1801
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Zhang L, Zhao G, Xia C, Jia J, Liu X, Kong X. A wheat R2R3-MYB gene, TaMYB30-B, improves drought stress tolerance in transgenic Arabidopsis. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:5873-85. [PMID: 23048128 DOI: 10.1093/jxb/ers237] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The MYB-type proteins are involved in various processes of plant growth, development, and stress response. In a previous work, a polyethylene glycol (PEG) stress-induced gene, TaMYB30, which encodes a R2R3-type MYB protein was identified in wheat. In this study, the isolation and functional characterization of the TaMYB30 gene are reported. Three homologous sequences of TaMYB30 were isolated from hexaploid wheat and designated as TaMYB30-A, TaMYB30-B, and TaMYB30-D genes based on the localizations of these three sequences to chromosomes 2A, 2B, and 2D, respectively. The expression levels of these three genes were similar under PEG stress conditions, and TaMYB30-B was selected for further analysis. The TaMYB30-B protein was localized to the nucleus where it activated transcription. The detailed characterization of Arabidopsis transgenic plants that overexpress the TaMYB30-B gene revealed that the TaMYB30-B protein can improve drought stress tolerance during the germination and the seedling stages. It was also found that overexpression of TaMYB30-B resulted in altered expression levels of some drought stress-responsive genes and changes in several physiological indices, which allow plants to overcome adverse conditions. These results indicate that the TaMYB30-B protein plays important roles in plant stress tolerance, and modification of its expression may improve drought stress tolerance in crop plants.
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Affiliation(s)
- Lichao Zhang
- Key Laboratory of Crop Germplasm Resources and Utilization, Ministry of Agriculture, The National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
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1802
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Davies KM, Albert NW, Schwinn KE. From landing lights to mimicry: the molecular regulation of flower colouration and mechanisms for pigmentation patterning. FUNCTIONAL PLANT BIOLOGY : FPB 2012; 39:619-638. [PMID: 32480814 DOI: 10.1071/fp12195] [Citation(s) in RCA: 169] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Accepted: 07/03/2012] [Indexed: 05/22/2023]
Abstract
Flower colour is a key component for plant signaling to pollinators and a staggering variety of colour variations are found in nature. Patterning of flower colour, such as pigment spots or stripes, is common and is important in promoting pollination success. Developmentally programmed pigmentation patterns are of interest with respect to the evolution of specialised plant-pollinator associations and as models for dissecting regulatory signaling in plants. This article reviews the occurrence and function of flower colour patterns, as well as the molecular genetics of anthocyanin pigmentation regulation. The transcription factors controlling anthocyanin biosynthesis have been characterised for many species and an 'MBW' regulatory complex of R2R3MYB, bHLH and WD-Repeat proteins is of central importance. In particular, R2R3MYBs are key determinants of pigmentation intensity and patterning in plants. Progress is now being made on how environmental or developmental signal pathways may in turn control the production of the MBW components. Furthermore, additional regulatory proteins that interact with the MBW activation complex are being identified, including a range of proteins that repress complex formation or action, either directly or indirectly. This review discusses some of the recent data on the regulatory factors and presents models of how patterns may be determined.
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Affiliation(s)
- Kevin M Davies
- The New Zealand Institute for Plant and Food Research Ltd, Private Bag 11600, Palmerston North, New Zealand
| | - Nick W Albert
- The New Zealand Institute for Plant and Food Research Ltd, Private Bag 11600, Palmerston North, New Zealand
| | - Kathy E Schwinn
- The New Zealand Institute for Plant and Food Research Ltd, Private Bag 11600, Palmerston North, New Zealand
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1803
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Arratia-Quijada J, Sánchez O, Scazzocchio C, Aguirre J. FlbD, a Myb transcription factor of Aspergillus nidulans, is uniquely involved in both asexual and sexual differentiation. EUKARYOTIC CELL 2012; 11:1132-42. [PMID: 22798393 PMCID: PMC3445977 DOI: 10.1128/ec.00101-12] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Accepted: 07/06/2012] [Indexed: 01/01/2023]
Abstract
In the fungus Aspergillus nidulans, inactivation of the flbA to -E, fluG, fluF, and tmpA genes results in similar phenotypes, characterized by a delay in conidiophore and asexual spore production. flbB to -D encode transcription factors needed for proper expression of the brlA gene, which is essential for asexual development. However, recent evidence indicates that FlbB and FlbE also have nontranscriptional functions. Here we show that fluF1 is an allele of flbD which results in an R47P substitution. Amino acids C46 and R47 are highly conserved in FlbD and many other Myb proteins, and C46 has been proposed to mediate redox regulation. Comparison of ΔflbD and flbD(R47P) mutants uncovered a new and specific role for flbD during sexual development. While flbD(R47P) mutants retain partial function during conidiation, both ΔflbD and flbD(R47P) mutants are unable to develop the peridium, a specialized external tissue that differentiates during fruiting body formation and ends up surrounding the sexual spores. This function, unique among other fluffy genes, does not affect the viability of the naked ascospores produced by mutant strains. Notably, ascospore development in these mutants is still dependent on the NADPH oxidase NoxA. We generated R47K, C46D, C46S, and C46A mutant alleles and evaluated their effects on asexual and sexual development. Conidiation defects were most severe in ΔflbD mutants and stronger in R47P, C46D, and C46S strains than in R47K strains. In contrast, mutants carrying the flbD(C46A) allele exhibited conidiation defects in liquid culture only under nitrogen starvation conditions. The R47K, R47P, C46D, and C46S mutants failed to develop any peridial tissue, while the flbD(C46A) strain showed normal peridium development and increased cleistothecium formation. Our results show that FlbD regulates both asexual and sexual differentiation, suggesting that both processes require FlbD DNA binding activity and that FlbD is involved in the response to nitrogen starvation.
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Affiliation(s)
- Jenny Arratia-Quijada
- Departamento de Biología Celular y Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Olivia Sánchez
- Departamento de Biología Celular y Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Claudio Scazzocchio
- Institut de Génétique et Microbiologie, Université Paris-Sud (XI), Orsay, France
- Department of Microbiology, Imperial College London, London, United Kingdom
| | - Jesús Aguirre
- Departamento de Biología Celular y Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
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1804
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Koschmann J, Machens F, Becker M, Niemeyer J, Schulze J, Bülow L, Stahl DJ, Hehl R. Integration of bioinformatics and synthetic promoters leads to the discovery of novel elicitor-responsive cis-regulatory sequences in Arabidopsis. PLANT PHYSIOLOGY 2012; 160:178-91. [PMID: 22744985 PMCID: PMC3440196 DOI: 10.1104/pp.112.198259] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 06/26/2012] [Indexed: 05/03/2023]
Abstract
A combination of bioinformatic tools, high-throughput gene expression profiles, and the use of synthetic promoters is a powerful approach to discover and evaluate novel cis-sequences in response to specific stimuli. With Arabidopsis (Arabidopsis thaliana) microarray data annotated to the PathoPlant database, 732 different queries with a focus on fungal and oomycete pathogens were performed, leading to 510 up-regulated gene groups. Using the binding site estimation suite of tools, BEST, 407 conserved sequence motifs were identified in promoter regions of these coregulated gene sets. Motif similarities were determined with STAMP, classifying the 407 sequence motifs into 37 families. A comparative analysis of these 37 families with the AthaMap, PLACE, and AGRIS databases revealed similarities to known cis-elements but also led to the discovery of cis-sequences not yet implicated in pathogen response. Using a parsley (Petroselinum crispum) protoplast system and a modified reporter gene vector with an internal transformation control, 25 elicitor-responsive cis-sequences from 10 different motif families were identified. Many of the elicitor-responsive cis-sequences also drive reporter gene expression in an Agrobacterium tumefaciens infection assay in Nicotiana benthamiana. This work significantly increases the number of known elicitor-responsive cis-sequences and demonstrates the successful integration of a diverse set of bioinformatic resources combined with synthetic promoter analysis for data mining and functional screening in plant-pathogen interaction.
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Affiliation(s)
- Jeannette Koschmann
- Institut für Genetik, Technische Universität Braunschweig, 38106 Braunschweig, Germany (J.K., F.M., M.B., J.N., L.B., R.H.); Institut für Pflanzenbiologie, Technische Universität Braunschweig, 38106 Braunschweig, Germany (J.S.); and KWS SAAT AG, 37555 Einbeck, Germany (D.J.S.)
| | - Fabian Machens
- Institut für Genetik, Technische Universität Braunschweig, 38106 Braunschweig, Germany (J.K., F.M., M.B., J.N., L.B., R.H.); Institut für Pflanzenbiologie, Technische Universität Braunschweig, 38106 Braunschweig, Germany (J.S.); and KWS SAAT AG, 37555 Einbeck, Germany (D.J.S.)
| | - Marlies Becker
- Institut für Genetik, Technische Universität Braunschweig, 38106 Braunschweig, Germany (J.K., F.M., M.B., J.N., L.B., R.H.); Institut für Pflanzenbiologie, Technische Universität Braunschweig, 38106 Braunschweig, Germany (J.S.); and KWS SAAT AG, 37555 Einbeck, Germany (D.J.S.)
| | - Julia Niemeyer
- Institut für Genetik, Technische Universität Braunschweig, 38106 Braunschweig, Germany (J.K., F.M., M.B., J.N., L.B., R.H.); Institut für Pflanzenbiologie, Technische Universität Braunschweig, 38106 Braunschweig, Germany (J.S.); and KWS SAAT AG, 37555 Einbeck, Germany (D.J.S.)
| | - Jutta Schulze
- Institut für Genetik, Technische Universität Braunschweig, 38106 Braunschweig, Germany (J.K., F.M., M.B., J.N., L.B., R.H.); Institut für Pflanzenbiologie, Technische Universität Braunschweig, 38106 Braunschweig, Germany (J.S.); and KWS SAAT AG, 37555 Einbeck, Germany (D.J.S.)
| | - Lorenz Bülow
- Institut für Genetik, Technische Universität Braunschweig, 38106 Braunschweig, Germany (J.K., F.M., M.B., J.N., L.B., R.H.); Institut für Pflanzenbiologie, Technische Universität Braunschweig, 38106 Braunschweig, Germany (J.S.); and KWS SAAT AG, 37555 Einbeck, Germany (D.J.S.)
| | - Dietmar J. Stahl
- Institut für Genetik, Technische Universität Braunschweig, 38106 Braunschweig, Germany (J.K., F.M., M.B., J.N., L.B., R.H.); Institut für Pflanzenbiologie, Technische Universität Braunschweig, 38106 Braunschweig, Germany (J.S.); and KWS SAAT AG, 37555 Einbeck, Germany (D.J.S.)
| | - Reinhard Hehl
- Institut für Genetik, Technische Universität Braunschweig, 38106 Braunschweig, Germany (J.K., F.M., M.B., J.N., L.B., R.H.); Institut für Pflanzenbiologie, Technische Universität Braunschweig, 38106 Braunschweig, Germany (J.S.); and KWS SAAT AG, 37555 Einbeck, Germany (D.J.S.)
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1805
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Zhu H, Xia R, Zhao B, An YQ, Dardick CD, Callahan AM, Liu Z. Unique expression, processing regulation, and regulatory network of peach (Prunus persica) miRNAs. BMC PLANT BIOLOGY 2012; 12:149. [PMID: 22909020 PMCID: PMC3542160 DOI: 10.1186/1471-2229-12-149] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Accepted: 08/13/2012] [Indexed: 05/19/2023]
Abstract
BACKGROUND MicroRNAs (miRNAs) have recently emerged as important gene regulators in plants. MiRNAs and their targets have been extensively studied in Arabidopsis and rice. However, relatively little is known about the characterization of miRNAs and their target genes in peach (Prunus persica), which is a complex crop with unique developmental programs. RESULTS We performed small RNA deep sequencing and identified 47 peach-specific and 47 known miRNAs or families with distinct expression patterns. Together, the identified miRNAs targeted 80 genes, many of which have not been reported previously. Like the model plant systems, peach has two of the three conserved trans-acting siRNA biogenesis pathways with similar mechanistic features and target specificity. Unique to peach, three of the miRNAs collectively target 49 MYBs, 19 of which are known to regulate phenylpropanoid metabolism, a key pathway associated with stone hardening and fruit color development, highlighting a critical role of miRNAs in the regulation of peach fruit development and ripening. We also found that the majority of the miRNAs were differentially regulated in different tissues, in part due to differential processing of miRNA precursors. Up to 16% of the peach-specific miRNAs were differentially processed from their precursors in a tissue specific fashion, which has been rarely observed in plant cells. The miRNA precursor processing activity appeared not to be coupled with its transcriptional activity but rather acted independently in peach. CONCLUSIONS Collectively, the data characterizes the unique expression pattern and processing regulation of peach miRNAs and demonstrates the presence of a complex, multi-level miRNA regulatory network capable of targeting a wide variety of biological functions, including phenylpropanoid pathways which play a multifaceted spatial-temporal role in peach fruit development.
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Affiliation(s)
- Hong Zhu
- Department of Horticulture, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA
- Appalachian Fruit Research Station, Agricultural Research Service, United States Department of Agriculture, Kearneysville, WV, 25430, USA
| | - Rui Xia
- Department of Horticulture, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA
- Alson H. Smith Agricultural Research and Extension Center, Virginia Polytechnic Institute and State University, Winchester, VA, 22602, USA
- Appalachian Fruit Research Station, Agricultural Research Service, United States Department of Agriculture, Kearneysville, WV, 25430, USA
| | - Bingyu Zhao
- Department of Horticulture, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA
| | - Yong-qiang An
- USDA-ARS, Plant Genetic Research, Danforth Plant Science Center, 975 N. Warson Road, St. Louis, MO, 63132, USA
| | - Chris D Dardick
- Appalachian Fruit Research Station, Agricultural Research Service, United States Department of Agriculture, Kearneysville, WV, 25430, USA
| | - Ann M Callahan
- Appalachian Fruit Research Station, Agricultural Research Service, United States Department of Agriculture, Kearneysville, WV, 25430, USA
| | - Zongrang Liu
- Department of Horticulture, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA
- Appalachian Fruit Research Station, Agricultural Research Service, United States Department of Agriculture, Kearneysville, WV, 25430, USA
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1806
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Kliebenstein DJ, Osbourn A. Making new molecules - evolution of pathways for novel metabolites in plants. CURRENT OPINION IN PLANT BIOLOGY 2012; 15:415-23. [PMID: 22683039 DOI: 10.1016/j.pbi.2012.05.005] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Revised: 05/09/2012] [Accepted: 05/09/2012] [Indexed: 05/22/2023]
Abstract
Plants have adapted to their environments by diversifying in various ways. This diversification is reflected at the phytochemical level in their production of numerous specialized secondary metabolites that provide protection against biotic and abiotic stresses. Plant speciation is therefore intimately linked to metabolic diversification, yet we do not currently have a deep understanding of how new metabolic pathways evolve. Recent evidence indicates that genes for individual secondary metabolic pathways can be either distributed throughout the genome or clustered, but the relative frequencies of these two pathway organizations remain to be established. While it is possible that clustering is a feature of pathways that have evolved in recent evolutionary time, the answer to this and how dispersed and clustered pathways may be related remain to be addressed. Recent advances enabled by genomics and systems biology are beginning to yield the first insights into network evolution in plant metabolism. This review focuses on recent progress in understanding the evolution of clustered and dispersed pathways for new secondary metabolites in plants.
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1807
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Du H, Yang SS, Liang Z, Feng BR, Liu L, Huang YB, Tang YX. Genome-wide analysis of the MYB transcription factor superfamily in soybean. BMC PLANT BIOLOGY 2012; 12:106. [PMID: 22776508 PMCID: PMC3462118 DOI: 10.1186/1471-2229-12-106] [Citation(s) in RCA: 243] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Accepted: 06/06/2012] [Indexed: 05/18/2023]
Abstract
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 study we identified the largest MYB gene family in plants known to date. Our findings indicate that members of this large gene family may be involved in different plant biological processes, some of which may be potentially involved in legume-specific nodulation. Our comparative genomics analysis provides a solid foundation for future functional dissection of this family gene.
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Affiliation(s)
- Hai Du
- Maize Research Institute, Sichuan Agricultural University, Chengdu Sichuan, China
- Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Maize Research Institute of Sichuan Agricultural University, Ministry of Agriculture, Chengdu Sichuan, China
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Si-Si Yang
- Maize Research Institute, Sichuan Agricultural University, Chengdu Sichuan, China
- Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Maize Research Institute of Sichuan Agricultural University, Ministry of Agriculture, Chengdu Sichuan, China
| | - Zhe Liang
- Department of Plant and Environmental Sciences, Norwegian University of Life Sciences, PO Box 5003N-1432, Norway
| | - Bo-Run Feng
- Maize Research Institute, Sichuan Agricultural University, Chengdu Sichuan, China
- Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Maize Research Institute of Sichuan Agricultural University, Ministry of Agriculture, Chengdu Sichuan, China
| | - Lei Liu
- Maize Research Institute, Sichuan Agricultural University, Chengdu Sichuan, China
| | - Yu-Bi Huang
- Maize Research Institute, Sichuan Agricultural University, Chengdu Sichuan, China
- Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Maize Research Institute of Sichuan Agricultural University, Ministry of Agriculture, Chengdu Sichuan, China
| | - Yi-Xiong Tang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
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1808
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Xu XH, Chen H, Sang YL, Wang F, Ma JP, Gao XQ, Zhang XS. Identification of genes specifically or preferentially expressed in maize silk reveals similarity and diversity in transcript abundance of different dry stigmas. BMC Genomics 2012; 13:294. [PMID: 22748054 PMCID: PMC3416702 DOI: 10.1186/1471-2164-13-294] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Accepted: 07/02/2012] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND In plants, pollination is a critical step in reproduction. During pollination, constant communication between male pollen and the female stigma is required for pollen adhesion, germination, and tube growth. The detailed mechanisms of stigma-mediated reproductive processes, however, remain largely unknown. Maize (Zea mays L.), one of the world's most important crops, has been extensively used as a model species to study molecular mechanisms of pollen and stigma interaction. A comprehensive analysis of maize silk transcriptome may provide valuable information for investigating stigma functionality. A comparative analysis of expression profiles between maize silk and dry stigmas of other species might reveal conserved and diverse mechanisms that underlie stigma-mediated reproductive processes in various plant species. RESULTS Transcript abundance profiles of mature silk, mature pollen, mature ovary, and seedling were investigated using RNA-seq. By comparing the transcriptomes of these tissues, we identified 1,427 genes specifically or preferentially expressed in maize silk. Bioinformatic analyses of these genes revealed many genes with known functions in plant reproduction as well as novel candidate genes that encode amino acid transporters, peptide and oligopeptide transporters, and cysteine-rich receptor-like kinases. In addition, comparison of gene sets specifically or preferentially expressed in stigmas of maize, rice (Oryza sativa L.), and Arabidopsis (Arabidopsis thaliana [L.] Heynh.) identified a number of homologous genes involved either in pollen adhesion, hydration, and germination or in initial growth and penetration of pollen tubes into the stigma surface. The comparison also indicated that maize shares a more similar profile and larger number of conserved genes with rice than with Arabidopsis, and that amino acid and lipid transport-related genes are distinctively overrepresented in maize. CONCLUSIONS Many of the novel genes uncovered in this study are potentially involved in stigma-mediated reproductive processes, including genes encoding amino acid transporters, peptide and oligopeptide transporters, and cysteine-rich receptor-like kinases. The data also suggest that dry stigmas share similar mechanisms at early stages of pollen-stigma interaction. Compared with Arabidopsis, maize and rice appear to have more conserved functional mechanisms. Genes involved in amino acid and lipid transport may be responsible for mechanisms in the reproductive process that are unique to maize silk.
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Affiliation(s)
- Xiao Hui Xu
- State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, Shandong, China
| | - Hao Chen
- State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, Shandong, China
| | - Ya Lin Sang
- State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, Shandong, China
- College of Forestry, Shandong Agricultural University, Tai’an, Shandong, China
| | - Fang Wang
- State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, Shandong, China
| | - Jun Ping Ma
- State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, Shandong, China
| | - Xin-Qi Gao
- State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, Shandong, China
| | - Xian Sheng Zhang
- State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, Shandong, China
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1809
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Beets CA, Huang JC, Madala NE, Dubery I. Activation of camalexin biosynthesis in Arabidopsis thaliana in response to perception of bacterial lipopolysaccharides: a gene-to-metabolite study. PLANTA 2012; 236:261-72. [PMID: 22350766 DOI: 10.1007/s00425-012-1606-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Accepted: 01/31/2012] [Indexed: 05/08/2023]
Abstract
Lipopolysaccharides (LPS), as lipoglycan microbe-associated molecular pattern molecules, trigger activation of signal transduction pathways involved in defence that generate an enhanced defensive capacity in plants. The transcriptional regulation of the genes for tryptophan synthase B, TSB1, and the cytochrome P450 monooxygenases CYP79B2 and CYP71B15, involved in the camalexin biosynthetic pathway, were investigated in response to LPS treatment. GUS-reporter assays for CYP71B15 and CYP79B2 gene promoter activation were performed on transgenic plants and showed positive histochemical staining in response to LPS treatment, indicating activation of the promoters. Quantitative PCR revealed that transcripts of TSB1, CYP79B2 and CYP71B15 exhibited differential, transient up-regulation. TSB1 transcript levels were up-regulated between 6 and 9 h after LPS-induction, while CYP71B15 and CYP79B2 both exhibited maxima at 12 h. To obtain information on the gene-to-metabolite network, the effect of the transcriptome changes on the metabolome was correlated to camalexin production. Increases in camalexin concentration were quantified by ultra pressure liquid chromatography-mass spectrometry and both absorbance spectra and elemental composition confirmed its identity. The concentrations increased from 0.03 to 3.7 μg g(-1) fresh weight over a 24-h time period, thus indicating that the up-regulation of the biosynthetic pathway in response to LPS was accompanied by a time-dependent increase in camalexin concentration. Metabolomic analysis through principal component analysis-derived scores plots revealed clusters of sample replicates for 0, 6, 12, 18 and 24 h while loadings plots for LPS data identified camalexin as a biomarker that clearly demonstrated the variability between samples.
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Affiliation(s)
- Caryn Ann Beets
- Department of Biochemistry, University of Johannesburg, Auckland Park, Johannesburg, South Africa
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1810
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Hancock KR, Collette V, Fraser K, Greig M, Xue H, Richardson K, Jones C, Rasmussen S. Expression of the R2R3-MYB transcription factor TaMYB14 from Trifolium arvense activates proanthocyanidin biosynthesis in the legumes Trifolium repens and Medicago sativa. PLANT PHYSIOLOGY 2012; 159:1204-20. [PMID: 22566493 PMCID: PMC3387705 DOI: 10.1104/pp.112.195420] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2012] [Accepted: 05/06/2012] [Indexed: 05/18/2023]
Abstract
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.
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Affiliation(s)
| | - Vern Collette
- AgResearch, Ltd., Palmerston North 4442, New Zealand
| | - Karl Fraser
- AgResearch, Ltd., Palmerston North 4442, New Zealand
| | | | - Hong Xue
- AgResearch, Ltd., Palmerston North 4442, New Zealand
| | | | - Chris Jones
- AgResearch, Ltd., Palmerston North 4442, New Zealand
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1811
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Fini A, Guidi L, Ferrini F, Brunetti C, Di Ferdinando M, Biricolti S, Pollastri S, Calamai L, Tattini M. Drought stress has contrasting effects on antioxidant enzymes activity and phenylpropanoid biosynthesis in Fraxinus ornus leaves: an excess light stress affair? JOURNAL OF PLANT PHYSIOLOGY 2012; 169:929-39. [PMID: 22537713 DOI: 10.1016/j.jplph.2012.02.014] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Revised: 02/02/2012] [Accepted: 02/07/2012] [Indexed: 05/18/2023]
Abstract
The experiment was conducted using Fraxinus ornus plants grown outside under full sunlight irradiance, and supplied with 100% (well-watered, WW), 40% (mild drought, MD), or 20% (severe drought, SD) of the daily evapotranspiration demand, with the main objective of exploring the effect of excess light stress on the activity of antioxidant enzymes and phenylpropanoid biosynthesis. Net CO₂ assimilation rate at saturating light and daily assimilated CO₂ were significantly smaller in SD than in WW and MD plants. Xanthophyll-cycle pigments supported nonphotochemical quenching to a significantly greater extent in SD than in MD and WW leaves. As a consequence, the actual efficiency of PSII (Φ(PSII)) was smaller, while the excess excitation-energy in the photosynthetic apparatus was greater in SD than in WW or MD plants. The concentrations of violaxanthin-cycle pigments relative to total chlorophyll (Chl(tot)) exceeded 200 mmol mol⁻¹ Chl(tot) in SD leaves at the end of the experiment. This leads to hypothesize for zeaxanthin a role not only as nonphotochemical quencher, but also as chloroplast antioxidant. Reductions in ascorbate peroxidase and catalase activities, as drought-stress progressed, were paralleled by greater accumulations of esculetin and quercetin 3-O-glycosides, both phenylpropanoids having effective capacity to scavenge H₂O₂. The drought-induced accumulation of esculetin and quercetin 3-O-glycosides in the vacuoles of mesophyll cells is consistent with their putative functions as reducing agents for H₂O₂ in excess light-stressed leaves. Nonetheless, the concentration of H₂O₂ and the lipid peroxidation were significantly greater in SD than in MD and WW leaves. It is speculated that vacuolar phenylpropanoids may constitute a secondary antioxidant system, even on a temporal basis, activated upon the depletion of primary antioxidant defences, and aimed at keeping whole-cell H₂O₂ within a sub-lethal concentration range.
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Affiliation(s)
- Alessio Fini
- Dipartimento di Scienze delle Produzioni Vegetali, del Suolo e dell'Ambiente Agroforestale, Università di Firenze, Viale delle Idee 30, I-50019 Sesto Fiorentino, Firenze, Italy
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1812
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Xia R, Zhu H, An YQ, Beers EP, Liu Z. Apple miRNAs and tasiRNAs with novel regulatory networks. Genome Biol 2012; 13:R47. [PMID: 22704043 PMCID: PMC3446319 DOI: 10.1186/gb-2012-13-6-r47] [Citation(s) in RCA: 211] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Revised: 05/30/2012] [Accepted: 06/15/2012] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND MicroRNAs (miRNAs) and their regulatory functions have been extensively characterized in model species but whether apple has evolved similar or unique regulatory features remains unknown. RESULTS We performed deep small RNA-seq and identified 23 conserved, 10 less-conserved and 42 apple-specific miRNAs or families with distinct expression patterns. The identified miRNAs target 118 genes representing a wide range of enzymatic and regulatory activities. Apple also conserves two TAS gene families with similar but unique trans-acting small interfering RNA (tasiRNA) biogenesis profiles and target specificities. Importantly, we found that miR159, miR828 and miR858 can collectively target up to 81 MYB genes potentially involved in diverse aspects of plant growth and development. These miRNA target sites are differentially conserved among MYBs, which is largely influenced by the location and conservation of the encoded amino acid residues in MYB factors. Finally, we found that 10 of the 19 miR828-targeted MYBs undergo small interfering RNA (siRNA) biogenesis at the 3' cleaved, highly divergent transcript regions, generating over 100 sequence-distinct siRNAs that potentially target over 70 diverse genes as confirmed by degradome analysis. CONCLUSIONS Our work identified and characterized apple miRNAs, their expression patterns, targets and regulatory functions. We also discovered that three miRNAs and the ensuing siRNAs exploit both conserved and divergent sequence features of MYB genes to initiate distinct regulatory networks targeting a multitude of genes inside and outside the MYB family.
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Affiliation(s)
- Rui Xia
- Department of Horticulture, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
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1813
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Du H, Feng BR, Yang SS, Huang YB, Tang YX. The R2R3-MYB transcription factor gene family in maize. PLoS One 2012; 7:e37463. [PMID: 22719841 PMCID: PMC3370817 DOI: 10.1371/journal.pone.0037463] [Citation(s) in RCA: 187] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Accepted: 04/20/2012] [Indexed: 12/15/2022] Open
Abstract
MYB proteins comprise a large family of plant transcription factors, members of which perform a variety of functions in plant biological processes. To date, no genome-wide characterization of this gene family has been conducted in maize (Zea mays). In the present study, we performed a comprehensive computational analysis, to yield a complete overview of the R2R3-MYB gene family in maize, including the phylogeny, expression patterns, and also its structural and functional characteristics. The MYB gene structure in maize and Arabidopsis were highly conserved, indicating that they were originally compact in size. Subgroup-specific conserved motifs outside the MYB domain may reflect functional conservation. The genome distribution strongly supports the hypothesis that segmental and tandem duplication contribute to the expansion of maize MYB genes. We also performed an updated and comprehensive classification of the R2R3-MYB gene families in maize and other plant species. The result revealed that the functions were conserved between maize MYB genes and their putative orthologs, demonstrating the origin and evolutionary diversification of plant MYB genes. Species-specific groups/subgroups may evolve or be lost during evolution, resulting in functional divergence. Expression profile study indicated that maize R2R3-MYB genes exhibit a variety of expression patterns, suggesting diverse functions. Furthermore, computational prediction potential targets of maize microRNAs (miRNAs) revealed that miR159, miR319, and miR160 may be implicated in regulating maize R2R3-MYB genes, suggesting roles of these miRNAs in post-transcriptional regulation and transcription networks. Our comparative analysis of R2R3-MYB genes in maize confirm and extend the sequence and functional characteristics of this gene family, and will facilitate future functional analysis of the MYB gene family in maize.
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Affiliation(s)
- Hai Du
- Maize Research Institute, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Maize Research Institute of Sichuan Agricultural University, Ministry of Agriculture, Chengdu, Sichuan, China
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Bo-Run Feng
- Maize Research Institute, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Si-Si Yang
- Maize Research Institute, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Yu-Bi Huang
- Maize Research Institute, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Maize Research Institute of Sichuan Agricultural University, Ministry of Agriculture, Chengdu, Sichuan, China
- * E-mail: (YBH); (YXT)
| | - Yi-Xiong Tang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
- * E-mail: (YBH); (YXT)
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1814
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De Geyter N, Gholami A, Goormachtig S, Goossens A. Transcriptional machineries in jasmonate-elicited plant secondary metabolism. TRENDS IN PLANT SCIENCE 2012; 17:349-59. [PMID: 22459758 DOI: 10.1016/j.tplants.2012.03.001] [Citation(s) in RCA: 309] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Revised: 03/01/2012] [Accepted: 03/02/2012] [Indexed: 05/18/2023]
Abstract
Jasmonates (JAs) act as conserved elicitors of plant secondary metabolism. JA perception triggers extensive transcriptional reprogramming leading to the concerted activation of entire metabolic pathways. This observation inspired numerous quests for 'master' regulators capable of enhancing the production of specific sets of valuable plant metabolites. Many transcription factors (TFs), often JA-activated themselves, with a role in the JA-modulated regulation of metabolism were discovered. At the same time, it became clear that metabolic reprogramming is subject to complex control mechanisms integrated in robust cellular networks. In this review, we discuss current knowledge of the effect of JA-modulated TFs in the elicitation of secondary metabolism in the model plant Arabidopsis (Arabidopsis thaliana) and a range of medicinal plant species with structurally divergent secondary metabolites. We draw parallels with the regulation of secondary metabolism in fungi and consider the remaining challenges to map and exploit the transcriptional machineries that drive JA-mediated elicitation of plant secondary metabolism.
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Affiliation(s)
- Nathan De Geyter
- Department of Plant Systems Biology, VIB, Ghent University, Technologiepark 927, B-9052 Gent, Belgium
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1815
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Routaboul JM, Dubos C, Beck G, Marquis C, Bidzinski P, Loudet O, Lepiniec L. Metabolite profiling and quantitative genetics of natural variation for flavonoids in Arabidopsis. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:3749-64. [PMID: 22442426 PMCID: PMC3388840 DOI: 10.1093/jxb/ers067] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Little is known about the range and the genetic bases of naturally occurring variation for flavonoids. Using Arabidopsis thaliana seed as a model, the flavonoid content of 41 accessions and two recombinant inbred line (RIL) sets derived from divergent accessions (Cvi-0×Col-0 and Bay-0×Shahdara) were analysed. These accessions and RILs showed mainly quantitative rather than qualitative changes. To dissect the genetic architecture underlying these differences, a quantitative trait locus (QTL) analysis was performed on the two segregating populations. Twenty-two flavonoid QTLs were detected that accounted for 11-64% of the observed trait variations, only one QTL being common to both RIL sets. Sixteen of these QTLs were confirmed and coarsely mapped using heterogeneous inbred families (HIFs). Three genes, namely TRANSPARENT TESTA (TT)7, TT15, and MYB12, were proposed to underlie their variations since the corresponding mutants and QTLs displayed similar specific flavonoid changes. Interestingly, most loci did not co-localize with any gene known to be involved in flavonoid metabolism. This latter result shows that novel functions have yet to be characterized and paves the way for their isolation.
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1816
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Shelton D, Stranne M, Mikkelsen L, Pakseresht N, Welham T, Hiraka H, Tabata S, Sato S, Paquette S, Wang TL, Martin C, Bailey P. Transcription factors of Lotus: regulation of isoflavonoid biosynthesis requires coordinated changes in transcription factor activity. PLANT PHYSIOLOGY 2012; 159:531-47. [PMID: 22529285 PMCID: PMC3375922 DOI: 10.1104/pp.112.194753] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Accepted: 04/23/2012] [Indexed: 05/20/2023]
Abstract
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.
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Affiliation(s)
- Dale Shelton
- Department of Plant Biology and Biotechnology, University of Copenhagen, 1871 Frederiksberg, Denmark (D.S., M.S., L.M., C.M.)
- John Innes Centre, Colney, Norwich NR4 7UH, United Kingdom (N.P., T.W., T.L.W., C.M., P.B.)
- Kazusa DNA Research Institute, 292–0818 Chiba, Japan (H.H., S.T., S.S.)
- Department of Genome Science, University of Washington, Seattle, Washington 98195 (S.P.)
| | - Maria Stranne
- Department of Plant Biology and Biotechnology, University of Copenhagen, 1871 Frederiksberg, Denmark (D.S., M.S., L.M., C.M.)
- John Innes Centre, Colney, Norwich NR4 7UH, United Kingdom (N.P., T.W., T.L.W., C.M., P.B.)
- Kazusa DNA Research Institute, 292–0818 Chiba, Japan (H.H., S.T., S.S.)
- Department of Genome Science, University of Washington, Seattle, Washington 98195 (S.P.)
| | - Lisbeth Mikkelsen
- Department of Plant Biology and Biotechnology, University of Copenhagen, 1871 Frederiksberg, Denmark (D.S., M.S., L.M., C.M.)
- John Innes Centre, Colney, Norwich NR4 7UH, United Kingdom (N.P., T.W., T.L.W., C.M., P.B.)
- Kazusa DNA Research Institute, 292–0818 Chiba, Japan (H.H., S.T., S.S.)
- Department of Genome Science, University of Washington, Seattle, Washington 98195 (S.P.)
| | - Nima Pakseresht
- Department of Plant Biology and Biotechnology, University of Copenhagen, 1871 Frederiksberg, Denmark (D.S., M.S., L.M., C.M.)
- John Innes Centre, Colney, Norwich NR4 7UH, United Kingdom (N.P., T.W., T.L.W., C.M., P.B.)
- Kazusa DNA Research Institute, 292–0818 Chiba, Japan (H.H., S.T., S.S.)
- Department of Genome Science, University of Washington, Seattle, Washington 98195 (S.P.)
| | - Tracey Welham
- Department of Plant Biology and Biotechnology, University of Copenhagen, 1871 Frederiksberg, Denmark (D.S., M.S., L.M., C.M.)
- John Innes Centre, Colney, Norwich NR4 7UH, United Kingdom (N.P., T.W., T.L.W., C.M., P.B.)
- Kazusa DNA Research Institute, 292–0818 Chiba, Japan (H.H., S.T., S.S.)
- Department of Genome Science, University of Washington, Seattle, Washington 98195 (S.P.)
| | - Hideki Hiraka
- Department of Plant Biology and Biotechnology, University of Copenhagen, 1871 Frederiksberg, Denmark (D.S., M.S., L.M., C.M.)
- John Innes Centre, Colney, Norwich NR4 7UH, United Kingdom (N.P., T.W., T.L.W., C.M., P.B.)
- Kazusa DNA Research Institute, 292–0818 Chiba, Japan (H.H., S.T., S.S.)
- Department of Genome Science, University of Washington, Seattle, Washington 98195 (S.P.)
| | - Satoshi Tabata
- Department of Plant Biology and Biotechnology, University of Copenhagen, 1871 Frederiksberg, Denmark (D.S., M.S., L.M., C.M.)
- John Innes Centre, Colney, Norwich NR4 7UH, United Kingdom (N.P., T.W., T.L.W., C.M., P.B.)
- Kazusa DNA Research Institute, 292–0818 Chiba, Japan (H.H., S.T., S.S.)
- Department of Genome Science, University of Washington, Seattle, Washington 98195 (S.P.)
| | - Shusei Sato
- Department of Plant Biology and Biotechnology, University of Copenhagen, 1871 Frederiksberg, Denmark (D.S., M.S., L.M., C.M.)
- John Innes Centre, Colney, Norwich NR4 7UH, United Kingdom (N.P., T.W., T.L.W., C.M., P.B.)
- Kazusa DNA Research Institute, 292–0818 Chiba, Japan (H.H., S.T., S.S.)
- Department of Genome Science, University of Washington, Seattle, Washington 98195 (S.P.)
| | - Suzanne Paquette
- Department of Plant Biology and Biotechnology, University of Copenhagen, 1871 Frederiksberg, Denmark (D.S., M.S., L.M., C.M.)
- John Innes Centre, Colney, Norwich NR4 7UH, United Kingdom (N.P., T.W., T.L.W., C.M., P.B.)
- Kazusa DNA Research Institute, 292–0818 Chiba, Japan (H.H., S.T., S.S.)
- Department of Genome Science, University of Washington, Seattle, Washington 98195 (S.P.)
| | - Trevor L. Wang
- Department of Plant Biology and Biotechnology, University of Copenhagen, 1871 Frederiksberg, Denmark (D.S., M.S., L.M., C.M.)
- John Innes Centre, Colney, Norwich NR4 7UH, United Kingdom (N.P., T.W., T.L.W., C.M., P.B.)
- Kazusa DNA Research Institute, 292–0818 Chiba, Japan (H.H., S.T., S.S.)
- Department of Genome Science, University of Washington, Seattle, Washington 98195 (S.P.)
| | | | - Paul Bailey
- Department of Plant Biology and Biotechnology, University of Copenhagen, 1871 Frederiksberg, Denmark (D.S., M.S., L.M., C.M.)
- John Innes Centre, Colney, Norwich NR4 7UH, United Kingdom (N.P., T.W., T.L.W., C.M., P.B.)
- Kazusa DNA Research Institute, 292–0818 Chiba, Japan (H.H., S.T., S.S.)
- Department of Genome Science, University of Washington, Seattle, Washington 98195 (S.P.)
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1817
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Atkinson NJ, Urwin PE. The interaction of plant biotic and abiotic stresses: from genes to the field. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:3523-43. [PMID: 22467407 DOI: 10.1093/jxb/ers100] [Citation(s) in RCA: 755] [Impact Index Per Article: 62.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Plant responses to different stresses are highly complex and involve changes at the transcriptome, cellular, and physiological levels. Recent evidence shows that plants respond to multiple stresses differently from how they do to individual stresses, activating a specific programme of gene expression relating to the exact environmental conditions encountered. Rather than being additive, the presence of an abiotic stress can have the effect of reducing or enhancing susceptibility to a biotic pest or pathogen, and vice versa. This interaction between biotic and abiotic stresses is orchestrated by hormone signalling pathways that may induce or antagonize one another, in particular that of abscisic acid. Specificity in multiple stress responses is further controlled by a range of molecular mechanisms that act together in a complex regulatory network. Transcription factors, kinase cascades, and reactive oxygen species are key components of this cross-talk, as are heat shock factors and small RNAs. This review aims to characterize the interaction between biotic and abiotic stress responses at a molecular level, focusing on regulatory mechanisms important to both pathways. Identifying master regulators that connect both biotic and abiotic stress response pathways is fundamental in providing opportunities for developing broad-spectrum stress-tolerant crop plants.
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Affiliation(s)
- Nicky J Atkinson
- Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK.
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1818
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Overexpression of a wheat MYB transcription factor gene, TaMYB56-B, enhances tolerances to freezing and salt stresses in transgenic Arabidopsis. Gene 2012; 505:100-7. [PMID: 22634104 DOI: 10.1016/j.gene.2012.05.033] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Revised: 05/13/2012] [Accepted: 05/15/2012] [Indexed: 11/23/2022]
Abstract
The MYB proteins play central roles in the stress response in plants. Our previous works identified a cold stress-related gene, TaMYB56, which encodes a MYB protein in wheat. In this study, we isolated the sequences of TaMYB56 genes, and mapped them to the wheat chromosomes 3B and 3D. The expression levels of TaMYB56-B and TaMYB56-D were strongly induced by cold stress, but slightly induced by salt stress in wheat. The detailed characterization of the Arabidopsis transgenic plants that overexpress TaMYB56-B revealed that TaMYB56-B is possibly involved in the responses of plant to freezing and salt stresses. The expression of some cold stress-responsive genes, such as DREB1A/CBF3 and COR15a, were found to be elevated in the TaMYB56-B-overexpressing Arabidopsis plants compared to wild-type. These results indicate that TaMYB56-B may act as a regulator in plant stress response.
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1819
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Lin Y, Son H, Min K, Lee J, Choi GJ, Kim JC, Lee YW. A putative transcription factor MYT2 regulates perithecium size in the ascomycete Gibberella zeae. PLoS One 2012; 7:e37859. [PMID: 22649560 PMCID: PMC3359310 DOI: 10.1371/journal.pone.0037859] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Accepted: 04/25/2012] [Indexed: 11/18/2022] Open
Abstract
The homothallic ascomycete fungus Gibberella zeae is a plant pathogen that is found worldwide, causing Fusarium head blight (FHB) in cereal crops and ear rot of maize. Ascospores formed in fruiting bodies (i.e., perithecia) are hypothesized to be the primary inocula for FHB disease. Perithecium development is a complex cellular differentiation process controlled by many developmentally regulated genes. In this study, we selected a previously reported putative transcription factor containing the Myb DNA-binding domain MYT2 for an in-depth study on sexual development. The deletion of MYT2 resulted in a larger perithecium, while its overexpression resulted in a smaller perithecium when compared to the wild-type strain. These data suggest that MYT2 regulates perithecium size differentiation. MYT2 overexpression affected pleiotropic phenotypes including vegetative growth, conidia production, virulence, and mycotoxin production. Nuclear localization of the MYT2 protein supports its role as a transcriptional regulator. Transcriptional analyses of trichothecene synthetic genes suggest that MYT2 additionally functions as a suppressor for trichothecene production. This is the first study characterizing a transcription factor required for perithecium size differentiation in G. zeae, and it provides a novel angle for understanding sexual development in filamentous fungi.
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Affiliation(s)
- Yang Lin
- Department of Agricultural Biotechnology and the Center for Fungal Pathogenesis, Seoul National University, Seoul, Republic of Korea
| | - Hokyoung Son
- Department of Agricultural Biotechnology and the Center for Fungal Pathogenesis, Seoul National University, Seoul, Republic of Korea
| | - Kyunghun Min
- Department of Agricultural Biotechnology and the Center for Fungal Pathogenesis, Seoul National University, Seoul, Republic of Korea
| | - Jungkwan Lee
- Department of Applied Biology, Dong-A University, Busan, Republic of Korea
| | - Gyung Ja Choi
- Eco-friendly New Materials Research Group, Research Center for Biobased Chemistry, Division of Convergence Chemistry, Korea Research Institute of Chemical Technology, Daejeon, Republic of Korea
| | - Jin-Cheol Kim
- Eco-friendly New Materials Research Group, Research Center for Biobased Chemistry, Division of Convergence Chemistry, Korea Research Institute of Chemical Technology, Daejeon, Republic of Korea
| | - Yin-Won Lee
- Department of Agricultural Biotechnology and the Center for Fungal Pathogenesis, Seoul National University, Seoul, Republic of Korea
- * E-mail:
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1820
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Functional divergence of MYB-related genes, WEREWOLF and AtMYB23 in Arabidopsis. Biosci Biotechnol Biochem 2012; 76:883-7. [PMID: 22738953 DOI: 10.1271/bbb.110811] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Epidermal cell differentiation in Arabidopsis is studied as a model system to understand the mechanisms that determine the developmental end state of plant cells. MYB-related transcription factors are involved in cell fate determination. To examine the molecular basis of this process, we analyzed the functional relationship of two R2R3-type MYB genes, AtMYB23 (MYB23) and WEREWOLF (WER). MYB23 is involved in leaf trichome formation. WER represses root-hair formation. Swapping domains between MYB23 and WER, we found that a low homology region of MYB23 might be involved in ectopic trichome initiation on hypocotyls. MYB23 and all MYB23-WER (MW) chimeric transgenes rescued the increased root-hair phenotype of the wer-1 mutant. Although WER did not rescue the gl1-1 no-trichome phenotype, MYB23 and all MW chimeric transgenes rescued gl1-1. These results suggest that MYB23 acquired a specific function for trichome differentiation during evolution.
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1821
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Hoang MHT, Nguyen XC, Lee K, Kwon YS, Pham HTT, Park HC, Yun DJ, Lim CO, Chung WS. Phosphorylation by AtMPK6 is required for the biological function of AtMYB41 in Arabidopsis. Biochem Biophys Res Commun 2012; 422:181-6. [PMID: 22575450 DOI: 10.1016/j.bbrc.2012.04.137] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Accepted: 04/25/2012] [Indexed: 11/16/2022]
Abstract
Mitogen-activated protein kinases (MPKs) are involved in a number of signaling pathways that control plant development and stress tolerance via the phosphorylation of target molecules. However, so far only a limited number of target molecules have been identified. Here, we provide evidence that MYB41 represents a new target of MPK6. MYB41 interacts with MPK6 not only in vitro but also in planta. MYB41 was phosphorylated by recombinant MPK6 as well as by plant MPK6. Ser(251) in MYB41 was identified as the site phosphorylated by MPK6. The phosphorylation of MYB41 by MPK6 enhanced its DNA binding to the promoter of a LTP gene. Interestingly, transgenic plants over-expressing MYB41(WT) showed enhanced salt tolerance, whereas transgenic plants over-expressing MYB41(S251A) showed decreased salt tolerance during seed germination and initial root growth. These results indicate that the phosphorylation of MYB41 by MPK6 is required for the biological function of MYB41 in salt tolerance.
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Affiliation(s)
- My Hanh Thi Hoang
- Division of Applied Life Science (BK21 Program), Gyeongsang National University, Jinju 660-701, Republic of Korea
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1822
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Albrecht U, Bowman KD. Transcriptional response of susceptible and tolerant citrus to infection with Candidatus Liberibacter asiaticus. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2012; 185-186:118-30. [PMID: 22325873 DOI: 10.1016/j.plantsci.2011.09.008] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Revised: 09/26/2011] [Accepted: 09/27/2011] [Indexed: 05/06/2023]
Abstract
Candidatus Liberibacter asiaticus (Las), a non-culturable phloem-limited bacterium, is the suspected causal agent of huanglongbing (HLB) in Florida. HLB is one of the most devastating diseases of citrus and no resistant cultivars have been identified to date, though tolerance has been observed in the genus Poncirus and some of its hybrids. This study compares transcriptional changes in tolerant US-897 (Citrus reticulata Blanco×Poncirus trifoliata L. Raf.) and susceptible 'Cleopatra' mandarin (C. reticulata) seedlings in response to infection with Las using the Affymetrix GeneChip citrus array, with the main objective of identifying genes associated with tolerance to HLB. Microarray analysis identified 326 genes which were significantly upregulated by at least 4-fold in the susceptible genotype, compared with only 17 genes in US-897. Exclusively upregulated in US-897 was a gene for a 2-oxoglutarate (2OG) and Fe(II)-dependant oxygenase, an important enzyme involved in the biosynthesis of plant secondary metabolites. More than eight hundred genes were expressed at much higher levels in US-897 independent of infection with Las. Among these, genes for a constitutive disease resistance protein (CDR1) were notable. The possible involvement of these and other detected genes in tolerance to HLB and their possible use for biotechnology are discussed.
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Affiliation(s)
- Ute Albrecht
- US Horticultural Research Laboratory, US Department of Agriculture, Agricultural Research Service, Fort Pierce, FL 34945, USA.
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1823
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Tang N, Zhang H, Li X, Xiao J, Xiong L. Constitutive activation of transcription factor OsbZIP46 improves drought tolerance in rice. PLANT PHYSIOLOGY 2012; 158:1755-68. [PMID: 22301130 PMCID: PMC3320183 DOI: 10.1104/pp.111.190389] [Citation(s) in RCA: 198] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Accepted: 01/31/2012] [Indexed: 05/18/2023]
Abstract
OsbZIP46 is one member of the third subfamily of bZIP transcription factors in rice (Oryza sativa). It has high sequence similarity to ABA-responsive element binding factor (ABF/AREB) transcription factors ABI5 and OsbZIP23, two transcriptional activators positively regulating stress tolerance in Arabidopsis (Arabidopsis thaliana) and rice, respectively. Expression of OsbZIP46 was strongly induced by drought, heat, hydrogen peroxide, and abscisic acid (ABA) treatment; however, it was not induced by salt and cold stresses. Overexpression of the native OsbZIP46 gene increased ABA sensitivity but had no positive effect on drought resistance. The activation domain of OsbZIP46 was defined by a series of deletions, and a region (domain D) was identified as having a negative effect on the activation. We produced a constitutive active form of OsbZIP46 (OsbZIP46CA1) with a deletion of domain D. Overexpression of OsbZIP46CA1 in rice significantly increased tolerance to drought and osmotic stresses. Gene chip analysis of the two overexpressors (native OsbZIP46 and the constitutive active form OsbZIP46CA1) revealed that a large number of stress-related genes, many of them predicted to be downstream genes of ABF/AREBs, were activated in the OsbZIP46CA1 overexpressor but not (even down-regulated) in the OsbZIP46 overexpressor. OsbZIP46 can interact with homologs of SnRK2 protein kinases that phosphorylate ABFs in Arabidopsis. These results suggest that OsbZIP46 is a positive regulator of ABA signaling and drought stress tolerance of rice depending on its activation. The stress-related genes activated by OsbZIP46CA1 are largely different from those activated by the other rice ABF/AREB homologs (such as OsbZIP23), further implying the value of OsbZIP46CA1 in genetic engineering of drought tolerance.
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1824
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Kaplan-Levy RN, Brewer PB, Quon T, Smyth DR. The trihelix family of transcription factors--light, stress and development. TRENDS IN PLANT SCIENCE 2012; 17:163-71. [PMID: 22236699 DOI: 10.1016/j.tplants.2011.12.002] [Citation(s) in RCA: 127] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Revised: 12/01/2011] [Accepted: 12/02/2011] [Indexed: 05/07/2023]
Abstract
GT factors are the founding members of the trihelix transcription factor family. They bind GT elements in light regulated genes, and their nature was uncovered in a burst of activity in the 1990s. Study of the trihelix family then slowed. However, interest is now re-awakening. Genomic studies have revealed 30 members of this family in Arabidopsis and 31 in rice, falling into five clades. Newly discovered functions involve responses to salt and pathogen stresses, the development of perianth organs, trichomes, stomata and the seed abscission layer, and the regulation of late embryogenesis. Thus the time is ripe for a review of the genomic and functional information now emerging for this neglected family.
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Affiliation(s)
- Ruth N Kaplan-Levy
- School of Biological Sciences, Monash University, Clayton Campus, Melbourne, Vic 3800, Australia
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1825
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Gray J, Caparrós-Ruiz D, Grotewold E. Grass phenylpropanoids: regulate before using! PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2012; 184:112-20. [PMID: 22284715 DOI: 10.1016/j.plantsci.2011.12.008] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Revised: 12/06/2011] [Accepted: 12/09/2011] [Indexed: 05/18/2023]
Abstract
The phenylpropanoid pathway is responsible for the synthesis of lignin as well as a large number of compounds of fundamental importance for the biology of plants. Over the years, important knowledge has accumulated on how dicotyledoneous plants control various branches of phenylpropanoid accumulation, but comparable information on the grasses is lagging significantly behind. In addition to playing fundamental roles in biotic and abiotic interactions, phenylpropanoids in the grasses play a very important function in the reinforcement of cell wall components. Understanding how phenylpropanoid metabolism is controlled in the grasses has been complicated by recent genome duplications, the difficulties in making transgenic plants and the absence of mutants in many genes. Recent studies in a particular subgroup of R2R3-MYB transcription factors suggest that they might play a central role in regulating a small set of phenylpropanoid genes, opening the door for the identification of other related regulators, and perhaps also finding out which combinations of biosynthesis genes function in particular cell types for the formation of specific compounds. This information will be essential for the rational metabolic engineering of this pathway, either to increase biomass or decrease phenolic accumulation for better accessibility of polysaccharides for forage quality and biofuel production.
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Affiliation(s)
- John Gray
- Dept. Biological Sciences, University of Toledo, Toledo, OH 43606, USA
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1826
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Huang YF, Doligez A, Fournier-Level A, Le Cunff L, Bertrand Y, Canaguier A, Morel C, Miralles V, Veran F, Souquet JM, Cheynier V, Terrier N, This P. Dissecting genetic architecture of grape proanthocyanidin composition through quantitative trait locus mapping. BMC PLANT BIOLOGY 2012; 12:30. [PMID: 22369244 PMCID: PMC3312867 DOI: 10.1186/1471-2229-12-30] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Accepted: 02/27/2012] [Indexed: 05/20/2023]
Abstract
BACKGROUND Proanthocyanidins (PAs), or condensed tannins, are flavonoid polymers, widespread throughout the plant kingdom, which provide protection against herbivores while conferring organoleptic and nutritive values to plant-derived foods, such as wine. However, the genetic basis of qualitative and quantitative PA composition variation is still poorly understood. To elucidate the genetic architecture of the complex grape PA composition, we first carried out quantitative trait locus (QTL) analysis on a 191-individual pseudo-F1 progeny. Three categories of PA variables were assessed: total content, percentages of constitutive subunits and composite ratio variables. For nine functional candidate genes, among which eight co-located with QTLs, we performed association analyses using a diversity panel of 141 grapevine cultivars in order to identify causal SNPs. RESULTS Multiple QTL analysis revealed a total of 103 and 43 QTLs, respectively for seed and skin PA variables. Loci were mainly of additive effect while some loci were primarily of dominant effect. Results also showed a large involvement of pairwise epistatic interactions in shaping PA composition. QTLs for PA variables in skin and seeds differed in number, position, involvement of epistatic interaction and allelic effect, thus revealing different genetic determinisms for grape PA composition in seeds and skin. Association results were consistent with QTL analyses in most cases: four out of nine tested candidate genes (VvLAR1, VvMYBPA2, VvCHI1, VvMYBPA1) showed at least one significant association with PA variables, especially VvLAR1 revealed as of great interest for further functional investigation. Some SNP-phenotype associations were observed only in the diversity panel. CONCLUSIONS This study presents the first QTL analysis on grape berry PA composition with a comparison between skin and seeds, together with an association study. Our results suggest a complex genetic control for PA traits and different genetic architectures for grape PA composition between berry skin and seeds. This work also uncovers novel genomic regions for further investigation in order to increase our knowledge of the genetic basis of PA composition.
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Affiliation(s)
- Yung-Fen Huang
- UMR AGAP, INRA, 2, place Viala, 34060 Montpellier, France
- INRA, UMR1083 SPO, 2, place, Viala, 34060 Montpellier, France
| | - Agnès Doligez
- UMR AGAP, INRA, 2, place Viala, 34060 Montpellier, France
| | - Alexandre Fournier-Level
- UMR AGAP, INRA, 2, place Viala, 34060 Montpellier, France
- Department of Ecology and Evolutionary Biology, Brown University, 80 Waterman Street, Box G-W, Providence, RI 02912, USA
| | - Loïc Le Cunff
- UMR AGAP, INRA, 2, place Viala, 34060 Montpellier, France
- UMT Geno-Vigne®, IFV, 2, place Viala, 34060 Montpellier, France
| | - Yves Bertrand
- UMR AGAP, INRA, 2, place Viala, 34060 Montpellier, France
| | - Aurélie Canaguier
- UMR Génomique Végétale, INRA UEVE ERL CNRS, 2, rue Gaston Crémieux, 91057 Evry, France
| | - Cécile Morel
- UMR AGAP, INRA, 2, place Viala, 34060 Montpellier, France
| | | | - Frédéric Veran
- INRA, UMR1083 SPO, 2, place, Viala, 34060 Montpellier, France
| | | | | | - Nancy Terrier
- INRA, UMR1083 SPO, 2, place, Viala, 34060 Montpellier, France
| | - Patrice This
- UMR AGAP, INRA, 2, place Viala, 34060 Montpellier, France
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1827
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Zhang B, Hu Z, Zhang Y, Li Y, Zhou S, Chen G. A putative functional MYB transcription factor induced by low temperature regulates anthocyanin biosynthesis in purple kale (Brassica Oleracea var. acephala f. tricolor). PLANT CELL REPORTS 2012; 31:281-9. [PMID: 21987119 DOI: 10.1007/s00299-011-1162-3] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Revised: 09/22/2011] [Accepted: 09/23/2011] [Indexed: 05/08/2023]
Abstract
The purple kale (Brassica Oleracea var. acephala f. tricolor) is a mutation in kales, giving the mutant phenotype of brilliant purple color in the interior. Total anthocyanin analysis showed that the amount of anthocyanins in the purple kale was up to 1.73 mg g(-1) while no anthocyanin was detected in the white kale. To elucidate the molecular mechanism of the anthocyanin biosynthesis in the purple kale, we analyzed the expression of structural genes and some transcription factors associated with anthocyanin biosynthesis in the purple cultivar "Red Dove" and the white cultivar "White Dove". The result showed that nearly all the anthocyanin biosynthetic genes showed higher expression levels in the purple cultivar than in the white cultivar, especially for DFR and ANS, they were barely detected in the white cultivar. Interestingly, the fact that a R2R3 MYB transcription factor named BoPAP1 was extremely up-regulated in the purple kale and induced by low temperature attracted our attention. Further sequence analysis showed that BoPAP1 shared high similarity with AtPAP1 and BoMYB1. In addition, the anthocyanin accumulation in the purple kale is strongly induced by the low temperature stress. The total anthocyanin contents in the purple kale under low temperature were about 50-fold higher than the plants grown in the greenhouse. The expression of anthocyanin biosynthetic genes C4H, F3H, DFR, ANS and UFGT were all enhanced under the low temperature. These evidences strongly suggest that BoPAP1 may play an important role in activating the anthocyanin structural genes for the abundant anthocyanin accumulation in the purple kale.
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Affiliation(s)
- Bin Zhang
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, Room 313, Bioengineering College, Chongqing University, Campus A, 174 Shapingba Main Street, Chongqing, 400044, People's Republic of China.
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1828
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He Y, Li W, Lv J, Jia Y, Wang M, Xia G. Ectopic expression of a wheat MYB transcription factor gene, TaMYB73, improves salinity stress tolerance in Arabidopsis thaliana. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:1511-22. [PMID: 22140235 DOI: 10.1093/jxb/err389] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
MYB transcription factors (TFs) play pivotal roles in the abiotic stress response in plants, but their characteristics and functions in wheat (Triticum aestivum L.) have not been fully investigated. A novel wheat MYB TF gene, TaMYB73, is reported here based on the observation that its targeting probe showed the highest salinity-inducibility level among all probes annotated as MYB TFs in the cDNA microarray. TaMYB73 is a R2R3 type MYB protein with transactivation activity, and binds with types I, II, and IIG MYB binding motifs. The gene was induced by NaCl, dehydration, and several phytohormones, as well as some stress-, ABA-, and GA-responsive cis-elements present in its promoter region. Its over-expression in Arabidopsis enhanced the tolerance to NaCl as well as to LiCl and KCl, whereas it had no contribution to mannitol tolerance. The over-expression lines had superior germination ability under NaCl and ABA treatments. The expression of many stress signalling genes such as AtCBF3 and AtABF3, as well as downstream responsive genes such as AtRD29A and AtRD29B, was improved in these over-expression lines, and TaMYB73 can bind with promoter sequences of AtCBF3 and AtABF3. Taken together, it is suggested that TaMYB73, a novel MYB transcription factor gene, participates in salinity tolerance based on improved ionic resistance partly via the regulation of stress-responsive genes.
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Affiliation(s)
- Yanan He
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, 27 Shandanan Road, Jinan, Shandong 250100, China
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1829
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MtPAR MYB transcription factor acts as an on switch for proanthocyanidin biosynthesis in Medicago truncatula. Proc Natl Acad Sci U S A 2012; 109:1766-71. [PMID: 22307644 DOI: 10.1073/pnas.1120916109] [Citation(s) in RCA: 101] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
MtPAR (Medicago truncatula proanthocyanidin regulator) is an MYB family transcription factor that functions as a key regulator of proanthocyanidin (PA) biosynthesis in the model legume Medicago truncatula. MtPAR expression is confined to the seed coat, the site of PA accumulation. Loss-of-function par mutants contained substantially less PA in the seed coat than the wild type, whereas levels of anthocyanin and other specialized metabolites were normal in the mutants. In contrast, massive accumulation of PAs occurred when MtPAR was expressed ectopically in transformed hairy roots of Medicago. Transcriptome analysis of par mutants and MtPAR-expressing hairy roots, coupled with yeast one-hybrid analysis, revealed that MtPAR positively regulates genes encoding enzymes of the flavonoid-PA pathway via a probable activation of WD40-1. Expression of MtPAR in the forage legume alfalfa (Medicago sativa) resulted in detectable levels of PA in shoots, highlighting the potential of this gene for biotechnological strategies to increase PAs in forage legumes for reduction of pasture bloat in ruminant animals.
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1830
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Thévenin J, Dubos C, Xu W, Le Gourrierec J, Kelemen Z, Charlot F, Nogué F, Lepiniec L, Dubreucq B. A new system for fast and quantitative analysis of heterologous gene expression in plants. THE NEW PHYTOLOGIST 2012; 193:504-12. [PMID: 22023451 DOI: 10.1111/j.1469-8137.2011.03936.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
• Large-scale analysis of transcription factor-cis-acting element interactions in plants, or the dissection of complex transcriptional regulatory mechanisms, requires rapid, robust and reliable systems for the quantification of gene expression. • Here, we describe a new system for transient expression analysis of transcription factors, which takes advantage of the fast and easy production and transfection of Physcomitrella patens protoplasts, coupled to flow cytometry quantification of a fluorescent protein (green fluorescent protein). Two small-sized and high-copy Gateway® vectors were specifically designed, although standard binary vectors can also be employed. • As a proof of concept, the regulation of BANYULS (BAN), a key structural gene involved in proanthocyanidin biosynthesis in Arabidopsis thaliana seeds, was used. In P. patens, BAN expression is activated by a complex composed of three proteins (TT2/AtMYB123, TT8/bHLH042 and TTG1), and is inhibited by MYBL2, a transcriptional repressor, as in Arabidopsis. Using this approach, two new regulatory sequences that are necessary and sufficient for specific BAN expression in proanthocyanidin-accumulating cells were identified. • This one hybrid-like plant system was successfully employed to quantitatively assess the transcriptional activity of four regulatory proteins, and to identify their target recognition sites on the BAN promoter.
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Affiliation(s)
- J Thévenin
- INRA AgroParisTech, IJPB, UMR 1318, INRA centre de Versailles, Versailles, France
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1831
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Renouard S, Corbin C, Lopez T, Montguillon J, Gutierrez L, Lamblin F, Lainé E, Hano C. Abscisic acid regulates pinoresinol-lariciresinol reductase gene expression and secoisolariciresinol accumulation in developing flax (Linum usitatissimum L.) seeds. PLANTA 2012; 235:85-98. [PMID: 21837520 DOI: 10.1007/s00425-011-1492-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2011] [Accepted: 07/25/2011] [Indexed: 05/24/2023]
Abstract
Secoisolariciresinol diglucoside (SDG), the main phytoestrogenic lignan of Linum usitatissimum, is accumulated in the seed coat of flax during its development and pinoresinol-lariciresinol reductase (PLR) is a key enzyme in flax for its synthesis. The promoter of LuPLR1, a flax gene encoding a pinoresinol lariciresinol reductase, contains putative regulatory boxes related to transcription activation by abscisic acid (ABA). Gel mobility shift experiments evidenced an interaction of nuclear proteins extracted from immature flax seed coat with a putative cis-acting element involved in ABA response. As ABA regulates a number of physiological events during seed development and maturation we have investigated its involvement in the regulation of this lignan synthesis by different means. ABA and SDG accumulation time courses in the seed as well as LuPLR1 expression were first determined in natural conditions. These results showed that ABA timing and localization of accumulation in the flax seed coat could be correlated with the LuPLR1 gene expression and SDG biosynthesis. Experimental modulations of ABA levels were performed by exogenous application of ABA or fluridone, an inhibitor of ABA synthesis. When submitted to exogenous ABA, immature seeds synthesized 3-times more SDG, whereas synthesis of SDG was reduced in immature seeds treated with fluridone. Similarly, the expression of LuPLR1 gene in the seed coat was up-regulated by exogenous ABA and down-regulated when fluridone was applied. These results demonstrate that SDG biosynthesis in the flax seed coat is positively controlled by ABA through the transcriptional regulation of LuPLR1 gene.
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Affiliation(s)
- Sullivan Renouard
- Laboratoire de Biologie des Ligneux et des Grandes Cultures (LBLGC), UPRES EA 1207, Antenne Scientifique Universitaire de Chartres (ASUC), Université d'Orléans, 21 rue de Loigny la Bataille, 28000, Chartres, France
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1832
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Prouse MB, Campbell MM. The interaction between MYB proteins and their target DNA binding sites. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2012; 1819:67-77. [DOI: 10.1016/j.bbagrm.2011.10.010] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 10/17/2011] [Accepted: 10/18/2011] [Indexed: 02/02/2023]
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1833
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Phan HA, Li SF, Parish RW. MYB80, a regulator of tapetal and pollen development, is functionally conserved in crops. PLANT MOLECULAR BIOLOGY 2012; 78:171-83. [PMID: 22086333 DOI: 10.1007/s11103-011-9855-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Accepted: 11/09/2011] [Indexed: 05/18/2023]
Abstract
The Arabidopsis AtMYB80 transcription factor (formerly AtMYB103) regulate genes essential for tapetal and pollen development. One of these genes, coding for an aspartic protease (UNDEAD), may control the timing of tapetal programmed cell death (PCD). In crop plants such as rice and wheat, abiotic stresses lead to abnormal tapetal development resulting in delayed PCD. Manipulation of AtMYB80 function has been used to develop a reversible male sterility system applicable to hybrid crop production. MYB80 homologs were cloned from wheat, rice, canola and cotton. The promoters of the homologs drove temporal and spatial expression patterns of the GUS reporter gene in the tapetum and microspores of Arabidopsis anthers identical to the AtMYB80 promoter. A short region is conserved in all five MYB80 promoters. The MYB80 homolog genes, driven by the AtMYB80 or their respective promoters, rescued the atmyb80 mutant, completely restoring male fertility. The canola MYB80 was fused to the EAR (ERF-associated amphiphilic repression) repressor and canola plants transgenic for the construct exhibited premature tapetal degradation and subsequent pollen abortion. The five MYB80 homologs all shared a 44 amino acid sequence immediately adjacent to the R2R3 domain which appears to be necessary for MYB80 function.
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Affiliation(s)
- Huy A Phan
- Botany Department, La Trobe University, Melbourne, Australia
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1834
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Zhang L, Zhao G, Jia J, Liu X, Kong X. Molecular characterization of 60 isolated wheat MYB genes and analysis of their expression during abiotic stress. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:203-14. [PMID: 21934119 PMCID: PMC3245462 DOI: 10.1093/jxb/err264] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The proteins of the MYB superfamily play central roles in developmental processes and defence responses in plants. Sixty unique wheat MYB genes that contain full-length cDNA sequences were isolated. These 60 genes were grouped into three categories, namely one R1R2R3-MYB, 22 R2R3-MYBs, and 37 MYB-related members. The sequence composition of the R2 and R3 repeats was conserved among the 22 wheat R2R3-MYB proteins. Phylogenetic comparison of the members of this superfamily among wheat, rice, and Arabidopsis revealed that the putative functions of some wheat MYB proteins were clustered into the Arabidopsis functional clades. Tissue-specific expression profiles showed that most of the wheat MYB genes were expressed in all of the tissues examined, suggesting that wheat MYB genes take part in multiple cellular processes. The expression analysis during abiotic stress identified a group of MYB genes that respond to one or more stress treatments. The overexpression of a salt-inducible gene, TaMYB32, enhanced the tolerance to salt stress in transgenic Arabidopsis. This study is the first comprehensive study of the MYB gene family in Triticeae.
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Affiliation(s)
| | | | | | | | - Xiuying Kong
- To whom correspondence should be addressed. E-mail:
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1835
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Zifkin M, Jin A, Ozga JA, Zaharia LI, Schernthaner JP, Gesell A, Abrams SR, Kennedy JA, Constabel CP. Gene expression and metabolite profiling of developing highbush blueberry fruit indicates transcriptional regulation of flavonoid metabolism and activation of abscisic acid metabolism. PLANT PHYSIOLOGY 2012; 158:200-24. [PMID: 22086422 PMCID: PMC3252089 DOI: 10.1104/pp.111.180950] [Citation(s) in RCA: 170] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Accepted: 10/25/2011] [Indexed: 05/19/2023]
Abstract
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 blueberry flavonoid biosynthesis.
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1836
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Large Scale In Silico Identification of MYB Family Genes from Wheat Expressed Sequence Tags. Mol Biotechnol 2011; 52:184-92. [DOI: 10.1007/s12033-011-9486-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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1837
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Yang X, Ye CY, Bisaria A, Tuskan GA, Kalluri UC. Identification of candidate genes in Arabidopsis and Populus cell wall biosynthesis using text-mining, co-expression network analysis and comparative genomics. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2011; 181:675-87. [PMID: 21958710 DOI: 10.1016/j.plantsci.2011.01.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2010] [Revised: 12/01/2010] [Accepted: 01/27/2011] [Indexed: 05/17/2023]
Abstract
Populus is an important bioenergy crop for bioethanol production. A greater understanding of cell wall biosynthesis processes is critical in reducing biomass recalcitrance, a major hindrance in efficient generation of biofuels from lignocellulosic biomass. Here, we report the identification of candidate cell wall biosynthesis genes through the development and application of a novel bioinformatics pipeline. As a first step, via text-mining of PubMed publications, we obtained 121 Arabidopsis genes that had the experimental evidence supporting their involvement in cell wall biosynthesis or remodeling. The 121 genes were then used as bait genes to query an Arabidopsis co-expression database, and additional genes were identified as neighbors of the bait genes in the network, increasing the number of genes to 548. The 548 Arabidopsis genes were then used to re-query the Arabidopsis co-expression database and re-construct a network that captured additional network neighbors, expanding to a total of 694 genes. The 694 Arabidopsis genes were computationally divided into 22 clusters. Queries of the Populus genome using the Arabidopsis genes revealed 817 Populus orthologs. Functional analysis of gene ontology and tissue-specific gene expression indicated that these Arabidopsis and Populus genes are high likelihood candidates for functional characterization in relation to cell wall biosynthesis.
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Affiliation(s)
- Xiaohan Yang
- Biosciences Division and BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
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1838
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Villar E, Klopp C, Noirot C, Novaes E, Kirst M, Plomion C, Gion JM. RNA-Seq reveals genotype-specific molecular responses to water deficit in eucalyptus. BMC Genomics 2011; 12:538. [PMID: 22047139 PMCID: PMC3248028 DOI: 10.1186/1471-2164-12-538] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Accepted: 11/02/2011] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND In a context of climate change, phenotypic plasticity provides long-lived species, such as trees, with the means to adapt to environmental variations occurring within a single generation. In eucalyptus plantations, water availability is a key factor limiting productivity. However, the molecular mechanisms underlying the adaptation of eucalyptus to water shortage remain unclear. In this study, we compared the molecular responses of two commercial eucalyptus hybrids during the dry season. Both hybrids differ in productivity when grown under water deficit. RESULTS Pyrosequencing of RNA extracted from shoot apices provided extensive transcriptome coverage - a catalog of 129,993 unigenes (49,748 contigs and 80,245 singletons) was generated from 398 million base pairs, or 1.14 million reads. The pyrosequencing data enriched considerably existing Eucalyptus EST collections, adding 36,985 unigenes not previously represented. Digital analysis of read abundance in 14,460 contigs identified 1,280 that were differentially expressed between the two genotypes, 155 contigs showing differential expression between treatments (irrigated vs. non irrigated conditions during the dry season), and 274 contigs with significant genotype-by-treatment interaction. The more productive genotype displayed a larger set of genes responding to water stress. Moreover, stress signal transduction seemed to involve different pathways in the two genotypes, suggesting that water shortage induces distinct cellular stress cascades. Similarly, the response of functional proteins also varied widely between genotypes: the most productive genotype decreased expression of genes related to photosystem, transport and secondary metabolism, whereas genes related to primary metabolism and cell organisation were over-expressed. CONCLUSIONS For the most productive genotype, the ability to express a broader set of genes in response to water availability appears to be a key characteristic in the maintenance of biomass growth during the dry season. Its strategy may involve a decrease of photosynthetic activity during the dry season associated with resources reallocation through major changes in the expression of primary metabolism associated genes. Further efforts will be needed to assess the adaptive nature of the genes highlighted in this study.
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Affiliation(s)
- Emilie Villar
- CIRAD, UMR AGAP, Campus de Baillarguet TA 10C, F-34398 Montpellier Cedex 5, France
- INRA, UMR1202 BIOGECO, F-33610 Cestas, France
- CRDPI, BP1291, Pointe Noire, République du Congo
| | - Christophe Klopp
- Plateforme bioinformatique Genotoul, UR875 Biométrie et Intelligence Artificielle, INRA, 31326 Castanet-Tolosan, France
| | - Céline Noirot
- Plateforme bioinformatique Genotoul, UR875 Biométrie et Intelligence Artificielle, INRA, 31326 Castanet-Tolosan, France
| | - Evandro Novaes
- School of Forest Resources and Conservation, University of Florida, PO Box 110410, Gainesville, USA
- Universidade Federal de Goiás, Caixa Postal 131, CEP 74690-900, Goiânia, Brazil
| | - Matias Kirst
- School of Forest Resources and Conservation, University of Florida, PO Box 110410, Gainesville, USA
| | - Christophe Plomion
- INRA, UMR1202 BIOGECO, F-33610 Cestas, France
- Université de Bordeaux, UMR1202 BIOGECO, F-33610 Cestas, France
| | - Jean-Marc Gion
- CIRAD, UMR AGAP, Campus de Baillarguet TA 10C, F-34398 Montpellier Cedex 5, France
- INRA, UMR1202 BIOGECO, F-33610 Cestas, France
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1839
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Pollastri S, Tattini M. Flavonols: old compounds for old roles. ANNALS OF BOTANY 2011; 108:1225-33. [PMID: 21880658 PMCID: PMC3197460 DOI: 10.1093/aob/mcr234] [Citation(s) in RCA: 185] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2011] [Accepted: 07/27/2011] [Indexed: 05/18/2023]
Abstract
BACKGROUND New roles for flavonoids, as developmental regulators and/or signalling molecules, have recently been proposed in eukaryotic cells exposed to a wide range of environmental stimuli. In plants, these functions are actually restricted to flavonols, the ancient and widespread class of flavonoids. In mosses and liverworts, the whole set of genes for flavonol biosynthesis - CHS, CHI, F3H, FLS and F3'H - has been detected. The flavonol branch pathway has remained intact for millions of years, and is almost exclusively involved in the responses of plants to a wide array of stressful agents, despite the fact that evolution of flavonoid metabolism has produced >10 000 structures. SCOPE Here the emerging functional roles of flavonoids in the responses of present-day plants to different stresses are discussed based on early, authoritative views of their primary functions during the colonization of land by plants. Flavonols are not as efficient as other secondary metabolites in absorbing wavelengths in the 290-320 nm spectral region, but display the greatest potential to keep stress-induced changes in cellular reactive oxygen species homeostasis under control, and to regulate the development of individual organs and the whole plant. Very low flavonol concentrations, as probably occurred in early terrestrial plants, may fully accomplish these regulatory functions. CONCLUSIONS During the last two decades the routine use of genomic, chromatography/mass spectrometry and fluorescence microimaging techniques has provided new insights into the regulation of flavonol metabolism as well as on the inter- and intracellular distribution of stress-responsive flavonols. These findings offer new evidence on how flavonols may have performed a wide array of functional roles during the colonization of land by plants. In our opinion this ancient flavonoid class is still playing the same old and robust roles in present-day plants.
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Affiliation(s)
- Susanna Pollastri
- Dipartimento di Scienze delle Produzioni Vegetali, del Suolo e dell'Ambiente Agroforestale, Sezione Coltivazioni Arboree, Università di Firenze, Viale delle Idee 30, I-50019, Sesto Fiorentino, Firenze, Italy
| | - Massimiliano Tattini
- Consiglio Nazionale delle Ricerche, Istituto per la Protezione delle Piante, Via Madonna del Piano, I-50019, Sesto Fiorentino, Firenze, Italy
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1840
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Galbiati M, Matus JT, Francia P, Rusconi F, Cañón P, Medina C, Conti L, Cominelli E, Tonelli C, Arce-Johnson P. 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. BMC PLANT BIOLOGY 2011; 11:142. [PMID: 22018045 PMCID: PMC3206852 DOI: 10.1186/1471-2229-11-142] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Accepted: 10/21/2011] [Indexed: 05/18/2023]
Abstract
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.
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Affiliation(s)
- Massimo Galbiati
- Dipartimento di Scienze Biomolecolari e Biotecnologie, Università degli Studi di Milano, Via Celoria 26, 20133 Milano, Italy
- Fondazione Filarete, Viale Ortles 22/4, 20139, Milano, Italy
| | - José Tomás Matus
- Pontificia Universidad Católica de Chile, Departamento de Genética Molecular y Microbiología. Alameda 340. Santiago, Chile
- Centre for Research in Agricultural Genomics (CRAG), 08193 Barcelona, Spain
| | - Priscilla Francia
- Dipartimento di Scienze Biomolecolari e Biotecnologie, Università degli Studi di Milano, Via Celoria 26, 20133 Milano, Italy
| | - Fabio Rusconi
- Fondazione Filarete, Viale Ortles 22/4, 20139, Milano, Italy
| | - Paola Cañón
- Pontificia Universidad Católica de Chile, Departamento de Genética Molecular y Microbiología. Alameda 340. Santiago, Chile
| | - Consuelo Medina
- Pontificia Universidad Católica de Chile, Departamento de Genética Molecular y Microbiología. Alameda 340. Santiago, Chile
| | - Lucio Conti
- Dipartimento di Scienze Biomolecolari e Biotecnologie, Università degli Studi di Milano, Via Celoria 26, 20133 Milano, Italy
- Fondazione Filarete, Viale Ortles 22/4, 20139, Milano, Italy
| | - Eleonora Cominelli
- Dipartimento di Scienze Biomolecolari e Biotecnologie, Università degli Studi di Milano, Via Celoria 26, 20133 Milano, Italy
- Istituto di Biologia e Biotecnologia Agraria, CNR; Milano, Italy
| | - Chiara Tonelli
- Dipartimento di Scienze Biomolecolari e Biotecnologie, Università degli Studi di Milano, Via Celoria 26, 20133 Milano, Italy
| | - Patricio Arce-Johnson
- Pontificia Universidad Católica de Chile, Departamento de Genética Molecular y Microbiología. Alameda 340. Santiago, Chile
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1841
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Kilian J, Peschke F, Berendzen KW, Harter K, Wanke D. Prerequisites, performance and profits of transcriptional profiling the abiotic stress response. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2011; 1819:166-75. [PMID: 22001611 DOI: 10.1016/j.bbagrm.2011.09.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Revised: 09/27/2011] [Accepted: 09/28/2011] [Indexed: 01/15/2023]
Abstract
During the last decade, microarrays became a routine tool for the analysis of transcripts in the model plant Arabidopsis thaliana and the crop plant species rice, poplar or barley. The overwhelming amount of data generated by gene expression studies is a valuable resource for every scientist. Here, we summarize the most important findings about the abiotic stress responses in plants. Interestingly, conserved patterns of gene expression responses have been found that are common between different abiotic stresses or that are conserved between different plant species. However, the individual histories of each plant affect the inter-comparability between experiments already before the onset of the actual stress treatment. This review outlines multiple aspects of microarray technology and highlights some of the benefits, limitations and also pitfalls of the technique. This article is part of a Special Issue entitled: Plant gene regulation in response to abiotic stress.
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Affiliation(s)
- Joachim Kilian
- Center of Plant Molecular Biology, ZMBP-Plant Physiology, University of Tuebingen, Tübingen, Germany.
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1842
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Lin Y, Son H, Lee J, Min K, Choi GJ, Kim JC, Lee YW. A putative transcription factor MYT1 is required for female fertility in the ascomycete Gibberella zeae. PLoS One 2011; 6:e25586. [PMID: 21984921 PMCID: PMC3184970 DOI: 10.1371/journal.pone.0025586] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Accepted: 09/06/2011] [Indexed: 11/19/2022] Open
Abstract
Gibberella zeae is an important pathogen of major cereal crops. The fungus produces ascospores that forcibly discharge from mature fruiting bodies, which serve as the primary inocula for disease epidemics. In this study, we characterized an insertional mutant Z39P105 with a defect in sexual development and identified a gene encoding a putative transcription factor designated as MYT1. This gene contains a Myb DNA-binding domain and is conserved in the subphylum Pezizomycotina of Ascomycota. The MYT1 protein fused with green fluorescence protein localized in nuclei, which supports its role as a transcriptional regulator. The MYT1 deletion mutant showed similar phenotypes to the wild-type strain in vegetative growth, conidia production and germination, virulence, and mycotoxin production, but had defect in female fertility. A mutant overexpressing MYT1 showed earlier germination, faster mycelia growth, and reduced mycotoxin production compared to the wild-type strain, suggesting that improper MYT1 expression affects the expression of genes involved in the cell cycle and secondary metabolite production. This study is the first to characterize a transcription factor containing a Myb DNA-binding domain that is specific to sexual development in G. zeae.
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Affiliation(s)
- Yang Lin
- Department of Agricultural Biotechnology and Center for Fungal Pathogenesis, Seoul National University, Seoul, Korea
| | - Hokyoung Son
- Department of Agricultural Biotechnology and Center for Fungal Pathogenesis, Seoul National University, Seoul, Korea
| | - Jungkwan Lee
- Department of Applied Biology, Dong-A University, Busan, Korea
| | - Kyunghun Min
- Department of Agricultural Biotechnology and Center for Fungal Pathogenesis, Seoul National University, Seoul, Korea
| | - Gyung Ja Choi
- Biological Function Research Team, Korea Research Institute of Chemical Technology, Daejeon, Korea
| | - Jin-Cheol Kim
- Biological Function Research Team, Korea Research Institute of Chemical Technology, Daejeon, Korea
| | - Yin-Won Lee
- Department of Agricultural Biotechnology and Center for Fungal Pathogenesis, Seoul National University, Seoul, Korea
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1843
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Machemer K, Shaiman O, Salts Y, Shabtai S, Sobolev I, Belausov E, Grotewold E, Barg R. Interplay of MYB factors in differential cell expansion, and consequences for tomato fruit development. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2011; 68:337-50. [PMID: 21707804 DOI: 10.1111/j.1365-313x.2011.04690.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
We previously identified SlFSM1 as an early fruit-specific gene encoding a short protein harboring a non-canonical SANT/MYB-like domain. Here, we investigated the role of FSM1 during fruit development in tomato and its mode of action. By analyzing tomato plants ectopically expressing FSM1, we established that it negatively affects cell expansion, particularly of those cells with the highest potential to expand, such as those residing inner to the vascular bundles in the fruit pericarp. This function of FSM1 differs from that of the snapdragon FSM1-like gene, RAD, which through an antagonistic activity with DIV participates in establishing floral asymmetry. Revealing an additional component of the FSM1/RAD regulatory complex, we show here that FSM1 physically interacts with FSB1, a previously uncharacterized factor harboring an atypical MYB repeat. We also demonstrate that FSB1 physically interacts with the transcription factor MYBI, a homolog of DIV. Our results show that the formation of the FSB1-MYBI complex is competed by FSM1, which recognizes in FSB1 the same region as MYBI does. Taken together, these studies expose a function for the FSM1/FSB1/MYBI complex in controlling tomato cell expansion, while revealing a mechanism by which competing MYB-MYB interactions could participate in the control of gene expression.
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Affiliation(s)
- Katja Machemer
- Plant Biotechnology Center and Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210, USA
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1844
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Cai H, Tian S, Liu C, Dong H. Identification of a MYB3R gene involved in drought, salt and cold stress in wheat (Triticum aestivum L.). Gene 2011; 485:146-52. [DOI: 10.1016/j.gene.2011.06.026] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Revised: 06/12/2011] [Accepted: 06/18/2011] [Indexed: 01/15/2023]
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1845
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Pastore JJ, Limpuangthip A, Yamaguchi N, Wu MF, Sang Y, Han SK, Malaspina L, Chavdaroff N, Yamaguchi A, Wagner D. LATE MERISTEM IDENTITY2 acts together with LEAFY to activate APETALA1. Development 2011; 138:3189-98. [PMID: 21750030 DOI: 10.1242/dev.063073] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The switch from producing vegetative structures (branches and leaves) to producing reproductive structures (flowers) is a crucial developmental transition that significantly affects the reproductive success of flowering plants. In Arabidopsis, this transition is in large part controlled by the meristem identity regulator LEAFY (LFY). The molecular mechanisms by which LFY orchestrates a precise and robust switch to flower formation is not well understood. Here, we show that the direct LFY target LATE MERISTEM IDENTITY2 (LMI2) has a role in the meristem identity transition. Like LFY, LMI2 activates AP1 directly; moreover, LMI2 and LFY interact physically. LFY, LMI2 and AP1 are connected in a feed-forward and positive feedback loop network. We propose that these intricate regulatory interactions not only direct the precision of this crucial developmental transition in rapidly changing environmental conditions, but also contribute to its robustness and irreversibility.
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Affiliation(s)
- Jennifer J Pastore
- Department of Biology, University of Pennsylvania, School of Arts and Sciences, Philadelphia, PA 19104, USA
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1846
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Wei SY, Lou YC, Tsai JY, Ho MR, Chou CC, Rajasekaran M, Hsu HM, Tai JH, Hsiao CD, Chen C. Structure of the Trichomonas vaginalis Myb3 DNA-binding domain bound to a promoter sequence reveals a unique C-terminal β-hairpin conformation. Nucleic Acids Res 2011; 40:449-60. [PMID: 21908401 PMCID: PMC3245928 DOI: 10.1093/nar/gkr707] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Trichomonas vaginalis Myb3 transcription factor (tvMyb3) recognizes the MRE-1 promoter sequence and regulates ap65-1 gene, which encodes a hydrogenosomal malic enzyme that may play a role in the cytoadherence of the parasite. Here, we identified tvMyb353–180 as the essential fragment for DNA recognition and report the crystal structure of tvMyb353–180 bound to MRE-1 DNA. The N-terminal fragment adopts the classical conformation of an Myb DNA-binding domain, with the third helices of R2 and R3 motifs intercalating in the major groove of DNA. The C-terminal extension forms a β-hairpin followed by a flexible tail, which is stabilized by several interactions with the R3 motif and is not observed in other Myb proteins. Interestingly, this unique C-terminal fragment does not stably connect with DNA in the complex structure but is involved in DNA binding, as demonstrated by NMR chemical shift perturbation, 1H-15N heteronuclear-nuclear Overhauser effect and intermolecular paramagnetic relaxation enhancement. Site-directed mutagenesis also revealed that this C-terminal fragment is crucial for DNA binding, especially the residue Arg153 and the fragment K170KRK173. We provide a structural basis for MRE-1 DNA recognition and suggest a possible post-translational regulation of tvMyb3 protein.
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Affiliation(s)
- Shu-Yi Wei
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan, ROC
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1847
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Petroni K, Tonelli C. Recent advances on the regulation of anthocyanin synthesis in reproductive organs. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2011; 181:219-29. [PMID: 21763532 DOI: 10.1016/j.plantsci.2011.05.009] [Citation(s) in RCA: 487] [Impact Index Per Article: 37.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2011] [Revised: 05/13/2011] [Accepted: 05/17/2011] [Indexed: 05/18/2023]
Abstract
Anthocyanins represent the major red, purple, violet and blue pigments in many flowers and fruits. They attract pollinators and seed dispersers and defend plants against abiotic and biotic stresses. Anthocyanins are produced by a specific branch of the flavonoid pathway, which is differently regulated in monocot and dicot species. In the monocot maize, the anthocyanin biosynthesis genes are activated as a single unit by a ternary complex of MYB-bHLH-WD40 transcription factors (MBW complex). In the dicot Arabidopsis, anthocyanin biosynthesis genes can be divided in two subgroups: early biosynthesis genes (EBGs) are activated by co-activator independent R2R3-MYB transcription factors, whereas late biosynthesis genes (LBGs) require an MBW complex. In addition to this, a complex regulatory network of positive and negative feedback mechanisms controlling anthocyanin synthesis in Arabidopsis has been described. Recent studies have broadened our understanding of the regulation of anthocyanin synthesis in flowers and fruits, indicating that a regulatory system based on the cooperation of MYB, bHLH and WD40 proteins that control floral and fruit pigmentation is common to many dicot species.
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Affiliation(s)
- Katia Petroni
- Dipartimento di Scienze Biomolecolari e Biotecnologie, Universita degli Studi di Milano, Via Celoria 26, 20133 Milano, Italy.
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1848
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Canonne J, Marino D, Jauneau A, Pouzet C, Brière C, Roby D, Rivas S. The Xanthomonas type III effector XopD targets the Arabidopsis transcription factor MYB30 to suppress plant defense. THE PLANT CELL 2011; 23:3498-511. [PMID: 21917550 PMCID: PMC3203416 DOI: 10.1105/tpc.111.088815] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Revised: 08/16/2011] [Accepted: 08/30/2011] [Indexed: 05/17/2023]
Abstract
Plant and animal pathogens inject type III effectors (T3Es) into host cells to suppress host immunity and promote successful infection. XopD, a T3E from Xanthomonas campestris pv vesicatoria, has been proposed to promote bacterial growth by targeting plant transcription factors and/or regulators. Here, we show that XopD from the B100 strain of X. campestris pv campestris is able to target MYB30, a transcription factor that positively regulates Arabidopsis thaliana defense and associated cell death responses to bacteria through transcriptional activation of genes related to very-long-chain fatty acid (VLCFA) metabolism. XopD specifically interacts with MYB30, resulting in inhibition of the transcriptional activation of MYB30 VLCFA-related target genes and suppression of Arabidopsis defense. The helix-loop-helix domain of XopD is necessary and sufficient to mediate these effects. These results illustrate an original strategy developed by Xanthomonas to subvert plant defense and promote development of disease.
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Affiliation(s)
- Joanne Canonne
- Institut National de la Recherche Agronomique, Laboratoire des Interactions Plantes-Microorganismes, Unité Mixte de Recherche 441, F-31326 Castanet-Tolosan, France
- Centre National de la Recherche Scientifique, Laboratoire des Interactions Plantes-Microorganismes, Unité Mixte de Recherche 2594, F-31326 Castanet-Tolosan, France
| | - Daniel Marino
- Institut National de la Recherche Agronomique, Laboratoire des Interactions Plantes-Microorganismes, Unité Mixte de Recherche 441, F-31326 Castanet-Tolosan, France
- Centre National de la Recherche Scientifique, Laboratoire des Interactions Plantes-Microorganismes, Unité Mixte de Recherche 2594, F-31326 Castanet-Tolosan, France
| | - Alain Jauneau
- Fédération de Recherche 3450, Plateforme Imagerie, Pôle de Biotechnologie Végétale, F-31320 Castanet-Tolosan, France
| | - Cécile Pouzet
- Fédération de Recherche 3450, Plateforme Imagerie, Pôle de Biotechnologie Végétale, F-31320 Castanet-Tolosan, France
| | - Christian Brière
- Surfaces Cellulaires et Signalisation Chez les Végétaux, Université de Toulouse, Unité Mixte de Recherche, Centre National de la Recherche Scientifique–Université Paul Sabatier 5546, F31320 Castanet-Tolosan, France
| | - Dominique Roby
- Institut National de la Recherche Agronomique, Laboratoire des Interactions Plantes-Microorganismes, Unité Mixte de Recherche 441, F-31326 Castanet-Tolosan, France
- Centre National de la Recherche Scientifique, Laboratoire des Interactions Plantes-Microorganismes, Unité Mixte de Recherche 2594, F-31326 Castanet-Tolosan, France
| | - Susana Rivas
- Institut National de la Recherche Agronomique, Laboratoire des Interactions Plantes-Microorganismes, Unité Mixte de Recherche 441, F-31326 Castanet-Tolosan, France
- Centre National de la Recherche Scientifique, Laboratoire des Interactions Plantes-Microorganismes, Unité Mixte de Recherche 2594, F-31326 Castanet-Tolosan, France
- Address correspondence to
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1849
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Liu H, Zhou X, Dong N, Liu X, Zhang H, Zhang Z. Expression of a wheat MYB gene in transgenic tobacco enhances resistance to Ralstonia solanacearum, and to drought and salt stresses. Funct Integr Genomics 2011; 11:431-43. [PMID: 21597961 DOI: 10.1007/s10142-011-0228-1] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Revised: 04/11/2011] [Accepted: 04/17/2011] [Indexed: 11/30/2022]
Abstract
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.
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Affiliation(s)
- Hongxia Liu
- The National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
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1850
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Hsiao YY, Pan ZJ, Hsu CC, Yang YP, Hsu YC, Chuang YC, Shih HH, Chen WH, Tsai WC, Chen HH. Research on orchid biology and biotechnology. PLANT & CELL PHYSIOLOGY 2011; 52:1467-86. [PMID: 21791545 DOI: 10.1093/pcp/pcr100] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Orchidaceae constitute one of the largest families of angiosperms. They are one of the most ecological and evolutionary significant plants and have successfully colonized almost every habitat on earth. Because of the significance of plant biology, market needs and the current level of breeding technologies, basic research into orchid biology and the application of biotechnology in the orchid industry are continually endearing scientists to orchids in Taiwan. In this introductory review, we give an overview of the research activities in orchid biology and biotechnology, including the status of genomics, transformation technology, flowering regulation, molecular regulatory mechanisms of floral development, scent production and color presentation. This information will provide a broad scope for study of orchid biology and serve as a starting point for uncovering the mysteries of orchid evolution.
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Affiliation(s)
- Yu-Yun Hsiao
- Department of Life Sciences, National Cheng Kung University, Tainan 701, Taiwan
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