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1.
Genome Biol Evol ; 15(1)2023 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-36574983

RESUMO

Poa annua L. is a globally distributed grass with economic and horticultural significance as a weed and as a turfgrass. This dual significance, and its phenotypic plasticity and ecological adaptation, have made P. annua an intriguing plant for genetic and evolutionary studies. Because of the lack of genomic resources and its allotetraploid (2n = 4x = 28) nature, a reference genome sequence would be a valuable asset to better understand the significance and polyploid origin of P. annua. Here we report a genome assembly with scaffolds representing the 14 haploid chromosomes that are 1.78 Gb in length with an N50 of 112 Mb and 96.7% of BUSCO orthologs. Seventy percent of the genome was identified as repetitive elements, 91.0% of which were Copia- or Gypsy-like long-terminal repeats. The genome was annotated with 76,420 genes spanning 13.3% of the 14 chromosomes. The two subgenomes originating from Poa infirma (Knuth) and Poa supina (Schrad) were sufficiently divergent to be distinguishable but syntenic in sequence and annotation with repetitive elements contributing to the expansion of the P. infirma subgenome.


Assuntos
Poa , Poa/genética , Sequências Repetitivas de Ácido Nucleico , Sintenia , Genoma de Planta , Cromossomos , Anotação de Sequência Molecular
2.
BMC Plant Biol ; 22(1): 509, 2022 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-36319971

RESUMO

BACKGROUND: Poa pratensis is one of the most common cold-season turfgrasses used for urban turf building, and it is also widely used in ecological environment management worldwide. Powdery mildew is a common disease of P. pratensis. To scientifically and ecologically control lawn powdery mildew, the molecular mechanism underlying the response of P. pratensis to powdery mildew infection must better understood. RESULTS: To explore molecular mechanism underlying the response of P. pratensis to powdery mildew infection, this study compared physiological changes and transcriptomic level differences between the highly resistant variety 'BlackJack' and the extremely susceptible variety 'EverGlade' under powdery mildew infection conditions. We analyzed DEGs using reference canonical pathways in the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, and the results showed that "starch and sucrose metabolism", "photosynthesis" and "fatty acid metabolism"pathways were only enriched in 'BlackJack', and the expression of DEGs such as HXK, INV, GS, SS, AGpase and ß-amylase in "starch and sucrose metabolism" pathway of 'BlackJack' were closely related to powdery mildew resistance. Meanwhile, compared with 'EverGlade', powdery mildew infection promoted synthesis of sucrose, expression of photosynthesis parameters and photosynthesis-related enzymes in leaves of 'BlackJack' and decreased accumulation of monosaccharides such as glucose and fructose. CONCLUSIONS: This study identified the key metabolic pathways of a P. pratensis variety with high resistance to powdery mildew infection and explored the differences in physiological characteristics and key genes related to sugar metabolism pathways under powdery mildew stress. These findings provide important insights for studying underlying molecular response mechanism.


Assuntos
Ascomicetos , Poa , Transcriptoma , Resistência à Doença/genética , Poa/genética , Ascomicetos/fisiologia , Doenças das Plantas/genética , Kentucky , Perfilação da Expressão Gênica , Erysiphe , Sacarose , Amido
3.
BMC Genomics ; 23(1): 784, 2022 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-36451103

RESUMO

BACKGROUND: Climate change will result in more frequent droughts that can impact soil-inhabiting microbiomes (rhizobiomes) in the agriculturally vital North American perennial grasslands. Rhizobiomes have contributed to enhancing drought resilience and stress resistance properties in plant hosts. In the predicted events of more future droughts, how the changing rhizobiome under environmental stress can impact the plant host resilience needs to be deciphered. There is also an urgent need to identify and recover candidate microorganisms along with their functions, involved in enhancing plant resilience, enabling the successful development of synthetic communities. RESULTS: In this study, we used the combination of cultivation and high-resolution genomic sequencing of bacterial communities recovered from the rhizosphere of a tallgrass prairie foundation grass, Andropogon gerardii. We cultivated the plant host-associated microbes under artificial drought-induced conditions and identified the microbe(s) that might play a significant role in the rhizobiome of Andropogon gerardii under drought conditions. Phylogenetic analysis of the non-redundant metagenome-assembled genomes (MAGs) identified a bacterial genome of interest - MAG-Pseudomonas. Further metabolic pathway and pangenome analyses recovered genes and pathways related to stress responses including ACC deaminase; nitrogen transformation including assimilatory nitrate reductase in MAG-Pseudomonas, which might be associated with enhanced drought tolerance and growth for Andropogon gerardii. CONCLUSIONS: Our data indicated that the metagenome-assembled MAG-Pseudomonas has the functional potential to contribute to the plant host's growth during stressful conditions. Our study also suggested the nitrogen transformation potential of MAG-Pseudomonas that could impact Andropogon gerardii growth in a positive way. The cultivation of MAG-Pseudomonas sets the foundation to construct a successful synthetic community for Andropogon gerardii. To conclude, stress resilience mediated through genes ACC deaminase, nitrogen transformation potential through assimilatory nitrate reductase in MAG-Pseudomonas could place this microorganism as an important candidate of the rhizobiome aiding the plant host resilience under environmental stress. This study, therefore, provided insights into the MAG-Pseudomonas and its potential to optimize plant productivity under ever-changing climatic patterns, especially in frequent drought conditions.


Assuntos
Andropogon , Poa , Rizosfera , Secas , Pseudomonas , Filogenia , Nitrogênio , Nitrato Redutases
4.
PLoS One ; 17(9): e0274404, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36084043

RESUMO

As the Latin name annua implies, the species Poa annua L. is thought to have an annual life cycle. Yet, there are many reports in literature of P. annua persisting as a perennial. Considering that P. annua senescence patterns do not align with other true annual species, we hypothesized that P. annua is similar to other perennial, C3 turfgrass species that are subject to a confluence of environmental factors that can cause mortality. Four experiments were conducted in Knoxville, TN with the objective of determining environmental factors lethal to P. annua. A field monitoring study assessed 100 P. annua plants across ten grassland micro-environments from May to October 2020. Forty plants survived the summer and confirmed the existence of perennial P. annua ecotypes. Analysis of environmental factors at the time of plant death indicated soil moisture, soil temperature, and pathogenic infection were associated with mortality. A series of glasshouse or field experiments were conducted to investigate the effects of each factor on P. annua mortality. Soil moisture and soil temperature were not lethal to P. annua in the glasshouse, except under extreme conditions not typical in the field. A field study assessed mortality of plants from pathogenic infection and indicated that P. annua plants treated with fungicide throughout the summer survived year-round, whereas plants not receiving fungicide applications senesced. These findings support our hypothesis that P. annua is of a perennial life cycle, which can be influenced by environmental conditions. We suggest that the name P. annua is likely a misnomer based on its modern interpretation.


Assuntos
Fungicidas Industriais , Poa , Fungicidas Industriais/farmacologia , Solo
5.
Am Nat ; 200(1): 17-31, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35737994

RESUMO

AbstractUnderstanding the mechanisms that generate biogeographic range limits is a long-standing goal of ecology. It is widely hypothesized that distributional limits reflect the environmental niche, but this hypothesis is complicated by the potential for intraspecific niche heterogeneity. In dioecious species, sexual niche differentiation may cause divergence between the sexes in their limits of environmental suitability. We studied range boundary formation in Texas bluegrass (Poa arachnifera), a perennial dioecious plant, testing the alternative hypotheses that range limits reflect the niche limits of females only versus the combined contributions of females and males, including their interdependence via mating. Common garden experiments across a longitudinal aridity gradient revealed female-biased flowering approaching eastern range limits, suggesting that mate limitation may constrain the species' distribution. However, a demographic model showed that declines in λ approaching range limits were driven almost entirely by female vital rates. The dominant role of females was attributable to seed viability being robust to sex ratio variation and to low sensitivity of λ to reproductive transitions. We suggest that female-dominant range limits may be common to long-lived species with polygamous mating systems and that female responses to environmental drivers may often be sufficient for predicting range shifts in response to environmental change.


Assuntos
Poa , Ecossistema , Plantas , Razão de Masculinidade , Texas
6.
Bioresour Technol ; 360: 127521, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35760251

RESUMO

The effective fractionation of structural components of abundantly available lignocellulosic biomass is essential to unlock its full biorefinery potential. In this study, the feasibility of humic acid on the pretreatment of Kentucky bluegrass biomass in alkaline condition was assessed to separate 70.1% lignin and hydrolyzable biocomponents. The humic acid-assisted delignification followed by enzymatic saccharification yielded 0.55 g/g of reducing sugars from 7.5% (w/v) pretreated biomass loading and 16 FPU/g of cellulase. Yeast fermentation of the biomass hydrolysate produced 76.6% (w/w) ethanol, which was subsequently separated and concentrated using direct contact membrane distillation. The hydrophobic microporous flat-sheet membrane housed in a rectangular-shaped crossflow module and counter-current mode of flow of the feed (hot) and distillate (cold) streams yielded a flux of 11.6 kg EtOH/m2/24 h. A modular, compact, flexible, and eco-friendly membrane-integrated hybrid approach is used for the first time to effectively valorize Kentucky bluegrass biomass for sustainable production of biofuel.


Assuntos
Poa , Biomassa , Destilação , Etanol/química , Estudos de Viabilidade , Fermentação , Substâncias Húmicas , Hidrólise , Kentucky , Lignina/química , Poa/metabolismo , Saccharomyces cerevisiae/metabolismo
7.
Int J Mol Sci ; 23(10)2022 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-35628537

RESUMO

In salt-sensitive plants, root hydraulic conductivity is severely inhibited by NaCl, rapidly leading to the loss of water balance. However, halophytic plants appear to effectively control plant water flow under salinity conditions. In this study, we tested the hypothesis that Na+ is the principal salt factor responsible for the enhancement of aquaporin-mediated water transport in the roots of halophytic grasses, and this enhancement plays a significant role in the maintenance of water balance, gas exchange, and the growth of halophytic plants exposed to salinity. We examined the effects of treatments with 150 mM of NaCl, KCl, and Na2SO4 to separate the factors that affect water relations and, consequently, physiological and growth responses in three related grass species varying in salt tolerance. The grasses included relatively salt-sensitive Poa pratensis, moderately salt-tolerant Poa juncifolia, and the salt-loving halophytic grass Puccinellia nuttalliana. Our study demonstrated that sustained growth, chlorophyll concentrations, gas exchange, and water transport in Puccinellia nuttalliana were associated with the presence of Na in the applied salt treatments. Contrary to the other examined grasses, the root cell hydraulic conductivity in Puccinellia nuttalliana was enhanced by the 150 mM NaCl and 150 mM Na2SO4 treatments. This enhancement was abolished by the 50 µM HgCl2 treatment, demonstrating that Na was the factor responsible for the increase in mercury-sensitive, aquaporin-mediated water transport. The observed increases in root Ca and K concentrations likely played a role in the transcriptional and (or) posttranslational regulation of aquaporins that enhanced root water transport capacity in Puccinellia nuttalliana. The study demonstrates that Na plays a key role in the aquaporin-mediated root water transport of the halophytic grass Puccinellia nuttalliana, contributing to its salinity tolerance.


Assuntos
Aquaporinas , Poa , Íons/farmacologia , Raízes de Plantas/metabolismo , Poa/metabolismo , Tolerância ao Sal , Plantas Tolerantes a Sal/metabolismo , Sódio/metabolismo , Cloreto de Sódio/farmacologia , Água/metabolismo
8.
Mol Biotechnol ; 64(11): 1244-1258, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35556219

RESUMO

Poa pratensis L. is a commonly used cool-season turfgrass and endemic to Iran. This research was carried out to examine the genetic diversity of this plant within and between ecoregions of Iran and the impact of climatic variables and elevation on the distribution of its genotypes, as well as habitat suitability modeling. We used fifty accessions collected from six ecoregions (West, South, North, North-West and North-East) for genetic diversity assessment using 20 ISSR marker primers. The prospective ecoregions for Kentucky bluegrass production were projected using habitat suitability modeling, which took into account important environmental parameters, such as annual mean temperature, annual mean rainfall, and elevation. According to the UPMGA dendrogram, the accessions were divided into two major types and four subclasses. The genetic distance between the North and North-east accessions, as well as the Center accessions, was greater than that of the other genotypes. Center accessions had the greatest levels of polymorphism, effective number of alleles, Shannon index, and Nei's genetic diversity. The FR method was used to create the habitat suitability map based on environmental factors. Rainfall had the largest influence on the genotype distribution of P. pratensis L. The findings of this study can be used as raw materials in future breeding programs to improve and generate new cultivars with superior characteristics. It can also assist programs in identifying rare cultivars as well as preserving and developing native P. pratensis L. genotypes.


Assuntos
Poa , Biomarcadores , Ecossistema , Variação Genética , Irã (Geográfico) , Kentucky , Repetições de Microssatélites , Filogenia , Melhoramento Vegetal , Poa/genética , Polimorfismo Genético , Estudos Prospectivos
9.
Ecotoxicol Environ Saf ; 236: 113492, 2022 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-35395602

RESUMO

In many studies, grasses were used to increase the biodegradation of polycyclic aromatic hydrocarbons (PAHs) in soil because they are the most common plant species on the ground level and are quite resistant to contamination with these compounds. One of the main failures in PAH remediation in soil using plant species was the negative impact on germination and seedling growth. The objective of this study was to evaluate grass seed germination and seedling growth affected by drill cuttings to determine the resistance of selected grass species to the impact of PAH and their suitability for an effective phytoremediation of soils contaminated with waste that contain compounds from this group. In the study four grass species: tall fescue (Festuca arundinacea), red fescue (Festuca rubra), perennial ryegrass (Lolium perenne) and common meadow-grass (Poa pratensis). The germination energy of all species decreased as the amount of drill cuttings increased. Among the species studied, the highest germination energy and capacity were found in Lolium perenne (54.1 and 73.2 respectively), and the lowest - in Poa pratensis (16.7 and 23.3 respectively). With an increasing amount of drill cuttings, the root and seedling height were decreased. Festuca arundinacea seedlings were distinctly the highest and had the longest roots (96.7 and 52.7, respectively), while Poa pratensis seedlings showed the significantly slowest seedling and root elongation rate (30.4 and 12.4, respectively). However, the strongest decrease in seedling height and root length compared to the control was observed in Festuca rubra. Based on IC50, the greatest tolerance to the addition of drilling waste to the substrate was found for Festuca arundinacea and Festuca rubra. The conducted investigation indicates that Festuca arundinacea and Lolium perenne are grass species that are least sensitive to drilling waste in the substrate because no significant differences were found in root length and seedling height between the control soil and the soil where a PAH dose of 5% and 10% was applied.


Assuntos
Festuca , Lolium , Poa , Hidrocarbonetos Policíclicos Aromáticos , Poluentes do Solo , Biodegradação Ambiental , Festuca/metabolismo , Germinação , Plantas/metabolismo , Poa/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Plântula/metabolismo , Solo/química , Poluentes do Solo/análise
10.
J Rural Health ; 38(3): 620-629, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-34541715

RESUMO

PURPOSE: To evaluate whether Kentucky counties that established a new syringe services program realized a significant decline in the incidence rate of a set of infectious disease diagnoses commonly transmitted via injection drug use. METHODS: Longitudinal count models of within-county rates of newly diagnosed infections among populations at risk were estimated using Medicaid claims/encounters data. Generalized estimating equation models were used to report incident rate ratios of 6 diagnoses: (1) HIV; (2) hepatitis C; (3) hepatitis B; (4) osteomyelitis; (5) endocarditis; and (6) skin/soft tissue infection. To investigate whether a delay in effect was present, separate models were fit to estimate the effects of establishing a syringe services program: at its opening date, and again at 1, 3, and 6 months postopening date. FINDINGS: Taken together, the aggregated within-county incidence rate of these 6 diagnoses was significantly lower following the implementation of a syringe services program (P < .05). Our models estimated that counties which opted to open a syringe services program realized an approximate month-over-month decline in new diagnoses of 0.5% among the population at risk. CONCLUSIONS: These results lend further support to previous conclusions made in the public health literature regarding the efficacy of syringe services programs. Specifically, declines in incidence rates were observable beginning at 1 month post syringe services program opening. These results are particularly notable due to the typical setting in which these syringe services programs operated-rural communities of fewer than 40,000 residents.


Assuntos
Infecções por HIV , Poa , Saúde da População , Abuso de Substâncias por Via Intravenosa , Infecções por HIV/epidemiologia , Humanos , Kentucky/epidemiologia , Medicaid , Programas de Troca de Agulhas , Abuso de Substâncias por Via Intravenosa/epidemiologia , Seringas
12.
Chemosphere ; 286(Pt 2): 131764, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34364229

RESUMO

In this study, a novel and sustainable approach was used to synthesize nitrogen-doped carbon dots (NCDs) from the waste biomass of Poa Pratensis (Kentucky bluegrass (KB)) by a facile hydrothermal method. The prepared KBNCDs were subjected to various characterization techniques, including X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, and Fourier-transform infrared spectroscopy to verify the formation of carbon dots and their surface functional groups. The KBNCDs exhibited good hydrophilic fluorescence (FLU) properties with an acceptable quantum yield (7%). The synthesized KBNCDs showed excitation wavelength-dependent FLU emission behavior with strong cyan-blue FLU upon irradiation with 365 nm UV-light. The hydrophilic optical properties of the as-synthesized KBNCDs were used to detect Fe3+ and Mn2+ ions in an aqueous medium with good selectivity and sensitivity. It was found that the FLU of the KBNCDs is quenched in the presence of Fe3+ and Mn2+ ions, and the quenching rate was linear with the concentration of Fe3+ and Mn2+ ions. The limit of detection (LOD) of KBNCDs with metal ions was calculated using the Stern-Volmer relationship. The LOD values for Fe3+ or Mn2+ ions were calculated as 1.4 and 1.2 µM, respectively with the detection range from 5.0 to 25 µM. Based on these results, this study provides an underpinning for the development of KBNCD as FLU sensors that can be used in aqueous media.


Assuntos
Poa , Pontos Quânticos , Biomassa , Carbono , Nitrogênio
13.
Nat Prod Res ; 36(9): 2434-2439, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-33183086

RESUMO

The chemical profile and phytotoxic activity of the essential oil extracted from Artemisia sieversiana was investigated. In total 17 compounds were identified by GC/MS, representing 99.17% of the entire oil, among which α-thujone (64.46%) and eucalyptol (10.15%) were the most abundant constituents. The major components, their mixture as well as the essential oil exhibited significant phytotoxic activity against Amaranthus retroflexus, Medicago sativa, Poa annua and Pennisetum alopecuroides, with their IC50 values ranged from 1.55 ∼ 6.21 mg/mL (α-thujone), 1.42 ∼ 17.81 mg/mL (eucalyptol), 0.23 ∼ 1.05 mg/mL (the mixture), and 1.89 ∼ 4.69 mg/mL (the essential oil) on the four tested species. The mixture of the major constituents exerted more potent effect compared with each individual compound, indicating the possible involvement of synergistic effect of these two compounds.


Assuntos
Amaranthus , Artemisia , Óleos Voláteis , Poa , Artemisia/química , Eucaliptol/farmacologia , Óleos Voláteis/química , Óleos Voláteis/farmacologia
14.
Pest Manag Sci ; 78(4): 1377-1385, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34894201

RESUMO

BACKGROUND: In initial screening, glyphosate was ineffective in controlling five Poa annua populations. These populations were tested for resistance, and studies undertaken to determine resistance mechanisms and inheritance pattern. RESULTS: Dose-response studies conducted at 16/12°C and 27/20°C on the five putative resistant populations showed low-level resistance (1.4- to 2.5-fold) to glyphosate. Shikimic acid accumulation in response to glyphosate confirmed differences among the populations, with greater shikimic acid accumulation in the susceptible population. The EPSPS gene copy number was 0.5- to 5.2-fold greater in one resistant population (HT) than in the susceptible (S) population, but not in the others. EPSPS gene expression was five- to tenfold higher in HT compared with the susceptible population. Target site mutations, differences in glyphosate absorption or translocation or altered expression of aldo-keto reductase (AKR) were not identified in any of the resistant populations. Crosses were successful between one resistant population and the susceptible population (P262-16♂ ✕ S♀) and inheritance of glyphosate resistance appears to be controlled by a single, nuclear dominant gene in this population. CONCLUSION: Our study identified EPSPS gene amplification in a South Australian glyphosate-resistant P. annua population (HT). This mechanism of resistance was not identified in the other four glyphosate-resistant populations, and other common mechanisms were excluded. Although the resistance mechanism in some P. annua populations remains unknown, inheritance studies with one population suggest the involvement of a single dominant gene. © 2021 Society of Chemical Industry.


Assuntos
Herbicidas , Poa , 3-Fosfoshikimato 1-Carboxiviniltransferase/genética , 3-Fosfoshikimato 1-Carboxiviniltransferase/metabolismo , Austrália , Glicina/análogos & derivados , Resistência a Herbicidas/genética , Herbicidas/farmacologia , Padrões de Herança , Poa/metabolismo
15.
Protoplasma ; 259(4): 1061-1079, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34743240

RESUMO

The inflorescence is composed of spikes, and the spike is the carrier of grass seed formation and development, so the development status of inflorescence implies grass seed yield and quality. So far, the systematic analysis of inflorescence development of Kentucky bluegrass has not been reported. The development process of the female gametophyte of wild germplasm materials of Kentucky bluegrass in Gannan, Gansu Province of China (KB-GN), was observed. Based on this, the key developmental stages of inflorescence in KB-GN were divided into premeiosis (GPreM), meiosis (GM), postmeiosis (GPostM), and anthesis (GA), and four stages of inflorescence were selected to analyze the transcriptome expression profile. We found that its sexual reproduction formed a polygonum-type embryo sac. Transcriptome analysis showed that 4256, 1125, 1699, and 3127 genes were highly expressed in GPreM, GM, GPostM, and GA, respectively. And a large number of transcription factors (TFs) such as MADS-box, MYB and NAC, AP2, C2H2, FAR1, B3, bHLH, WRKY, and TCP were highly expressed throughout the inflorescence development stages. KEGG enrichment and MapMan analysis showed that genes involved in plant hormone metabolism were also highly expressed at the entire stages of inflorescence development. However, a few TFs belong to stage-specific genes, such as TRAF proteins with unknown function in plants was screened firstly, which was specifically and highly expressed in the GPreM, indicating that TRAF may regulate the preparatory events of meiosis or be essential for the development of megaspore mother cell (MMC). The expression patterns of 15 MADS-box genes were analyzed by qRT-PCR, and the expression results were consistent with that of the transcriptome. The study on the inflorescence development of KB-GN will be great significant works and contribution to illustrate the basic mechanism of grass seeds formation and development.


Assuntos
Óvulo Vegetal , Poa , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/genética , Inflorescência , Kentucky , Proteínas de Plantas/genética , Reprodução
16.
Pest Manag Sci ; 78(3): 1164-1175, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34821014

RESUMO

BACKGROUND: Metabolic resistance is a worldwide concern for weed control but has not yet been well-characterized at the genetic level. Previously, we have identified an Asia minor bluegrass (Polypogon fugax Nees ex Steud.) population AHHY exhibiting cytochrome P450 (P450)-involved metabolic resistance to fenoxaprop-P-ethyl. In this study, we aimed to confirm the metabolic fenoxaprop-P-ethyl resistance in AHHY and uncover the potential herbicide metabolism-related genes in this economically damaging weed species. RESULTS: Liquid chromatography-tandem mass spectrometry (LC-MS/MS) assays indicated the metabolic rates of fenoxaprop-P-ethyl were significantly faster in resistant (R, AHHY) than in susceptible (S, SDTS) plants. The amount of phytotoxic fenoxaprop-P peaked at 12 h after herbicide treatment (HAT) and started to decrease at 24 HAT in both biotypes. R and S plants at 24 HAT were sampled to conduct isoform-sequencing (Iso-Seq) and RNA-sequencing (RNA-Seq). A reference transcriptome containing 24 972 full-length isoforms was obtained, of which 24 329 unigenes were successfully annotated. Transcriptomic profiling identified 28 detoxifying enzyme genes constitutively and/or herbicide-induced up-regulated in R than in S plants. Real-time quantitative polymerase chain reaction (RT-qPCR) confirmed 17 genes were consistently up-regulated in R and its F1 generation plants. They were selected as potential fenoxaprop-P-ethyl metabolism-related genes, including ten P450s, one glutathione-S-transferase, one UDP-glucosyltransferase, and five adenosine triphosphate (ATP)-binding cassette transporters. CONCLUSION: This study revealed that the enhanced rates of fenoxaprop-P-ethyl metabolism in P. fugax were very likely driven by the herbicide metabolism-related genes. The transcriptome data generated by Iso-Seq combined with RNA-Seq will provide abundant gene resources for understanding the molecular mechanisms of resistance in P. fugax.


Assuntos
Herbicidas , Poa , Acetil-CoA Carboxilase/genética , Cromatografia Líquida , Genes Essenciais , Resistência a Herbicidas/genética , Herbicidas/farmacologia , Proteínas de Plantas/genética , Poa/genética , Poaceae/genética , Espectrometria de Massas em Tandem
17.
Int J Mol Sci ; 24(1)2022 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-36613971

RESUMO

Asia minor bluegrass (Polypogon fugax) is a common and problematic weed throughout China. P. fugax that is often controlled by acetyl-CoA carboxylase (ACCase) inhibitors in canola fields. Herein, we confirmed a P. fugax population (R) showing resistance to all ACCase inhibitors tested with resistance indexes ranging from 5.4-18.4. We further investigated the resistance mechanisms of this R population. Molecular analyses revealed that an amino acid mutation (Asp-2078-Gly) was present in the R population by comparing ACCase gene sequences of the sensitive population (S). In addition, differences in susceptibility between the R and S population were unlikely to be related to herbicide metabolism. Furthermore, a new derived cleaved amplified polymorphic sequence (dCAPS) method was developed for detecting the Asp-2078-Gly mutation in P. fugax efficiently. We found that 93.75% of plants in the R population carried the Asp-2078-Gly mutation, and all the herbicide-resistant phenotype of this R population is inseparable from this mutation. This is the first report of cross resistance to ACCase inhibitors conferred by the Asp-2078-Gly target-site mutation in P. fugax. The research suggested the urgent need to improve the diversity of weed management practices to prevent the widespread evolution of herbicide resistance in P. fugax in China.


Assuntos
Herbicidas , Poa , Acetil-CoA Carboxilase/genética , Acetil-CoA Carboxilase/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Poaceae/genética , Poaceae/metabolismo , Mutação , Poa/metabolismo , China , Herbicidas/farmacologia , Resistência a Herbicidas/genética
18.
PLoS One ; 16(12): e0261472, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34914788

RESUMO

Kentucky bluegrass (Poa pratensis L.) is an excellent cool-season turfgrass utilized widely in Northern China. However, turf quality of Kentucky bluegrass declines significantly due to drought. Ethephon seeds-soaking treatment has been proved to effectively improve the drought tolerance of Kentucky bluegrass seedlings. In order to investigate the effect of ethephon leaf-spraying method on drought tolerance of Kentucky bluegrass and understand the underlying mechanism, Kentucky bluegrass plants sprayed with and without ethephon are subjected to either drought or well watered treatments. The relative water content and malondialdehyde conent were measured. Meanwhile, samples were sequenced through Illumina. Results showed that ethephon could improve the drought tolerance of Kentucky bluegrass by elevating relative water content and decreasing malondialdehyde content under drought. Transcriptome analysis showed that 58.43% transcripts (254,331 out of 435,250) were detected as unigenes. A total of 9.69% (24,643 out of 254,331) unigenes were identified as differentially expressed genes in one or more of the pairwise comparisons. Differentially expressed genes due to drought stress with or without ethephon pre-treatment showed that ethephon application affected genes associated with plant hormone, signal transduction pathway and plant defense, protein degradation and stabilization, transportation and osmosis, antioxidant system and the glyoxalase pathway, cell wall and cuticular wax, fatty acid unsaturation and photosynthesis. This study provides a theoretical basis for revealing the mechanism for how ethephon regulates drought response and improves drought tolerance of Kentucky bluegrass.


Assuntos
Aclimatação/efeitos dos fármacos , Secas , Compostos Organofosforados/farmacologia , Poa/genética , Estresse Fisiológico/efeitos dos fármacos , China , Meio Ambiente , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Malondialdeído/metabolismo , Fotossíntese/efeitos dos fármacos , Reguladores de Crescimento de Plantas/farmacologia , Folhas de Planta/efeitos dos fármacos , Poa/metabolismo , Plântula/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Transcriptoma/genética , Água/metabolismo
19.
Int J Mol Sci ; 22(23)2021 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-34884890

RESUMO

Arbuscular mycorrhiza (AM), i.e., the interaction of plants with arbuscular mycorrhizal fungi (AMF), often influences plant growth, physiology, and metabolism. Effects of AM on the metabolic composition of plant phloem sap may affect aphids. We investigated the impacts of AM on primary metabolites in phloem exudates of the plant species Plantago major and Poa annua and on the aphid Myzus persicae. Plants were grown without or with a generalist AMF species, leaf phloem exudates were collected, and primary metabolites were measured. Additionally, the performance of M. persicae on control and mycorrhizal plants of both species was assessed. While the plant species differed largely in the relative proportions of primary metabolites in their phloem exudates, metabolic effects of AM were less pronounced. Slightly higher proportions of sucrose and shifts in proportions of some amino acids in mycorrhizal plants indicated changes in phloem upload and resource allocation patterns within the plants. Aphids showed a higher performance on P. annua than on P. major. AM negatively affected the survival of aphids on P. major, whereas positive effects of AM were found on P. annua in a subsequent generation. Next to other factors, the metabolic composition of the phloem exudates may partly explain these findings.


Assuntos
Afídeos , Exsudatos e Transudatos/química , Micorrizas , Floema/metabolismo , Plantago/fisiologia , Poa/fisiologia , Aminoácidos , Animais , Folhas de Planta/metabolismo , Plantago/metabolismo , Poa/metabolismo , Sacarose
20.
Mycologia ; 113(5): 956-967, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34236950

RESUMO

Leptosphaerulina leaf blight occurs on most turfgrasses. Hitherto, Leptosphaerulina species associated with this disease include L. americana, L. argentinensis, L. australis, and L. trifolii. However, following Koch's postulates, L. australis was confirmed as saprobes but not pathogens, and the other three species have not been tested. The pathogenicity of Leptosphaerulina spp. is still questionable. In this study, we isolated 19 Leptosphaerulina strains from diseased golf turfgrasses in China, and they were identified as L. gaeumannii, L. saccharicola, and a new species, L. macrospora, through multilocus (ITS, 28S, rpb2, and tub2) phylogenetic analyses and morphological observations. Pathogenicity test revealed that the three Leptosphaerulina species identified in this study cannot infect live/healthy turfgrass tissues of Poa pratensis and Agrostis stolonifera and only produced pseudothecia on the dead leaves of stressed seedlings. Considering the results of pathogenicity tests in this and previous studies, we speculate that most Leptosphaerulina species isolated from diseased turfgrass are not pathogens but saprobes. Applying proper management practices to prevent severe turfgrass stress is a key measure to reduce or eliminate the effects of Leptosphaerulina on golf turfgrass.


Assuntos
Agrostis , Ascomicetos , Golfe , Poa , Filogenia
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