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1.
Cell ; 181(5): 1097-1111.e12, 2020 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-32442406

RESUMO

The evolutionary features and molecular innovations that enabled plants to first colonize land are not well understood. Here, insights are provided through our report of the genome sequence of the unicellular alga Penium margaritaceum, a member of the Zygnematophyceae, the sister lineage to land plants. The genome has a high proportion of repeat sequences that are associated with massive segmental gene duplications, likely facilitating neofunctionalization. Compared with representatives of earlier diverging algal lineages, P. margaritaceum has expanded repertoires of gene families, signaling networks, and adaptive responses that highlight the evolutionary trajectory toward terrestrialization. These encompass a broad range of physiological processes and protective cellular features, such as flavonoid compounds and large families of modifying enzymes involved in cell wall biosynthesis, assembly, and remodeling. Transcriptome profiling further elucidated adaptations, responses, and selective pressures associated with the semi-terrestrial ecosystems of P. margaritaceum, where a simple body plan would be an advantage.


Assuntos
Desmidiales/genética , Desmidiales/metabolismo , Embriófitas/genética , Evolução Biológica , Parede Celular/genética , Parede Celular/metabolismo , Ecossistema , Evolução Molecular , Filogenia , Plantas
2.
Nucleic Acids Res ; 52(9): 4906-4921, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38407438

RESUMO

Eukaryotic genomes are spatially organized within the nucleus in a nonrandom manner. However, fungal genome arrangement and its function in development and adaptation remain largely unexplored. Here, we show that the high-order chromosome structure of Fusarium graminearum is sculpted by both H3K27me3 modification and ancient genome rearrangements. Active secondary metabolic gene clusters form a structure resembling chromatin jets. We demonstrate that these jet-like domains, which can propagate symmetrically for 54 kb, are prevalent in the genome and correlate with active gene transcription and histone acetylation. Deletion of GCN5, which encodes a core and functionally conserved histone acetyltransferase, blocks the formation of the domains. Insertion of an exogenous gene within the jet-like domain significantly augments its transcription. These findings uncover an interesting link between alterations in chromatin structure and the activation of fungal secondary metabolism, which could be a general mechanism for fungi to rapidly respond to environmental cues, and highlight the utility of leveraging three-dimensional genome organization in improving gene transcription in eukaryotes.


Assuntos
Cromatina , Cromossomos Fúngicos , Fusarium , Metabolismo Secundário , Acetilação , Cromatina/metabolismo , Cromatina/genética , Cromossomos Fúngicos/genética , Cromossomos Fúngicos/metabolismo , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/genética , Fusarium/genética , Fusarium/metabolismo , Regulação Fúngica da Expressão Gênica , Genoma Fúngico , Histona Acetiltransferases/metabolismo , Histona Acetiltransferases/genética , Histonas/metabolismo , Histonas/genética , Família Multigênica , Metabolismo Secundário/genética , Transcrição Gênica
3.
Opt Express ; 32(8): 14102-14115, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38859365

RESUMO

A novel parallel beam combined lens (PBCL) was designed based on a parabolic monocapillary x-ray lens (PMXRL). The proposed PBCL converted a divergent X-ray beam into a near-solid parallel one, which retains the low divergence characteristics of PMXRL and significantly improves the intensity gain by about one order of magnitude. Compared with the traditional polycapillary parallel x-ray lens (PPXRL), the divergence performance of this lens is improved by an order of magnitude, and the light intensity gain is improved by 3-4 times. In addition, we developed a MATLAB-based visualization tool to simulate X-ray transmission within the PBCL through ray tracing. This tool facilitated the assessment of the PBCL's transmission efficiency and its comparison with conventional PMXRL and the PPXRL. The transport process of the PBCL is systematically investigated under the comprehensive consideration of multiple parameters. This study provided a new idea and theoretical basis for the further development of X-ray modulation technology.

4.
Opt Lett ; 49(2): 274-277, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38194546

RESUMO

X ray ghost imaging (XGI) offers both radiation dose-reduction potential and cost-effective benefits owing to the utilization of a single-pixel detector. Most XGI schemes with laboratory x ray sources require a mechanically moving mask for either structured illumination or structured detection. In either configuration, however, its resolution remains limited by the source size and the unit size of the mask. Upon propagation, the details of the object can actually be magnified by the divergence of x rays, but at the same time, the penumbra effect produced by the finite source size is dramatically intensified, which ultimately leads to a degradation of image quality in XGI. To address these limitations, this work proposes a magnified XGI scheme using structured detection equipped with tapered polycapillary optics, which can efficiently suppress the object's penumbra as well as resolve the magnified details of the object. In general, the resolution of this scheme is no longer affected by the source size but by the microcapillary size of polycapillary. Our work fundamentally achieves cancellation of penumbra effect-induced aberration, thus paving the way for high-resolution magnified XGI.

5.
BMC Plant Biol ; 23(1): 484, 2023 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-37817059

RESUMO

BACKGROUND: Light-harvesting chlorophyll a/b b evelopment of higher plants and in response to abiotic stress. Previous works has demonstrated that that Lhcb genes were involved in the phytochrome regulation and responded to the different light and temperature conditions in Poaceae (such as maize). However, the evolution and functions of Lhcb genes remains poorly characterized in important Rosaceae species. RESULTS: In this investigation, we conducted a genome-wide analysis and identified a total of 212 Lhcb genes across nine Rosaceae species. Specifically, we found 23 Lhcb genes in Fragaria vesca, 20 in Prunus armeniaca, 33 in Malus domestica 'Gala', 21 in Prunus persica, 33 in Rosa chinensis, 29 in Pyrus bretschneideri, 18 in Rubus occidentalis, 20 in Prunus mume, and 15 in Prunus salicina. Phylogenetic analysis revealed that the Lhcb gene family could be classified into seven major subfamilies, with members of each subfamily sharing similar conserved motifs. And, the functions of each subfamily was predicted based on the previous reports from other species. The Lhcb proteins were highly conserved within their respective subfamilies, suggesting similar functions. Interestingly, we observed similar peaks in Ks values (0.1-0.2) for Lhcb genes in apple and pear, indicating a recent whole genome duplication event (about 30 to 45 million years ago). Additionally, a few Lhcb genes underwent tandem duplication and were located across all chromosomes of nine species of Rosaceae. Furthermore, the analysis of the cis-acting elements in the 2000 bp promoter region upstream of the pear Lhcb gene revealed four main categories: light response correlation, stress response correlation, hormone response correlation, and plant growth. Quantitative expression analysis demonstrated that Lhcb genes exhibited tissue-specific expression patterns and responded differently to low-temperature stress in Rosaceae species. CONCLUSIONS: These findings shed light on the evolution and phylogeny of Lhcb genes in Rosaceae and highlight the critical role of Lhcb in pear's response to low temperatures. The results obtained provide valuable insights for further investigations into the functions of Lhcb genes in Rosaceae, and these functional genes will be used for further fruit tree breeding and improvement to cope with the current climate changes.


Assuntos
Malus , Pyrus , Rosaceae , Rosaceae/genética , Rosaceae/metabolismo , Frutas/genética , Frutas/metabolismo , Filogenia , Clorofila A/metabolismo , Genoma de Planta/genética , Melhoramento Vegetal , Malus/genética , Malus/metabolismo , Pyrus/genética , Genômica , Evolução Molecular , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
6.
Plant Physiol ; 190(2): 1334-1348, 2022 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-35751605

RESUMO

Basic helix-loop-helix (bHLH) transcription factors constitute a superfamily in eukaryotes, but their roles in plant immunity remain largely uncharacterized. We found that the transcript abundance in tomato (Solanum lycopersicum) leaves of one bHLH transcription factor-encoding gene, negative regulator of resistance to DC3000 1 (Nrd1), increased significantly after treatment with the immunity-inducing flgII-28 peptide. Plants carrying a loss-of-function mutation in Nrd1 (Δnrd1) showed enhanced resistance to Pseudomonas syringae pv. tomato (Pst) DC3000 although early pattern-triggered immunity responses, such as generation of reactive oxygen species and activation of mitogen-activated protein kinases after treatment with flagellin-derived flg22 and flgII-28 peptides, were unaltered compared to wild-type plants. RNA-sequencing (RNA-seq) analysis identified a gene, Arabinogalactan protein 1 (Agp1), whose expression is strongly suppressed in an Nrd1-dependent manner. Agp1 encodes an arabinogalactan protein, and overexpression of the Agp1 gene in Nicotiana benthamiana led to ∼10-fold less Pst growth compared to the control. These results suggest that the Nrd1 protein promotes tomato susceptibility to Pst by suppressing the defense gene Agp1. RNA-seq also revealed that the loss of Nrd1 function has no effect on the transcript abundance of immunity-associated genes, including AvrPtoB tomato-interacting 9 (Bti9), Cold-shock protein receptor (Core), Flagellin sensing 2 (Fls2), Flagellin sensing (Fls3), and Wall-associated kinase 1 (Wak1) upon Pst inoculation, suggesting that the enhanced immunity observed in the Δnrd1 mutants is due to the activation of key PRR signaling components as well as the loss of Nrd1-regulated suppression of Agp1.


Assuntos
Pseudomonas syringae , Solanum lycopersicum , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Flagelina/metabolismo , Regulação da Expressão Gênica de Plantas , Solanum lycopersicum/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Peptídeos/metabolismo , Doenças das Plantas/genética , Pseudomonas syringae/fisiologia , RNA/metabolismo , Espécies Reativas de Oxigênio/metabolismo
7.
Int J Mol Sci ; 24(3)2023 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-36768888

RESUMO

The MYB transcription factor superfamily includes key regulators of plant development and responses to environmental changes. The diversity of lifestyles and morphological characteristics exhibited by plants are potentially associated with the genomic dynamics of the MYB superfamily. With the release of the plant genomes, a comprehensive phylogenomic analysis of the MYB superfamily across Viridiplantae is allowed. The present study performed phylogenetic, phylogenomic, syntenic, horizontal gene transfer, and neo/sub-functionalization analysis of the MYB superfamily to explore the evolutionary contributions of MYB members to species diversification, trait formation, and environmental adaptation in 437 different plant species. We identified major changes in copy number variation and genomic context within subclades across lineages. Multiple MYB subclades showed highly conserved copy number patterns and synteny across flowering plants, whereas others were more dynamic and showed lineage-specific patterns. As examples of lineage-specific morphological divergence, we hypothesize that the gain of a MYB orthogroup associated with flower development and environmental responses and an orthogroup associated with auxin and wax biosynthesis in angiosperms were correlated with the emergence of flowering plants, unbiased neo-/sub-functionalization of gene duplicates contributed to environmental adaptation, and species-specific neo-/sub-functionalization contributed to phenotype divergence between species. Transposable element insertion in promoter regions may have facilitated the sub-/neo-functionalization of MYB genes and likely played a tissue-specific role contributing to sub-/neo-functionalization in plant root tissues. This study provides new insights into the evolutionary divergence of the MYB superfamily across major flowering and non-flowering lineages and emphasizes the need for lineage-/tissue-specific characterization to further understand trait variability and environmental adaptation.


Assuntos
Magnoliopsida , Fatores de Transcrição , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Filogenia , Variações do Número de Cópias de DNA , Plantas/genética , Plantas/metabolismo , Genoma de Planta , Magnoliopsida/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas , Evolução Molecular
8.
Int J Mol Sci ; 24(19)2023 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-37834283

RESUMO

The ever-increasing food requirement with globally growing population demands advanced agricultural practices to improve grain yield, to gain crop resilience under unpredictable extreme weather, and to reduce production loss caused by insects and pathogens. To fulfill such requests, genome engineering technology has been applied to various plant species. To date, several generations of genome engineering methods have been developed. Among these methods, the new mainstream technology is clustered regularly interspaced short palindromic repeats (CRISPR) with nucleases. One of the most important processes in genome engineering is to deliver gene cassettes into plant cells. Conventionally used systems have several shortcomings, such as being labor- and time-consuming procedures, potential tissue damage, and low transformation efficiency. Taking advantage of nanotechnology, the nanoparticle-mediated gene delivery method presents technical superiority over conventional approaches due to its high efficiency and adaptability in different plant species. In this review, we summarize the evolution of plant biomolecular delivery methods and discussed their characteristics as well as limitations. We focused on the cutting-edge nanotechnology-based delivery system, and reviewed different types of nanoparticles, preparation of nanomaterials, mechanism of nanoparticle transport, and advanced application in plant genome engineering. On the basis of established methods, we concluded that the combination of genome editing, nanoparticle-mediated gene transformation and de novo regeneration technologies can accelerate crop improvement efficiently in the future.


Assuntos
Sistemas CRISPR-Cas , Engenharia Genética , Plantas Geneticamente Modificadas/genética , Sistemas CRISPR-Cas/genética , Edição de Genes , Genoma de Planta , Grão Comestível/genética , Nanotecnologia , Melhoramento Vegetal
9.
Ecotoxicol Environ Saf ; 234: 113398, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35278992

RESUMO

Autophagy is a conserved degradation pathway in plants, which plays an important role in plant cellular homeostasis during abiotic stress. Although various abiotic stressors have been reported to induce autophagic activity in plants, the specific role of autophagy in plant cadmium (Cd) tolerance remains undiscovered. In this study, we treated three MdATG10-overexpressing apple lines with hydroponic Cd stress and found the enhanced Cd tolerance in transgenic plants. Transgenic apple plants exhibited less growth limitation and reduced Cd damage on the photosynthetic system. That was accompanied by higher antioxidant enzymes activity and lower harmful ROS accumulation in apple leaves under Cd stress. The higher autophagic activity led to a more active metabolic system of Pro, His, and Arg in transgenic plants under Cd stress, which was closely related to the plant Cd tolerance. In addition, the transcriptional activities of several Cd transport and detoxification-related genes were regulated by MdATG10-overexpression in response to Cd stress. This study is the first to demonstrate the protective role of autophagy in the Cd tolerance of plants.

10.
Mol Plant Microbe Interact ; 34(7): 726-732, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33689393

RESUMO

Alternaria brown spot (ABS), caused by Alternaria alternata, is an economically important fungal disease of citrus worldwide. The ABS pathogen A. alternata tangerine pathotype can produce a host-specific ACT toxin, which is regulated by ACT toxin gene cluster located in the conditionally dispensable chromosome (CDC). Previously, we have assembled a draft genome of A. alternata tangerine pathotype strain Z7, which comprises 165 contigs. In this study, we report a chromosome-level genome assembly of A. alternata Z7 through the combination of Oxford Nanopore sequencing and Illumina sequencing technologies. The assembly of A. alternata Z7 had a total size of 34.28 Mb, with a GC content of 51.01% and contig N50 of 3.08 Mb. The genome is encompassed 12,067 protein-coding genes, 34 ribosomal RNAs, and 107 transfer RNAs. Interestingly, A. alternata Z7 is composed of 10 essential chromosomes and 2 CDCs, which is consistent with the experimental evidences of pulsed-field gel electrophoresis. To our best knowledge, this is the first chromosome-level genome assembly of A. alternata. In addition, a database for citrus-related Alternaria genomes has been established to provide public resources for the sequences, annotation and comparative genomics data of Alternaria spp. The improved genome sequence and annotation at the chromosome level is a significant step toward a better understanding of the pathogenicity of A. alternata. The database will be updated regularly whenever the genomes of newly isolated Alternaria spp. are available. The citrus-related Alternaria genomes database is open accessible through the Citrus Fungal Disease Database.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.


Assuntos
Alternaria , Citrus , Alternaria/genética , Cromossomos , Família Multigênica
11.
Phytopathology ; 111(11): 2041-2051, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33870727

RESUMO

Erysiphe necator, the fungal pathogen of grape powdery mildew disease, poses a great threat to the grape market and the wine industry. To better understand the molecular basis of grape responses to E. necator, we performed comparative transcriptome profiling on two Chinese wild grape accessions with varying degrees of resistance to E. necator. At 6-, 24-, and 96-h postinoculation of E. necator, 2,856, 2,678, and 1,542 differentially expressed genes (DEGs) were identified in the susceptible accession Vitis pseudoreticulata 'Hunan-1', and at those same time points, 1,921, 2,498, and 3,249 DEGs, respectively, were identified in the resistant accession V. quinquangularis 'Shang-24'. 'Hunan-1' had a substantially larger fraction of down-regulated genes than 'Shang-24' at every infection stage. Analysis of DEGs revealed that up-regulated genes were mostly associated with defense response and disease resistance-related metabolite biosynthesis, and such signaling genes were significantly suppressed in 'Hunan-1'. Interestingly, fatty acid biosynthesis- and elongation-related genes were suppressed by the fungus in the 'Shang-24' accession but somehow induced in the 'Hunan-1' accession, consistent with the concept that E. necator is likely to be a fatty acid auxotroph that requires lipids from the host. Moreover, genes involved in biosynthesis and signaling of phytohormones, such as jasmonic acid and cytokinin, as well as genes encoding protein kinases and nucleotide-binding domain leucine-rich repeat proteins, differentially responded to E. necator in the two wild grapes. The variation of gene regulation associated with nutrient uptake by the fungus and with signaling transduction and pathogen recognition suggests a multilayered regulatory network that works in concert to assist in the establishment of fungal pathogen infections.


Assuntos
Ascomicetos , Vitis , Ascomicetos/genética , China , Resistência à Doença/genética , Perfilação da Expressão Gênica , Proteínas de Repetições Ricas em Leucina , Doenças das Plantas , Transcriptoma , Vitis/genética
12.
Curr Genet ; 65(1): 201-212, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29951697

RESUMO

RNA binding proteins (RBPs) can regulate the stability, localization, and translation of their target mRNAs. Among them, Puf3p is a well-known Pumilio family RBP whose biology has been intensively studied. Nevertheless, the impact of Puf3p on the translational regulation of its downstream genes still remains to be investigated at the genome-wide level. In this study, we combined ribosome profiling and RNA-Seq in budding yeast (Saccharomyces cerevisiae) to investigate Puf3p's functions in translational regulation. Comparison of translational efficiency (TE) between wild-type and puf3Δ strains demonstrates extensive translational modulation in the absence of Puf3p (over 27% genes are affected at the genome level). Besides confirming its known role in regulating mitochondrial metabolism, our data demonstrate that Puf3p serves as a key post-transcriptional regulator of downstream RBPs by regulating their translational efficiencies, indicating a network of interactions among RBPs at the post-transcriptional level. Furthermore, Puf3p switches the balance of translational flux between mitochondrial and cytosolic ribosome biogenesis to adapt to changes in cellular metabolism. In summary, our results indicate that TE can be utilized as an informative index to interrogate the mechanism underlying RBP functions, and provide novel insights into Puf3p's mode-of-action.


Assuntos
Regulação Fúngica da Expressão Gênica , Biossíntese de Proteínas/genética , Proteínas de Ligação a RNA/genética , Ribossomos/genética , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/genética , Metabolismo dos Carboidratos/genética , Ontologia Genética , Redes Reguladoras de Genes , Genoma Fúngico/genética , Mitocôndrias/genética , Mitocôndrias/metabolismo , Mutação , Proteínas de Ligação a RNA/metabolismo , Ribossomos/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Análise de Sequência de RNA/métodos
13.
Plant Biotechnol J ; 17(5): 982-997, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30451358

RESUMO

Pith cavity formation is critical for bamboo to overcome the bending force during its fast growth; however, the underlying molecular mechanisms remain largely unknown. Multiple approaches, including anatomical dissection, mathematical modelling and transcriptome profiling, were employed in this study to investigate the biology of pith cavity formation in bamboo Pseudosasa japonica. We found that the corruption of pith tissue occurred sequentially and asymmetrically from the top-centre of the internode down to the bottom, which might be caused by the combined effects of asymmetrical radial and axial tensile forces during shoot-wall cell elongation and spiral growth of bamboo internodes. Programmed cell death (PCD) in pitch manifested by TUNEL positive nuclei, DNA cleavage and degraded organelles, and potentially regulated by ethylene and calcium signalling pathway, ROS burst, cell wall modification, proteolysis and nutrient recycle genes, might be responsible for pith tissue corruption of Ps. japonica. Although similar physiological changes and transcriptome profiles were found in different bamboo species, different formation rates of pith cavity were observed, which might be caused by different pith cells across the internode that were negatively correlated with the culm diameter. These findings provided a systematical view on the formation of bamboo pith cavity and revealed that PCD plays an important role in the bamboo pith cavity formation.


Assuntos
Apoptose/genética , Genes de Plantas/genética , Poaceae/genética , Transcriptoma/genética , Clivagem do DNA , Perfilação da Expressão Gênica , Genes de Plantas/fisiologia , Marcação In Situ das Extremidades Cortadas , Microscopia Eletrônica de Transmissão , Poaceae/anatomia & histologia , Poaceae/crescimento & desenvolvimento , Poaceae/metabolismo , RNA de Plantas/metabolismo , Transcriptoma/fisiologia
14.
New Phytol ; 221(3): 1556-1573, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30368822

RESUMO

Arbuscular mycorrhizal (AM) fungi form endosymbioses with most plants, and they themselves are hosts for Mollicutes/Mycoplasma-related endobacteria (MRE). Despite their significance, genomic information for AM fungi and their MRE are relatively sparse, which hinders our understanding of their biology and evolution. We assembled the genomes of the AM fungus Diversispora epigaea (formerly Glomus versiforme) and its MRE and performed comparative genomics and evolutionary analyses. The D. epigaea genome showed a pattern of substantial gene duplication and differential evolution of gene families, including glycosyltransferase family 25, whose activities are exclusively lipopolysaccharide biosynthesis. Genes acquired by horizontal transfer from bacteria possibly function in defense against foreign DNA or viruses. The MRE population was diverse, with multiple genomes displaying characteristics of differential evolution and encoding many MRE-specific genes as well as genes of AM fungal origin. Gene family expansion in D. epigaea may enhance adaptation to both external and internal environments, such as expansion of kinases for signal transduction upon external stimuli and expansion of nucleoside salvage pathway genes potentially for competition with MRE, whose genomes lack purine and pyrimidine biosynthetic pathways. Collectively, this metagenome provides high-quality references and begins to reveal the diversity within AM fungi and their MRE.


Assuntos
Evolução Biológica , Genoma Fúngico , Glomeromycota/genética , Mycoplasma/fisiologia , Micorrizas/genética , Simbiose/genética , Tenericutes/fisiologia , Duplicação Gênica , Transferência Genética Horizontal/genética , Genes Fúngicos , Glomeromycota/metabolismo , Família Multigênica , Filogenia , Esporos Fúngicos/fisiologia
15.
Plant Cell Environ ; 42(5): 1758-1774, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30578745

RESUMO

Sorghum is an important crop grown worldwide for feed and fibre. Like most plants, it has the capacity to benefit from symbioses with arbuscular mycorrhizal (AM) fungi, and its diverse genotypes likely vary in their responses. Currently, the genetic basis of mycorrhiza-responsiveness is largely unknown. Here, we investigated transcriptional and physiological responses of sorghum accessions, founders of a bioenergy nested association mapping panel, for their responses to four species of AM fungi. Transcriptome comparisons across four accessions identified mycorrhiza-inducible genes; stringent filtering criteria revealed 278 genes that show mycorrhiza-inducible expression independent of genotype and 55 genes whose expression varies with genotype. The latter suggests variation in phosphate transport and defence across these accessions. The mycorrhiza growth and nutrient responses of 18 sorghum accessions varied tremendously, ranging from mycorrhiza-dependent to negatively mycorrhiza-responsive. Additionally, accessions varied in the number of AM fungi to which they showed positive responses, from one to several fungal species. Mycorrhiza growth and phosphorus responses were positively correlated, whereas expression of two mycorrhiza-inducible phosphate transporters, SbPT8 and SbPT9, correlated negatively with mycorrhizal growth responses. AM fungi improve growth and mineral nutrition of sorghum, and the substantial variation between lines provides the potential to map loci influencing mycorrhiza responses.


Assuntos
Micorrizas , Raízes de Plantas/metabolismo , Sorghum/genética , Sorghum/microbiologia , Simbiose/genética , Metabolismo Energético/genética , Metabolismo Energético/fisiologia , Perfilação da Expressão Gênica , Genes de Plantas/fisiologia , Micorrizas/fisiologia , Proteínas de Transporte de Fosfato/genética , Fósforo/metabolismo , Raízes de Plantas/microbiologia , Sorghum/crescimento & desenvolvimento , Sorghum/fisiologia
16.
J Exp Bot ; 70(15): 3911-3926, 2019 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-31037305

RESUMO

Little is known about the mechanisms underlying the development of bamboo culm. Using anatomical, mathematical modeling, and genomics methods, we investigated the role of shoot apical meristem (SAM) in the development of the transverse morphology of bamboo culm and explored the underlying cellular and molecular processes. We discovered that maintenance of SAM morphology that can produce circular culm and increase in SAM cell numbers, especially corpus cells, is the means by which bamboo makes a larger culm with a regular pith cavity and culm wall during development. A less cellular form of SAM with a lower proportion of corpus cells causes an abnormal higher ratio of wall component cells to pith cells, which breaks the balance of their interaction and triggers the random invasion of wall component cells into pith tissues during development, and finally results in the various thick culm walls of Phyllostachys nidularia f. farcta. The smaller SAM also results in a lower level of hormones such as cytokinin and auxin, and down-regulates hormone signaling and the downstream functional genes such as those related to metabolism, which finally results in a dwarf and smaller diameter culm with lower biomass. These results provide an important perspective on the culm development of bamboo, and support a plausible mechanism causing the size-reduced culm and various thick culm walls of P. nidularia f. farcta.


Assuntos
Regulação da Expressão Gênica de Plantas/fisiologia , Meristema/citologia , Meristema/fisiologia , Brotos de Planta/citologia , Brotos de Planta/fisiologia , Poaceae/citologia , Poaceae/fisiologia , Citocininas/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Meristema/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Brotos de Planta/metabolismo , Poaceae/metabolismo
17.
Appl Opt ; 58(5): 1291-1295, 2019 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-30874002

RESUMO

The inner diameter is one of most important parameters in the design and fabrication of monocapillary x-ray optics, which are widely used in x-ray technology. The confocal x-ray scattering method based on x-ray capillary optics was proposed to nondestructively measure the inner and outer diameters of the monocapillary. The positions of the boundaries of monocapillary x-ray optics were determined by a knife-edge scanning method, and the x-ray optics were profiled in two planes or in three-dimensional space accordingly. This confocal method could conveniently give the inner surface topography of the monocapillary optics, which can be used to show the difference between the actual inner surface and the theoretical one, and has potential applications in nondestructive measurements of stratified substances, or the profile morphology of a specific interface.

19.
J Virol ; 91(11)2017 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-28331089

RESUMO

Tomato is a major vegetable crop that has tremendous popularity. However, viral disease is still a major factor limiting tomato production. Here, we report the tomato virome identified through sequencing small RNAs of 170 field-grown samples collected in China. A total of 22 viruses were identified, including both well-documented and newly detected viruses. The tomato viral community is dominated by a few species, and they exhibit polymorphisms and recombination in the genomes with cold spots and hot spots. Most samples were coinfected by multiple viruses, and the majority of identified viruses are positive-sense single-stranded RNA viruses. Evolutionary analysis of one of the most dominant tomato viruses, Tomato yellow leaf curl virus (TYLCV), predicts its origin and the time back to its most recent common ancestor. The broadly sampled data have enabled us to identify several unreported viruses in tomato, including a completely new virus, which has a genome of ∼13.4 kb and groups with aphid-transmitted viruses in the genus Cytorhabdovirus Although both DNA and RNA viruses can trigger the biogenesis of virus-derived small interfering RNAs (vsiRNAs), we show that features such as length distribution, paired distance, and base selection bias of vsiRNA sequences reflect different plant Dicer-like proteins and Argonautes involved in vsiRNA biogenesis. Collectively, this study offers insights into host-virus interaction in tomato and provides valuable information to facilitate the management of viral diseases.IMPORTANCE Tomato is an important source of micronutrients in the human diet and is extensively consumed around the world. Virus is among the major constraints on tomato production. Categorizing virus species that are capable of infecting tomato and understanding their diversity and evolution are challenging due to difficulties in detecting such fast-evolving biological entities. Here, we report the landscape of the tomato virome in China, the leading country in tomato production. We identified dozens of viruses present in tomato, including both well-documented and completely new viruses. Some newly emerged viruses in tomato were found to spread fast, and therefore, prompt attention is needed to control them. Moreover, we show that the virus genomes exhibit considerable degree of polymorphisms and recombination, and the virus-derived small interfering RNA (vsiRNA) sequences indicate distinct vsiRNA biogenesis mechanisms for different viruses. The Chinese tomato virome that we developed provides valuable information to facilitate the management of tomato viral diseases.


Assuntos
Begomovirus/genética , Evolução Molecular , Variação Genética , Folhas de Planta/virologia , Vírus de Plantas/genética , Vírus de Plantas/isolamento & purificação , Solanum lycopersicum/virologia , Animais , Afídeos/virologia , China , Genoma Viral , Interações Hospedeiro-Patógeno , Doenças das Plantas/prevenção & controle , Doenças das Plantas/virologia , RNA Interferente Pequeno/genética , RNA Viral/genética , Rhabdoviridae/genética , Rhabdoviridae/isolamento & purificação , Análise de Sequência de RNA/métodos
20.
J Synchrotron Radiat ; 24(Pt 5): 1000-1005, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-28862622

RESUMO

A confocal fluorescence endstation for depth-resolved micro-X-ray absorption spectroscopy is described. A polycapillary half-lens defines the incident beam path and a second polycapillary half-lens at 90° defines the probe sample volume. An automatic alignment program based on an evolutionary algorithm is employed to make the alignment procedure efficient. This depth-resolved system was examined on a general X-ray absorption spectroscopy (XAS) beamline at the Beijing Synchrotron Radiation Facility. Sacrificial red glaze (AD 1368-1644) china was studied to show the capability of the instrument. As a mobile endstation to be applied on multiple beamlines, the confocal system can improve the function and flexibility of general XAS beamlines, and extend their capabilities to a wider user community.

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