a source-sink transition and defense response status. PMID:27242887

  2. Detection, distribution, and genetic diversity of Australian grapevine viroid in grapevines in India.

    PubMed

    Adkar-Purushothama, Charith Raj; Kanchepalli, Poornachandra Rao; Yanjarappa, Sreenivasa Marikunte; Zhang, Zhixiang; Sano, Teruo

    2014-10-01

    Australian grapevine viroid (AGVd) is a viroid specific to grapevine with the least records in the world till date. Here, we report for the first time the presence of AGVd in grapevines in Indian sub-continent. The overall infection rate of AGVd in major grapevine producing areas in India was 9.3 %, which is conspicuously higher than the other regions of the world except for Tunisia and Iran. To understand the AGVd diversity in India, the genetic divergence was examined based on the disparity in the cultivars and the locations. Nucleotide sequence analysis revealed the existence of five major AGVd variants in India besides other 44 minor variants implying the "quasi-species" nature. Further, sequence alignment of all the Indian AGVd variants along with Australian type species underscored the presence of eleven mutation points which are archetypal for Indian AGVd, irrespective of the region, and cultivar of grapevines. Plotting of Indian AGVd sequence variants against Australian type species unveiled that all these eleven mutations are distributed on upper and lower left terminal and pathogenicity regions of the molecule. Phylogenetic analysis divulged all the major Indian AGVd variants formed two distinct clusters, suggesting the two separate evolutionary lineages of AGVd in Indian viticulture. PMID:24854143

  3. Identification of reference genes suitable for qRT-PCR in grapevine and application for the study of the expression of genes involved in pterostilbene synthesis.

    PubMed

    Gamm, Magdalena; Héloir, Marie-Claire; Kelloniemi, Jani; Poinssot, Benoît; Wendehenne, David; Adrian, Marielle

    2011-04-01

    The recent publication of the grapevine genome sequence facilitates the use of qRT-PCR to study gene expression changes. For this approach, reference genes are commonly used to normalize data and their stability of expression should be systematically validated. Among grapevine defenses is the production of the antimicrobial stilbenic phytoalexins, notably the highly fungitoxic pterostilbene, which plays a crucial role in grapevine interaction with Plasmopara viticola and Botrytis cinerea. As a resveratrol O-methyltransferase (ROMT) gene involved in pterostilbene synthesis was recently identified, we investigated the accumulation of the corresponding transcripts to those of two other stilbene biosynthesis related genes phenylalanine ammonia lyase (PAL) and stilbene synthase (STS) in response to pathogen infection. Using three computer-based statistical methods and C(t) values or LRE method generated values as input data, we have first identified two reference genes (VATP16 and 60SRP) suitable for normalization of qPCR expression data obtained in grapevine leaves and berries infected by P. viticola and B. cinerea, respectively. Next, we have highlighted that the expression of ROMT is induced in P. viticola-infected leaves and also in B. cinerea-infected berries, confirming the involvement of pterostilbene in grapevine defenses. PMID:21340517

  4. Evaluating wild grapevine germplasm with genotyping-by-sequencing methods for conservation, preservation, genetics and breeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The USDA-ARS cold hardy grapevine germplasm represents one of the best collections of publically available grapevine material for grape breeding and improvement. The repository holds in excess of 1300 different grapevine genotypes, with roughly a quarter made up of wild grapevine species. Efforts ...

  5. Transmission of grapevine Pinot gris virus by Colomerus vitis (Acari: Eriophyidae) to grapevine.

    PubMed

    Malagnini, Valeria; de Lillo, Enrico; Saldarelli, Pasquale; Beber, Roberta; Duso, Carlo; Raiola, Alessandro; Zanotelli, Livia; Valenzano, Domenico; Giampetruzzi, Annalisa; Morelli, Massimiliano; Ratti, Claudio; Causin, Roberto; Gualandri, Valeria

    2016-09-01

    Grapevine Pinot gris virus (GPGV) is a new virus reported in Europe and several other grape-growing countries. In an attempt to identify a vector for GPGV, samples of the eriophyid mite Colomerus vitis collected from buds and erinea in GPGV-infected vines were analysed by RT-PCR, using specific primers. Molecular analysis revealed the presence of GPGV in C. vitis. Transmission trials were conducted using C. vitis collected from GPGV-infected vines. Mites were able to transmit GPGV to healthy grapevines, suggesting that C. vitis is a potential vector of this virus. PMID:27344161

  6. Grapevine Red Blotch-Associated Virus, an Emerging Threat to the Grapevine Industry.

    PubMed

    Sudarshana, Mysore R; Perry, Keith L; Fuchs, Marc F

    2015-07-01

    Grapevine red blotch-associated virus (GRBaV) is a newly identified virus of grapevines and a putative member of a new genus within the family Geminiviridae. This virus is associated with red blotch disease that was first reported in California in 2008. It affects the profitability of vineyards by substantially reducing fruit quality and ripening. In red-berried grapevine cultivars, foliar disease symptoms consist of red blotches early in the season that can expand and coalesce across most of the leaf blade later in the season. In white-berried grapevine cultivars, foliar disease symptoms are less conspicuous and generally involve irregular chlorotic areas that may become necrotic late in the season. Determining the GRBaV genome sequence yielded critical information for the design of primers for polymerase chain reaction-based diagnostics. To date, GRBaV has been reported in the major grape-growing areas in North America and two distinct phylogenetic clades have been described. Spread of GRBaV is suspected in certain vineyards but a vector of epidemiological significance has yet to be identified. Future research will need to focus on virus spread, the production of clean planting stocks, and the development of management options that are effective, economical, and environmentally friendly. PMID:25738551

  7. Changes in Plant Metabolism and Accumulation of Fungal Metabolites in Response to Esca Proper and Apoplexy Expression in the Whole Grapevine.

    PubMed

    Magnin-Robert, Maryline; Spagnolo, Alessandro; Boulanger, Anna; Joyeux, Cécile; Clément, Christophe; Abou-Mansour, Eliane; Fontaine, Florence

    2016-06-01

    Trunk diseases have become among the most important grapevine diseases worldwide. They are caused by fungal pathogens that attack the permanent woody structure of the vines and cause various symptoms in woody and annual organs. This study examined modifications of plant responses in green stem, cordon, and trunk of grapevines expressing Esca proper (E) or apoplexy (A) event, which are the most frequent grapevine trunk disease symptoms observed in Europe. Transcript expression of a set of plant defense- and stress-related genes was monitored by quantitative reverse-transcription polymerase chain reaction while plant phytoalexins and fungal metabolites were quantified by high-performance liquid chromatography-mass spectrometry in order to characterize the interaction between the grapevine and trunk disease agents. Expression of genes encoding enzymes of the phenylpropanoid pathway and trans-resveratrol content were altered in the three organs of diseased plants, especially in the young tissues of A plants. Pathogenesis-related proteins and the antioxidant system were severely modulated in A plants, which indicates a drastic stress effect. In the meantime, fungal polyketides 6-MSA, (R)-mellein, and (3R,4R)-4-hydroxymellein, were accumulated in A plants, which suggests their potential effect on plant metabolism during the appearance of foliar symptoms. PMID:26882851

  8. VESPUCCI: Exploring Patterns of Gene Expression in Grapevine

    PubMed Central

    Moretto, Marco; Sonego, Paolo; Pilati, Stefania; Malacarne, Giulia; Costantini, Laura; Grzeskowiak, Lukasz; Bagagli, Giorgia; Grando, Maria Stella; Moser, Claudio; Engelen, Kristof

    2016-01-01

    Large-scale transcriptional studies aim to decipher the dynamic cellular responses to a stimulus, like different environmental conditions. In the era of high-throughput omics biology, the most used technologies for these purposes are microarray and RNA-Seq, whose data are usually required to be deposited in public repositories upon publication. Such repositories have the enormous potential to provide a comprehensive view of how different experimental conditions lead to expression changes, by comparing gene expression across all possible measured conditions. Unfortunately, this task is greatly impaired by differences among experimental platforms that make direct comparisons difficult. In this paper, we present the Vitis Expression Studies Platform Using COLOMBOS Compendia Instances (VESPUCCI), a gene expression compendium for grapevine which was built by adapting an approach originally developed for bacteria, and show how it can be used to investigate complex gene expression patterns. We integrated nearly all publicly available microarray and RNA-Seq expression data: 1608 gene expression samples from 10 different technological platforms. Each sample has been manually annotated using a controlled vocabulary developed ad hoc to ensure both human readability and computational tractability. Expression data in the compendium can be visually explored using several tools provided by the web interface or can be programmatically accessed using the REST interface. VESPUCCI is freely accessible at http://vespucci.colombos.fmach.it. PMID:27242836

  9. Cultivar-specific kinetics of gene induction during downy mildew early infection in grapevine.

    PubMed

    Figueiredo, Andreia; Monteiro, Filipa; Fortes, Ana Margarida; Bonow-Rex, Martina; Zyprian, Eva; Sousa, Lisete; Pais, Maria Salomé

    2012-06-01

    The oomycete pathogen Plasmopara viticola (Berk. et Curt.) Berl. et de Toni is the causing agent of the destructive downy mildew disease in grapevine. Despite the advances towards elucidation of grapevine resistance mechanisms to downy mildew, increased knowledge of the biological and genetic components of the pathosystem is important to design suitable breeding strategies. Previously, a cDNA microarray approach was used to compare two Vitis vinifera genotypes Regent and Trincadeira (resistant and susceptible to downy mildew, respectively) in field conditions. The same cDNA microarray chip was used to confirm field-based results and to compare both genotypes under greenhouse conditions at 0, 6, and 12 h post-inoculation with P. viticola. Results show that when comparing both cultivars after pathogen inoculation, there is a preferential modulation of several defense, signaling, and metabolism associated transcripts in Regent. Early transcriptional changes are discussed in terms of genetic background and resistance mechanism. This study is the first to directly compare resistant and susceptible cultivars responses as early as 6 hpi with P. viticola, providing several candidate genes potentially related to the expression of resistance traits. PMID:22246600

  10. Initiation and transformation of grapevine embryogenic cultures.

    PubMed

    Dhekney, Sadanand A; Li, Zhijian T; Dutt, Manjul; Gray, Dennis J

    2012-01-01

    Protocols for the production and transformation of grapevine embryogenic cultures are described. Embryogenic cultures are initiated from leaves or stamens and pistils and transformed with Agrobacterium containing an enhanced green fluorescent protein/neomycin phosphotransferase II (egfp/nptII) fusion gene. Cultures are transferred to induction medium in the dark for callus formation and proliferation. Resulting cultures are transferred to somatic embryo development medium to induce secondary embryogenesis and formation of transgenic somatic embryos. Transgenic embryos identified on the basis on GFP fluorescence and kanamycin resistance are transferred to germination medium to regenerate transgenic plants. The presence of transgenes in independent plant lines is confirmed by PCR. PMID:22351011

  11. Monitoring Water Status of Grapevine by Means of THz Waves

    NASA Astrophysics Data System (ADS)

    Torres, Víctor; Palacios, Inés; Iriarte, Juan Carlos; Liberal, Iñigo; Santesteban, Luis G.; Miranda, Carlos; Royo, José B.; Gonzalo, Ramón

    2016-05-01

    Monitoring grapevine water status by means of measuring the reflectivity at the trunk in the terahertz band is presented. A grapevine is located inside a growth chamber to simulate diverse outdoor conditions and correlate them with variations produced in the reflected signal of the trunk. Modifications of light conditions, temperature, and irrigation of the grapevine are recorded either in time domain broadband measurements as well as in the magnitude and phase of narrowband measurements in the frequency domain. The results are compared with traditional techniques using a dendrometer and a humidity probe with excellent agreement.

  12. Ecology and management of grapevine leafroll disease

    PubMed Central

    Almeida, Rodrigo P. P.; Daane, Kent M.; Bell, Vaughn A.; Blaisdell, G. Kai; Cooper, Monica L.; Herrbach, Etienne; Pietersen, Gerhard

    2013-01-01

    Grapevine leafroll disease (GLD) is caused by a complex of vector-borne virus species in the family Closteroviridae. GLD is present in all grape-growing regions of the world, primarily affecting wine grape varieties. The disease has emerged in the last two decades as one of the major factors affecting grape fruit quality, leading to research efforts aimed at reducing its economic impact. Most research has focused on the pathogens themselves, such as improved detection protocols, with limited work directed toward disease ecology and the development of management practices. Here we discuss the ecology and management of GLD, focusing primarily on Grapevine leafroll-associated virus 3, the most important virus species within the complex. We contextualize research done on this system within an ecological framework that forms the backbone of the discussion regarding current and potential GLD management strategies. To reach this goal, we introduce various aspects of GLD biology and ecology, followed by disease management case studies from four different countries and continents (South Africa, New Zealand, California-USA, and France). We review ongoing regional efforts that serve as models for improved strategies to control this economically important and worldwide disease, highlighting scientific gaps that must be filled for the development of knowledge-based sustainable GLD management practices. PMID:23630520

  13. Developmental, transcriptome, and genetic alterations associated with parthenocarpy in the grapevine seedless somatic variant Corinto bianco.

    PubMed

    Royo, Carolina; Carbonell-Bejerano, Pablo; Torres-Pérez, Rafael; Nebish, Anna; Martínez, Óscar; Rey, Manuel; Aroutiounian, Rouben; Ibáñez, Javier; Martínez-Zapater, José M

    2016-01-01

    Seedlessness is a relevant trait in grapevine cultivars intended for fresh consumption or raisin production. Previous DNA marker analysis indicated that Corinto bianco (CB) is a parthenocarpic somatic variant of the seeded cultivar Pedro Ximenes (PX). This study compared both variant lines to determine the basis of this parthenocarpic phenotype. At maturity, CB seedless berries were 6-fold smaller than PX berries. The macrogametophyte was absent from CB ovules, and CB was also pollen sterile. Occasionally, one seed developed in 1.6% of CB berries. Microsatellite genotyping and flow cytometry analyses of seedlings generated from these seeds showed that most CB viable seeds were formed by fertilization of unreduced gametes generated by meiotic diplospory, a process that has not been described previously in grapevine. Microarray and RNA-sequencing analyses identified 1958 genes that were differentially expressed between CB and PX developing flowers. Genes downregulated in CB were enriched in gametophyte-preferentially expressed transcripts, indicating the absence of regular post-meiotic germline development in CB. RNA-sequencing was also used for genetic variant calling and 14 single-nucleotide polymorphisms distinguishing the CB and PX variant lines were detected. Among these, CB-specific polymorphisms were considered as candidate parthenocarpy-responsible mutations, including a putative deleterious substitution in a HAL2-like protein. Collectively, these results revealed that the absence of a mature macrogametophyte, probably due to meiosis arrest, coupled with a process of fertilization-independent fruit growth, caused parthenocarpy in CB. This study provides a number of grapevine parthenocarpy-responsible candidate genes and shows how genomic approaches can shed light on the genetic origin of woody crop somatic variants. PMID:26454283

  14. Detection and molecular characterization of Egyptian isolates of grapevine viruses.

    PubMed

    Fattouh, F; Ratti, C; El-Ahwany, A M D; Aleem, E Abdel; Babini, A R; Autonell, C Rubies

    2014-01-01

    Selected commercial and/or local vineyards and nurseries in three different governorates of Egypt (Alexandria, El-Beheira and El-Menofia) were surveyed for symptoms indicative of infection by grapevine viruses. Leaf samples from red-fruited and white-fruited Vitis vinefera were tested for grapevine leafroll associated viruses (GLRaV-1, GLRaV-2, and GLRaV-3), grapevine viruses A and B (GVA, GVB), grapevine rupestris stem pitting virus (GRSPaV), grapevine fanleaf virus (GFLV), and grapevine fleck virus (GFKV) from early April to late October 2010. Incidence of these viruses was assessed by RT-PCR in 60 different samples. Selected amplicons were sequenced. While GVA was the most wide spread (30%), GLRaV-1, GVB, GFLV, and GFKV were not detected during the survey. However, GVA, GLRaV-2, GLRaV-3, and GRSPaV were detected in the form of single infection or in mixed infections of 2 to 4 viruses. Phylogenetic analysis was performed on all Egyptian isolates of GLRaV-2 (4), GLRaV-3 (7), GVA (3), and GRSPaV (6). GRSPaV was detected for the first time in Egypt. Phylogenetic analysis provided insights into the evolutionary relationship between the reported Egyptian isolates and other previously reported isolates. PMID:24957718

  15. Methionine elicits H2O2 generation and defense gene expression in grapevine and reduces Plasmopara viticola infection.

    PubMed

    Boubakri, Hatem; Wahab, Mohamed Ali; Chong, Julie; Gertz, Claude; Gandoura, Samia; Mliki, Ahmed; Bertsch, Christophe; Soustre-Gacougnolle, Isabelle

    2013-12-15

    Methionine (Met) is a nutritionally essential sulfur-containing amino acid (SAA) known for its preponderant role as initiator in protein synthesis. However, other functions for Met in plants are not well described. The implication of this SAA in oxidative stress tolerance has been recently reported, however the mode of action of Met is still poorly understood. Here, we analyzed the elicitor activity of Met in grapevine as well as its effect on Plasmopara viticola resistance. The results show that Met induces hydrogen peroxide (H2O2) generation, a key element in plant defense signaling, and upregulates the expression of a battery of defense-related genes. Transcript levels of these genes were not further modulated by P. viticola inoculation of Met-pretreated plants, suggesting an elicitor role rather than a priming role for Met in grapevine. Met treatment also reduces P. viticola development in grapevine plants grown under glasshouse controlled-conditions. Fungitoxicity assays revealed that Met possesses a moderate antifungal activity compared with cysteine (Cys), another SAA known for its toxic effect to a large spectrum of fungi. PMID:23859561

  16. Gibberellin metabolism in Vitis vinifera L. during bloom and fruit-set: functional characterization and evolution of grapevine gibberellin oxidases.

    PubMed

    Giacomelli, Lisa; Rota-Stabelli, Omar; Masuero, Domenico; Acheampong, Atiako Kwame; Moretto, Marco; Caputi, Lorenzo; Vrhovsek, Urska; Moser, Claudio

    2013-11-01

    Gibberellins (GAs) are involved in the regulation of flowering and fruit-set in grapes (Vitis vinifera L.), but the molecular mechanisms behind this process are mostly unknown. In this work, the family of grapevine GA oxidases involved in the biosynthesis and deactivation of GAs was characterized. Six putative GA 20-oxidase (GA20ox), three GA 3-oxidase (GA3ox), and eight GA 2-oxidase (GA2ox) proteins, the latter further divided into five C19-GA 2ox and three C20-GA2ox proteins, were identified. Phylogenetic analyses suggest a common origin of the GA3ox and C19-GA2ox groups and challenge previous evolutionary models. In vitro analysis revealed that all GA3ox and GA20ox enzymes prefer substrates of the non-13-hydroxylation pathway. In addition, ectopic expression of GA2ox genes in Arabidopsis thaliana confirmed the activity of their encoded proteins in vivo. The results show that bioactive GA1 accumulates in opening grapevine flowers, whereas at later developmental stages only GA4 is detected in the setting fruit. By studying the expression pattern of the grapevine GA oxidase genes in different organs, and at different stages of flowering and fruit-set, it is proposed that the pool of bioactive GAs is controlled by a fine regulation of the abundance and localization of GA oxidase transcripts. PMID:24006417

  17. Gibberellin metabolism in Vitis vinifera L. during bloom and fruit-set: functional characterization and evolution of grapevine gibberellin oxidases

    PubMed Central

    Giacomelli, Lisa

    2013-01-01

    Gibberellins (GAs) are involved in the regulation of flowering and fruit-set in grapes (Vitis vinifera L.), but the molecular mechanisms behind this process are mostly unknown. In this work, the family of grapevine GA oxidases involved in the biosynthesis and deactivation of GAs was characterized. Six putative GA 20-oxidase (GA20ox), three GA 3-oxidase (GA3ox), and eight GA 2-oxidase (GA2ox) proteins, the latter further divided into five C19-GA 2ox and three C20-GA2ox proteins, were identified. Phylogenetic analyses suggest a common origin of the GA3ox and C19-GA2ox groups and challenge previous evolutionary models. In vitro analysis revealed that all GA3ox and GA20ox enzymes prefer substrates of the non-13-hydroxylation pathway. In addition, ectopic expression of GA2ox genes in Arabidopsis thaliana confirmed the activity of their encoded proteins in vivo. The results show that bioactive GA1 accumulates in opening grapevine flowers, whereas at later developmental stages only GA4 is detected in the setting fruit. By studying the expression pattern of the grapevine GA oxidase genes in different organs, and at different stages of flowering and fruit-set, it is proposed that the pool of bioactive GAs is controlled by a fine regulation of the abundance and localization of GA oxidase transcripts. PMID:24006417

  18. Metabolic Consequences of Infection of Grapevine (Vitis vinifera L.) cv. “Modra frankinja” with Flavescence Dorée Phytoplasma

    PubMed Central

    Prezelj, Nina; Covington, Elizabeth; Roitsch, Thomas; Gruden, Kristina; Fragner, Lena; Weckwerth, Wolfram; Chersicola, Marko; Vodopivec, Maja; Dermastia, Marina

    2016-01-01

    Flavescence dorée, caused by the quarantine phytoplasma FDp, represents the most devastating of the grapevine yellows diseases in Europe. In an integrated study we have explored the FDp–grapevine interaction in infected grapevines of cv. “Modra frankinja” under natural conditions in the vineyard. In FDp-infected leaf vein-enriched tissues, the seasonal transcriptional profiles of 14 genes selected from various metabolic pathways showed an FDp-specific plant response compared to other grapevine yellows and uncovered a new association of the SWEET17a vacuolar transporter of fructose with pathogens. Non-targeted metabolome analysis from leaf vein-enriched tissues identified 22 significantly changed compounds with increased levels during infection. Several metabolites corroborated the gene expression study. Detailed investigation of the dynamics of carbohydrate metabolism revealed significant accumulation of sucrose and starch in the mesophyll of FDp-infected leaves, as well as significant up-regulation of genes involved in their biosynthesis. In addition, infected leaves had high activities of ADP-glucose pyrophosphorylase and, more significantly, sucrose synthase. The data support the conclusion that FDp infection inhibits phloem transport, resulting in accumulation of carbohydrates and secondary metabolites that provoke a source-sink transition and defense response status. PMID:27242887

  19. Expression of a wheat MYB gene in transgenic tobacco enhances resistance to Ralstonia solanacearum, and to drought and salt stresses.

    PubMed

    Liu, Hongxia; Zhou, Xianyao; Dong, Na; Liu, Xin; Zhang, Huaiyu; Zhang, Zengyan

    2011-09-01

    MYB transcription factors play diverse roles in plant growth, developmental processes and stress responses. A full-length cDNA sequence of a MYB gene, namely TaPIMP1, was isolated from wheat (Triticum aestivum L.). The TaPIMP1 transcript level was significantly up-regulated by inoculation with a fungal pathogen Bipolaris sorokiniana and by drought treatment. TaPIMP1 encodes the MYB protein TaPIMP1 consisting of 323 amino acids. TaPIMP1 contains two MYB DNA binding domains (R2, R3), two putative nuclear localization sites and two putative transcription activation domains. TaPIMP1 is a new member of the R2R3-MYB transcription factor subfamily. Transient expression in onion epidermal cells of GFP fused with TaPIMP1 proved that subcellular localization of TaPIMP1 occurred in the nucleus. The TaPIMP1 gene was transferred into tobacco (Nicotiana tabacum L.) cultivar W38 by Agrobacterium-mediated transformation. After screening through PCR and RT-PCR analyses, transgenic tobacco lines expressing TaPIMP1 were identified and evaluated for pathogen resistance, and drought and salt tolerance. Compared to untransformed tobacco host plants, TaPIMP1 expressing plants displayed significantly enhanced resistance to Ralstonia solanacearum and exhibited improved tolerances to drought and salt stresses. In these transgenic lines, the activities of phenylalanine ammonia-lyase (PAL) and superoxide dismutase (SOD) were significantly increased relative to wild-type tobacco plants. The results suggested that the wheat R2R3-MYB transcription factor plays an important role in modulating responses to biotic and abiotic stresses. PMID:21597961

  20. Relative quantification of phosphoproteomic changes in grapevine (Vitis vinifera L.) leaves in response to abscisic acid.

    PubMed

    Rattanakan, Supakan; George, Iniga; Haynes, Paul A; Cramer, Grant R

    2016-01-01

    In a previous transcriptomic analysis, abscisic acid (ABA) was found to affect the abundance of a number of transcripts in leaves of Cabernet Sauvignon grapevines with roots that had been exposed to 10 μm ABA for 2 h. Other work has indicated that ABA affects protein abundance and protein phosphorylation as well. In this study we investigated changes in protein abundance and phosphorylation of Cabernet Sauvignon grapevine leaves. Protein abundance was assessed by both label-free and isobaric-label quantitive proteomic methods. Each identified common proteins, but also additional proteins not found with the other method. Overall, several thousand proteins were identified and several hundred were quantified. In addition, hundreds of phosphoproteins were identified. Tens of proteins were found to be affected in the leaf after the roots had been exposed to ABA for 2 h, more than half of them were phosphorylated proteins. Many phosphosites were confirmed and several new ones were identified. ABA increased the abundance of some proteins, but the majority of the proteins had their protein abundance decreased. Many of these proteins were involved in growth and plant organ development, including proteins involved in protein synthesis, photosynthesis, sugar and amino-acid metabolism. This study provides new insights into how ABA regulates plant responses and acclimation to water deficits. PMID:27366326

  1. Relative quantification of phosphoproteomic changes in grapevine (Vitis vinifera L.) leaves in response to abscisic acid

    PubMed Central

    Rattanakan, Supakan; George, Iniga; Haynes, Paul A; Cramer, Grant R

    2016-01-01

    In a previous transcriptomic analysis, abscisic acid (ABA) was found to affect the abundance of a number of transcripts in leaves of Cabernet Sauvignon grapevines with roots that had been exposed to 10 μm ABA for 2 h. Other work has indicated that ABA affects protein abundance and protein phosphorylation as well. In this study we investigated changes in protein abundance and phosphorylation of Cabernet Sauvignon grapevine leaves. Protein abundance was assessed by both label-free and isobaric-label quantitive proteomic methods. Each identified common proteins, but also additional proteins not found with the other method. Overall, several thousand proteins were identified and several hundred were quantified. In addition, hundreds of phosphoproteins were identified. Tens of proteins were found to be affected in the leaf after the roots had been exposed to ABA for 2 h, more than half of them were phosphorylated proteins. Many phosphosites were confirmed and several new ones were identified. ABA increased the abundance of some proteins, but the majority of the proteins had their protein abundance decreased. Many of these proteins were involved in growth and plant organ development, including proteins involved in protein synthesis, photosynthesis, sugar and amino-acid metabolism. This study provides new insights into how ABA regulates plant responses and acclimation to water deficits. PMID:27366326

  2. Grapevine red blotch-associated virus is widespread in California and U.S. vineyards.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In fall 2011, Grapevine red blotch-associated virus (GRBaV), a circular ssDNA virus, was detected in grapevines exhibiting leaves with red blotch symptoms in Napa, CA. Extensive sampling of symptomatic grapevines in California vineyards and analysis of the nucleic acid fractions by SYBR®Green qPCR a...

  3. Transcriptomic Analysis of Grapevine (cv. Summer Black) Leaf, Using the Illumina Platform

    PubMed Central

    Pervaiz, Tariq; Haifeng, Jia; Salman Haider, Muhammad; Cheng, Zhang; Cui, Mengjie; Wang, Mengqi; Cui, Liwen; Wang, Xicheng; Fang, Jinggui

    2016-01-01

    Proceeding to illumina sequencing, determining RNA integrity numbers for poly RNA were separated from each of the four developmental stages of cv. Summer Black leaves by using Illumina HiSeq™ 2000. The sums of 272,941,656 reads were generated from vitis vinifera leaf at four different developmental stages, with more than 27 billion nucleotides of the sequence data. At each growth stage, RNA samples were indexed through unique nucleic acid identifiers and sequenced. KEGG annotation results depicted that the highest number of transcripts in 2,963 (2Avs4A) followed by 1Avs4A (2,920), and 3Avs4A (2,294) out of 15,614 (71%) transcripts were recorded. In comparison, a total of 1,532 transcripts were annotated in GOs, including Cellular component, with the highest number in “Cell part” 251 out of 353 transcripts (71.1%), followed by intracellular organelle 163 out of 353 transcripts (46.2%), while in molecular function and metabolic process 375 out of 525 (71.4%) transcripts, multicellular organism process 40 out of 525 (7.6%) transcripts in biological process were most common in 1Avs2A. While in case of 1Avs3A, cell part 476 out of 662 transcripts (71.9%), and membrane-bounded organelle 263 out of 662 transcripts (39.7%) were recorded in Cellular component. In the grapevine transcriptome, during the initial stages of leaf development 1Avs2A showed single transcript was down-regulated and none of them were up-regulated. While in comparison of 1A to 3A showed one up-regulated (photosystem II reaction center protein C) and one down regulated (conserved gene of unknown function) transcripts, during the hormone regulating pathway namely SAUR-like auxin-responsive protein family having 2 up-regulated and 7 down-regulated transcripts, phytochrome-associated protein showed 1 up-regulated and 9 down-regulated transcripts, whereas genes associated with the Leucine-rich repeat protein kinase family protein showed 7 up-regulated and 1 down-regulated transcript, meanwhile Auxin

  4. Response of grapevines to fluoride under field conditions

    SciTech Connect

    Murray, F.

    1983-07-01

    Grapevines (Vitis vinifera L. cv. Shiraz) were fumigated in open-top chambers with hydrogen fluoride for 64 days at mean atmospheric fluoride concentrations of 0.17 or 0.28 ..mu..gHFm/sup -3/. Other grapevines grown under ambient conditions in the vineyard or maintained in control chambers were exposed to 0.13 or 0.05 ..mu..gHFm/sup -3/, respectively. Leaves of grapevines exposed to 0.28, 0.17, 0.13, or 0.05 ..mu..gHFm/sup -3/ accumulated up to 85, 55, 20, or 11 ..mu..gFg/sup -1/, respectively. Foliar necrosis was observed on plants exposed to 0.28 ..mu..gHFm/sup -3/, but no injury symptoms were observed at 0.17 ..mu..gHFm/sup -3/ or in control plants. Grapevines growing under ambient conditions had significantly greater mean bunch weight, peduncle weight, number of grapes per bunch, and leaf protein levels than the fumigated treatments. However, these differences may be associated with a chamber effect rather than with an effect of fluoride on grapevines. No significant differences were found between treatments for grape potential alcohol content, fruit acids, number of bunches or grapes per vine, fresh weight of grapes, or leaf chlorophyll content, despite foliar fluoride concentrations in the highest fluoride fumigation level reaching 85 ..mu..gFg/sup -1/. No evidence was found of significant fluoride accumulation in berries or canes. 26 references, 4 tables.

  5. RNA Silencing Is Resistant to Low-Temperature in Grapevine

    PubMed Central

    Romon, Marjorie; Soustre-Gacougnolle, Isabelle; Schmitt, Carine; Perrin, Mireille; Burdloff, Yannick; Chevalier, Elodie; Mutterer, Jérome; Himber, Christophe; Zervudacki, Jérôme; Montavon, Thomas; Zimmermann, Aude; Elmayan, Taline; Vaucheret, Hervé; Dunoyer, Patrice; Masson, Jean E.

    2013-01-01

    RNA silencing is a natural defence mechanism against viruses in plants, and transgenes expressing viral RNA-derived sequences were previously shown to confer silencing-based enhanced resistance against the cognate virus in several species. However, RNA silencing was shown to dysfunction at low temperatures in several species, questioning the relevance of this strategy in perennial plants such as grapevines, which are often exposed to low temperatures during the winter season. Here, we show that inverted-repeat (IR) constructs trigger a highly efficient silencing reaction in all somatic tissues in grapevines. Similarly to other plant species, IR-derived siRNAs trigger production of secondary transitive siRNAs. However, and in sharp contrast to other species tested to date where RNA silencing is hindered at low temperature, this process remained active in grapevine cultivated at 4°C. Consistently, siRNA levels remained steady in grapevines cultivated between 26°C and 4°C, whereas they are severely decreased in Arabidopsis grown at 15°C and almost undetectable at 4°C. Altogether, these results demonstrate that RNA silencing operates in grapevine in a conserved manner but is resistant to far lower temperatures than ever described in other species. PMID:24376561

  6. Genetic characterization of some Romanian red wine grapevine varieties

    NASA Astrophysics Data System (ADS)

    Ghetea, Ligia Gabriela; Motoc, Rozalia Magda; Niculescu, Ana-Maria; Litescu, Simona Carmen; Duma, Virgil-Florin; Popescu, Carmen Florentina

    2008-04-01

    In our study we have considered three of the most valuable Romanian red wine grapevine cultivars: Feteasca neagra, Feteasca alba and Novac. We have chosen to study grapevine because grapes and wine are an important part of a healthy diet, and because red grapes have the highest content of proanthocyanidins, that act as antioxidants (free radical scavengers) in the human body. Proanthocyanidins possess anti-mutagenic, anti-tumor, anti-viral activities and they present many other confirmed or potential benefits. Genotyping method was applied in order to asses the genetic profile at 14 microsatellite loci, for two cultivars: Feteasca neagra and Feteasca alba. In order to achieve this, the HPLC-DAD method was used. The content of anthocyans in grape skin from two cultivars - Feteasca neagra and Novac - was measured. Microsatellite markers have been certified as powerful tools for assessing genetic identities and genetic relationships between grapevine gene pools. Genetic characterization of grapevine cultivars can certify their authenticity and purity, two features that have a direct effect on the quality and value of the finished product, the wine. In our country, this is the first attempt in order to establish a genetic profile for valuable Romanian origin grapevine varieties. In some of the 14 microsatellitic loci, Feteasca neagra and Feteasca alba cultivars presented allele size variants different from the values cited in the literature, proving that these cultivars belong to a geographical distinct gene pool. The content of anthocyans in Feteasca neagra grape skin was significantly higher than in Novac.

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

    PubMed Central

    Pattanaik, Sitakanta; Patra, Barunava; Singh, Sanjay Kumar; Yuan, Ling

    2014-01-01

    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 (TFs): 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 controlling

  8. Ferrisia gilli (Hemiptera: Pseudococcidae) Transmits Grapevine Leafroll-Associated Viruses.

    PubMed

    Wistrom, C M; Blaisdell, G K; Wunderlich, L R; Almeida, R P P; Daane, K M

    2016-08-01

    Several mealybug species are vectors of grapevine leafroll-associated viruses (GLRaV), which cause the economically important grapevine leafroll disease in grape-producing regions worldwide. The mealybug Ferrisia gilli Gullan is a new pest of grapevines in El Dorado County, located in the Sierra Foothill wine-growing region of California. GLRaV species 1, 2, 3, and 4LV have been detected in vineyards with symptomatic vines in the Sierra Foothills. We conducted controlled virus acquisition and transmission experiments using source vine accessions infected with different combinations of GLRaV. We determined that F. gilli acquired GLRaV 1, 2, 3, and 4LV, and transmitted GLRaV-3 and GLRaV-4LV to uninfected recipient vines. Like numerous other mealybug species, in addition to causing direct damage to vines, F. gilli poses a threat to the grape industry as a vector of economically damaging viruses. PMID:27329635

  9. Metagenomic next-generation sequencing of viruses infecting grapevines.

    PubMed

    Burger, Johan T; Maree, Hans J

    2015-01-01

    Next-generation sequencing (NGS) technologies, for the first time, provide a truly "complete" representation of the viral (and other) pathogens present in a host organism. This is achieved in an unbiased way, and without any prior biological or molecular knowledge of these pathogen(s). During recent years a number of broad approaches, for most of the popular NGS platforms, have been developed. Here we describe such a protocol-one that accurately and reliably analyze viruses (and viroids) infecting grapevine. Our strategy relies on the synthesis of cDNA sequencing libraries from dsRNA, extracted from diseased grapevine tissues; the sequencing of these on an Illumina platform, and a streamlined bioinformatics pipeline to analyze the NGS data, yielding the virus composition (virome) of a specific grapevine tissue type, organ, entire plant, or even a vineyard. PMID:25981264

  10. Over-expression of VvWRKY1 in grapevines induces expression of jasmonic acid pathway-related genes and confers higher tolerance to the downy mildew.

    PubMed

    Marchive, Chloé; Léon, Céline; Kappel, Christian; Coutos-Thévenot, Pierre; Corio-Costet, Marie-France; Delrot, Serge; Lauvergeat, Virginie

    2013-01-01

    Most WRKY transcription factors activate expression of defence genes in a salicylic acid- and/or jasmonic acid-dependent signalling pathway. We previously identified a WRKY gene, VvWRKY1, which is able to enhance tolerance to fungal pathogens when it is overexpressed in tobacco. The present work analyzes the effects of VvWRKY1 overexpression in grapevine. Microarray analysis showed that genes encoding defence-related proteins were up-regulated in the leaves of transgenic 35S::VvWRKY1 grapevines. Quantitative RT-PCR analysis confirmed that three genes putatively involved in jasmonic acid signalling pathway were overexpressed in the transgenic grapes. The ability of VvWRKY1 to trans-activate the promoters of these genes was demonstrated by transient expression in grape protoplasts. The resistance to the causal agent of downy mildew, Plasmopara viticola, was enhanced in the transgenic plants. These results show that VvWRKY1 can increase resistance of grapevine against the downy mildew through transcriptional reprogramming leading to activation of the jasmonic acid signalling pathway. PMID:23342101

  11. Grapevine microRNAs responsive to exogenous gibberellin

    PubMed Central

    2014-01-01

    Background MicroRNAs (miRNAs), involving in various biological and metabolic processes, have been discovered and analyzed in quite a number of plants species, such as Arabidopsis, rice and other plants. However, there have been few reports about grapevine miRNAs in response to gibberelline (GA3). Results Solexa technology was used to sequence small RNA libraries constructed from grapevine berries treated with GA3 and the control. A total of 122 known and 90 novel grapevine miRNAs (Vvi-miRNAs) were identified. Totally, 137 ones were found to be clearly responsive to GA3, among which 58 were down-regulated, 51 were up-regulated, 21 could only be detected in the control, and seven were only detected in the treatment. Subsequently, we found that 28 of them were differentially regulated by GA3, with 12 conserved and 16 novel Vvi-miRNAs, based on the analysis of qRT-PCR essays. There existed some consistency in expression levels of GA3-responsive Vvi-miRNAs between high throughput sequencing and qRT-PCR essays. In addition, 117 target genes for 29 novel miRNAs were predicted. Conclusions Deep sequencing of short RNAs from grapevine berries treated with GA3 and the control identified 137 GA3-responsive miRNAs, among which 28 exhibited different expression profiles of response to GA3 in the diverse developmental stages of grapevine berries. These identified Vvi-miRNAs might be involved in the grapevine berry development and response to environmental stresses. PMID:24507455

  12. Cold-night responses in grapevine inflorescences.

    PubMed

    Sawicki, Mélodie; Ait Barka, Essaid; Clément, Christophe; Gilard, Françoise; Tcherkez, Guillaume; Baillieul, Fabienne; Vaillant-Gaveau, Nathalie; Jacquard, Cédric

    2015-10-01

    Cold nights impact grapevine flower development and fruit set. Regulation at the female meiosis stepmay be of considerable importance for further understanding on how flower reacts to cold stress. In this study, the impact of chilling temperature (0 °C overnight) on carbon metabolism was investigated in the inflorescencesof two cultivars, Pinot noir (Pinot) and Gewurztraminer (Gewurtz.). Fluctuations in photosynthetic activity and carbohydrate metabolism were monitored by analyzing gas exchanges, simultaneous photosystem I and II activities, andcarbohydrate content. Further, the expression of PEPc, PC, FNR, ISO, OXO, AGPase, amylases and invertase genes, activities of various enzymes, as well as metabolomic analysis were attained. Results showed that the chilling night has different impacts depending on cultivars. Thus, in Gewurtz., net photosynthesis (Pn) was transiently increased whereas, in Pinot, the Pn increase was persistent and concomitant with an inhibition of respiration. However, during the days following the cold night, photosynthetic activity was decreased, and the cyclic electron flow was inhibited in Gewurtz., suggesting lower efficient energy dissipation. Likewise, metabolomic analysis revealed that several metabolites contents (namely alanine, GABA, lysine and succinate)were distinctly modulated in the two cultivars. Taking together, these results reflect a photosynthetic metabolism alteration or internal CO2 conductance in Gewurtz. explaining partly why Pinot is less susceptible to cold stress. PMID:26398796

  13. Effects of acid rain on grapevines

    SciTech Connect

    Forsline, P.L.; Musselman, R.C.; Dee, R.J.; Kender, W.J.

    1983-01-01

    Mature vineyard-growing Concord grapevines were sprayed with simulated acid rain solutions ranging from pH 2.5 to 5.5 both as acute treatments at anthesis and chronically throughout the season in 1980 and 1981. In 1981, 8 additional varieties were also treated with simulated acid rain solutions at pH 2.75 and 3.25. With Concord in 1981, few foliar lesions on leaves were visible at pH 2.75. In contrast, many leaf lesions with decreased fruit soluble solids were observed at pH 2.5 in 1980. The relationship between acid-rain and oxidant stipple, chlorosis, and soluble solids in the absence of acid rain leaf lesions at pH>2.5 remains unclear. Acute sprays (pH2.75) at anthesis reduced pollen germination in four grape cultivars. However, fruit set was reduced in only one of these. Grape yields were not influenced by acid rain treatments. There was no evidence that acid-rain at ambient pH levels had negative effects on grape production or fruit quality.

  14. Effects of acid rain on grapevines

    SciTech Connect

    Forsline, P.L.; Musselman, R.C.; Dee, R.J.; Kender, W.J.

    1983-01-01

    Mature vineyard-growing Concord grapevines (Vitis labrusca, Bailey) were sprayed with simulated acid rain solutions ranging from pH 2.5 to pH 5.5 both as acute treatments at anthesis and chronically throughout the season in 1980 and 1981. In 1981, eight additional varieties were also treated with simulated acid rain solutions at pH 2.75 and pH 3.25. With Concord in 1981, few foliar lesions on leaves were visible at pH 2.75. In contrast, many leaf lesions with decreased fruit soluble solids in the absence of acid rain leaf lesions at pH>2.5 remains unclear. Acute sprays (pH 2.75) at anthesis reduced pollen germination in four grape cultivars. However, fruit set was reduced in only one of these. Only the cultivars de Chaunac and Ives had reduced berry soluble solids with chronic weekly sprays at pH 2.75. Reduction in soluble solids was not associated with increased oxidant stipple (ozone injury) in Concord and de Chaunac cultivars, but this association was observed in Ives. There was no evidence that acid rain in combination with ozone increased oxidant stipple as occurs when ozone and SO/sub 2/ are combined. Grape yields were not influenced by acid rain treatments. There was no evidence that acid rain at ambient pH levels had negative effects on grape production or fruit quality.

  15. Peace, a MYB-like transcription factor, regulates petal pigmentation in flowering peach ‘Genpei’ bearing variegated and fully pigmented flowers

    PubMed Central

    Uematsu, Chiyomi; Inagaki, Azusa

    2014-01-01

    Flowering peach Prunus persica cv. Genpei bears pink and variegated flowers on a single tree. The structural genes involved in anthocyanin biosynthesis were expressed strongly in pink petals but only very weakly or not at all in variegated petals. A cDNA clone encoding a MYB-like gene, isolated from pink petals was strongly expressed only in pink petals. Introduction of this gene, via biolistics gave magenta spots in the white areas of variegated petals, therefore this gene was named as Peace (peach anthocyanin colour enhancement). Differences in Peace expression determine the pattern of flower colouration in flowering peach. The R2R3 DNA-binding domain of Peace is similar to those of other plant MYBs regulating anthocyanin biosynthesis. Key amino acids for tertiary structure and the motif for interaction with bHLH proteins were conserved in Peace. Phylogenetic analysis indicates that Peace is closely related to AtMYB123 (TT2), which regulates proanthocyanidin biosynthesis in Arabidopsis, and to anthocyanin regulators in monocots rather than to regulators in dicots. This is the first report that a TT2-like R2R3 MYB has been shown to regulate anthocyanin biosynthesis. PMID:24453228

  16. Research promises earlier warning for grapevine canker diseases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    When it comes to detecting and treating vineyards for grapevine canker diseases (also called trunk diseases), like Botryosphaeria dieback (Bot canker), Esca, Eutypa dieback and Phomopsis dieback, the earlier the better, says plant pathologist Kendra Baumgartner, with the USDA’s Agricultural Research...

  17. Proteomic analysis of grapevines in response to Xylella fastidiosa infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Xylella fastidiosa (Xf) is the bacterial causal agent of Pierce’s disease (PD) of grapevines, as well as of other economically important diseases in a number of agronomic, horticultural and ornamental plants. The objective of this research was to tentatively identify proteins that are expressed in ...

  18. Intercontinental genetic structure of the fungal grapevine pathogen Eutypa lata

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ascomycete fungus Eutypa lata, causal agent of Eutypa dieback of grapevine (Vitis vinifera), impacts all vineyard production systems worldwide. Our objectives were to characterize the population structure of E. lata at different geographical scales to identify migration patterns through ascospor...

  19. Bacterial endophytic communities in the grapevine depend on pest management.

    PubMed

    Campisano, Andrea; Antonielli, Livio; Pancher, Michael; Yousaf, Sohail; Pindo, Massimo; Pertot, Ilaria

    2014-01-01

    Microbial plant endophytes are receiving ever-increasing attention as a result of compelling evidence regarding functional interaction with the host plant. Microbial communities in plants were recently reported to be influenced by numerous environmental and anthropogenic factors, including soil and pest management. In this study we used automated ribosomal intergenic spacer analysis (ARISA) fingerprinting and pyrosequencing of 16S rDNA to assess the effect of organic production and integrated pest management (IPM) on bacterial endophytic communities in two widespread grapevines cultivars (Merlot and Chardonnay). High levels of the dominant Ralstonia, Burkholderia and Pseudomonas genera were detected in all the samples We found differences in the composition of endophytic communities in grapevines cultivated using organic production and IPM. Operational taxonomic units (OTUs) assigned to the Mesorhizobium, Caulobacter and Staphylococcus genera were relatively more abundant in plants from organic vineyards, while Ralstonia, Burkholderia and Stenotrophomonas were more abundant in grapevines from IPM vineyards. Minor differences in bacterial endophytic communities were also found in the grapevines of the two cultivars. PMID:25387008

  20. Bacterial Endophytic Communities in the Grapevine Depend on Pest Management

    PubMed Central

    Campisano, Andrea; Antonielli, Livio; Pancher, Michael; Yousaf, Sohail; Pindo, Massimo; Pertot, Ilaria

    2014-01-01

    Microbial plant endophytes are receiving ever-increasing attention as a result of compelling evidence regarding functional interaction with the host plant. Microbial communities in plants were recently reported to be influenced by numerous environmental and anthropogenic factors, including soil and pest management. In this study we used automated ribosomal intergenic spacer analysis (ARISA) fingerprinting and pyrosequencing of 16S rDNA to assess the effect of organic production and integrated pest management (IPM) on bacterial endophytic communities in two widespread grapevines cultivars (Merlot and Chardonnay). High levels of the dominant Ralstonia, Burkholderia and Pseudomonas genera were detected in all the samples We found differences in the composition of endophytic communities in grapevines cultivated using organic production and IPM. Operational taxonomic units (OTUs) assigned to the Mesorhizobium, Caulobacter and Staphylococcus genera were relatively more abundant in plants from organic vineyards, while Ralstonia, Burkholderia and Stenotrophomonas were more abundant in grapevines from IPM vineyards. Minor differences in bacterial endophytic communities were also found in the grapevines of the two cultivars. PMID:25387008

  1. Genetic mapping in grapevine using a SNP microarray: intensity values

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genotyping microarrays are widely used for genome wide association studies, but in high-diversity organisms, the quality of SNP calls can be diminished by genetic variation near the assayed nucleotide. To address this limitation in grapevine, we developed a simple heuristic that uses hybridization i...

  2. MICROSATELLITE MARKERS FOR THE GRAPEVINE PATHOGEN, EUTYPA LATA.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We isolated and characterized nine polymorphic microsatellite markers for Eutypa lata, a fungal pathogen responsible for Eutypa dieback of grapevine, in populations from two California vineyards (24 isolates per vineyard). Allele frequency ranged from two to 11 alleles per locus and haploid gene di...

  3. A computer model for predicting grapevine cold hardiness

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We developed a robust computer model of grapevine bud cold hardiness that will aid in the anticipation of and response to potential injury from fluctuations in winter temperature and from extreme cold events. The model uses time steps of 1 day along with the measured daily mean air temperature to ca...

  4. Immunological detection of glassy-winged sharpshooter saliva in grapevine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Glassy-winged sharpshooter (GWSS), Homalodisca vitripennis, is a major vector for transmission of Xylella fastidiosa (Xf), the causative agent of Pierce’s Disease in grapevine. During the feeding process of stylet penetration and xylem fluid ingestion, GWSS inject saliva into the plant. Inoculation...

  5. Global genetic structure of the fungal grapevine pathogen Eutypa lata

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ascomycete fungus Eutypa lata is a trunk pathogen of cultivated grapevine (Vitis vinifera) in all major grape-growing regions of the world. Throughout its geographic range, it is considered a generalist pathogen that can complete its life cycle on a broad range of hosts. To decipher the cosmopol...

  6. Messenger RNA exchange between scions and rootstocks in grafted grapevines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We demonstrated the existence of genome-scale mRNA exchange in grafted grapevines, a woody fruit species with significant economic importance. By using diagnostic SNPs derived from high throughput genome sequencing, we identified more than three thousand genes transporting mRNAs across graft junctio...

  7. PCR Assays That Identify the Grapevine Dieback Fungus Eutypa lata

    PubMed Central

    Lecomte, Pascal; Péros, Jean-Pierre; Blancard, Dominique; Bastien, Nicolas; Délye, Christophe

    2000-01-01

    Eutypa lata is the causal fungal agent of Eutypa dieback, a serious grapevine necrotic disease. The erratic and delayed (1 to 2 months) appearance of characteristic conidia on culture media and the presence of numerous microorganisms in decaying wood make it difficult either to identify or to detect E. lata in grapevine wood samples. We designed six pairs of PCR primers for diagnosis of E. lata. Three primer pairs were derived from ribosomal DNA internal transcribed spacer sequences, and three pairs were derived from randomly amplified polymorphic DNA fragments. The six primer pairs could be used to amplify DNAs extracted from all of the E. lata isolates tested. They did not amplify DNAs from fungi and bacteria representing more than 50 different species of microorganisms associated with grapevine. We developed a simple protocol, leading to a rapid release of DNA, that enabled us to identify E. lata from pure or mixed cultures as well as from grapevine wood samples. Identification of E. lata in wood was achieved within a few hours, instead of the several weeks required for classical cultures on agar medium. We believe that the procedure described here can be adapted to detect other microorganisms involved in woody plant diseases. PMID:11010901

  8. Vitis vinifera terpenoid cyclases: functional identification of two sesquiterpene synthase cDNAs encoding (+)-valencene synthase and (-)-germacrene D synthase and expression of mono- and sesquiterpene synthases in grapevine flowers and berries.

    PubMed

    Lücker, Joost; Bowen, Pat; Bohlmann, Jörg

    2004-10-01

    Valencene is a volatile sesquiterpene emitted from flowers of grapevine, Vitis vinifera L. A full-length cDNA from the cultivar Gewürztraminer was functionally expressed in Escherichia coli and found to encode valencene synthase (VvVal). The two major products formed by recombinant VvVal enzyme activity with farnesyl diphosphate (FPP) as substrate are (+)-valencene and (-)-7-epi-alpha-selinene. Grapevine valencene synthase is closely related to a second sesquiterpene synthase from this species, (-)-germacrene D synthase (VvGerD). VvVal and VvGerD cDNA probes revealed strong signals in Northern hybridizations with RNA isolated from grapevine flower buds. Transcript levels were lower in open pre-anthesis flowers, flowers after anthesis, or at early onset of fruit development. Similar results were obtained using a third probe, (-)-alpha-terpineol synthase, a monoterpenol synthase. Sesquiterpene synthase and monoterpene synthase transcripts were not detected in the mesocarp and exocarp during early stages of fruit development, but transcripts hybridizing with VvVal appeared during late ripening of the berries. Sesquiterpene synthase transcripts were also detected in young seeds. PMID:15464152

  9. A 48 SNP set for grapevine cultivar identification

    PubMed Central

    2011-01-01

    Background Rapid and consistent genotyping is an important requirement for cultivar identification in many crop species. Among them grapevine cultivars have been the subject of multiple studies given the large number of synonyms and homonyms generated during many centuries of vegetative multiplication and exchange. Simple sequence repeat (SSR) markers have been preferred until now because of their high level of polymorphism, their codominant nature and their high profile repeatability. However, the rapid application of partial or complete genome sequencing approaches is identifying thousands of single nucleotide polymorphisms (SNP) that can be very useful for such purposes. Although SNP markers are bi-allelic, and therefore not as polymorphic as microsatellites, the high number of loci that can be multiplexed and the possibilities of automation as well as their highly repeatable results under any analytical procedure make them the future markers of choice for any type of genetic identification. Results We analyzed over 300 SNP in the genome of grapevine using a re-sequencing strategy in a selection of 11 genotypes. Among the identified polymorphisms, we selected 48 SNP spread across all grapevine chromosomes with allele frequencies balanced enough as to provide sufficient information content for genetic identification in grapevine allowing for good genotyping success rate. Marker stability was tested in repeated analyses of a selected group of cultivars obtained worldwide to demonstrate their usefulness in genetic identification. Conclusions We have selected a set of 48 stable SNP markers with a high discrimination power and a uniform genome distribution (2-3 markers/chromosome), which is proposed as a standard set for grapevine (Vitis vinifera L.) genotyping. Any previous problems derived from microsatellite allele confusion between labs or the need to run reference cultivars to identify allele sizes disappear using this type of marker. Furthermore, because SNP

  10. Polyols in grape berry: transport and metabolic adjustments as a physiological strategy for water-deficit stress tolerance in grapevine.

    PubMed

    Conde, Artur; Regalado, Ana; Rodrigues, Diana; Costa, J Miguel; Blumwald, Eduardo; Chaves, M Manuela; Gerós, Hernâni

    2015-02-01

    Polyols are important metabolites that often function as carbon and energy sources and/or osmoprotective solutes in some plants. In grapevine, and in the grape berry in particular, the molecular aspects of polyol transport and metabolism and their physiological relevance are virtually unknown to date. Here, the biochemical function of a grapevine fruit mesocarp polyol transporter (VvPLT1) was characterized after its heterologous expression in yeast. This H(+)-dependent plasma membrane carrier transports mannitol (K m=5.4mM) and sorbitol (K m=9.5mM) over a broad range of polyols and monosaccharides. Water-deficit stress triggered an increase in the expression of VvPLT1 at the fully mature stage, allowing increased polyol uptake into pulp cells. Plant polyol dehydrogenases are oxireductases that reversibly oxidize polyols into monosaccharides. Mannitol catabolism in grape cells (K m=30.1mM mannitol) and mature berry mesocarps (K m=79mM) was, like sorbitol dehydrogenase activity, strongly inhibited (50-75%) by water-deficit stress. Simultaneously, fructose reduction into polyols via mannitol and sorbitol dehydrogenases was stimulated, contributing to their higher intracellular concentrations in water-deficit stress. Accordingly, the concentrations of mannitol, sorbitol, galactinol, myo-inositol, and dulcitol were significantly higher in berry mesocarps from water-deficit-stressed Tempranillo grapevines. Metabolomic profiling of the berry pulp by GC-TOF-MS also revealed many other changes in its composition induced by water deficit. The impact of polyols on grape berry composition and plant response to water deficit stress, via modifications in polyol transport and metabolism, was analysed by integrating metabolomics with transcriptional analysis and biochemical approaches. PMID:25433029

  11. A transcriptomic study of grapevine (Vitis vinifera cv. Cabernet-Sauvignon) interaction with the vascular ascomycete fungus Eutypa lata

    PubMed Central

    Camps, Céline; Kappel, Christian; Lecomte, Pascal; Léon, Céline; Gomès, Eric; Coutos-Thévenot, Pierre; Delrot, Serge

    2010-01-01

    Eutypa dieback is a vascular disease that may severely affect vineyards throughout the world. In the present work, microarrays were made in order (i) to improve our knowledge of grapevine (Vitis vinifera cv. Cabernet-Sauvignon) responses to Eutypa lata, the causal agent of Eutypa dieback; and (ii) to identify genes that may prevent symptom development. Qiagen/Operon grapevine microarrays comprising 14 500 probes were used to compare, under three experimental conditions (in vitro, in the greenhouse, and in the vineyard), foliar material of infected symptomatic plants (S+R+), infected asymptomatic plants (S–R+), and healthy plants (S–R–). These plants were characterized by symptom notation after natural (vineyard) or experimental (in vitro and greenhouse) infection, re-isolation of the fungus located in the lignified parts, and the formal identification of E. lata mycelium by PCR. Semi-quantitative real-time PCR experiments were run to confirm the expression of some genes of interest in response to E. lata. Their expression profiles were also studied in response to other grapevine pathogens (Erysiphe necator, Plasmopara viticola, and Botrytis cinerea). (i) Five functional categories of genes, that is those involved in metabolism, defence reactions, interaction with the environment, transport, and transcription, were up-regulated in S+R+ plants compared with S–R– plants. These genes, which cannot prevent infection and symptom development, are not specific since they were also up-regulated after infection by powdery mildew, downy mildew, and black rot. (ii) Most of the genes that may prevent symptom development are associated with the light phase of photosynthesis. This finding is discussed in the context of previous data on the mode of action of eutypin and the polypeptide fraction secreted by Eutypa. PMID:20190040

  12. Defence responses in Rpv3-dependent resistance to grapevine downy mildew.

    PubMed

    Casagrande, Karen; Falginella, Luigi; Castellarin, Simone Diego; Testolin, Raffaele; Di Gaspero, Gabriele

    2011-12-01

    The Rpv3 locus determines the ability to operate an isolate-specific hypersensitive response (HR) against Plasmopara viticola in grapevines that carry a resistant Rpv3 (+) haplotype. Artificial infection was performed on leaf discs of Rpv3 (+) and Rpv3 (-) grapevines with two distinct isolates of the pathogen (avrRpv3 (+) and avrRpv3 (-)). The plant response, including the establishment of HR and changes in expression of 33 genes, was compared to the development of the pathogen. HR was induced exclusively in the Rpv3 (+) host upon inoculation with the avrRpv3 (+) isolate of the pathogen, which is assumed to use avrRpv3 (+) effectors that are recognised by/through the plant Rpv3 (+) gene product. The limitation imposed on pathogen growth was the result of inducible responses elicited by the Rpv3 (+)-avrRpv3 (+) interaction. This host reaction relied on transcriptional induction of the HR-associated gene HSR1 and salicylic acid-induced pathogenesis-related (PR) genes PR-1 and PR-2 during the initial 24-48 h post-inoculation. These events had no parallel in the Rpv3 (-) host or upon infection with the avrRpv3 (-) isolate. The emerging model for Rpv3-mediated defence, which is dependent upon race-specific recognition, associated with up-regulation of PR-1 and PR-2 genes, and enforced by localised HR-type necrosis, is compatible with the cascade of events initiated by the products of NB-LRR and LRR-kinase receptor-like genes, such as those residing in the Rpv3 locus. PMID:21735199

  13. VitisNet: “Omics” Integration through Grapevine Molecular Networks

    PubMed Central

    Grimplet, Jérôme; Cramer, Grant R.; Dickerson, Julie A.; Mathiason, Kathy; Van Hemert, John; Fennell, Anne Y.

    2009-01-01

    Background Genomic data release for the grapevine has increased exponentially in the last five years. The Vitis vinifera genome has been sequenced and Vitis EST, transcriptomic, proteomic, and metabolomic tools and data sets continue to be developed. The next critical challenge is to provide biological meaning to this tremendous amount of data by annotating genes and integrating them within their biological context. We have developed and validated a system of Grapevine Molecular Networks (VitisNet). Methodology/Principal Findings The sequences from the Vitis vinifera (cv. Pinot Noir PN40024) genome sequencing project and ESTs from the Vitis genus have been paired and the 39,424 resulting unique sequences have been manually annotated. Among these, 13,145 genes have been assigned to 219 networks. The pathway sets include 88 “Metabolic”, 15 “Genetic Information Processing”, 12 “Environmental Information Processing”, 3 “Cellular Processes”, 21 “Transport”, and 80 “Transcription Factors”. The quantitative data is loaded onto molecular networks, allowing the simultaneous visualization of changes in the transcriptome, proteome, and metabolome for a given experiment. Conclusions/Significance VitisNet uses manually annotated networks in SBML or XML format, enabling the integration of large datasets, streamlining biological functional processing, and improving the understanding of dynamic processes in systems biology experiments. VitisNet is grounded in the Vitis vinifera genome (currently at 8x coverage) and can be readily updated with subsequent updates of the genome or biochemical discoveries. The molecular network files can be dynamically searched by pathway name or individual genes, proteins, or metabolites through the MetNet Pathway database and web-portal at http://metnet3.vrac.iastate.edu/. All VitisNet files including the manual annotation of the grape genome encompassing pathway names, individual genes, their genome identifier, and

  14. Genome Wide Transcriptional Profile Analysis of Vitis amurensis and Vitis vinifera in Response to Cold Stress

    PubMed Central

    Xin, Haiping; Zhu, Wei; Wang, Lina; Xiang, Yue; Fang, Linchuan; Li, Jitao; Sun, Xiaoming; Wang, Nian; Londo, Jason P.; Li, Shaohua

    2013-01-01

    Grape is one of the most important fruit crops worldwide. The suitable geographical locations and productivity of grapes are largely limited by temperature. Vitis amurensis is a wild grapevine species with remarkable cold-tolerance, exceeding that of Vitis vinifera, the dominant cultivated species of grapevine. However, the molecular mechanisms that contribute to the enhanced freezing tolerance of V. amurensis remain unknown. Here we used deep sequencing data from restriction endonuclease-generated cDNA fragments to evaluate the whole genome wide modification of transcriptome of V. amurensis under cold treatment. Vitis vinifera cv. Muscat of Hamburg was used as control to help investigate the distinctive features of V. amruensis in responding to cold stress. Approximately 9 million tags were sequenced from non-cold treatment (NCT) and cold treatment (CT) cDNA libraries in each species of grapevine sampled from shoot apices. Alignment of tags into V. vinifera cv. Pinot noir (PN40024) annotated genome identified over 15,000 transcripts in each library in V. amruensis and more than 16,000 in Muscat of Hamburg. Comparative analysis between NCT and CT libraries indicate that V. amurensis has fewer differential expressed genes (DEGs, 1314 transcripts) than Muscat of Hamburg (2307 transcripts) when exposed to cold stress. Common DEGs (408 transcripts) suggest that some genes provide fundamental roles during cold stress in grapes. The most robust DEGs (more than 20-fold change) also demonstrated significant differences between two kinds of grapevine, indicating that cold stress may trigger species specific pathways in V. amurensis. Functional categories of DEGs indicated that the proportion of up-regulated transcripts related to metabolism, transport, signal transduction and transcription were more abundant in V. amurensis. Several highly expressed transcripts that were found uniquely accumulated in V. amurensis are discussed in detail. This subset of unique candidate

  15. Pseudomonas fluorescens PTA-CT2 Triggers Local and Systemic Immune Response Against Botrytis cinerea in Grapevine.

    PubMed

    Gruau, Charlotte; Trotel-Aziz, Patricia; Villaume, Sandra; Rabenoelina, Fanja; Clément, Christophe; Baillieul, Fabienne; Aziz, Aziz

    2015-10-01

    Although induced systemic resistance (ISR) is well-documented in the context of plant-beneficial bacteria interactions, knowledge about the local and systemic molecular and biochemical defense responses before or upon pathogen infection in grapevine is very scarce. In this study, we first investigated the capacity of grapevine plants to express immune responses at both above- and below-ground levels upon interaction with a beneficial bacterium, Pseudomonas fluorescens PTA-CT2. We then explored whether the extent of priming state could contribute to the PTA-CT2-induced ISR in Botrytis cinerea-infected leaves. Our data provide evidence that this bacterium colonized grapevine roots but not the above-ground plant parts and altered the plant phenotype that displayed multiple defense responses both locally and systemically. The grapevine roots and leaves exhibited distinct patterns of defense-related gene expression during root colonization by PTA-CT2. Roots responded faster than leaves and some responses were more strongly upregulated in roots than in leaves and vice versa for other genes. These responses appear to be associated with some induction of cell death in roots and a transient expression of HSR, a hypersensitive response-related gene in both local (roots) and systemic (leaves) tissues. However, stilbenic phytoalexin patterns followed opposite trends in roots compared with leaves but no phytoalexin was exuded during plant-bacterium interaction, suggesting that roots could play an important role in the transfer of metabolites contributing to immune response at the systemic level. Unexpectedly, in B. cinerea-infected leaves PTA-CT2-mediated ISR was accompanied in large part by a downregulation of different defense-related genes, including HSR. Only phytoalexins and glutathion-S-transferase 1 transcripts were upregulated, while the expression of anthocyanin biosynthetic genes was maintained at a higher level than the control. This suggests that decreased

  16. Modulation of flavonoid biosynthetic pathway genes and anthocyanins due to virus infection in grapevine (Vitis vinifera L.) leaves

    PubMed Central

    2010-01-01

    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-infected symptomatic

  17. Day and night heat stress trigger different transcriptomic responses in green and ripening grapevine (vitis vinifera) fruit

    PubMed Central

    2014-01-01

    Background Global climate change will noticeably affect plant vegetative and reproductive development. The recent increase in temperatures has already impacted yields and composition of berries in many grapevine-growing regions. Physiological processes underlying temperature response and tolerance of the grapevine fruit have not been extensively investigated. To date, all studies investigating the molecular regulation of fleshly fruit response to abiotic stress were only conducted during the day, overlooking possible critical night-specific variations. The present study explores the night and day transcriptomic response of grapevine fruit to heat stress at several developmental stages. Short heat stresses (2 h) were applied at day and night to vines bearing clusters sequentially ordered according to the developmental stages along their vertical axes. The recently proposed microvine model (DRCF-Dwarf Rapid Cycling and Continuous Flowering) was grown in climatic chambers in order to circumvent common constraints and biases inevitable in field experiments with perennial macrovines. Post-véraison berry heterogeneity within clusters was avoided by constituting homogenous batches following organic acids and sugars measurements of individual berries. A whole genome transcriptomic approach was subsequently conducted using NimbleGen 090818 Vitis 12X (30 K) microarrays. Results Present work reveals significant differences in heat stress responsive pathways according to day or night treatment, in particular regarding genes associated with acidity and phenylpropanoid metabolism. Precise distinction of ripening stages led to stage-specific detection of malic acid and anthocyanin-related transcripts modulated by heat stress. Important changes in cell wall modification related processes as well as indications for heat-induced delay of ripening and sugar accumulation were observed at véraison, an effect that was reversed at later stages. Conclusions This first day - night

  18. Identification of Plasmopara viticola genes potentially involved in pathogenesis on grapevine suggests new similarities between oomycetes and true fungi.

    PubMed

    Luis, P; Gauthier, A; Trouvelot, S; Poinssot, B; Frettinger, P

    2013-10-01

    Plant diseases caused by fungi and oomycetes result in significant economic losses every year. Although phylogenetically distant, these organisms share many common features during infection. We identified genes in the oomycete Plasmopara viticola that are potentially involved in pathogenesis in grapevine by using fungal databases and degenerate primers. Fragments of P. viticola genes encoding NADH-ubiquinone oxidoreductase (PvNuo), laccase (PvLac), and invertase (PvInv) were obtained. PvNuo was overexpressed at 2 days postinoculation (dpi), during the development of the first hyphal structures and haustoria. PvLac was overexpressed at 5 dpi when genes related to pterostilbene biosynthesis were induced in grapevine. Transcript level for PvInv increased between 1 and 4 dpi before reaching a plateau. These results might suggest a finely tuned strategy of infection depending on nutrition and plant response. Phylogenetic analyses of PvNuo showed that P. viticola clustered with other oomycetes and was associated with brown algae and diatoms, forming a typical Straminipila clade. Based on the comparison of available sequences for laccases and invertases, the group formed by P. viticola and other oomycetes tended to be more closely related to Opisthokonta than to Straminipila. Convergent evolution or horizontal gene transfer could explain the presence of fungus-like genes in P. viticola. PMID:23634808

  19. The grapevine expression atlas reveals a deep transcriptome shift driving the entire plant into a maturation program.

    PubMed

    Fasoli, Marianna; Dal Santo, Silvia; Zenoni, Sara; Tornielli, Giovanni Battista; Farina, Lorenzo; Zamboni, Anita; Porceddu, Andrea; Venturini, Luca; Bicego, Manuele; Murino, Vittorio; Ferrarini, Alberto; Delledonne, Massimo; Pezzotti, Mario

    2012-09-01

    We developed a genome-wide transcriptomic atlas of grapevine (Vitis vinifera) based on 54 samples representing green and woody tissues and organs at different developmental stages as well as specialized tissues such as pollen and senescent leaves. Together, these samples expressed ∼91% of the predicted grapevine genes. Pollen and senescent leaves had unique transcriptomes reflecting their specialized functions and physiological status. However, microarray and RNA-seq analysis grouped all the other samples into two major classes based on maturity rather than organ identity, namely, the vegetative/green and mature/woody categories. This division represents a fundamental transcriptomic reprogramming during the maturation process and was highlighted by three statistical approaches identifying the transcriptional relationships among samples (correlation analysis), putative biomarkers (O2PLS-DA approach), and sets of strongly and consistently expressed genes that define groups (topics) of similar samples (biclustering analysis). Gene coexpression analysis indicated that the mature/woody developmental program results from the reiterative coactivation of pathways that are largely inactive in vegetative/green tissues, often involving the coregulation of clusters of neighboring genes and global regulation based on codon preference. This global transcriptomic reprogramming during maturation has not been observed in herbaceous annual species and may be a defining characteristic of perennial woody plants. PMID:22948079

  20. Grapevine rootstock effects on scion sap phenolic levels, resistance to Xylella fastidiosa infection, and progression of Pierce’s disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The xylem-limited bacterium Xylella fastidiosa (Xf) causes Pierce’s disease (PD), an important disease of grapevine, Vitis vinifera L. Grapevine rootstocks were developed to provide increased resistance to root disease, but rootstock effects on cane and vine diseases remain unclear. Grapevines that ...

  1. Current perspectives in proteomic analysis of abiotic stress in Grapevines

    PubMed Central

    George, Iniga S.; Haynes, Paul A.

    2014-01-01

    Grapes are an important crop plant which forms the basis of a globally important industry. Grape and wine production is particularly vulnerable to environmental and climatic fluctuations, which makes it essential for us to develop a greater understanding of the molecular level responses of grape plants to various abiotic stresses. The completion of the initial grape genome sequence in 2007 has led to a significant increase in research on grapes using proteomics approaches. In this article, we discuss some of the current research on abiotic stress in grapevines, in the context of abiotic stress research in other plant species. We also highlight some of the current limitations in grapevine proteomics and identify areas with promising scope for potential future research. PMID:25538720

  2. Transport and accumulation of flavonoids in grapevine (Vitis vinifera L.)

    PubMed Central

    Braidot, Enrico; Zancani, Marco; Petrussa, Elisa; Peresson, Carlo; Bertolini, Alberto; Patui, Sonia; Macrì, Francesco

    2008-01-01

    Flavonoids are a group of secondary metabolites widely distributed in plants that represent a huge portion of the soluble phenolics present in grapevine (Vitis vinifera L.). These compounds play different physiological roles and are often involved in protection against biotic and abiotic stress. Even if the flavonoid biosynthetic pathways have been largely characterized, the mechanisms of their transport and accumulation in cell wall and vacuole are still not completely understood. This review analyses the known mechanisms of flavonoid uptake and accumulation in grapevine, with reference to the transport models and membrane carrier proteins described in other plant species. The effect of different environmental factors on flavonoid biosynthesis and transporters is also discussed. PMID:19513253

  3. Histological responses to downy mildew in resistant and susceptible grapevines.

    PubMed

    Liu, Ruiqi; Wang, Lan; Zhu, Jiali; Chen, Tingting; Wang, Yuejin; Xu, Yan

    2015-01-01

    Downy mildew in grapevines, caused by Plasmopara viticola, is a very serious disease throughout the grape-producing nations, especially in more humid climates. Downy mildew mainly affects the cultivated varieties of Vitis vinifera. A promising way to minimize or eliminate P. viticola infections is by the adoption of resistant cultivars. Chinese wild grapevines are reported to possess resistance to many fungal diseases. In this study, three Chinese wild grapevines (Vitis pseudoreticulata Baihe-35-1, Vitis davidii var. cyanocarpa Langao-5, and Vitis piasezkii Liuba-8) and a European cultivated variety (V. vinifera cv. Pinot noir) were inoculated with P. viticola, and a histological survey was undertaken. Macroscopic observations revealed no sporulation in V. piasezkii Liuba-8, little sporulation in V. pseudoreticulata Baihe-35-1 and V. davidii var. cyanocarpa Langao-5, but serious sporulation in V. vinifera cv. Pinot noir. Aniline blue staining indicated callose deposition in V. pseudoreticulata Baihe-35-1, V. davidii var. cyanocarpa Langao-5, and V. piasezkii Liuba-8. Cells with distinctive fluorescence were also observed in V. pseudoreticulata Baihe-35-1. After staining with 3,3-diaminobenzidine, production of H₂O₂ was observed early on, after infection in V. davidii var. cyanocarpa Langao-5 and V. piasezkii Liuba-8. No H₂O₂ accumulation was observed in V. vinifera cv. Pinot noir. It is concluded that V. piasezkii Liuba-8 should be classified as "highly resistant" to downy mildew, V. pseudoreticulata Baihe-35-1 and V. davidii var. cyanocarpa Langao-5 as "resistant," and V. vinifera Pinot noir as "susceptible." The possible roles of stomatal callose deposition in the defense r6eactions of the mildew-resistant grapevines are discussed. PMID:25027553

  4. An Automated Field Phenotyping Pipeline for Application in Grapevine Research

    PubMed Central

    Kicherer, Anna; Herzog, Katja; Pflanz, Michael; Wieland, Markus; Rüger, Philipp; Kecke, Steffen; Kuhlmann, Heiner; Töpfer, Reinhard

    2015-01-01

    Due to its perennial nature and size, the acquisition of phenotypic data in grapevine research is almost exclusively restricted to the field and done by visual estimation. This kind of evaluation procedure is limited by time, cost and the subjectivity of records. As a consequence, objectivity, automation and more precision of phenotypic data evaluation are needed to increase the number of samples, manage grapevine repositories, enable genetic research of new phenotypic traits and, therefore, increase the efficiency in plant research. In the present study, an automated field phenotyping pipeline was setup and applied in a plot of genetic resources. The application of the PHENObot allows image acquisition from at least 250 individual grapevines per hour directly in the field without user interaction. Data management is handled by a database (IMAGEdata). The automatic image analysis tool BIVcolor (Berries in Vineyards-color) permitted the collection of precise phenotypic data of two important fruit traits, berry size and color, within a large set of plants. The application of the PHENObot represents an automated tool for high-throughput sampling of image data in the field. The automated analysis of these images facilitates the generation of objective and precise phenotypic data on a larger scale. PMID:25730485

  5. An automated field phenotyping pipeline for application in grapevine research.

    PubMed

    Kicherer, Anna; Herzog, Katja; Pflanz, Michael; Wieland, Markus; Rüger, Philipp; Kecke, Steffen; Kuhlmann, Heiner; Töpfer, Reinhard

    2015-01-01

    Due to its perennial nature and size, the acquisition of phenotypic data in grapevine research is almost exclusively restricted to the field and done by visual estimation. This kind of evaluation procedure is limited by time, cost and the subjectivity of records. As a consequence, objectivity, automation and more precision of phenotypic data evaluation are needed to increase the number of samples, manage grapevine repositories, enable genetic research of new phenotypic traits and, therefore, increase the efficiency in plant research. In the present study, an automated field phenotyping pipeline was setup and applied in a plot of genetic resources. The application of the PHENObot allows image acquisition from at least 250 individual grapevines per hour directly in the field without user interaction. Data management is handled by a database (IMAGEdata). The automatic image analysis tool BIVcolor (Berries in Vineyards-color) permitted the collection of precise phenotypic data of two important fruit traits, berry size and color, within a large set of plants. The application of the PHENObot represents an automated tool for high-throughput sampling of image data in the field. The automated analysis of these images facilitates the generation of objective and precise phenotypic data on a larger scale. PMID:25730485

  6. Molecular identification and detection of Eutypa lata in grapevine.

    PubMed

    Lardner, Richard; Stummer, Belinda E; Sosnowskip, Mark R; Scott, Eileen S

    2005-07-01

    Eutypa lata, the causal agent of Eutypa dieback of grapevines, is difficult to identify on the basis of colony morphology and is often out-competed by other fungi when isolated from wood. To facilitate diagnosis of the pathogen, we designed SCAR primers capable of amplifying DNA of E. lata and constructed a genomic DNA library from which DNA sequences specific to E. lata were identified and sequenced. SCAR primers were used to identify E. lata directly from culture without the requirement for DNA extraction or prolonged incubation periods and could also detect the pathogen in DNA isolated from grapevine wood. RFLP probes were used in slot-blot assays to detect the pathogen in DNA isolated from 1 yr old cane as well as from mature grapevine trunks. The markers developed in this study have the potential to be used as a research tool to gather information on the epidemiology of the disease and to assess the efficacy of potential control agents against E. lata. PMID:16121566

  7. The soil microbiome influences grapevine-associated microbiota

    DOE PAGESBeta

    Zarraonaindia, Iratxe; Owens, Sarah M.; Weisenhorn, Pamela; West, Kristin; Hampton-Marcell, Jarrad; Lax, Simon; Bokulich, Nicholas A.; Mills, David A.; Martin, Gilles; Taghavi, Safiyh; et al

    2015-03-24

    Grapevine is a well-studied, economically relevant crop, whose associated bacteria could influence its organoleptic properties. In this study, the spatial and temporal dynamics of the bacterial communities associated with grapevine organs (leaves, flowers, grapes, and roots) and soils were characterized over two growing seasons to determine the influence of vine cultivar, edaphic parameters, vine developmental stage (dormancy, flowering, preharvest), and vineyard. Belowground bacterial communities differed significantly from those aboveground, and yet the communities associated with leaves, flowers, and grapes shared a greater proportion of taxa with soil communities than with each other, suggesting that soil may serve as a bacterialmore » reservoir. A subset of soil microorganisms, including root colonizers significantly enriched in plant growth-promoting bacteria and related functional genes, were selected by the grapevine. In addition to plant selective pressure, the structure of soil and root microbiota was significantly influenced by soil pH and C:N ratio, and changes in leaf- and grape-associated microbiota were correlated with soil carbon and showed interannual variation even at small spatial scales. Diazotrophic bacteria, e.g., Rhizobiaceae and Bradyrhizobium spp., were significantly more abundant in soil samples and root samples of specific vineyards. Vine-associated microbial assemblages were influenced by myriad factors that shape their composition and structure, but the majority of organ-associated taxa originated in the soil, and their distribution reflected the influence of highly localized biogeographic factors and vineyard management.« less

  8. The soil microbiome influences grapevine-associated microbiota

    SciTech Connect

    Zarraonaindia, Iratxe; Owens, Sarah M.; Weisenhorn, Pamela; West, Kristin; Hampton-Marcell, Jarrad; Lax, Simon; Bokulich, Nicholas A.; Mills, David A.; Martin, Gilles; Taghavi, Safiyh; van der Lelie, Daniel; Gilbert, Jack A.

    2015-03-24

    Grapevine is a well-studied, economically relevant crop, whose associated bacteria could influence its organoleptic properties. In this study, the spatial and temporal dynamics of the bacterial communities associated with grapevine organs (leaves, flowers, grapes, and roots) and soils were characterized over two growing seasons to determine the influence of vine cultivar, edaphic parameters, vine developmental stage (dormancy, flowering, preharvest), and vineyard. Belowground bacterial communities differed significantly from those aboveground, and yet the communities associated with leaves, flowers, and grapes shared a greater proportion of taxa with soil communities than with each other, suggesting that soil may serve as a bacterial reservoir. A subset of soil microorganisms, including root colonizers significantly enriched in plant growth-promoting bacteria and related functional genes, were selected by the grapevine. In addition to plant selective pressure, the structure of soil and root microbiota was significantly influenced by soil pH and C:N ratio, and changes in leaf- and grape-associated microbiota were correlated with soil carbon and showed interannual variation even at small spatial scales. Diazotrophic bacteria, e.g., Rhizobiaceae and Bradyrhizobium spp., were significantly more abundant in soil samples and root samples of specific vineyards. Vine-associated microbial assemblages were influenced by myriad factors that shape their composition and structure, but the majority of organ-associated taxa originated in the soil, and their distribution reflected the influence of highly localized biogeographic factors and vineyard management.

  9. The Soil Microbiome Influences Grapevine-Associated Microbiota

    PubMed Central

    Zarraonaindia, Iratxe; Owens, Sarah M.; Weisenhorn, Pamela; West, Kristin; Hampton-Marcell, Jarrad; Lax, Simon; Bokulich, Nicholas A.; Mills, David A.; Martin, Gilles; Taghavi, Safiyh; van der Lelie, Daniel

    2015-01-01

    ABSTRACT Grapevine is a well-studied, economically relevant crop, whose associated bacteria could influence its organoleptic properties. In this study, the spatial and temporal dynamics of the bacterial communities associated with grapevine organs (leaves, flowers, grapes, and roots) and soils were characterized over two growing seasons to determine the influence of vine cultivar, edaphic parameters, vine developmental stage (dormancy, flowering, preharvest), and vineyard. Belowground bacterial communities differed significantly from those aboveground, and yet the communities associated with leaves, flowers, and grapes shared a greater proportion of taxa with soil communities than with each other, suggesting that soil may serve as a bacterial reservoir. A subset of soil microorganisms, including root colonizers significantly enriched in plant growth-promoting bacteria and related functional genes, were selected by the grapevine. In addition to plant selective pressure, the structure of soil and root microbiota was significantly influenced by soil pH and C:N ratio, and changes in leaf- and grape-associated microbiota were correlated with soil carbon and showed interannual variation even at small spatial scales. Diazotrophic bacteria, e.g., Rhizobiaceae and Bradyrhizobium spp., were significantly more abundant in soil samples and root samples of specific vineyards. Vine-associated microbial assemblages were influenced by myriad factors that shape their composition and structure, but the majority of organ-associated taxa originated in the soil, and their distribution reflected the influence of highly localized biogeographic factors and vineyard management. PMID:25805735

  10. Genetics of downy mildew resistance in two interspecific hybrid grapevine families

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Due to lack of co-evolution with Plasmopara viticola, the causal pathogen of grapevine downy mildew, nearly all cultivated grapevines are susceptible to downy mildew, whereas their wild relatives are frequently resistant. In order to find QTL for downy mildew resistance and susceptibility, we perfor...