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1.
Nature ; 544(7651): 427-433, 2017 04 26.
Artículo en Inglés | MEDLINE | ID: mdl-28447635

RESUMEN

Cereal grasses of the Triticeae tribe have been the major food source in temperate regions since the dawn of agriculture. Their large genomes are characterized by a high content of repetitive elements and large pericentromeric regions that are virtually devoid of meiotic recombination. Here we present a high-quality reference genome assembly for barley (Hordeum vulgare L.). We use chromosome conformation capture mapping to derive the linear order of sequences across the pericentromeric space and to investigate the spatial organization of chromatin in the nucleus at megabase resolution. The composition of genes and repetitive elements differs between distal and proximal regions. Gene family analyses reveal lineage-specific duplications of genes involved in the transport of nutrients to developing seeds and the mobilization of carbohydrates in grains. We demonstrate the importance of the barley reference sequence for breeding by inspecting the genomic partitioning of sequence variation in modern elite germplasm, highlighting regions vulnerable to genetic erosion.


Asunto(s)
Cromosomas de las Plantas/genética , Genoma de Planta/genética , Hordeum/genética , Núcleo Celular/genética , Centrómero/genética , Cromatina/genética , Cromatina/metabolismo , Mapeo Cromosómico , Cromosomas Artificiales Bacterianos/genética , Variación Genética , Genómica , Haplotipos/genética , Meiosis/genética , Secuencias Repetitivas de Ácidos Nucleicos/genética , Semillas/genética
2.
Development ; 146(11)2019 06 12.
Artículo en Inglés | MEDLINE | ID: mdl-31076487

RESUMEN

Many plants dramatically elongate their stems during flowering, yet how this response is coordinated with the reproductive phase is unclear. We demonstrate that microRNA (miRNA) control of APETALA2 (AP2) is required for rapid, complete elongation of stem internodes in barley, especially of the final 'peduncle' internode directly underneath the inflorescence. Disrupted miR172 targeting of AP2 in the Zeo1.b barley mutant caused lower mitotic activity, delayed growth dynamics and premature lignification in the peduncle leading to fewer and shorter cells. Stage- and tissue-specific comparative transcriptomics between Zeo1.b and its parent cultivar showed reduced expression of proliferation-associated genes, ectopic expression of maturation-related genes and persistent, elevated expression of genes associated with jasmonate and stress responses. We further show that applying methyl jasmonate (MeJA) phenocopied the stem elongation of Zeo1.b, and that Zeo1.b itself was hypersensitive to inhibition by MeJA but less responsive to promotion by gibberellin. Taken together, we propose that miR172-mediated restriction of AP2 may modulate the jasmonate pathway to facilitate gibberellin-promoted stem growth during flowering.


Asunto(s)
Flores/crecimiento & desarrollo , Proteínas de Homeodominio/fisiología , Hordeum/crecimiento & desarrollo , Hordeum/genética , Proteínas de Arabidopsis/genética , Flores/genética , Regulación del Desarrollo de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Genes de Plantas/fisiología , Proteínas de Homeodominio/genética , Meristema/genética , Meristema/crecimiento & desarrollo , Plantas Modificadas Genéticamente , Homología de Secuencia
3.
Plant J ; 103(4): 1263-1274, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32623778

RESUMEN

Interactions between plant-parasitic nematodes and their hosts are mediated by effectors, i.e. secreted proteins that manipulate the plant to the benefit of the pathogen. To understand the role of effectors in host adaptation in nematodes, we analysed the transcriptome of Heterodera sacchari, a cyst nematode parasite of rice (Oryza sativa) and sugarcane (Saccharum officinarum). A multi-gene phylogenetic analysis showed that H. sacchari and the cereal cyst nematode Heterodera avenae share a common evolutionary origin and that they evolved to parasitise monocot plants from a common dicot-parasitic ancestor. We compared the effector repertoires of H. sacchari with those of the dicot parasites Heterodera glycines and Globodera rostochiensis to understand the consequences of this transition. While, in general, effector repertoires are similar between the species, comparing effectors and non-effectors of H. sacchari and G. rostochiensis shows that effectors have accumulated more mutations than non-effectors. Although most effectors show conserved spatiotemporal expression profiles and likely function, some H. sacchari effectors are adapted to monocots. This is exemplified by the plant-peptide hormone mimics, the CLAVATA3/EMBRYO SURROUNDING REGION-like (CLE) effectors. Peptide hormones encoded by H. sacchari CLE effectors are more similar to those from rice than those from other plants, or those from other plant-parasitic nematodes. We experimentally validated the functional significance of these observations by demonstrating that CLE peptides encoded by H. sacchari induce a short root phenotype in rice, whereas those from a related dicot parasite do not. These data provide a functional example of effector evolution that co-occurred with the transition from a dicot-parasitic to a monocot-parasitic lifestyle.


Asunto(s)
Enfermedades de las Plantas/parasitología , Tylenchoidea/metabolismo , Tylenchoidea/patogenicidad , Animales , Proteínas del Helminto/genética , Proteínas del Helminto/metabolismo , Interacciones Huésped-Parásitos , Hormonas Peptídicas/genética , Hormonas Peptídicas/metabolismo , Transcriptoma/genética , Tylenchoidea/genética
4.
Plant J ; 103(6): 2263-2278, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32593210

RESUMEN

Potato tuber formation is a secondary developmental programme by which cells in the subapical stolon region divide and radially expand to further differentiate into starch-accumulating parenchyma. Although some details of the molecular pathway that signals tuberisation are known, important gaps in our knowledge persist. Here, the role of a member of the TERMINAL FLOWER 1/CENTRORADIALIS gene family (termed StCEN) in the negative control of tuberisation is demonstrated for what is thought to be the first time. It is shown that reduced expression of StCEN accelerates tuber formation whereas transgenic lines overexpressing this gene display delayed tuberisation and reduced tuber yield. Protein-protein interaction studies (yeast two-hybrid and bimolecular fluorescence complementation) demonstrate that StCEN binds components of the recently described tuberigen activation complex. Using transient transactivation assays, we show that the StSP6A tuberisation signal is an activation target of the tuberigen activation complex, and that co-expression of StCEN blocks activation of the StSP6A gene by StFD-Like-1. Transcriptomic analysis of transgenic lines misexpressing StCEN identifies early transcriptional events in tuber formation. These results demonstrate that StCEN suppresses tuberisation by directly antagonising the function of StSP6A in stolons, identifying StCEN as a breeding marker to improve tuber initiation and yield through the selection of genotypes with reduced StCEN expression.


Asunto(s)
Proteínas de Plantas/fisiología , Tubérculos de la Planta/crecimiento & desarrollo , Solanum tuberosum/crecimiento & desarrollo , Genes de Plantas , Proteínas de Plantas/metabolismo , Tubérculos de la Planta/metabolismo , Plantas Modificadas Genéticamente , Solanum tuberosum/metabolismo , Transcriptoma
5.
Plant Cell Environ ; 44(1): 290-303, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33094513

RESUMEN

Current crop protection strategies against the fungal pathogen Botrytis cinerea rely on a combination of conventional fungicides and host genetic resistance. However, due to pathogen evolution and legislation in the use of fungicides, these strategies are not sufficient to protect plants against this pathogen. Defence elicitors can stimulate plant defence mechanisms through a phenomenon known as defence priming. Priming results in a faster and/or stronger expression of resistance upon pathogen recognition by the host. This work aims to study defence priming by a commercial formulation of the elicitor chitosan. Treatments with chitosan result in induced resistance (IR) in solanaceous and brassicaceous plants. In tomato plants, enhanced resistance has been linked with priming of callose deposition and accumulation of the plant hormone jasmonic acid (JA). Large-scale transcriptomic analysis revealed that chitosan primes gene expression at early time-points after infection. In addition, two novel tomato genes with a characteristic priming profile were identified, Avr9/Cf-9 rapidly elicited protein 75 (ACRE75) and 180 (ACRE180). Transient and stable over-expression of ACRE75, ACRE180 and their Nicotiana benthamiana homologs, revealed that they are positive regulators of plant resistance against B. cinerea. This provides valuable information in the search for strategies to protect Solanaceae plants against B. cinerea.


Asunto(s)
Botrytis , Quitosano/metabolismo , Resistencia a la Enfermedad , Enfermedades de las Plantas/inmunología , Solanum lycopersicum/microbiología , Arabidopsis , Western Blotting , Clonación Molecular , Perfilación de la Expresión Génica , Glucanos/metabolismo , Solanum lycopersicum/inmunología , Solanum lycopersicum/fisiología , Microscopía Confocal , Enfermedades de las Plantas/microbiología , Plantas Modificadas Genéticamente , Nicotiana/inmunología , Nicotiana/metabolismo , Nicotiana/microbiología
6.
Int J Mol Sci ; 21(24)2020 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-33352760

RESUMEN

Fresh produce is often a source of enterohaemorrhagic Escherichia coli (EHEC) outbreaks. Fimbriae are extracellular structures involved in cell-to-cell attachment and surface colonisation. F9 (Fml) fimbriae have been shown to be expressed at temperatures lower than 37 °C, implying a function beyond the mammalian host. We demonstrate that F9 fimbriae recognize plant cell wall hemicellulose, specifically galactosylated side chains of xyloglucan, using glycan arrays. E. coli expressing F9 fimbriae had a positive advantage for adherence to spinach hemicellulose extract and tissues, which have galactosylated oligosaccharides as recognized by LM24 and LM25 antibodies. As fimbriae are multimeric structures with a molecular pattern, we investigated whether F9 fimbriae could induce a transcriptional response in model plant Arabidopsis thaliana, compared with flagella and another fimbrial type, E. coli common pilus (ECP), using DNA microarrays. F9 induced the differential expression of 435 genes, including genes involved in the plant defence response. The expression of F9 at environmentally relevant temperatures and its recognition of plant xyloglucan adds to the suite of adhesins EHEC has available to exploit the plant niche.


Asunto(s)
Adhesinas de Escherichia coli/metabolismo , Arabidopsis/microbiología , Escherichia coli O157/fisiología , Fimbrias Bacterianas/fisiología , Glucanos/metabolismo , Xilanos/metabolismo , Arabidopsis/metabolismo
7.
BMC Genomics ; 20(1): 968, 2019 Dec 11.
Artículo en Inglés | MEDLINE | ID: mdl-31829136

RESUMEN

BACKGROUND: The time required to analyse RNA-seq data varies considerably, due to discrete steps for computational assembly, quantification of gene expression and splicing analysis. Recent fast non-alignment tools such as Kallisto and Salmon overcome these problems, but these tools require a high quality, comprehensive reference transcripts dataset (RTD), which are rarely available in plants. RESULTS: A high-quality, non-redundant barley gene RTD and database (Barley Reference Transcripts - BaRTv1.0) has been generated. BaRTv1.0, was constructed from a range of tissues, cultivars and abiotic treatments and transcripts assembled and aligned to the barley cv. Morex reference genome (Mascher et al. Nature; 544: 427-433, 2017). Full-length cDNAs from the barley variety Haruna nijo (Matsumoto et al. Plant Physiol; 156: 20-28, 2011) determined transcript coverage, and high-resolution RT-PCR validated alternatively spliced (AS) transcripts of 86 genes in five different organs and tissue. These methods were used as benchmarks to select an optimal barley RTD. BaRTv1.0-Quantification of Alternatively Spliced Isoforms (QUASI) was also made to overcome inaccurate quantification due to variation in 5' and 3' UTR ends of transcripts. BaRTv1.0-QUASI was used for accurate transcript quantification of RNA-seq data of five barley organs/tissues. This analysis identified 20,972 significant differentially expressed genes, 2791 differentially alternatively spliced genes and 2768 transcripts with differential transcript usage. CONCLUSION: A high confidence barley reference transcript dataset consisting of 60,444 genes with 177,240 transcripts has been generated. Compared to current barley transcripts, BaRTv1.0 transcripts are generally longer, have less fragmentation and improved gene models that are well supported by splice junction reads. Precise transcript quantification using BaRTv1.0 allows routine analysis of gene expression and AS.


Asunto(s)
Perfilación de la Expresión Génica/métodos , Hordeum/genética , Proteínas de Plantas/genética , Empalme Alternativo , Bases de Datos Genéticas , Regulación de la Expresión Génica de las Plantas , Análisis de Secuencia de ARN , Secuenciación del Exoma
8.
J Exp Bot ; 70(20): 5703-5714, 2019 10 24.
Artículo en Inglés | MEDLINE | ID: mdl-31328229

RESUMEN

For many potato cultivars, tuber yield is optimal at average daytime temperatures in the range 14-22 °C. Above this range, tuber yield is reduced for most cultivars. We previously reported that moderately elevated temperature increases steady-state expression of the core circadian clock gene TIMING OF CAB EXPRESSION 1 (StTOC1) in developing tubers, whereas expression of the StSP6A tuberization signal is reduced, along with tuber yield. In this study we provide evidence that StTOC1 links environmental signalling with potato tuberization by suppressing StSP6A autoactivation in the stolons. We show that transgenic lines silenced in StTOC1 expression exhibit enhanced StSP6A transcript levels and changes in gene expression in developing tubers that are indicative of an elevated sink strength. Nodal cuttings of StTOC1 antisense lines displayed increased tuber yields at moderately elevated temperatures, whereas tuber yield and StSP6A expression were reduced in StTOC1 overexpressor lines. Here we identify a number of StTOC1 binding partners and demonstrate that suppression of StSP6A expression is independent of StTOC1 complex formation with the potato homolog StPIF3. Down-regulation of StTOC1 thus provides a strategy to mitigate the effects of elevated temperature on tuber yield.


Asunto(s)
Proteínas de Plantas/metabolismo , Tubérculos de la Planta/fisiología , Solanum tuberosum/fisiología , Relojes Circadianos/genética , Relojes Circadianos/fisiología , Calor , Proteínas de Plantas/genética , Tubérculos de la Planta/genética , Solanum tuberosum/genética , Temperatura
9.
Ann Bot ; 123(5): 831-843, 2019 05 20.
Artículo en Inglés | MEDLINE | ID: mdl-30561497

RESUMEN

BACKGROUND AND AIMS: Micronutrient deficiency in cereals is a problem of global significance, severely reducing grain yield and quality in marginal soils. Ancient landraces represent, through hundreds of years of local adaptation to adverse soil conditions, a unique reservoir of genes and unexplored traits for enhancing yield and abiotic stress tolerance. Here we explored and compared the genetic variation in a population of Northern European barley landraces and modern elite varieties, and their tolerance to manganese (Mn) limitation. METHODS: A total of 135 barley accessions were genotyped and the genetic diversity was explored using Neighbor-Joining clustering. Based on this analysis, a sub-population of genetically diverse landraces and modern elite control lines were evaluated phenotypically for their ability to cope with Mn-deficient conditions, across three different environments increasing in complexity from hydroponics through pot experiments to regional field trials. KEY RESULTS: Genetically a group of Scottish barley landraces (Bere barley) were found to cluster according to their island of origin, and accessions adapted to distinct biogeographical zones with reduced soil fertility had particularly larger Mn, but also zinc (Zn) and copper (Cu) concentrations in the shoot. Strikingly, when grown in an alkaline sandy soil in the field, the locally adapted landraces demonstrated an exceptional ability to acquire and translocate Mn to developing leaves, maintain photosynthesis and generate robust grain yields, whereas modern elite varieties totally failed to complete their life cycle. CONCLUSIONS: Our results highlight the importance of gene pools of local adaptation and the value of ancient landrace material to identify and characterize genes that control nutrient use efficiency traits in adverse environments to raise future crop production and improve agricultural sustainability in marginal soils. We propose and discuss a model summarizing the physiological mechanisms involved in the complex trait of tolerance to Mn limitation.


Asunto(s)
Hordeum , Suelo , Grano Comestible , Genotipo , Manganeso
10.
Plant Physiol ; 174(1): 356-369, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28270626

RESUMEN

An emerging area in plant research focuses on antagonism between regulatory systems governing growth and immunity. Such cross talk represents a point of vulnerability for pathogens to exploit. AVR2, an RXLR effector secreted by the potato blight pathogen Phytophthora infestans, interacts with potato BSL1, a putative phosphatase implicated in growth-promoting brassinosteroid (BR) hormone signaling. Transgenic potato (Solanum tuberosum) plants expressing the effector exhibit transcriptional and phenotypic hallmarks of overactive BR signaling and show enhanced susceptibility to P. infestans Microarray analysis was used to identify a set of BR-responsive marker genes in potato, all of which are constitutively expressed to BR-induced levels in AVR2 transgenic lines. One of these genes was a bHLH transcription factor, designated StCHL1, homologous to AtCIB1 and AtHBI1, which are known to facilitate antagonism between BR and immune responses. Transient expression of either AVR2 or CHL1 enhanced leaf colonization by P. infestans and compromised immune cell death activated by perception of the elicitin Infestin1 (INF1). Knockdown of CHL1 transcript using Virus-Induced Gene Silencing (VIGS) reduced colonization of P. infestans on Nicotiana benthamiana Moreover, the ability of AVR2 to suppress INF1-triggered cell death was attenuated in NbCHL1-silenced plants, indicating that NbCHL1 was important for this effector activity. Thus, AVR2 exploits cross talk between BR signaling and innate immunity in Solanum species, representing a novel, indirect mode of innate immune suppression by a filamentous pathogen effector.


Asunto(s)
Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Phytophthora infestans/metabolismo , Proteínas de Plantas/metabolismo , Solanum tuberosum/metabolismo , Factores de Virulencia/metabolismo , Secuencia de Aminoácidos , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Brasinoesteroides/metabolismo , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Interacciones Huésped-Patógeno/genética , Phytophthora infestans/genética , Phytophthora infestans/patogenicidad , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Inmunidad de la Planta/genética , Proteínas de Plantas/genética , Plantas Modificadas Genéticamente , Homología de Secuencia de Aminoácido , Solanum tuberosum/genética , Solanum tuberosum/microbiología , Regulación hacia Arriba , Factores de Virulencia/genética
11.
Plant Cell Environ ; 41(5): 1083-1097, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-28369975

RESUMEN

The redox state of the apoplast is largely determined by ascorbate oxidase (AO) activity. The influence of AO activity on leaf acclimation to changing irradiance was explored in wild-type (WT) and transgenic tobacco (Nicotiana tobaccum) lines containing either high [pumpkin AO (PAO)] or low [tobacco AO (TAO)] AO activity at low [low light (LL); 250 µmol m-2  s-1 ] and high [high light (HL); 1600 µmol m-2  s-1 ] irradiance and following the transition from HL to LL. AO activities changed over the photoperiod, particularly in the PAO plants. AO activity had little effect on leaf ascorbate, which was significantly higher under HL than under LL. Apoplastic ascorbate/dehydroascorbate (DHA) ratios and threonate levels were modified by AO activity. Despite decreased levels of transcripts encoding ascorbate synthesis enzymes, leaf ascorbate increased over the first photoperiod following the transition from HL to LL, to much higher levels than LL-grown plants. Photosynthesis rates were significantly higher in the TAO leaves than in WT or PAO plants grown under HL but not under LL. Sub-sets of amino acids and fatty acids were lower in TAO and WT leaves than in the PAO plants under HL, and following the transition to LL. Light acclimation processes are therefore influenced by the apoplastic as well as chloroplastic redox state.


Asunto(s)
Ascorbato Oxidasa/metabolismo , Ácido Ascórbico/metabolismo , Nicotiana/fisiología , Aclimatación , Ascorbato Oxidasa/genética , Cloroplastos/metabolismo , Luz , Oxidación-Reducción , Fotosíntesis , Hojas de la Planta/enzimología , Hojas de la Planta/genética , Hojas de la Planta/fisiología , Hojas de la Planta/efectos de la radiación , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Nicotiana/enzimología , Nicotiana/genética , Nicotiana/efectos de la radiación
12.
BMC Genet ; 19(1): 59, 2018 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-30111279

RESUMEN

BACKGROUND: The changing climate is altering timing of key fruit ripening processes and increasing the occurrence of fruit defects. To improve our understanding of the genetic control of raspberry fruit development an enhanced genetic linkage map was developed and used to examine ripening phenotypic data. RESULTS: In this study we developed an enhanced genetic linkage map for the raspberry cvs. Glen Moy x Latham reference mapping population using genotyping by sequencing (GbS). Alignment to a newly sequenced draft reference genome of red raspberry, cultivar (cv.) Glen Moy, identified 8019 single nucleotide polymorphisms (SNPs). After stringent filtering to take account of read coverage over all the progeny individuals, association with a single chromosome, heterozygosity and marker regression mapping, 2348 high confidence SNPs were retained and integrated with an existing raspberry genetic map. The linkage map contained many more SNPs segregating in Latham than in Glen Moy. This caused difficulties in quantitative trait loci (QTL) mapping with standard software and a novel analysis based on a hidden Markov model was used to improve the mapping. QTL mapping using the newly generated dense genetic map not only corroborated previously identified genetic locations but also provided additional genetic elements controlling fruit ripening in raspberry. CONCLUSION: The high-density GbS map located the QTL peaks more precisely than in earlier studies, aligned the QTLs with Glen Moy genome scaffolds, narrowed the range of potential candidate genes to these regions that can be utilised in other populations or in gene expression studies to confirm their role and increased the repertoire of markers available to understand the genetic control of fruit ripening traits.


Asunto(s)
Frutas/genética , Ligamiento Genético , Organogénesis de las Plantas/genética , Polimorfismo de Nucleótido Simple , Rubus/genética , Mapeo Cromosómico , Frutas/crecimiento & desarrollo , Sitios de Carácter Cuantitativo , Rubus/crecimiento & desarrollo
13.
BMC Plant Biol ; 17(1): 232, 2017 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-29202692

RESUMEN

BACKGROUND: Nonhost resistance (NHR) protects plants against a vast number of non-adapted pathogens which implicates a potential exploitation as source for novel disease resistance strategies. Aiming at a fundamental understanding of NHR a global analysis of transcriptome reprogramming in the economically important Triticeae cereals wheat and barley, comparing host and nonhost interactions in three major fungal pathosystems responsible for powdery mildew (Blumeria graminis ff. ssp.), cereal blast (Magnaporthe sp.) and leaf rust (Puccinia sp.) diseases, was performed. RESULTS: In each pathosystem a significant transcriptome reprogramming by adapted- or non-adapted pathogen isolates was observed, with considerable overlap between Blumeria, Magnaporthe and Puccinia. Small subsets of these general pathogen-regulated genes were identified as differentially regulated between host and corresponding nonhost interactions, indicating a fine-tuning of the general pathogen response during the course of co-evolution. Additionally, the host- or nonhost-related responses were rather specific for each pair of adapted and non-adapted isolates, indicating that the nonhost resistance-related responses were to a great extent pathosystem-specific. This pathosystem-specific reprogramming may reflect different resistance mechanisms operating against non-adapted pathogens with different lifestyles, or equally, different co-option of the hosts by the adapted isolates to create an optimal environment for infection. To compare the transcriptional reprogramming between wheat and barley, putative orthologues were identified. Within the wheat and barley general pathogen-regulated genes, temporal expression profiles of orthologues looked similar, indicating conserved general responses in Triticeae against fungal attack. However, the comparison of orthologues differentially expressed between host and nonhost interactions revealed fewer commonalities between wheat and barley, but rather suggested different host or nonhost responses in the two cereal species. CONCLUSIONS: Taken together, our results suggest independent co-evolutionary forces acting on host pathosystems mirrored by barley- or wheat-specific nonhost responses. As a result of evolutionary processes, at least for the pathosystems investigated, NHR appears to rely on rather specific plant responses.


Asunto(s)
Resistencia a la Enfermedad/genética , Hordeum/inmunología , Enfermedades de las Plantas/inmunología , Triticum/inmunología , Adaptación Fisiológica , Ascomicetos , Evolución Biológica , Resistencia a la Enfermedad/inmunología , Hordeum/genética , Hordeum/microbiología , Magnaporthe , Enfermedades de las Plantas/genética , Transcriptoma , Triticum/genética , Triticum/microbiología
14.
Plant Physiol ; 170(3): 1549-65, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26754666

RESUMEN

Within the cereal grain, the endosperm and its nutrient reserves are critical for successful germination and in the context of grain utilization. The identification of molecular determinants of early endosperm development, particularly regulators of cell division and cell wall deposition, would help predict end-use properties such as yield, quality, and nutritional value. Custom microarray data have been generated using RNA isolated from developing barley grain endosperm 3 d to 8 d after pollination (DAP). Comparisons of transcript abundance over time revealed 47 gene expression modules that can be clustered into 10 broad groups. Superimposing these modules upon cytological data allowed patterns of transcript abundance to be linked with key stages of early grain development. Here, attention was focused on how the datasets could be mined to explore and define the processes of cell wall biosynthesis, remodeling, and degradation. Using a combination of spatial molecular network and gene ontology enrichment analyses, it is shown that genes involved in cell wall metabolism are found in multiple modules, but cluster into two main groups that exhibit peak expression at 3 DAP to 4 DAP and 5 DAP to 8 DAP. The presence of transcription factor genes in these modules allowed candidate genes for the control of wall metabolism during early barley grain development to be identified. The data are publicly available through a dedicated web interface (https://ics.hutton.ac.uk/barseed/), where they can be used to interrogate co- and differential expression for any other genes, groups of genes, or transcription factors expressed during early endosperm development.


Asunto(s)
Endospermo/genética , Perfilación de la Expresión Génica/métodos , Regulación del Desarrollo de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Hordeum/genética , Pared Celular/genética , Pared Celular/metabolismo , Análisis por Conglomerados , Grano Comestible/citología , Grano Comestible/embriología , Grano Comestible/genética , Endospermo/citología , Endospermo/embriología , Ontología de Genes , Redes Reguladoras de Genes , Hordeum/citología , Hordeum/embriología , Análisis de Secuencia por Matrices de Oligonucleótidos , Proteínas de Plantas/clasificación , Proteínas de Plantas/genética , Polinización/genética , Factores de Tiempo
15.
Theor Appl Genet ; 130(2): 269-281, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27734096

RESUMEN

KEY MESSAGE: Awn length was mapped using a multiparent population derived from cv. Morex and four wild accessions. One QTL was fine mapped and candidate genes were identified in NILs by RNA-seq. Barley awns are photosynthetically active and contribute to grain yield. Awn length is variable among both wild and cultivated barley genotypes and many mutants with alterations in awn length have been identified. Here, we used a multiparent mapping population derived from cv. Morex and four genetically diverse wild barley lines to detect quantitative trait loci (QTLs) for awn length. Twelve QTLs, distributed over the barley genome, were identified with the most significant one located on chromosome arm 7HL (QTL AL7.1). The effect of AL7.1 was confirmed using near isogenic lines (NILs) and fine-mapped in two independent heterogeneous inbred families to a < 0.9 cM interval. With exception of a small effect on grain width, no other traits such as plant height or flowering time were affected by AL7.1. Variant calling on transcripts obtained from RNA sequencing reads in NILs was used to narrow down the list of candidate genes located in the interval. This data may be used for further characterization and unravelling of the mechanisms underlying natural variation in awn length.


Asunto(s)
Mapeo Cromosómico , Hordeum/genética , Sitios de Carácter Cuantitativo , Grano Comestible/crecimiento & desarrollo , Genotipo , Hordeum/crecimiento & desarrollo , Modelos Lineales , Modelos Genéticos , ARN de Planta/genética , Análisis de Secuencia de ARN
16.
Mol Plant Microbe Interact ; 29(10): 822-828, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-27681277

RESUMEN

Field-grown tubers of potato were examined for infection by Tobacco rattle virus (TRV) and consequent production of corky ringspot or spraing symptoms. A microarray study identified genes that are differentially expressed in tuber tissue in response to TRV infection and to spraing production, suggesting that hypersensitive response (HR) pathways are activated in spraing-symptomatic tubers. This was confirmed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) of a selected group of HR-related genes and by histochemical staining of excised tuber tissue with spraing symptoms. qRT-PCR of TRV in different regions of the same tuber slice showed that nonsymptomatic areas contained higher levels of virus relative to spraing-symptomatic areas. This suggests that spraing formation is associated with an active plant defense that reduces the level of virus in the infected tuber. Expression of two of the same plant defense genes was similarly upregulated in tubers that were infected with Potato mop-top virus, a virus that also induces spraing formation.


Asunto(s)
Regulación de la Expresión Génica de las Plantas , Enfermedades de las Plantas/inmunología , Virus de Plantas/fisiología , Solanum tuberosum/genética , Análisis de Secuencia por Matrices de Oligonucleótidos , Enfermedades de las Plantas/virología , Tubérculos de la Planta/genética , Tubérculos de la Planta/inmunología , Tubérculos de la Planta/virología , Solanum tuberosum/inmunología , Solanum tuberosum/virología
17.
Plant J ; 79(6): 981-92, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24947331

RESUMEN

The low-recombining pericentromeric region of the barley genome contains roughly a quarter of the genes of the species, embedded in low-recombining DNA that is rich in repeats and repressive chromatin signatures. We have investigated the effects of pericentromeric region residency upon the expression, diversity and evolution of these genes. We observe no significant difference in average transcript level or developmental RNA specificity between the barley pericentromeric region and the rest of the genome. In contrast, all of the evolutionary parameters studied here show evidence of compromised gene evolution in this region. First, genes within the pericentromeric region of wild barley show reduced diversity and significantly weakened purifying selection compared with the rest of the genome. Second, gene duplicates (ohnolog pairs) derived from the cereal whole-genome duplication event ca. 60MYa have been completely eliminated from the barley pericentromeric region. Third, local gene duplication in the pericentromeric region is reduced by 29% relative to the rest of the genome. Thus, the pericentromeric region of barley is a permissive environment for gene expression but has restricted gene evolution in a sizeable fraction of barley's genes.


Asunto(s)
Evolución Molecular , Variación Genética , Genoma de Planta/genética , Hordeum/genética , Secuencia de Bases , Duplicación de Gen , Expresión Génica , Ontología de Genes , Heterocromatina/genética , Datos de Secuencia Molecular , Recombinación Genética , Análisis de Secuencia de ARN
19.
Plant Physiol ; 164(1): 412-23, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24243933

RESUMEN

Barley (Hordeum vulgare) is an important cereal crop and a model species for Triticeae genomics. To lay the foundation for hierarchical map-based sequencing, a genome-wide physical map of its large and complex 5.1 billion-bp genome was constructed by high-information content fingerprinting of almost 600,000 bacterial artificial chromosomes representing 14-fold haploid genome coverage. The resultant physical map comprises 9,265 contigs with a cumulative size of 4.9 Gb representing 96% of the physical length of the barley genome. The reliability of the map was verified through extensive genetic marker information and the analysis of topological networks of clone overlaps. A minimum tiling path of 66,772 minimally overlapping clones was defined that will serve as a template for hierarchical clone-by-clone map-based shotgun sequencing. We integrated whole-genome shotgun sequence data from the individuals of two mapping populations with published bacterial artificial chromosome survey sequence information to genetically anchor the physical map. This novel approach in combination with the comprehensive whole-genome shotgun sequence data sets allowed us to independently validate and improve a previously reported physical and genetic framework. The resources developed in this study will underpin fine-mapping and cloning of agronomically important genes and the assembly of a draft genome sequence.


Asunto(s)
Hordeum/genética , Mapeo Físico de Cromosoma , Polimorfismo de Nucleótido Simple , Cromosomas Artificiales Bacterianos , Mapeo Contig , Reproducibilidad de los Resultados , Análisis de Secuencia de ADN
20.
Physiol Plant ; 155(1): 12-20, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25625434

RESUMEN

A biological pathway is the set of molecular entities involved in a given biological process and the interrelations among them. Even though biological pathways have been studied extensively, discovering missing genes in pathways remains a fundamental challenge. Here, we present an easy-to-use tool that allows users to run MORPH (MOdule-guided Ranking of candidate PatHway genes), an algorithm for revealing missing genes in biological pathways, and demonstrate its capabilities. MORPH supports the analysis in tomato, Arabidopsis and the two new species: rice and the newly sequenced potato genome. The new tool, called MORPH-R, is available both as a web server (at http://bioinformatics.psb.ugent.be/webtools/morph/) and as standalone software that can be used locally. In the standalone version, the user can apply the tool to new organisms using any proprietary and public data sources.


Asunto(s)
Vías Biosintéticas/genética , Biología Computacional/métodos , Genes de Plantas/genética , Programas Informáticos , Algoritmos , Arabidopsis/genética , Ontología de Genes , Internet , Solanum lycopersicum/genética , Oryza/genética , Reproducibilidad de los Resultados , Solanum tuberosum/genética
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