Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
Filtros adicionais











Intervalo de ano
1.
Artigo em Inglês | MEDLINE | ID: mdl-31425044

RESUMO

Although plenty of structural variant detecting approaches for human genomes can be looked up in the literatures, little has been acknowledged on the effectiveness of those structural variant softwares for plant genomes. It has been demonstrated frequent occurrences for those structural variant detecting softwares to find too many false structural variants. In this paper, we devote to detect deletions, insertions, inversions, in total of three kinds of structural variants occurring in Hedou12 genome in contrast to Williams82 genome. Aiming to enhance the precision of structural variant detections, we propose two new sequencing characteristic based probability models, which use the sequencing parameters of Hedou12 genome, as well as the parameters for Hedou12 paired-end reads to be aligned onto Williams82, to evaluate the probability a potential structural variant can occur in. To remove the false members from those potential structural variants, we propose a set cover problem model to describe formally on which potential structural variants it should accept to achieve as high as possible a probability summation. This will achieve a solution with more credible structural variants, which can be verified by comparing with DELLY and LUMPY.

2.
Plant Mol Biol ; 99(1-2): 95-111, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30535849

RESUMO

KEY MESSAGE: That overexpression of GmKR3 enhances innate virus resistance by stimulating. Soybean mosaic virus (SMV) is found in many soybean production areas, and SMV infection is one of the prevalent viral diseases that can cause significant yield losses in soybean. In plants, resistance (R) genes are involved in pathogen reorganization and innate immune response activation. Most R proteins have nucleotide-binding site and leucine-rich repeat (NBS-LRR) domains, and some of the NBS-LRR type R proteins in dicots have Toll/Interleukin-1 Receptor (TIR) motifs. We report here the analysis of the over-expression of GmKR3, a soybean TIR-NBS-LRR type R gene on virus resistance in soybean. When over-expressed in soybean, GmKR3 enhanced the plant's resistance to several strains of SMV, the closely related potyviruses bean common mosaic virus (BCMV) and watermelon mosaic virus (WMV), and the secovirus bean pod mottle virus (BPMV). Importantly, over-expression of GmKR3 did not affect plant growth and development, including yield and qualities of the seeds. HPLC analysis showed that abscisic acid (ABA) content increased in the 35S:GmKR3 transgenic plants, and in both wild-type and 35S:GmKR3 transgenic plants in response to virus inoculation. Consistent with this observation, we found that the expression of two ABA catabolism genes was down-regulated in 35S:GmKR3 transgenic plants. We also found that the expression of Gm04.3, an ABA responsive gene encoding BURP domain-containing protein, was up-regulated in 35S:GmKR3 transgenic plants. Taken together, our results suggest that overexpression of GmKR3 enhanced virus resistance in soybean, which was achieved at least in part via ABA signaling.


Assuntos
Resistência à Doença/genética , Doenças das Plantas/imunologia , Proteínas de Plantas/metabolismo , Potyvirus/imunologia , Transdução de Sinais , Soja/genética , Expressão Gênica , Doenças das Plantas/virologia , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Soja/imunologia , Soja/virologia
3.
Front Plant Sci ; 9: 223, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29541083

RESUMO

The endosperm occupies most of the available space within mature rice seeds, contains abundant nutrients, and directly influences both the quality and quantity of rice production. Initial reports noted that AtZHOUPI (AtZOU) coordinates endosperm breakdown and the concomitant separation of the embryo from this structure in Arabidopsis. The results of this study show that rice genomes contain two most closely related homologs of AtZOU, OsZOU-1 and OsZOU-2; of these, OsZOU-1 expression is limited to within the endosperm where it can be detected throughout this structure 5 days after pollination (DAP). Its expression gradually decreases from seven DAP to nine DAP. The second of the two most closely related homologs, OsZOU-2, is highly expressed in leaves and stem, but is not detected in developing seeds. Heterologous expression of OsZOU-1 and OsZOU-2 in Atzou-4 mutants also revealed that OsZOU-1 partially complements the seed phenotypes of these individuals, while its counterpart, OsZOU-2, was unable to recover these phenotypes. The over-expression of OsZOU-1 severely disrupts both seed development and plant growth in transgenic rice lines, as plants in which this gene has been knocked down failed in the separation of endosperm from embryo and cuticle formation during seed development. The results of this study therefore suggest that OsZOU-1 is orthologous to the AtZOU, and regulates both endosperm development and cuticle formation in rice.

4.
Plant Physiol ; 174(2): 1167-1176, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28336772

RESUMO

Leaf petiole angle (LPA) is an important plant architectural trait that affects canopy coverage, photosynthetic efficiency, and ultimately productivity in many legume crops. However, the genetic basis underlying this trait remains unclear. Here, we report the identification, isolation, and functional characterization of Glycine max Increased Leaf Petiole Angle1 (GmILPA1), a gene encoding an APC8-like protein, which is a subunit of the anaphase-promoting complex/cyclosome in soybean (Glycine max). A gamma ray-induced deletion of a fragment involving the fourth exon of GmILPA1 and its flanking sequences led to extension of the third exon and formation of, to our knowledge, a novel 3'UTR from intronic and intergenic sequences. Such changes are responsible for enlarged LPAs that are associated with reduced motor cell proliferation in the Gmilpa1 mutant. GmILPA1 is mainly expressed in the basal cells of leaf primordia and appears to function by promoting cell growth and division of the pulvinus that is critical for its establishment. GmILPA1 directly interacts with GmAPC13a as part of the putative anaphase-promoting complex. GmILPA1 exhibits variable expression levels among varieties with different degrees of LPAs, and expression levels are correlated with the degrees of the LPAs. Together, these observations revealed a genetic mechanism modulating the plant petiole angle that could pave the way for modifying soybean plant architecture with optimized petiole angles for enhanced yield potential.


Assuntos
Folhas de Planta/fisiologia , Proteínas de Plantas/metabolismo , Soja/fisiologia , Mapeamento Cromossômico , Regulação da Expressão Gênica de Plantas , Teste de Complementação Genética , Loci Gênicos , Mutação/genética , Fenótipo , Proteínas de Plantas/genética , Ligação Proteica , Reprodutibilidade dos Testes , Homologia de Sequência do Ácido Nucleico , Soja/genética , Frações Subcelulares/metabolismo
5.
Front Plant Sci ; 8: 139, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28228767

RESUMO

Soybean (Glycine max Merr.) is the world's most widely grown legume and provides an important source of protein and oil. Improvement of seed quality requires deep insights into the genetic regulation of seed development. The endosperm serves as a temporary source of nutrients that are transported from maternal to filial tissues, and it also generates signals for proper embryo formation. Endosperm cell death is associated with the processes of nutrient transfer and embryo expansion. The bHLH domain transcription factor AtZHOUPI (AtZOU) plays a key role in both the lysis of the transient endosperm and the formation of embryo cuticle in Arabidopsis thaliana. There are two copies of soybean GmZOU (GmZOU-1 and GmZOU-2), which fall into the same phylogenetic clade as AtZOU. These two copies share the same transcription orientation and are the result of tandem duplication. The expression of GmZOUs is limited to the endosperm, where it peaks during the heart embryo stage. When the exogenous GmZOU-1 and GmZOU-2 were expressed in the zou-4 mutant of Arabidopsis, only GmZOU-1 partially complemented the zou mutant phenotype, as indicated by endosperm breakdown and embryo cuticle formation in the transgenic lines. This research confirmed that the GmZOU-1 is a ZOU ortholog that may be responsible for endosperm breakdown and embryo cuticle formation in soybean.

6.
Int J Mol Sci ; 18(1)2016 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-28025485

RESUMO

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


Assuntos
Regulação da Expressão Gênica de Plantas , Oryza/genética , Proteínas de Plantas/genética , Tolerância ao Sal , Fatores de Transcrição/genética , Secas , Ácidos Indolacéticos/metabolismo , Proteínas de Plantas/metabolismo , Transdução de Sinais , Fatores de Transcrição/metabolismo , Regulação para Cima
7.
Plant Mol Biol ; 91(4-5): 549-61, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27164978

RESUMO

T-DNA insertion mutants have been widely used to investigate plant gene functions. Unexpectedly, in several reported cases, the phenotype of T-DNA insertion mutations can be suppressed because of trans T-DNA interactions associated with epigenetic modification, which indicates that caution is needed when T-DNA mutants are used. In the present study, we characterized a novel process suppressing a T-DNA mutation. The spz2 (suppressor of zou 2) mutant was isolated as a suppressor of the phenotype of the zou-4 mutant caused by a T-DNA insertion in the first intron. The spz2 mutation partially recovered the native ZOU gene expression in the zou-4 background, but not in two other zou alleles, zou-2 and zou-3, with T-DNAs inserted in the exon and intron, respectively. The suppressed phenotype was inherited in a Mendelian fashion and is not associated with epigenetic modification. The recovery of the native ZOU gene expression in the spz2 zou-4 double mutant is caused by transcriptional read-through of the intronic T-DNA as a result of decreased proximal polyadenylation. SPZ2 encodes an RNA-binding protein, FPA, which is known to regulate polyadenylation site selection. This is the first example of FPA rescuing a T-DNA insertion mutation by affecting the polyadenylation site selection.


Assuntos
Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , DNA Bacteriano/genética , Genes de Plantas , Mutagênese Insercional/genética , Proteínas de Ligação a RNA/metabolismo , Transcrição Genética , Alelos , Arabidopsis/crescimento & desenvolvimento , Sequência de Bases , Clonagem Molecular , Resistência Microbiana a Medicamentos/genética , Epigênese Genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes Supressores , Íntrons/genética , Mutação , Fenótipo , Poliadenilação/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Sementes/genética , Sementes/crescimento & desenvolvimento
8.
Plant Mol Biol ; 90(1-2): 33-47, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26482479

RESUMO

Soybean (Glycine max) is one of the most important crops in the world, and its yield is largely determined by grain weight and grain size. However, the genes that regulate soybean seed size have not been identified. CYP78A, which is highly conserved within terrestrial plants, regulates organ development. In Arabidopsis, AtCYP78A5/KLU has been shown to determine seed size. In the present study, soybean CYP78A72 (GmCYP78A72), one of the orthologs of KLU, was over-expressed in both Arabidopsis and soybean to examine its function in plant development. GmCYP78A72 heterologous expression in Arabidopsis resulted in enlarged sepals, petals, seeds and carpel. Over-expression of GmCYP78A72 in soybean resulted in increased pea size, which is an extremely desirable trait for enhancing productivity. Moreover, knock-down of GmCYP78A72 does not reduce grain size. However, silencing of GmCYP78A57, GmCYP78A70 and GmCYP78A72 genes in triplet reduces the seed size significantly indicating functional redundancy of these three GmCYP78A genes. In conclusion, we investigated the role of CYP78A in soybean seed regulation, and our strategy can be effectively used to engineer large seed traits in soybean varieties as well as other crops.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Sistema Enzimático do Citocromo P-450/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Soja/genética , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Flores/genética , Flores/crescimento & desenvolvimento , Flores/metabolismo , Expressão Gênica , Inativação Gênica , Fenótipo , Filogenia , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Sementes/genética , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Alinhamento de Sequência , Soja/crescimento & desenvolvimento , Soja/metabolismo
9.
G3 (Bethesda) ; 5(12): 2793-9, 2015 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-26483012

RESUMO

Soybean [Glycine max (L.) Merrill] is an important crop worldwide. In this study, a Chinese local soybean cultivar, Hedou 12, was resequenced by next generation sequencing technology to develop INsertion/DELetion (INDEL) markers for genetic mapping. 49,276 INDEL polymorphisms and 242,059 single nucleotide polymorphisms were detected between Hedou 12 and the Williams 82 reference sequence. Of these, 243 candidate INDEL markers ranging from 5-50 bp in length were chosen for validation, and 165 (68%) of them revealed polymorphisms between Hedou 12 and Williams 82. The validated INDEL markers were also tested in 12 other soybean cultivars. The number of polymorphisms in the pairwise comparisons of 14 soybean cultivars varied from 27 to 165. To test the utility of these INDEL markers, they were used to perform genetic mapping of a crinkly leaf mutant, and the CRINKLY LEAF locus was successfully mapped to a 360 kb region on chromosome 7. This research shows that high-throughput sequencing technologies can facilitate the development of genome-wide molecular markers for genetic mapping in soybean.


Assuntos
Mapeamento Cromossômico , Marcadores Genéticos , Genoma de Planta , Sequenciamento de Nucleotídeos em Larga Escala , Mutação INDEL , Soja/genética , Cromossomos de Plantas , Genômica , Fenótipo , Filogenia , Polimorfismo Genético , Reprodutibilidade dos Testes , Soja/classificação
10.
Proc Natl Acad Sci U S A ; 112(40): 12432-7, 2015 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-26396256

RESUMO

The suspensor is a temporary supporting structure of proembryos. It has been proposed that suspensor cells also possess embryogenic potential, which is suppressed by the embryo as an effect of the embryo-suspensor interaction. However, data to support this hypothesis are not yet available. In this report, using an in vivo living cell laser ablation technique, we show that Arabidopsis suspensor cells can develop into embryos after removing the embryo proper. The embryo proper plays a critical role in maintaining suspensor cell identity. However, this depends on the developmental stage; after the globular embryo stage, the suspensors no longer possess the potential to develop into embryos. We also reveal that hypophysis formation may be essential for embryo differentiation. Furthermore, we show that, after removing the embryo, auxin gradually accumulates in the top suspensor cell where cell division occurs to produce an embryo. Auxin redistribution likely reprograms the fate of the suspensor cell and triggers embryogenesis in suspensor cells. Thus, we provide direct evidence that the embryo suppresses the embryogenic potential of suspensor cells.


Assuntos
Arabidopsis/citologia , Arabidopsis/embriologia , Sementes/citologia , Sementes/embriologia , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Diferenciação Celular , Divisão Celular , Células Cultivadas , Glucuronidase/genética , Glucuronidase/metabolismo , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Ácidos Indolacéticos/metabolismo , Microdissecção e Captura a Laser , Microscopia Confocal , Morfogênese , Plantas Geneticamente Modificadas , Sementes/genética , Fatores de Tempo , Técnicas de Cultura de Tecidos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
11.
New Phytol ; 196(4): 1251-9, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23025531

RESUMO

Heteroblasty refers to the changes in leaf shape and size (allometry) along stems. Although evolutionary changes involving heteroblasty might contribute to leaf diversity, little is known of the extent to which heteroblasty differs between species or how it might relate to other aspects of allometry or other developmental transitions. Here, we develop a computational model that can quantify differences in leaf allometry between Antirrhinum (snapdragon) species, including variation in heteroblasty. It allows the underlying genes to be mapped in inter-species hybrids, and their effects to be studied in similar genetic backgrounds. Heteroblasty correlates with overall variation in leaf allometry, so species with smaller, rounder leaves produce their largest leaves earlier in development. This involves genes that affect both characters together and is exaggerated by additional genes with multiplicative effects on leaf size. A further heteroblasty gene also alters leaf spacing, but none affect other developmental transitions, including flowering. We suggest that differences in heteroblasty have co-evolved with overall leaf shape and size in Antirrhinum because these characters are constrained by common underlying genes. By contrast, heteroblasty is not correlated with other developmental transitions, with the exception of internode length, suggesting independent genetic control and evolution.


Assuntos
Antirrhinum/genética , Modelos Biológicos , Folhas de Planta/anatomia & histologia , Folhas de Planta/genética , Evolução Biológica , Quimera , Regulação da Expressão Gênica de Plantas , Variação Genética , Modelos Genéticos , Fenótipo , Folhas de Planta/crescimento & desenvolvimento , Locos de Características Quantitativas
12.
J Integr Plant Biol ; 53(10): 770-82, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21902804

RESUMO

Previous studies have demonstrated that petal shape and size in legume flowers are determined by two separate mechanisms, dorsoventral (DV) and organ internal (IN) asymmetric mechanisms, respectively. However, little is known about the molecular mechanisms controlling petal development in legumes. To address this question, we investigated petal development along the floral DV axis in Lotus japonicus with respect to cell and developmental biology by comparing wild-type legumes to mutants. Based on morphological markers, the entire course of petal development, from initiation to maturity, was grouped to define 3 phases or 13 stages. In terms of epidermal micromorphology from adaxial surface, mature petals were divided into several distinct domains, and characteristic epidermal cells of each petal differentiated at stage 9, while epidermal cells of all domains were observed until stage 12. TCP and MIXTA-like genes were found to be differentially expressed in various domains of petals at stages 9 and 12. Our results suggest that DV and IN mechanisms interplay at different stages of petal development, and their interaction at the cellular and molecular level guides the elaboration of domains within petals to achieve their ideal shape, and further suggest that TCP genes determine petal identity along the DV axis by regulating MIXTA-like gene expression.


Assuntos
Flores/crescimento & desenvolvimento , Lotus/crescimento & desenvolvimento , Padronização Corporal/genética , Flores/genética , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Lotus/genética , Mutação/genética , Epiderme Vegetal/citologia
13.
Plant Cell ; 21(10): 2999-3007, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19880796

RESUMO

Correlated variation in shape and size (allometry) is a major component of natural diversity. We examined the evolutionary and genetic basis for allometry using leaves and flower petals of snapdragon species (Antirrhinum). A computational method was developed to capture shape and size variation in both types of organ within the Antirrhinum species group. The results show that the major component of variation between species involves positively correlated changes in leaf and petal size. The correlation was maintained in an F2 population derived from crossing two species with organs of different sizes, suggesting that developmental constraints were involved. Identification of the underlying genes as quantitative trait loci revealed that the larger species carried alleles that increased organ size at all loci. Although this was initially taken as evidence that directional selection has driven diversity in both leaf and petal size, simulations revealed that evolution without consistent directional selection, an undirected walk, could also account for the parental distribution of organ size alleles.


Assuntos
Antirrhinum/genética , Evolução Biológica , Antirrhinum/anatomia & histologia , Antirrhinum/classificação , Flores/anatomia & histologia , Flores/genética , Folhas de Planta/anatomia & histologia , Folhas de Planta/genética
14.
Proc Natl Acad Sci U S A ; 105(30): 10414-9, 2008 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-18650395

RESUMO

Floral zygomorphy (flowers with bilateral symmetry) has multiple origins and typically manifests two kinds of asymmetries, dorsoventral (DV) and organ internal (IN) asymmetries in floral and organ planes, respectively, revealing the underlying key regulators in plant genomes that generate and superimpose various mechanisms to build up complexity and different floral forms during plant development. In this study, we investigate the loci affecting these asymmetries during the development of floral zygomorphy in pea (Pisum sativum L.). Two genes, LOBED STANDARD 1 (LST1) and KEELED WINGS (K), were cloned that encode TCP transcription factors and have divergent functions to constitute the DV asymmetry. A previously undescribed regulator, SYMMETRIC PETALS 1 (SYP1), has been isolated as controlling IN asymmetry. Genetic analysis demonstrates that DV and IN asymmetries could be controlled independently by the two kinds of regulators in pea, and their interactions help to specify the type of zygomorphy. Based on the genetic analysis in pea, we suggest that variation in both the functions and interactions of these regulators could give rise to the wide spectrum of floral symmetries among legume species and other flowering plants.


Assuntos
Regulação da Expressão Gênica de Plantas , Genes de Plantas , Ervilhas/genética , Clonagem Molecular , Flores/genética , Variação Genética , Genoma de Planta , Genômica/métodos , Modelos Genéticos , Mutação , Fenótipo , Filogenia , Mapeamento Físico do Cromossomo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Fatores de Transcrição
15.
Proc Natl Acad Sci U S A ; 103(13): 4970-5, 2006 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-16549774

RESUMO

Zygomorphic flowers, with bilateral (dorsoventral) symmetry, are considered to have evolved several times independently in flowering plants. In Antirrhinum majus, floral dorsoventral symmetry depends on the activity of two TCP-box genes, CYCLOIDEA (CYC) and DICHOTOMA (DICH). To examine whether the same molecular mechanism of floral asymmetry operates in the distantly related Rosid clade of eudicots, in which asymmetric flowers are thought to have evolved independently, we investigated the function of a CYC homologue LjCYC2 in a papilionoid legume, Lotus japonicus. We showed a role for LjCYC2 in establishing dorsal identity by altering its expression in transgenic plants and analyzing its mutant allele squared standard 1 (squ1). Furthermore, we identified a lateralizing factor, Keeled wings in Lotus 1 (Kew1), which plays a key role in the control of lateral petal identity, and found LjCYC2 interacted with Kew1, resulting in a double mutant that bore all petals with ventralized identity to some extents. Thus, we demonstrate that CYC homologues have been independently recruited as determinants of petal identities along the dorsoventral axis in two distant lineages of flowering plants, suggesting a common molecular origin for the mechanisms controlling floral zygomorphy.


Assuntos
Flores/anatomia & histologia , Flores/crescimento & desenvolvimento , Lotus/anatomia & histologia , Lotus/crescimento & desenvolvimento , Alelos , Sequência de Aminoácidos , Sequência Conservada , Flores/genética , Flores/metabolismo , Regulação da Expressão Gênica de Plantas , Lotus/genética , Lotus/metabolismo , Dados de Sequência Molecular , Mutação/genética , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Alinhamento de Sequência
16.
Environ Geochem Health ; 28(1-2): 103-10, 2006 Feb-Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16528587

RESUMO

Perennial monoculture forming grasses are very important natural remediators of pollutants. Their genetic improvement is an important task because introduction of key transgenes can dramatically improve their remediation potential. Transfer of key genes for mercury phytoremediation into the salt marsh cordgrass (Spartina alterniflora) is reported here. S. alterniflora plays an important role in the salt marsh by cycling of elements, both nutrients and pollutants, protects the coastline from erosion, is a keystone species in the salt marsh supporting a large food web, which in turn supports a significant segment of economy, including tourism, has an impact on cloud formation and consequently on global weather, and is thus an ecologically important species relevant for our life-support systems. Embryogenic callus of S. alterniflora was co-inoculated with a pair of Agrobacterium strains LBA4404 carrying the organomercurial lyase (merB) and mercuric reductase (merA) genes, respectively, in order to co-introduce both the merA and the merB genes. Seven stable geneticin resistant lines were recovered. The presence of merA and merB genes was verified by PCR and Southern blotting. All but one transgenic lines contained both the merA and the merB sequences proving that co-introduction into Spartina of two genes from separate Agrobacterium strains is feasible and frequent, although the overall frequency of transformation is low. Northern blotting showed differences in relative expression of the two transgenes among individual transformants. The steady-state RNA levels appeared to correlate with the phenotype. Line #7 showed the highest resistance to HgCl(2) (up to 500 microM), whereas line #3 was the most resistant to phenylmercuric acetate (PMA). Wild-type (WT) callus is sensitive to PMA at 50 microM and to HgCl(2) at 225 microM.


Assuntos
Plantas Geneticamente Modificadas , Poaceae/fisiologia , Rhizobium/fisiologia , Biodegradação Ambiental , Técnicas de Cultura de Células , Clima , Engenharia Genética , Liases/genética , Liases/metabolismo , Cloreto de Mercúrio/metabolismo , Cloreto de Mercúrio/toxicidade , Oxirredutases/genética , Oxirredutases/metabolismo , Fenótipo , Acetato de Fenilmercúrio/metabolismo , Acetato de Fenilmercúrio/toxicidade , Poaceae/genética , Poaceae/crescimento & desenvolvimento , Reação em Cadeia da Polimerase , Rhizobium/genética , Rhizobium/crescimento & desenvolvimento
17.
Proc Natl Acad Sci U S A ; 102(29): 10221-6, 2005 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-16009935

RESUMO

Understanding evolutionary change requires phenotypic differences between organisms to be placed in a genetic context. However, there are few cases where it has been possible to define an appropriate genotypic space for a range of species. Here we address this problem by defining a genetically controlled space that captures variation in shape and size between closely related species of Antirrhinum. The axes of the space are based on an allometric model of leaves from an F2 of an interspecific cross between Antirrhinum majus and Antirrhinum charidemi. Three principal components were found to capture most of the genetic variation in shape and size, allowing a three-dimensional allometric space to be defined. The contribution of individual genetic loci was determined from QTL analysis, allowing each locus to be represented as a vector in the allometric space. Leaf shapes and sizes of 18 different Antirrhinum taxa, encompassing a broad range of leaf morphologies, could be accurately represented as clouds within the space. Most taxa overlapped with, or were near to, at least one other species in the space, so that together they defined a largely interconnected domain of viable forms. It is likely that the pattern of evolution within this domain reflects a combination of directional selection and evolutionary tradeoffs within a high dimensional space.


Assuntos
Antirrhinum/anatomia & histologia , Antirrhinum/genética , Evolução Biológica , Hibridização Genética , Modelos Biológicos , Fenótipo , Folhas de Planta/anatomia & histologia , Biometria , Mapeamento Cromossômico , Genótipo , Escore Lod , Análise de Componente Principal , Locos de Características Quantitativas , Especificidade da Espécie
18.
Z Naturforsch C ; 60(3-4): 285-91, 2005 Mar-Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15948597

RESUMO

Wetland grasses and grass-like monocots are very important natural remediators of pollutants. Their genetic improvement is an important task because introduction of key transgenes can dramatically improve their remediation potential. Tissue culture is prerequisite for genetic manipulation, and methods are reported here for in vitro culture and micropropagation of a number of wetland plants of various ecological requirements such as salt marsh, brackish water, riverbanks, and various zones of lakes and ponds, and bogs. The monocots represent numerous genera in various families such as Poaceae, Cyperaceae, Juncaceae, and Typhaceae. The reported species are in various stages of micropropagation and Arundo donax is scaled for mass propagation for selecting elite lines for pytoremediation. Transfer of key genes for mercury phytoremediation into the salt marsh cordgrass (Spartina alterniflora) is also reported here. All but one transgenic lines contained both the organomercurial lyase (merB) and mercuric reductase (merA) sequences showing that co-introduction into Spartina of two genes from separate Agrobacterium strains is possible.


Assuntos
Proteínas de Bactérias/metabolismo , Biodegradação Ambiental , Liases/metabolismo , Mercúrio/metabolismo , Oxirredutases/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Poaceae/genética , Poaceae/metabolismo , Poluentes do Solo/farmacocinética , Proteínas de Bactérias/genética , Vetores Genéticos , Liases/genética , Mercúrio/farmacocinética , Oxirredutases/genética , Especificidade da Espécie , Transfecção
19.
Artigo em Inglês | MEDLINE | ID: mdl-15627706

RESUMO

The LjCYC1 (Lotus japonicus Cycloidea-like 1) gene, a homolog of CYC (Cycloidea) belonging to the TCP [TB1(teosinte branched 1), CYC, PCFs (PCF1 and PCF2)] gene family and encoding a predicted transcription factor and being proposed controlling different aspects of plant development, was isolated from the papilionaceous plant Lotus japonicus by screening the genomic DNA library, in order to test the functional conservation and divarication of CYC-like genes in legume. Sequence analyses indicate that LjCYC1 gene contains two exons and one intron and encodes a 370-AA peptide LjCYC1. The putative protein, LjCYC1, contains a TCP domain and an R domain, being a member of the CYC/TB1 subfamily of TCP family, and has 39.0% identity with and 42.6% similarity to CYC. LjCYC1-cDNA was cloned through RT-PCR. Different regions of the LjCYC1-cDNA were fused with the report gene GUS and then the fused constructs were transiently expressed in the onion epidermal cells through particle bombardment. Results of GUS and DAPI staining showed that the chimeric proteins with TCP domain were localized within the nucleus, confirming that LjCYC1 may act as a transcription factor. But the TCP domain itself could not confer the nuclear localization because the chimeric proteins with TCP domain alone were dispersed all over the transformed cells.


Assuntos
Genes de Plantas , Lotus/genética , Proteínas de Plantas/genética , Sequência de Aminoácidos , Clonagem Molecular , Proteínas de Ligação a DNA , Dosagem de Genes , Lotus/química , Dados de Sequência Molecular , Sinais de Localização Nuclear , Fatores de Transcrição
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA