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1.
Sci Total Environ ; 946: 174198, 2024 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-38914330

RESUMO

The use of glyphosate-based herbicides (GBHs) to control weeds has increased exponentially in recent decades, and their residues and degradation products have been found in soils across the globe. GBH residues in soil have been shown to affect plant physiology and specialised metabolite biosynthesis, which, in turn, may impact plant resistance to biotic stressors. In a greenhouse study, we investigated the interactive effects between soil GBH residues and herbivory on the performance, phytohormone concentrations, phenolic compound concentrations and volatile organic compound (VOC) emissions of two woodland strawberry (Fragaria vesca) genotypes, which were classified as herbivore resistant and herbivore susceptible. Plants were subjected to herbivory by strawberry leaf beetle (Galerucella tenella) larvae, and to GBH residues by growing in soil collected from a field site with GBH treatments twice a year over the past eight years. Soil GBH residues reduced the belowground biomass of the susceptible genotype and the aboveground biomass of both woodland strawberry genotypes. Herbivory increased the belowground biomass of the resistant genotype and the root-shoot ratio of both genotypes. At the metabolite level, herbivory induced the emission of several VOCs. Jasmonic acid, abscisic acid and auxin concentrations were induced by herbivory, in contrast to salicylic acid, which was only induced by herbivory in combination with soil GBH residues in the resistant genotype. The concentrations of phenolic compounds were higher in the resistant genotype compared to the susceptible genotype and were induced by soil GBH residues in the resistant genotype. Our results indicate that soil GBH residues can differentially affect plant performance, phytohormone concentrations and phenolic compound concentrations under herbivore attack, in a genotype-dependent manner. Soil GBH altered plant responses to herbivory, which may impact plant resistance traits and species interactions. With ongoing agrochemical pollution, we need to consider plant cultivars with better resistance to polluted soils while maintaining plant resilience under challenging environmental conditions.


Assuntos
Fragaria , Genótipo , Herbicidas , Herbivoria , Poluentes do Solo , Solo , Fragaria/genética , Poluentes do Solo/metabolismo , Solo/química , Animais , Reguladores de Crescimento de Plantas/metabolismo , Compostos Orgânicos Voláteis/metabolismo
2.
Pest Manag Sci ; 80(5): 2461-2470, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-37467342

RESUMO

BACKGROUND: Cultivation of oilseed rape Brassica napus is pesticide-intensive, and alternative plant protection strategies are needed because both pesticide resistance and legislation narrow the range of effective chemical pesticides. The entomopathogenic fungus Beauveria bassiana is used as a biocontrol agent against various insect pests, but little is known about its endophytic potential and role in plant protection for oilseed rape. First, we studied whether B. bassiana can establish as an endophyte in oilseed rape, following seed inoculation. To evaluate the plant protection potential of endophytic B. bassiana on oilseed rape, we next examined its ability to induce plant metabolite biosynthesis. In another experiment, we tested the effect of seed inoculation on seedling survival in a semi-field experiment. RESULTS: Beauveria bassiana endophytically colonized oilseed rape following seed inoculation, and, in addition, natural colonization was also recorded. Maximum colonization rate was 40%, and generally increased with inoculation time. Seed inoculation did not affect the germination probability or growth of oilseed rape, but B. bassiana inoculated seeds germinated more slowly compared to controls. Endophytic colonization of B. bassiana induced biosynthesis of several flavonoids in oilseed rape leaves under controlled conditions. In the experiment conducted in semi-field conditions, inoculated seedlings had slightly higher mortality compared to control seedlings. CONCLUSION: Beauveria bassiana showed endophytic potential on oilseed rape via both natural colonization and seed inoculation, and it induced the biosynthesis of flavonoids. However, its use as an endophyte for plant protection against pests or pathogens for oilseed rape remains unclear. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.


Assuntos
Beauveria , Brassica napus , Praguicidas , Animais , Sementes , Insetos , Plantas , Endófitos , Plântula/microbiologia
3.
FEMS Microbiol Ecol ; 99(7)2023 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-37316439

RESUMO

Pollinator decline is one of the gravest challenges facing the world today, and the overuse of pesticides may be among its causes. Here, we studied whether glyphosate, the world's most widely used pesticide, affects the bumblebee gut microbiota. We exposed the bumblebee diet to glyphosate and a glyphosate-based herbicide and quantified the microbiota community shifts using 16S rRNA gene sequencing. Furthermore, we estimated the potential sensitivity of bee gut microbes to glyphosate based on previously reported presence of target enzyme. Glyphosate increased, whereas the glyphosate-based herbicide decreased gut microbiota diversity, indicating that negative effects are attributable to co-formulants. Both glyphosate and the glyphosate-based herbicide treatments significantly decreased the relative abundance of potentially glyphosate-sensitive bacterial species Snodgrasella alvi. However, the relative abundance of potentially glyphosate-sensitive Candidatus Schmidhempelia genera increased in bumblebees treated with glyphosate. Overall, 50% of the bacterial genera detected in the bee gut microbiota were classified as potentially resistant to glyphosate, while 36% were classified as sensitive. Healthy core microbiota have been shown to protect bees from parasite infections, change metabolism, and decrease mortality. Thus, the heavy use of glyphosate-based herbicides may have implications on bees and ecosystems.


Assuntos
Microbioma Gastrointestinal , Herbicidas , Microbiota , Abelhas , Animais , Microbioma Gastrointestinal/genética , Herbicidas/farmacologia , RNA Ribossômico 16S/genética , Bactérias/genética , Glifosato
4.
J Fungi (Basel) ; 9(1)2023 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-36675911

RESUMO

Plants harbor a large diversity of endophytic microbes. Meadow fescue (Festuca pratensis) is a cool-season grass known for its symbiotic relationship with the systemic and vertically-via seeds-transmitted fungal endophyte Epichloë uncinata, yet its effects on plant hormones and the microbial community is largely unexplored. Here, we sequenced the endophytic bacterial and fungal communities in the leaves and roots, analyzing phytohormone concentrations and plant performance parameters in Epichloë-symbiotic (E+) and Epichloë-free (E-) individuals of two meadow fescue cultivars. The endophytic microbial community differed between leaf and root tissues independent of Epichloë symbiosis, while the fungal community was different in the leaves of Epichloë-symbiotic and Epichloë-free plants in both cultivars. At the same time, Epichloë symbiosis decreased salicylic acid and increased auxin concentrations in leaves. Epichloë-symbiotic plants showed higher biomass and higher seed mass at the end of the season. Our results demonstrate that Epichloë symbiosis alters the leaf fungal microbiota, which coincides with changes in phytohormone concentrations, indicating that Epichloë endophytes affect both plant immune responses and other fungal endophytes. Whether the effect of Epichloë endophytes on other fungal endophytes is connected to changes in phytohormone concentrations remains to be elucidated.

5.
J Appl Microbiol ; 134(2)2023 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-36639128

RESUMO

AIMS: In a field study, the effects of treatments of glyphosate-based herbicides (GBHs) in soil, alone and in combination with phosphate fertilizer, were examined on the performance and endophytic microbiota of garden strawberry. METHODS AND RESULTS: The root and leaf endophytic microbiota of garden strawberries grown in GBH-treated and untreated soil, with and without phosphate fertilizer, were analyzed. Next, bioinformatics analysis on the type of 5-enolpyruvylshikimate-3-phosphate synthase enzyme was conducted to assess the potential sensitivity of strawberry-associated bacteria and fungi to glyphosate, and to compare the results with field observations. GBH treatments altered the abundance and/or frequency of several operational taxonomic units (OTUs), especially those of root-associated fungi and bacteria. These changes were partly related to their sensitivity to glyphosate. Still, GBH treatments did not shape the overall community structure of strawberry microbiota or affect plant performance. Phosphate fertilizer increased the abundance of both glyphosate-resistant and glyphosate-sensitive bacterial OTUs, regardless of the GBH treatments. CONCLUSIONS: These findings demonstrate that although the overall community structure of strawberry endophytic microbes is not affected by GBH use, some individual taxa are.


Assuntos
Fragaria , Herbicidas , Microbiota , Herbicidas/farmacologia , Fertilizantes , Solo , Bactérias , Fungos/genética , Glifosato
6.
Trends Ecol Evol ; 38(1): 35-43, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36243622

RESUMO

Non-target organisms are globally exposed to herbicides. While many herbicides - for example, glyphosate - were initially considered safe, increasing evidence demonstrates that they have profound effects on ecosystem functions via altered microbial communities. We provide a comprehensive framework on how herbicide residues may modulate ecosystem-level outcomes via alteration of microbiomes. The changes in soil microbiome are likely to influence key nutrient cycling and plant-soil processes. Herbicide-altered microbiome affects plant and animal performance and can influence trophic interactions such as herbivory and pollination. These changes are expected to lead to ecosystem and even evolutionary consequences for both microbes and hosts. Tackling the threats caused by agrochemicals to ecosystem functions and services requires tools and solutions based on a comprehensive understanding of microbe-mediated risks.


Assuntos
Herbicidas , Microbiota , Animais , Herbicidas/farmacologia , Herbicidas/química , Ecossistema , Plantas , Solo/química , Evolução Biológica
7.
Sci Rep ; 12(1): 21556, 2022 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-36513732

RESUMO

Increasing agricultural soil carbon sequestration without compromising the productivity of the land is a key challenge in global climate change mitigation. The carbon mitigation potential of grass-based agriculture is particularly high because grasslands represent 70% of the world's agricultural area. The root systems of grasses transfer large amounts of carbon to below-ground storage, and the carbon allocation to the roots is dependent on the grasses' photosynthesizing shoot biomass. In a common-garden experiment, Festuca pratensis was used as a model species to study how mowing and weed control practices of perennial cool-season fodder grasses affect total yield and root biomass. Additionally, grass-associated Epichloë endophytes and soil residual glyphosate were tested for their effect on the total yield and root biomass alone or in interaction with mowing. The results demonstrate that elevating the cutting height increases both cumulative yield and root biomass in F. pratensis. Endophyte symbiosis increased the total yield, while glyphosate-based herbicide residues in the soil decreased the root biomass, which indicates a reduction of soil bound carbon sequestration. The findings demonstrate that carbon sequestration and yield quantities on farmed grasslands may significantly be improved by optimizing strategies for the use of plant protection products and adjustment of mowing intensity.


Assuntos
Epichloe , Festuca , Lolium , Simbiose , Biomassa , Endófitos/metabolismo , Poaceae , Solo/química , Carbono/metabolismo
8.
Chemosphere ; 308(Pt 2): 136366, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36113650

RESUMO

Conventional agricultural practices favoring the use of glyphosate-based herbicides (GBHs) increase the risk of GBH residues ending up in animal feed, feces, and, eventually, manure. The use of poultry manure as organic fertilizer in the circular food economy increases the unintentional introduction of GBH residues into horticultural and agricultural systems, with reportedly negative effects on the growth and reproduction of crop plants. To understand the potential lasting effects of exposure to GBH residues via organic manure fertilizers, we studied strawberry (Fragaria x vescana) plant performance, yield quantity, biochemistry, folivory, phytochemistry, and soil elemental composition the year after exposure to GBH. Although plants exposed to GBH residues via manure fertilizer were, on average, 23% smaller in the year of exposure, they were able to compensate for their growth during the following growing season. Interestingly, GBH residue exposure in the previous growing season led to a trend in altered plant size preferences of folivores during the following growing season. Furthermore, the plants that had been exposed to GBH residues in the previous growing season produced 20% heavier fruits with an altered composition of phenolic compounds compared to non-exposed plants. Our results indicate that GBHs introduced via manure fertilizer following circular economy practices in one year can have effects on perennial crop plants in the following year, although GBH residues in soil have largely vanished.


Assuntos
Herbicidas , Agroquímicos , Animais , Fertilizantes , Glicina/análogos & derivados , Esterco , Solo/química , Glifosato
9.
Neurology ; 99(1): e33-e45, 2022 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-35314503

RESUMO

BACKGROUND AND OBJECTIVE: Little is known about trajectories of recovery 12 months after hospitalization for severe COVID-19. METHODS: We conducted a prospective, longitudinal cohort study of patients with and without neurologic complications during index hospitalization for COVID-19 from March 10, 2020, to May 20, 2020. Phone follow-up batteries were performed at 6 and 12 months after COVID-19 onset. The primary 12-month outcome was the modified Rankin Scale (mRS) score comparing patients with or without neurologic complications using multivariable ordinal analysis. Secondary outcomes included activities of daily living (Barthel Index), telephone Montreal Cognitive Assessment (t-MoCA), and Quality of Life in Neurologic Disorders (Neuro-QoL) batteries for anxiety, depression, fatigue, and sleep. Changes in outcome scores from 6 to 12 months were compared using nonparametric paired-samples sign test. RESULTS: Twelve-month follow-up was completed in 242 patients (median age 65 years, 64% male, 34% intubated during hospitalization) and 174 completed both 6- and 12-month follow-up. At 12 months, 197/227 (87%) had ≥1 abnormal metric: mRS >0 (75%), Barthel Index <100 (64%), t-MoCA ≤18 (50%), high anxiety (7%), depression (4%), fatigue (9%), or poor sleep (10%). Twelve-month mRS scores did not differ significantly among those with (n = 113) or without (n = 129) neurologic complications during hospitalization after adjusting for age, sex, race, pre-COVID-19 mRS, and intubation status (adjusted OR 1.4, 95% CI 0.8-2.5), although those with neurologic complications had higher fatigue scores (T score 47 vs 44; p = 0.037). Significant improvements in outcome trajectories from 6 to 12 months were observed in t-MoCA scores (56% improved, median difference 1 point; p = 0.002) and Neuro-QoL anxiety scores (45% improved; p = 0.003). Nonsignificant improvements occurred in fatigue, sleep, and depression scores in 48%, 48%, and 38% of patients, respectively. Barthel Index and mRS scores remained unchanged between 6 and 12 months in >50% of patients. DISCUSSION: At 12 months after hospitalization for severe COVID-19, 87% of patients had ongoing abnormalities in functional, cognitive, or Neuro-QoL metrics and abnormal cognition persisted in 50% of patients without a history of dementia/cognitive abnormality. Only fatigue severity differed significantly between patients with or without neurologic complications during index hospitalization. However, significant improvements in cognitive (t-MoCA) and anxiety (Neuro-QoL) scores occurred in 56% and 45% of patients, respectively, between 6 and 12 months. These results may not be generalizable to those with mild or moderate COVID-19.


Assuntos
COVID-19 , Disfunção Cognitiva , Fadiga , Qualidade de Vida , Atividades Cotidianas , Idoso , Ansiedade/epidemiologia , Ansiedade/etiologia , COVID-19/complicações , Disfunção Cognitiva/epidemiologia , Disfunção Cognitiva/etiologia , Depressão/epidemiologia , Depressão/etiologia , Fadiga/epidemiologia , Fadiga/etiologia , Feminino , Hospitalização , Humanos , Estudos Longitudinais , Masculino , Estudos Prospectivos , Transtornos do Sono-Vigília/epidemiologia , Transtornos do Sono-Vigília/etiologia
10.
J Neurol Sci ; 438: 120146, 2022 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-35031121

RESUMO

BACKGROUND: Persistent cognitive symptoms have been reported following COVID-19 hospitalization. We investigated the relationship between demographics, social determinants of health (SDOH) and cognitive outcomes 6-months after hospitalization for COVID-19. METHODS: We analyzed 6-month follow-up data collected from a multi-center, prospective study of hospitalized COVID-19 patients. Demographic and SDOH variables (age, race/ethnicity, education, employment, health insurance status, median income, primary language, living arrangements, and pre-COVID disability) were compared between patients with normal versus abnormal telephone Montreal Cognitive Assessments (t-MOCA; scores<18/22). Multivariable logistic regression models were constructed to evaluate predictors of t-MoCA. RESULTS: Of 382 patients available for 6-month follow-up, 215 (56%) completed the t-MoCA (n = 109/215 [51%] had normal and n = 106/215 [49%] abnormal results). 14/215 (7%) patients had a prior history of dementia/cognitive impairment. Significant univariate predictors of abnormal t-MoCA included older age, ≤12 years of education, unemployment pre-COVID, Black race, and a pre-COVID history of cognitive impairment (all p < 0.05). In multivariable analyses, education ≤12 years (adjusted OR 5.21, 95%CI 2.25-12.09), Black race (aOR 5.54, 95%CI 2.25-13.66), and the interaction of baseline functional status and unemployment prior to hospitalization (aOR 3.98, 95%CI 1.23-12.92) were significantly associated with abnormal t-MoCA scores after adjusting for age, history of dementia, language, neurological complications, income and discharge disposition. CONCLUSIONS: Fewer years of education, Black race and unemployment with baseline disability were associated with abnormal t-MoCA scores 6-months post-hospitalization for COVID-19. These associations may be due to undiagnosed baseline cognitive dysfunction, implicit biases of the t-MoCA, other unmeasured SDOH or biological effects of SARS-CoV-2.


Assuntos
COVID-19 , Disfunção Cognitiva , Demência , COVID-19/complicações , COVID-19/epidemiologia , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/epidemiologia , Disfunção Cognitiva/etiologia , Demência/complicações , Hospitalização , Humanos , Estudos Prospectivos , SARS-CoV-2 , Determinantes Sociais da Saúde
11.
Planta ; 255(1): 16, 2021 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-34878607

RESUMO

MAIN CONCLUSION: Elms, which have received insect eggs as a 'warning' of larval herbivory, enhance their anti-herbivore defences by accumulating salicylic acid and amplifying phenylpropanoid-related transcriptional and metabolic responses to hatching larvae. Plant responses to insect eggs can result in intensified defences against hatching larvae. In annual plants, this egg-mediated effect is known to be associated with changes in leaf phenylpropanoid levels. However, little is known about how trees-long-living, perennial plants-improve their egg-mediated, anti-herbivore defences. The role of phytohormones and the phenylpropanoid pathway in egg-primed anti-herbivore defences of a tree species has until now been left unexplored. Using targeted and untargeted metabolome analyses we studied how the phenylpropanoid pathway of Ulmus minor responds to egg-laying by the elm leaf beetle and subsequent larval feeding. We found that when compared to untreated leaves, kaempferol and quercetin concentrations increased in feeding-damaged leaves with prior egg deposition, but not in feeding-damaged leaves without eggs. PCR analyses revealed that prior insect egg deposition intensified feeding-induced expression of phenylalanine ammonia lyase (PAL), encoding the gateway enzyme of the phenylpropanoid pathway. Salicylic acid (SA) concentrations were higher in egg-treated, feeding-damaged leaves than in egg-free, feeding-damaged leaves, but SA levels did not increase in response to egg deposition alone-in contrast to observations made of Arabidopsis thaliana. Our results indicate that prior egg deposition induces a SA-mediated response in elms to feeding damage. Furthermore, egg deposition boosts phenylpropanoid biosynthesis in subsequently feeding-damaged leaves by enhanced PAL expression, which results in the accumulation of phenylpropanoid derivatives. As such, the elm tree shows similar, yet distinct, responses to insect eggs and larval feeding as the annual model plant A. thaliana.


Assuntos
Besouros , Ulmus , Animais , Herbivoria , Insetos , Larva , Folhas de Planta
12.
J Neurol Sci ; 426: 117486, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-34000678

RESUMO

BACKGROUND: Little is known regarding long-term outcomes of patients hospitalized with COVID-19. METHODS: We conducted a prospective study of 6-month outcomes of hospitalized COVID-19 patients. Patients with new neurological complications during hospitalization who survived were propensity score-matched to COVID-19 survivors without neurological complications hospitalized during the same period. The primary 6-month outcome was multivariable ordinal analysis of the modified Rankin Scale(mRS) comparing patients with or without neurological complications. Secondary outcomes included: activities of daily living (ADLs;Barthel Index), telephone Montreal Cognitive Assessment and Neuro-QoL batteries for anxiety, depression, fatigue and sleep. RESULTS: Of 606 COVID-19 patients with neurological complications, 395 survived hospitalization and were matched to 395 controls; N = 196 neurological patients and N = 186 controls completed follow-up. Overall, 346/382 (91%) patients had at least one abnormal outcome: 56% had limited ADLs, 50% impaired cognition, 47% could not return to work and 62% scored worse than average on ≥1 Neuro-QoL scale (worse anxiety 46%, sleep 38%, fatigue 36%, and depression 25%). In multivariable analysis, patients with neurological complications had worse 6-month mRS (median 4 vs. 3 among controls, adjusted OR 1.98, 95%CI 1.23-3.48, P = 0.02), worse ADLs (aOR 0.38, 95%CI 0.29-0.74, P = 0.01) and were less likely to return to work than controls (41% versus 64%, P = 0.04). Cognitive and Neuro-QOL metrics were similar between groups. CONCLUSIONS: Abnormalities in functional outcomes, ADLs, anxiety, depression and sleep occurred in over 90% of patients 6-months after hospitalization for COVID-19. In multivariable analysis, patients with neurological complications during index hospitalization had significantly worse 6-month functional outcomes than those without.


Assuntos
COVID-19 , Atividades Cotidianas , Humanos , Estudos Prospectivos , Qualidade de Vida , SARS-CoV-2
13.
Sensors (Basel) ; 21(4)2021 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-33669514

RESUMO

The three-dimensional (3D) characterization of antenna far field patterns at terahertz frequencies is addressed. This task is challenging, because the phase of the electric field is difficult to measure accurately and reliably. From the sub-millimeter wave range, the small wavelength indeed significantly increases the impact of mechanical and electrical errors. Models and procedures to estimate these errors are proposed to mitigate their effects. The 3D far field patterns of a circularly polarized horn measured at 300 GHz and a multibeam pillbox antenna at 270 GHz are shown. The agreement between the 3D measurements and the two-dimensional (2D) patterns of reference as well as the radiated pattern before and after correction demonstrates the interest of the proposed approach and experimentally validate the proposed error estimation procedures. The methodology can be applied to direct far field measurement facilities as well as compact antenna test ranges.

14.
Sci Total Environ ; 750: 141422, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32858290

RESUMO

Glyphosate-based herbicides (GBHs) are the most frequently used herbicides globally. They were launched as a safe solution for weed control, but recently, an increasing number of studies have shown the existence of GBH residues and highlighted the associated risks they pose throughout ecosystems. Conventional agricultural practices often include the use of GBHs, and the use of glyphosate-resistant genetically modified crops is largely based on the application of glyphosate, which increases the likelihood of its residues ending up in animal feed. These residues persist throughout the digestive process of production animals and accumulate in their excretion products. The poultry industry, in particular, is rapidly growing, and excreted products are used as plant fertilizers in line with circular food economy practices. We studied the potential effects of unintentional glyphosate contamination on an agronomically important forage grass, meadow fescue (Festuca pratensis) and a horticulturally important strawberry (Fragaria x vescana) using glyphosate residues containing poultry manure as a plant fertilizer in a common garden experiment. Glyphosate in the manure decreased plant growth in both species and vegetative reproduction in F. x vescana. Furthermore, our results indicate that glyphosate residues in organic fertilizers might have indirect effects on sexual reproduction in F. pratensis and herbivory in F. x vescana because they positively correlate with plant size. Our results highlight that glyphosate can be unintentionally spread via organic fertilizer, counteracting its ability to promote plant growth.


Assuntos
Fertilizantes , Herbicidas , Animais , Produtos Agrícolas/genética , Ecossistema , Glicina/análogos & derivados , Herbicidas/toxicidade , Esterco , Plantas Geneticamente Modificadas , Glifosato
15.
Front Plant Sci ; 12: 787958, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35154181

RESUMO

Glyphosate is the most widely used herbicide with a yearly increase in global application. Recent studies report glyphosate residues from diverse habitats globally where the effect on non-target plants are still to be explored. Glyphosate disrupts the shikimate pathway which is the basis for several plant metabolites. The central role of phytohormones in regulating plant growth and responses to abiotic and biotic environment has been ignored in studies examining the effects of glyphosate residues on plant performance and trophic interactions. We studied interactive effects of glyphosate-based herbicide (GBH) residues and phosphate fertilizer in soil on the content of main phytohormones, their precursors and metabolites, as well as on plant performance and herbivore damage, in three plant species, oat (Avena sativa), potato (Solanum tuberosum), and strawberry (Fragaria x ananassa). Plant hormonal responses to GBH residues were highly species-specific. Potato responded to GBH soil treatment with an increase in stress-related phytohormones abscisic acid (ABA), indole-3-acetic acid (IAA), and jasmonic acid (JA) but a decrease in cytokinin (CK) ribosides and cytokinin-O-glycosides. GBH residues in combination with phosphate in soil increased aboveground biomass of potato plants and the concentration of the auxin phenylacetic acid (PAA) but decreased phaseic acid and cytokinin ribosides (CKR) and O-glycosides. Chorismate-derived compounds [IAA, PAA and benzoic acid (BzA)] as well as herbivore damage decreased in oat, when growing in GBH-treated soil but concentrations of the cytokinin dihydrozeatin (DZ) and CKR increased. In strawberry plants, phosphate treatment was associated with an elevation of auxin (IAA) and the CK trans-zeatin (tZ), while decreasing concentrations of the auxin PAA and CK DZ was observed in the case of GBH treatment. Our results demonstrate that ubiquitous herbicide residues have multifaceted consequences by modulating the hormonal equilibrium of plants, which can have cascading effects on trophic interactions.

16.
Front Microbiol ; 12: 786619, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35087489

RESUMO

Plants host taxonomically and functionally complex communities of microbes. However, ecological studies on plant-microbe interactions rarely address the role of multiple co-occurring plant-associated microbes. Here, we contend that plant-associated microbes interact with each other and can have joint consequences for higher trophic levels. In this study we recorded the occurrence of the plant seed pathogenic fungus Claviceps purpurea and aphids (Sitobion sp.) on an established field experiment with red fescue (Festuca rubra) plants symbiotic to a seed transmitted endophytic fungus Epichloë festucae (E+) or non-symbiotic (E-). Both fungi are known to produce animal-toxic alkaloids. The study was conducted in a semi-natural setting, where E+ and E- plants from different origins (Spain and Northern Finland) were planted in a randomized design in a fenced common garden at Kevo Subarctic Research Station in Northern Finland. The results reveal that 45% of E+ plants were infected with Claviceps compared to 31% of E- plants. Uninfected plants had 4.5 times more aphids than Claviceps infected plants. By contrast, aphid infestation was unaffected by Epichloë symbiosis. Claviceps alkaloid concentrations correlated with a decrease in aphid numbers, which indicates their insect deterring features. These results show that plant mutualistic fungi can increase the infection probability of a pathogenic fungus, which then becomes beneficial to the plant by controlling herbivorous insects. Our study highlights the complexity and context dependency of species-species and multi-trophic interactions, thus challenging the labeling of species as plant mutualists or pathogens.

17.
Trends Plant Sci ; 26(4): 312-323, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33277187

RESUMO

Glyphosate has become the best-selling herbicide used in agriculture, horticulture, silviculture, and urban environments. It disrupts the shikimate metabolic pathway and thereby blocks the production of aromatic amino acids, which are the basis for several plant metabolites. Glyphosate residues are reported in soils from diverse environments, but the effects on plant physiology and consequences for species interactions are largely unknown. Here, we emphasize the complexity of these physiological processes, and argue that glyphosate residues modulate biosynthetic pathways, individually or interactively, which may affect interactions between plants and heterotrophic organisms. In this way, glyphosate residues can substantially interfere with plant resistance and the attraction of beneficial insects, both of which are essential elements in integrated pest management and healthy ecosystems.


Assuntos
Ecossistema , Herbicidas , Glicina/análogos & derivados , Plantas , Glifosato
18.
J Fungi (Basel) ; 6(3)2020 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-32961967

RESUMO

Mycotoxins in agriculturally used plants can cause intoxication in animals and can lead to severe financial losses for farmers. The endophytic fungus Epichloë festucae var. lolii living symbiotically within the cool season grass species Lolium perenne can produce vertebrate and invertebrate toxic alkaloids. Hence, an exact quantitation of alkaloid concentrations is essential to determine intoxication risk for animals. Many studies use different methods to detect alkaloid concentrations, which complicates the comparability. In this study, we showed that alkaloid concentrations of individual plants exceeded toxicity thresholds on real world grasslands in Germany, but not on the population level. Alkaloid concentrations on five German grasslands with high alkaloid levels peaked in summer but were also below toxicity thresholds on population level. Furthermore, we showed that alkaloid concentrations follow the same seasonal trend, regardless of whether plant fresh or dry weight was used, in the field and in a common garden study. However, alkaloid concentrations were around three times higher when detected with dry weight. Finally, we showed that alkaloid concentrations can additionally be biased to different alkaloid detection methods. We highlight that toxicity risks should be analyzed using plant dry weight, but concentration trends of fresh weight are reliable.

19.
J Chem Ecol ; 46(4): 422-429, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32125581

RESUMO

Systemic grass-endophytes of the genus Epichloë symbiotically infect the above-ground plant parts of many grass species, where they produce alkaloids in a grass- and endophyte-specific manner that are toxic or deterrent to herbivores. An increasing number of studies show cascading negative effects of endophyte-derived alkaloids that extend to higher trophic levels, harming beneficial insects, including those that control aphid populations. Lacewings are one of the major biological aphid controls, and are especially resistant to insecticides and pollutants, but their susceptibility to endophyte infection in the food chain has never been studied. Our study found variability in aphid population growth depending on the endophyte-grass chemotype, where aphid population growth was lowest on chemotypes known for producing high amounts of loline alkaloids. We also showed that larval and pupal development and mortality of the Common Green Lacewing (Chrysoperla carnea) was, in a non-choice experiment, not affected by endophyte infection in the food chain. This is a first indication that lacewings might be resistant to endophyte-derived alkaloids and could be robust biocontrol agents when applied together with endophyte-infected grass, possibly replacing chemical pesticides.


Assuntos
Afídeos/fisiologia , Endófitos/química , Epichloe/química , Insetos/crescimento & desenvolvimento , Lolium/microbiologia , Simbiose , Animais , Afídeos/química , Dieta , Cadeia Alimentar , Herbivoria , Larva/crescimento & desenvolvimento , Lolium/química , Longevidade , Crescimento Demográfico
20.
Cereb Cortex ; 28(7): 2422-2430, 2018 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-28591836

RESUMO

Individuals with copy number variants (CNV) in the 16p11.2 chromosomal region are at high risk for language disorders. We investigate whether the extent and location of focal cortical anomalies are associated with language impairment in individuals with 16p11.2 CNVs. High-resolution T1-weighted MRI scans from 30 16p11.2 deletion (16p-del), 25 16p11.2 duplication (16p-dup), and 90 noncarrier controls (NCC) were analyzed to derive personalized cortical anomaly maps through single-case cortical thickness (CT) comparison to age-matched normative samples. Focal cortical anomalies were elevated in both 16p-del and 16p-dup and their total extent was inversely correlated with Full-Scale IQ. Clusters of abnormally thick cortex were more extensive in the 16p-del group and clusters of abnormally thin cortex were more extensive in the 16p-dup group. Abnormally thick clusters were more extensive in left lateral temporal and bilateral postcentral and mesial occipital regions in 16p-del. Focal cortical anomalies in the left middle temporal region and pars opercularis (Broca's region) of children with 16-del were associated with lower scores on a comprehensive language evaluation. Results extend neuroanatomical findings in 16p11.2 syndrome to include spatially heterogenous focal cortical anomalies that appear to disrupt language ability in accordance with the functional specialization of left frontotemporal regions.


Assuntos
Transtorno Autístico/complicações , Transtornos Cromossômicos/complicações , Duplicação Cromossômica/genética , Deficiência Intelectual/complicações , Transtornos da Linguagem/etiologia , Malformações do Desenvolvimento Cortical/complicações , Malformações do Desenvolvimento Cortical/genética , Adolescente , Adulto , Transtorno Autístico/diagnóstico por imagem , Córtex Cerebral/diagnóstico por imagem , Distribuição de Qui-Quadrado , Criança , Deleção Cromossômica , Transtornos Cromossômicos/diagnóstico por imagem , Cromossomos Humanos Par 16/genética , Feminino , Humanos , Deficiência Intelectual/diagnóstico por imagem , Transtornos da Linguagem/diagnóstico por imagem , Transtornos da Linguagem/genética , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Tomógrafos Computadorizados , Adulto Jovem
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