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1.
Sci Total Environ ; 792: 148411, 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34465037

RESUMO

Biodegradation of soil contaminants may be promoted near plant roots due to the "rhizosphere effect" which may enhance microbial growth and activity. However, the effects of different plant cultivars within a single species on degradation remains unclear. Here, we evaluated the removal of soil total petroleum hydrocarbons (TPHs) by ten different cultivars of tall fescue grass (Festuca arundinacea L.) and their associated rhizosphere microbiomes. TPH removal efficiency across the ten different cultivars was not significantly correlated with plant biomass. Rhizing Star and Greenbrooks cultivars showed the maximum (76.6%) and minimum (62.2%) TPH removal efficiencies, respectively, after 120 days. Significant differences were observed between these two cultivars in the composition of rhizosphere bacterial and fungal communities, especially during the early stages (day 30) of remediation but the differences decreased later (day 90). Putative petroleum-degrading bacterial and fungal guilds were enriched in the presence of tall fescue. Moreover, the complexity of microbial networks declined in treatments with higher TPH removal efficiency. The relative abundances of saprotrophic fungi and putative genes alkB and C12O in bacetria involved in petroleum degradation increased, especially in the presence of Rhizing Star cultivar, and this was consistent with the TPH removal efficiency results. These results indicate the potential of tall fescue grass cultivars and their associated rhizosphere microbiomes to phytoremediate petroleum hydrocarbon-contaminated soils.


Assuntos
Festuca , Microbiota , Petróleo , Poluentes do Solo , Biodegradação Ambiental , Hidrocarbonetos , Solo , Microbiologia do Solo , Poluentes do Solo/análise
2.
J Dairy Sci ; 104(10): 10863-10878, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34389144

RESUMO

Dairy heifers developed in certified organic programs, especially those utilizing pasture-based management schemes, have lower rates of gain than heifers raised in nonorganic confinement production systems in temperate climates, such as in the Intermountain West region of the United States. This study investigates the effects that different forages in a rotational grazing system have on development of organically raised Jersey heifers. Over 3 years, 210 yearling Jersey heifers were randomly assigned to one of 9 treatments, including a conventional confinement control where animals were fed a total mixed ration or one of 8 pasture treatments: Cache Meadow bromegrass (Bromus riparius Rehmann), QuickDraw orchard grass (Dactylis glomerata L.), Amazon perennial ryegrass (Lolium perenne L.), or Fawn tall fescue (Schendonorus arundinaceus [Schreb.] Dumort) and each individual grass interseeded with birdsfoot trefoil (Lotus corniculatus L., BFT). Each treatment had 3 blocks/yr over the 3-yr period, with each block having a 0.4 ha pasture of each treatment. Every 35 d, over a 105-d period, heifers were weighed and measured for hip height, and blood samples were collected to determine serum insulin-like growth factor-1 and blood urea nitrogen concentrations. Fecal egg counts were also assessed. Heifer body weight (BW), blood urea nitrogen, and insulin-like growth factor-1 concentrations were affected by treatment when analyzed over time. Heifers on grass-BFT pastures had increased BW compared with heifers on monoculture grass pastures. Heifers receiving a total mixed ration or perennial ryegrass+BFT had increased BW gain over the 105-d period compared with heifers grazing tall fescue+BFT, orchard grass, perennial ryegrass, meadow bromegrass, or tall fescue. Individually for all grass species, heifers grazing +BFT pastures had greater ending BW and weight gain than heifers grazing the respective grass monocultures. Furthermore, weight gain for heifers on perennial ryegrass+BFT, meadow bromegrass+BFT, and orchard grass+BFT were not different from those on a total mixed ration. Heifers grazing grass-BFT pastures had increased blood urea nitrogen compared with heifers grazing monoculture grass pastures. Heifer hip height and fecal egg counts were not affected by treatment. These results show that the addition of BFT to organic pasture improves growth of grazing replacement heifers. Economic analyses also demonstrate that interseeding grass pastures with BFT results in an increased economic return compared with grazing monoculture grass pastures. Grass pastures interseeded with BFT may be a sustainable option to achieve adequate growth of Jersey heifers raised in an organic pasture scenario in a temperate climate.


Assuntos
Festuca , Lotus , Ração Animal/análise , Animais , Bovinos , Dieta/veterinária , Ganho de Peso
3.
Ecotoxicol Environ Saf ; 223: 112568, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34332250

RESUMO

Tall fescue (Festuca arundinacea Schreb.) shows huge potential for lead (Pb) phytoremediation, while little is known on the molecular mechanisms involved in Pb tolerance and accumulation. Here, genetic engineering strategy was firstly used to investigate Pb tolerance and accumulation in tall fescue. The transgenic tall fescue overexpressing a class II (CII) sHSP gene FaHSP17.8-CII was generated. After exposure to 1000 mg/L Pb(NO3)2, two FaHSP17.8-CII overexpressing lines, OE#3 and OE#7, showed higher tolerance to Pb as illustrated by the reduced levels of electrolyte leakage (EL) and malondialdehyde (MDA) as compared to the wild-type (WT) plants under Pb stress. Moreover, the FaHSP17.8-CII overexpression lines, OE#3 and OE#7, exhibited 36.3% and 46.6% higher shoot Pb accumulation relative to the WT grasses. When the grasses were exposed to Pb stress, the two OE lines had higher CAT, POD and SOD activities as compared to WT. Additionally, overexpression of FaHSP17.8-CII improved the synthesis of chlorophyll and transcript abundance of FapsbC, FapsbD and FapsbE, and alleviated the photoinhibition of PSII in tall fescue under Pb stress. This study provides an initial genetic engineering strategy to improve Pb phytoremediation efficiency in tall fescue by FaHSP17.8-CII overexpression.


Assuntos
Festuca , Lolium , Antioxidantes , Clorofila , Festuca/genética , Chumbo/toxicidade
4.
J Environ Radioact ; 237: 106694, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34229188

RESUMO

Grasslands in Tohoku and North Kanto, Japan were contaminated with radiocesium released from the Fukushima Dai-ichi Nuclear Power Plant in March 2011. The dominant pasture species in the permanent grasslands of these areas is orchardgrass (Dactylis glomerata L.). Two field studies were conducted to determine the potential of a low radiocesium-uptake forage grass to replace orchardgrass for remediation of contaminated grasslands. From 2012 to 2014, tall fescue (Festuca arundinacea Schreb.) showed lower 137Cs uptake than orchardgrass under harvesting condition. The annual mean 137Cs activity concentration and transfer factor in tall fescue were half of those in orchardgrass. There was no significant difference in the 137Cs activity concentration among the five cultivars of tall fescue at the third harvest in 2012. From 2016 to 2019, another field study was conducted in a pasture with tall fescue and orchardgrass introduced by overseeding under heavy grazing pressure after the Fukushima Dai-ichi Nuclear Power Plant accident. Tall fescue and orchardgrass were collected in May, July, and September from four paddocks before rotational grazing. Three grasses that were originally present, Kentucky bluegrass (Poa pratensis L.), perennial ryegrass (Lolium perenne L.), and white clover (Trifolium repens L.), were collected each time that tall fescue and orchardgrass were sampled in 2016-2017. They were also collected at the sampling time in May of 2018 and 2019. Tall fescue showed a consistently lower transfer factor than orchardgrass during the four years. Tall fescue had the lowest transfer factor compared with the three originally grown plant species. The Ministry of Agriculture, Forestry and Fisheries of Japan recommends an exchangeable K2O content of 0.3-0.4 g kg-1 in soil (0-15 cm depth) to keep the 137Cs activity concentration in forage grass below the provisional tolerance level for feed. The soil exchangeable K2O content in both field studies was lower than this. Tall fescue is considered a low radiocesium-uptake grass and a potential replacement for orchardgrass in Japan. The use of tall fescue might reduce the amount of potassium fertilizer needed in contaminated grasslands.


Assuntos
Festuca , Lolium , Monitoramento de Radiação , Dactylis , Japão , Poaceae , Estações do Ano
5.
Genes (Basel) ; 12(6)2021 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-34208200

RESUMO

Polyploidy has played an important evolutionary role in the genus Festuca (Poaceae), and several ploidy levels (ranging from 2n = 2x = 14 to 2n = 12x = 84) have been detected to date. This study aimed to estimate the genome size and ploidy level of two subspecies belonging to the F. yvesii polyploid complex by flow cytometry and chromosome counting. The phenotypic variation of the cytotypes was also explored, based on herbarium material. The genome size of F. yvesii subsp. lagascae has been estimated for the first time. Nuclear 2C DNA content of F. yvesii subsp. summilusitana ranged from 21.44 to 31.91 pg, while that of F. yvesii subsp. lagascae was from 13.60 to 22.31 pg. We report the highest ploidy level detected for Festuca (2n = 14x = 98) and previously unknown cytotypes. A positive correlation between holoploid genome size and chromosome number counts shown herein was confirmed. The morphometric approach showed a slight trend towards an increase in the size of some organs consistent with the variation in the ploidy level. Differences in characters were usually significant only among the most extreme cytotypes of each subspecies, but, even in this case, the high overlapping ranges prevent their distinction.


Assuntos
Festuca/genética , Tamanho do Genoma , Polimorfismo Genético , Poliploidia , Cromossomos de Plantas/genética
6.
Chemosphere ; 283: 131186, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34157621

RESUMO

Phytoremediation as an efficient and eco-friendly soil detoxification method has received widespread attention. In this study, two newly screened Chromium (Cr) reducing strains (Bacillus sp. AK-1 and Lysinibacillus sp. AK-5) were used to remediate Cr contaminated soil in conjunction with the application of hyperaccumulator tall fescue (Festuca arundinacea), thus establishing a soil Cr decontamination system. In this system, soil urease and dehydrogenase activities were increased, the malondialdehyde (MDA) contents in leaves of tall fescue were significantly decreased, while glutathione (GSH) contents increased. In terms of Cr fractions, the proportion of acetic acid extractable Cr decreased by 12.82-20.00% in treatment groups, respectively, compared with CK, while residual Cr increased by 9.41-22.37%. Moreover, biomass, root length and shoot length of tall fescue in treatment groups increased by 80.77-139.74%, 60.85-68.04%, 7.06-27.10%, respectively. In addition, the root system of tall fescue accumulated 303.887-372.167 mg kg-1 of Cr, and the aboveground part accumulated 16.289-19.289 mg kg-1 of Cr. Therefore, the application of strains AK-1 and AK-5 reduced the toxicity of Cr to plants and greatly increased plant accumulation potential, which indicated that AK-1 and AK-5 could improve removal efficiency of phytoremediation in Cr contaminated soil by reducing its bio-toxicity and promoting growth of tall fescue growth.


Assuntos
Bacillus , Festuca , Poluentes do Solo , Biodegradação Ambiental , Cromo/toxicidade , Descontaminação , Solo , Poluentes do Solo/toxicidade
7.
New Phytol ; 231(6): 2319-2332, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34091913

RESUMO

Demographic studies measure drivers of plant fecundity including seed production and survival, but few address both abiotic and biotic drivers of germination such as variation in climate among sites, population density, maternal plants, seed type and fungal pathogen abundance. We examined germination and microbial communities of seeds of Danthonia californica, which are either chasmogamous (external, wind-pollinated) or cleistogamous (internal, self-fertilized) and Festuca roemeri, which are solely chasmogamous. Seed populations were sourced across environmental gradients. We tested germination and used high-throughput sequencing to characterize seed fungal community structure. For F. roemeri, maternal plants significantly influenced germination as did climate and pathogens; germination increased from wetter, cooler sites. For D. californica, the main drivers of germination were maternal plant, seed type and pathogens; on average, more chasmogamous seeds germinated. Fungal communities depended largely on seed type, with fewer fungi associated with cleistogamous seeds, but the communities also depended on site factors such as vapor pressure deficit, plant density and whether the seeds had germinated. Putative pathogens that were negatively correlated with germination were more abundant for both D. californica and F. roemeri chasmogamous seeds than D. californica cleistogamous seeds. In D. californica, cleistogamous and chasmogamous seeds contain vastly different fungal communities.


Assuntos
Festuca , Micobioma , Demografia , Germinação , Poaceae , Sementes
8.
Bull Entomol Res ; 111(5): 553-559, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34128461

RESUMO

The vegetation community affects the composition and diversity of the insect community in grasslands. To explore the effects of vegetation management on insect community abundance and diversity, regular mowing of the vegetation was conducted, and tall fescue (Festuca arundinacea) and ryegrass (Lolium perenne) were exclusively planted at Tianjin Binhai International Airport. A total of 1886 insects were collected, representing 8 orders, 23 families, and 29 species; Acrididae (Orthoptera), Coccinellidae (Coleoptera), and Chironomidae (Diptera) were the dominant taxa. The abundance and biomass of insects in the turf areas were significantly lower than those in the control area and were reduced by 45.8 and 48.5% in the ryegrass area, respectively. In all areas, insect abundance and biomass peaked in summer, and the abundance of individuals and taxa decreased as the temperature decreased. Greater diversity and richness were found in summer compared with the other two seasons, and the turf areas had lower diversity and richness indices than the control areas in spring and summer. Our results suggest that the abundance, biomass and diversity of insects can be effectively decreased by artificial regulation of grassland vegetation at the airport, the planting of a single turfgrass - specifically ryegrass had the greatest effect. The present study provides a theoretical basis for the ecological control of insects at the airport.


Assuntos
Biodiversidade , Pradaria , Insetos/classificação , Aeroportos , Animais , Biota , China , Festuca , Lolium , Estações do Ano
9.
J Hazard Mater ; 417: 125932, 2021 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-34020353

RESUMO

Genetic improvement could play a significant role in enhancing the Cd accumulation, translocation and tolerance in plants. In this study, for the first time, we constructed transgenic tall fescue overexpressing a class II (CII) sHSP gene FaHSP17.8-CII, which enhanced Cd tolerance and the root-to-shoot Cd translocation. After exposed to 400 µM CdCl2, two FaHSP17.8-CII overexpressing lines (OE#3 and OE#7) exhibited 30% and 40% more shoot fresh weight, respectively, relative to the wild-type (WT). Both transgenic lines showed higher tolerance to Cd, as evidenced by lower levels of electrolyte leakage and malondialdehyde compared to the WT plants under Cd stress. FaHSP17.8-CII overexpression increased shoot Cd contents 49-59% over the WT plants. The Cd translocation factor of root-to-shoot in OE grasses was 69-85% greater than WT under Cd stress. Furthermore, overexpression of FaHSP17.8-CII reduced Cd-induced damages of chloroplast ultra-structure and chlorophyll synthesis, and then improved photosystem II (PSII) function under Cd stress, which resulted in less reactive oxygen species (ROS) accumulation in OE grasses than that in WT exposed to Cd stress. The study suggests a novel FaHSP17.8-CII-PSII-ROS module to understand the mechanisms of Cd detoxification and tolerance, which provides a new strategy to improve phytoremediation efficiency in Cd-stressed grasses.


Assuntos
Cádmio , Festuca , Cádmio/toxicidade , Cloroplastos , Elétrons , Fotossíntese
10.
Chemosphere ; 281: 130908, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34034084

RESUMO

Exploring efficient remediation technologies to remediate potentially toxic element (PTE) in soil around the mining area has become a trendy research topic. This study conducted material composed of sawdust ash (SA) and sawdust biochar (SB) with mass ratio of SA:SB = 1:2 in combination with Medicago sativa L. and Festuca arundinacea to remediate soil contaminated by zinc (Zn), cadmium (Cd), and arsenic (As) in a mining area. The result showed that the removal rates of Zn, Cd, and As were the highest under the treatment of Festuca arundinacea combined with 5% material with values of 22.15%, 22.05%, and 12.47%, respectively. Festuca arundinacea had the most potent ability to absorb and tolerate composite PTEs, and the co-remediation process could remarkably improve soil enzyme environment and microbial community diversity. The distribution of PTEs in plant subcellular showed that the accumulation of Zn, Cd, and As in the cell wall of Festuca arundinacea root was significantly increased by adding 2% materials. The concentrations of Zn, Cd, and As in the cell wall were 4486.25, 33.59, and 124.15 mg/kg, respectively. The combination of 2% material and Festuca arundinacea could effectively remove PTEs in soil and enhance the detoxification ability of the plant, thus effectively improving the soil environment and remediating PTEs pollution. This study provided insights into the remediation of PTE-contaminated soil in mining area by combining materials and plants.


Assuntos
Festuca , Poluentes do Solo , Temperatura Alta , Mineração , Solo , Poluentes do Solo/análise
11.
Sheng Wu Gong Cheng Xue Bao ; 37(4): 1324-1333, 2021 Apr 25.
Artigo em Chinês | MEDLINE | ID: mdl-33973445

RESUMO

Photoperiod plays an important role in transformation from vegetative growth to reproductive growth in plants. CONSTANS (CO), as a unique gene in the photoperiod pathway, responds to changes of day length to initiate flowering in the plant. In this study, the expression level of FaCONSTANS (FaCO) gene under long-day, short-day, continuous light and continuous darkness conditions was analyzed by real-time quantitative PCR. We constructed the over-expression vector p1300-FaCO and infected into Arabidopsis thaliana by Agrobacterium-mediated method. We constructed the silencing vector p1300-FaCO-RNAi and infected into Festuca arundinacea by Agrobacterium-mediated method. The expression of FaCO gene was regulated by photoperiod. The over-expression of FaCO promoted flowering in wild type of Arabidopsis thaliana under long day condition and rescued the late flowering phenotype in co-2 mutant of Arabidopsis thaliana. Silencing FaCO gene in Festuca arundinacea by RNAi showed late-flowering phenotype or always kept in the vegetative growth stage. Our understanding the function of FaCO in flowering regulation will help further understand biological function of this gene in Festuca arundinacea.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Festuca , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Festuca/genética , Festuca/metabolismo , Flores/genética , Regulação da Expressão Gênica de Plantas , Fotoperíodo
12.
PLoS One ; 16(4): e0249636, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33831050

RESUMO

Ryegrasses (Lolium spp.) and fescues (Festuca spp.) are closely related and widely cultivated perennial forage grasses. As such, resilience in the face of abiotic stresses is an important component of their traits. We have compared patterns of differentially expressed genes (DEGs) in roots and leaves of two perennial ryegrass genotypes and a single genotype of each of a festulolium (predominantly Italian ryegrass) and meadow fescue with the onset of water stress, focussing on overall patterns of DEGs and gene ontology terms (GOs) shared by all four genotypes. Plants were established in a growing medium of vermiculite watered with nutrient solution. Leaf and root material were sampled at 35% (saturation) and, as the medium dried, at 15%, 5% and 1% estimated water contents (EWCs) and RNA extracted. Differential gene expression was evaluated comparing the EWC sampling points from RNAseq data using a combination of analysis methods. For all genotypes, the greatest numbers of DEGs were identified in the 35/1 and 5/1 comparisons in both leaves and roots. In total, 566 leaf and 643 root DEGs were common to all 4 genotypes, though a third of these leaf DEGs were not regulated in the same up/down direction in all 4 genotypes. For roots, the equivalent figure was 1% of the DEGs. GO terms shared by all four genotypes were often enriched by both up- and down-regulated DEGs in the leaf, whereas generally, only by either up- or down-regulated DEGs in the root. Overall, up-regulated leaf DEGs tended to be more genotype-specific than down-regulated leaf DEGs or root DEGs and were also associated with fewer GOs. On average, only 5-15% of the DEGs enriching common GO terms were shared by all 4 genotypes, suggesting considerable variation in DEGs between related genotypes in enacting similar biological processes.


Assuntos
Desidratação , Festuca/metabolismo , Regulação da Expressão Gênica de Plantas , Lolium/metabolismo , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Festuca/genética , Festuca/crescimento & desenvolvimento , Perfilação da Expressão Gênica , Ontologia Genética , Genótipo , Lolium/genética , Lolium/crescimento & desenvolvimento , Fenótipo , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Proteínas de Plantas/genética , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento
13.
Bull Environ Contam Toxicol ; 107(1): 154-159, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33830282

RESUMO

Planting density can influence the biomass generation and element uptake capacity of various plants, which are two critical factors that determine the phytoremediation efficiency of plants. A series of 70 d experiments was performed to evaluate the influence of the planting density (10, 15, 20, 25, and 30 g seeds·m- 2, namely D10, D15, D20, D25, and D30, respectively) of Festuca arundinacea on the decontamination of Cd-polluted soils. The variations in the biomass yield, falling tissue (senescent and dead leaf tissues) proportion, and Cd extraction capacity of the species under different cultivation strategies were determined. The results showed that the biomass generation of the species per square meter increased as the planting density increased, reached a peak at D20, and then decreased significantly. In addition, planting density can change the proportions of different leaf types, and the highest amount of senescent and dead leaves which accumulated significantly more Cd compared with the emerging and mature leaf tissues was observed at D20. A suitable planting density can also drive the species to secrete more dissolved organic matter (DOM), especially hydrophilic fractionations in to the soil, activating more Cd. Therefore, the phytoremediation efficiency of the species was determined by the dry weight of the falling tissues, which contained more than 75% of the leaf Cd. A suitable planting density can enhance the Cd decontamination capacity of F. arundinacea, and the adjustment of the planting density is a practicable and economical method that can be performed in real fields.


Assuntos
Festuca , Lolium , Poluentes do Solo , Biodegradação Ambiental , Solo , Poluentes do Solo/análise
14.
Chemosphere ; 276: 130137, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33721629

RESUMO

Intercropping with Cicer arietinum L has been suggested to improve the Cd decontamination capacity of Festuca arundinacea. However, the mechanisms stimulating this effect have not been revealed. The current study was designed to evaluate the changes in the subcellular distribution and chemical forms of Cd in different leaf types of F. arundinacea intercropped with C. arietinum L under different schemes. The results indicated that more than half of the Cd was bound in the cell wall in plant organs under all planting schemes, showing that cell wall deposition is an important detoxication pathway for the metal. Relative to the monoculture scheme, coordinate and malposed intercropping schemes increased the Cd concentration deposited in the cytoplasm of below-ground tissues from 37.6% to 45.2% and 45.1%, respectively. Additionally, the proportion of inorganic and water-soluble Cd in the below-ground parts of F. arundinacea increased from 73.6% in the monoculture scheme to 80.6% and 84.7%, in the coordinate and malposed intercropping schemes, respectively. The results exhibited that intercropping schemes can activate the metal in below-ground tissues and move it to aerial parts. The present study revealed the promoting mechanism of intercropping schemes on the phytoremediation efficiency of F. arundinacea for Cd at a subcellular level.


Assuntos
Festuca , Lolium , Poluentes do Solo , Biodegradação Ambiental , Cádmio/análise , Solo , Poluentes do Solo/análise
15.
Chemosphere ; 276: 130186, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33725620

RESUMO

Phytoexcretion is a novel strategy to remediate cadmium (Cd) pollution by leaf excretion in tall fescue (Festuca arundinacea), which involves the processes of Cd leaf excretion, root-to-leaf translocation, and root uptake. A hydroponic experiment was designed to investigate a series of 11 zinc (Zn) concentrations on Cd leaf excretion in tall fescue under 75 µM Cd stress. The results showed that the promotions of Zn on Cd leaf excretion, root-to-leaf translocation, and leaf accumulation were concentration-dependent in tall fescue. Zn treatments at 90 and 135 µM resulted in the highest Cd leaf excretion with 118.1 and 123.6 mg/kg of Cd excretion amount and 27.0 and 26.6% of excretion ratio, which were 2.6 and 2.7 fold of the control (15 µM of Zn), respectively. Cd leaf excretion was decreased when Zn treatments reached 180 µM, which could be toxic to plants as indicated by the decline of plant biomass. Zn also promoted leaf Cd accumulation and Cd translocation from roots to leaves and reached the highest at 90 and 180 µM respectively. Root Cd accumulation decreased with the increase of Zn concentrations, but the total plant Cd uptake did not decrease significantly until Zn concentration reached 90 µM. Our results indicate that 90 µM of Zn treatment can be served as the threshold to promote Cd leaf excretion and improve the efficiency of Cd phytoexcretion in tall fescue.


Assuntos
Festuca , Poluentes do Solo , Cádmio/toxicidade , Folhas de Planta , Raízes de Plantas , Poluentes do Solo/toxicidade , Zinco
16.
Molecules ; 26(4)2021 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-33557353

RESUMO

Haematobia irritans is an obligate bloodsucking ectoparasite of cattle and is the global major pest of livestock production. Currently, H. irritans management is largely dependent upon broad-spectrum pesticides, which lately has led to the development of insecticide resistance. Thus, alternative control methods are necessary. Endophyte-infected grasses have been studied as an alternative due to their capability to biosynthesize alkaloids associated with anti-insect activities. Thus, the main aim of this study was to evaluate the antifeedant and repellent activity of lolines obtained from endophyte-infected tall fescue against H. irritans adults in laboratory conditions. The alkaloid extract (ALKE) was obtained by acid-base extraction. N-formyl loline (NFL) and N-acetyl loline (NAL) were isolated by preparative thin layer chromatography (pTLC) and column chromatography (CC), and the loline was prepared by acid hydrolysis of a NFL/NAL mixture. Loline identification was performed by gas chromatography coupled to mass spectrometry (GC/MS). Feeding behavior was evaluated by a non-choice test, and olfactory response was evaluated using a Y-tube olfactometer. Accordingly, all samples showed antifeedant activities. NFL was the most antifeedant compound at 0.5 µg/µL and 1.0 µg/µL, and it was statistically equal to NAL but different to loline; however, NAL was not statistically different to loline. NFL and NAL at 0.25 µg/µL were more active than loline. All samples except loline exhibited spatial repellency in the olfactometer. Thus, the little or non-adverse effects for cattle and beneficial activities of those lolines make them suitable candidates for horn fly management.


Assuntos
Alcaloides/farmacologia , Endófitos/fisiologia , Festuca/química , Festuca/microbiologia , Repelentes de Insetos/farmacologia , Muscidae/efeitos dos fármacos , Alcaloides/química , Alcaloides/isolamento & purificação , Animais , Repelentes de Insetos/química , Repelentes de Insetos/isolamento & purificação
17.
Environ Pollut ; 274: 116559, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33529892

RESUMO

The study aimed to assess the effects of melatonin, a plant growth regulator, on the degradation of phenanthrene (Phe) and pyrene (Py), in the rhizosphere of the Festuca grass. The experiments were divided into the following groups: 1) soil contaminated with Phe and Py, without the Festuca, 2) contaminated soil + Festuca, 3-5), contaminated soil + Festuca + the application of melatonin in three separate doses: 10, 50, or 100 µM. After 90 days, the effects of melatonin supplementation on the degradation of polycyclic aromatic hydrocarbons (PAHs) were analyzed by evaluating the rate of PAHs degradation, the expression of genes encoding salicylaldehyde dehydrogenase (SDH) and glutathione peroxidase (GPX) enzymes in Pseudomonas putida, as well as by measuring the total activity of dehydrogenase and peroxidase enzymes. Our results have shown that in soil contaminated by 300 mg kg-1 PAHs, application of melatonin (10, 50, 100 µM), resulted in the following increase in the dehydrogenase and peroxidase activity in all three applied doses (19% and 5.7%), (45.3% and 34.3%), (40.9% and 14.3%), respectively in comparison to the control group. The experiment showed that soil supplementation with melatonin at 50 µM, resulted in the highest removal rate of PAHs. According to our results, melatonin demonstrated a potentially favorable role in enhancing plant biomass, as well as an increase in soil bacterial population, and the activity of antioxidative enzymes in P. putida, causing all tested parameters of the soil and the expression of desired genes to be advantageously altered for the degradation of the chosen PAHs.


Assuntos
Festuca , Melatonina , Hidrocarbonetos Policíclicos Aromáticos , Poluentes do Solo , Biodegradação Ambiental , Hidrocarbonetos Policíclicos Aromáticos/análise , Rizosfera , Solo , Microbiologia do Solo , Poluentes do Solo/análise
18.
Ecotoxicol Environ Saf ; 213: 112021, 2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33582412

RESUMO

Cadmium is a common heavy metal pollutant. In some plants, its absorption is inhibited by exogenous phosphorus. Here, the effect of P supplementation on the growth of tall fescue exposed to Cd was evaluated in a hydroponic culture experiment. Plants were exposed to five concentrations of P (0, 0.25, 0.5, 0.75, and 1.0 mmol L-1) and three concentrations of Cd (50, 100, and 150 mg L-1), and plant growth, Cd content, absorption, physiological characteristics, and nutrient accumulation were investigated. P supplementation significantly reduced the Cd content, Cd translocation factor (TF), Cd removal efficiency, plant P absorption, chlorophyll content, glutathione levels, glutathione reductase levels, and superoxide dismutase (SOD) activity in tall fescue under Cd stress (P < 0.05). Moreover, it increased the vertical growth rate and biomass of tall fescue. At a constant P concentration, the biomass and vertical growth rate significantly decreased with an increasing Cd concentration, and the shoot Cd content, SOD activity, and TF significantly increased (P < 0.05). High P supplementation (0.75 and 1.0 mmol L-1) ameliorated the damage caused by 150 mg L-1 Cd stress, and the biomass, vertical shoot and vertical root growth rates were increased by 72.06-82.06%, 250.00-316.67%, 300.00-312.00%, respectively. In the plants subjected to 50 mg L-1 Cd stress, 0.5 mmol L-1 P supplementation enhanced biomass, vertical shoot and vertical root growth rates by 29.99%, 20.41%, and 21.43%, respectively, and reduced the Cd content in shoots (45.85%) and roots (9.71%). Except for the total potassium content and catalase activity, different concentrations of Cd negatively affected all parameters tested. Such negative effects were limited by P supplementation. Optimizing the nutrient composition and concentrations could minimize the potential negative impacts of Cd on plant growth.


Assuntos
Cádmio/toxicidade , Festuca/fisiologia , Poluentes do Solo/toxicidade , Antioxidantes/metabolismo , Transporte Biológico , Clorofila , Suplementos Nutricionais , Festuca/efeitos dos fármacos , Glutationa Redutase , Lolium , Metais Pesados/toxicidade , Nutrientes , Fósforo/farmacologia , Raízes de Plantas/efeitos dos fármacos
19.
Plant Cell Environ ; 44(4): 1215-1230, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33455010

RESUMO

Soil legacies play an important role for the creation of priority effects. However, we still poorly understand to what extent the metabolome found in the soil solution of a plant community is conditioned by its species composition and whether soil chemical legacies affect subsequent species during assembly. To test these hypotheses, we collected soil solutions from forb or grass communities and evaluated how the metabolome of these soil solutions affected the growth, biomass allocation and functional traits of a forb (Dianthus deltoides) and a grass species (Festuca rubra). Results showed that the metabolomes found in the soil solutions of forb and grass communities differed in composition and chemical diversity. While soil chemical legacies did not have any effect on F. rubra, root foraging by D. deltoides decreased when plants received the soil solution from a grass or a forb community. Structural equation modelling showed that reduced soil exploration by D. deltoides arose via either a root growth-dependent pathway (forb metabolome) or a root trait-dependent pathway (grass metabolome). Reduced root foraging was not connected to a decrease in total N uptake. Our findings reveal that soil chemical legacies can create belowground priority effects by affecting root foraging in later arriving plants.


Assuntos
Dianthus/fisiologia , Festuca/fisiologia , Raízes de Plantas/fisiologia , Solo , Biomassa , Dianthus/crescimento & desenvolvimento , Ecologia , Festuca/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Solo/química
20.
J Exp Bot ; 72(2): 254-267, 2021 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-33029645

RESUMO

Crossing over, in addition to its strictly genetic role, also performs a critical mechanical function, by bonding homologues in meiosis. Hence, it is responsible for an orderly reduction of the chromosome number. As such, it is strictly controlled in frequency and distribution. The well-known crossover control is positive crossover interference which reduces the probability of a crossover in the vicinity of an already formed crossover. A poorly studied aspect of the control is chromatid interference. Such analyses are possible in very few organisms as they require observation of all four products of a single meiosis. Here, we provide direct evidence of chromatid interference. Using in situ probing in two interspecific plant hybrids (Lolium multiflorum×Festuca pratensis and Allium cepa×A. roylei) during anaphase I, we demonstrate that the involvement of four chromatids in double crossovers is significantly more frequent than expected (64% versus 25%). We also provide a physical measure of the crossover interference distance, covering ~30-40% of the relative chromosome arm length, and show that the centromere acts as a barrier for crossover interference. The two arms of a chromosome appear to act as independent units in the process of crossing over. Chromatid interference has to be seriously addressed in genetic mapping approaches and further studies.


Assuntos
Festuca , Lolium , Cromátides/genética , Troca Genética , Festuca/genética , Lolium/genética , Meiose/genética , Cebolas
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