Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 40
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Ecotoxicol Environ Saf ; 263: 115359, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37595349

RESUMO

This paper characterizes the heat stress response (HSR) and explores the impact of temperatures on the immune response of larvae from two chironomid species, Prodiamesa olivacea and Chironomus riparius. Genes involved in crucial metabolic pathways were de novo identified in P. olivacea: Hsp27, Hsp60, Hsp70, Hsc70, Cdc37, and HSF for the heat stress response (HSR) and TOLL, PGRP, C-type lectin, and JAK/hopscotch for the immune system response (ISR). Quantitative real-time PCR was used to evaluate the expression levels of the selected genes in short-term treatments (up to 120') at high temperatures (35 °C and 39 °C). Exposing P. olivacea to elevated temperatures resulted in HSR induction with increased expression of specific heat shock genes, suggesting the potential of HSPs as early indicators of acute thermal stress. Surprisingly, we found that heat shock represses multiple immune genes, revealing the antagonist relation between the heat shock response and the innate immune response in P. olivacea. Our results also showed species-dependent gene responses, with more significant effects in P. olivacea, for most of the biomarkers studied, demonstrating a higher sensitivity in this species to environmental stress conditions than that of C. riparius. This work shows a multi-species approach that enables a deeper understanding of the effects of heat stress at the molecular level in aquatic dipterans.


Assuntos
Chironomidae , Animais , Chironomidae/genética , Resposta ao Choque Térmico/genética , Larva/genética , Chaperonina 60/genética , Proteínas de Choque Térmico HSP70/genética
2.
J Insect Sci ; 22(4)2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35780387

RESUMO

When quinoa, Chenopodium quinoa Willd., is cultivated in South America outside of its Andean origin, the heteropterans Liorhyssus hyalinus (Fabricius) and Nysius simulans Stål may emerge as important pests. Here we studied the development and reproduction of both species at different constant temperatures in the laboratory. Egg and nymphal development were investigated at 18, 22, 26, 30, 34, and 36°C. For both species, egg incubation time significantly decreased as the temperature increased. Nymphs did not successfully develop at 18°C and the total nymphal time significantly decreased as the temperature increased from 22 to 36°C. Based on a linear day-degree (DD) model, the lower developmental threshold (LDT) temperatures for eggs and nymphs were estimated to be 16.0 and 17.9°C for L. hyalinus, and 16.1 and 19.7°C for N. simulans, respectively. Thermal requirements for egg and nymphal development were 68.6 and 114.8 DD for L. hyalinus, and 77.7 and 190.3 DD for N. simulans, respectively. Reproduction and adult longevity were studied at 22, 26, 30, and 34°C. For both species preoviposition time decreased as temperature increased, and the oviposition period was longest at 26°C. The highest fecundity and egg viability were observed at 30°C, whereas longevities were higher at 22-26°C than at 30-34°C. As the lowest tested temperatures were not suitable to both heteropterans and 30°C was found to be the optimal temperature for development and reproduction, peak densities are expected in warm areas and seasons.


Assuntos
Heterópteros , Temperatura , Zea mays , Animais , Biologia , Dieta , Feminino , Heterópteros/crescimento & desenvolvimento , Ninfa/crescimento & desenvolvimento , Óvulo
3.
New Phytol ; 226(1): 254-266, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31793000

RESUMO

A frequent hypothesis explaining the high susceptibility of many crops to pests and diseases is that, in the process of domestication, crops have lost defensive genes and traits against pests and diseases. Ecological theory predicts trade-offs whereby resistance and tolerance go at the cost of each other. We used wild relatives, early domesticated varieties, traditional local landraces and cultivars of tomato (Solanum lycopersicum) to test whether resistance and tolerance trade-offs were phylogenetically structured or varied according to degree of domestication. We exposed tomato genotypes to the aphid Macrosiphum euphorbiae, the cotton leafworm Spodoptera littoralis, the root knot nematode Meloidogyne incognita and two common insect-transmitted plant viruses, and reconstructed their phylogenetic relationships using Genotyping-by-Sequencing. We found differences in the performance and effect of pest and diseases but such differences were not related with domestication degree nor genetic relatedness, which probably underlie a complex genetic basis for resistance and indicate that resistance traits appeared at different stages and in unrelated genetic lineages. Still, wild and early domesticated accessions showed greater resistance to aphids and tolerance to caterpillars, nematodes and diseases than modern cultivars. Our findings help to understand how domestication affects plant-pest interactions and underline the importance of tolerance in crop breeding.


Assuntos
Afídeos , Domesticação , Solanum lycopersicum , Animais , Solanum lycopersicum/genética , Controle Biológico de Vetores , Filogenia , Melhoramento Vegetal
4.
Biol Res ; 52(1): 55, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31601259

RESUMO

BACKGROUND: Epanorin (EP) is a secondary metabolite of the Acarospora lichenic species. EP has been found in lichenic extracts with antimicrobial activity, and UV-absorption properties have been described for closely related molecules; however, its antiproliferative activity in cancer cells has not yet been explored. It has been hypothesized that EP inhibits cancer cell growth. MCF-7 breast cancer cells, normal fibroblasts, and the non-transformed HEK-293 cell line were exposed to increasing concentrations of EP, and proliferation was assessed by the sulforhodamine-B assay. RESULTS: MCF-7 cells exposed to EP were examined for cell cycle progression using flow cytometry, and DNA fragmentation was examined using the TUNEL assay. In addition, EP's mutagenic activity was assessed using the Salmonella typhimurium reverse mutation assay. The data showed that EP inhibits proliferation of MCF-7 cells, and it induces cell cycle arrest in G0/G1 through a DNA fragmentation-independent mechanism. Furthermore, EP's lack of overt cytotoxicity in the normal cell line HEK-293 and human fibroblasts in cell culture is supported by the absence of mutagenic activity of EP. CONCLUSION: EP emerges as a suitable molecule for further studies as a potential antineoplastic agent.


Assuntos
Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Neoplasias da Mama/tratamento farmacológico , Proliferação de Células/efeitos dos fármacos , Líquens/química , Antineoplásicos/isolamento & purificação , Fragmentação do DNA , Feminino , Citometria de Fluxo , Humanos , Células MCF-7
5.
Plant Dis ; 101(7): 1306-1313, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30682955

RESUMO

Gray mold, caused by the necrotrophic fungus Botrytis cinerea., is one of the most economically important diseases of strawberry. Gray mold control involves the application of fungicides throughout the strawberry growing season; however, B. cinerea isolates resistant to multiple classes of site-specific fungicides have been recently reported in the Spanish gray mold population. Succinate dehydrogenase inhibitors (SDHI) constitute a relatively novel class of fungicides registered for gray mold control representing new alternatives for strawberry growers. In the present study, 37 B. cinerea isolates previously characterized for their sensitivity to boscalid and amino acid changes in the SdhB protein were used to determine the effective concentration that reduces mycelial growth by 50% (EC50) to fluopyram, fluxapyroxad, and penthiopyrad. The present study was also conducted to obtain discriminatory doses to monitor SDHI fungicide resistance in 580 B. cinerea isolates collected from 27 commercial fields in Spain during 2014, 2015, and 2016. The EC50 values ranged from 0.01 to >100 µg/ml for fluopyram, <0.01 to 4.19 µg/ml for fluxapyroxad, and, finally, <0.01 to 59.65 µg/ml for penthiopyrad. Based on these results, as well as findings from a previous publication, the discriminatory doses chosen to examine sensitivities to boscalid, fluopyram, fluxapyroxad, and penthiopyrad were 100, 15, 1, and 6 µg/ml, respectively. Over the course of the 3-year monitoring period, the overall frequencies of resistance to the four SDHI were 56.9, 6.9, 12.9, and 24.6%, respectively. The frequency of boscalid-resistant isolates decreased from 73 to 41% over the years; however, the fluopyram-resistant isolates increased from 5 to 10% after 1 year of registration. Four SDHI resistance patterns were observed in our population, which included patterns I (30%; resistance to boscalid), II (13.8%; resistance to boscalid and penthiopyrad), III (5.7%; boscalid, fluxapyroxad, and penthiopyrad), and IV (7.9%; resistance to boscalid, fluopyram, fluxapyroxad, and penthiopyrad). Patterns I and II were associated with the amino acid substitutions H272R and H272Y; pattern III was associated only with the H272Y mutation; and, finally, pattern IV was associated with the N230I allele in the SdhB subunit. For gray mold management, it is suggested that the simultaneous use of boscalid and penthiopyrad should be limited to one application per season; however, fluxapyroxad and, especially, fluopyram could be used as valid SDHI alternatives for gray mold control, although they should be applied with caution.

6.
Skinmed ; 14(1): 17-21, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27072723

RESUMO

The aim of this study was to investigate whether the amount of serum antibodies to melanocyte antigens could predict clinical activity or disease progression in patients with vitiligo. A solid-phase enzyme immunoassay was developed to semiquantitate serum antibodies to a human melanocyte extract and was used in 127 patients, 93 of whom showed clinical progression of the disease, while the remaining 34 were quiescent. Results showed different values for clinical sensitivity and specificity depending on the cutoff level for decision, but the overall performance of the test was adequate and supported statistical significance to predict clinical activity/progression or quietness of the disease process. The test might prove useful in deciding the indication and aggressiveness of immunosuppressive therapy in patients with vitiligo. Previous findings suggest that melanocyte-specific antibodies might play a pathogenetic role in the depletion of melanocytes, which characterizes this disorder, and that this depletion might be due to apoptosis following antibody internalization.


Assuntos
Anticorpos/sangue , Melanócitos/imunologia , Vitiligo/imunologia , Progressão da Doença , Humanos , Técnicas Imunoenzimáticas/métodos , Vitiligo/sangue
7.
J Ethnobiol Ethnomed ; 20(1): 20, 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38373968

RESUMO

BACKGROUND: The use of medicinal plants is integral to global healthcare systems, with Sub-Saharan Africa maintaining a robust tradition of herbal medicine alongside Western-oriented healthcare. As migrant communities tend to continue traditional herbal practices after migration, documenting this use is vital to develop culturally sensitive healthcare. This study investigates plant usage and perspectives in the context of sexual and reproductive health among the Congolese community in Belgium, particularly in the Matongé quarter of Brussels. Our research questions were: (1) What is the current knowledge of medicinal plants among the Congolese community in Belgium in the context of sexual health, and what are the applications and commonly employed administration methods of these plants? (2) What role does herbal medicine play in the context of sexual health for people of Congolese descent in Belgium and how this is influenced by perceptions of sexuality? and (3) Is there a gender bias in the use of medicinal plants, and if so, can this be related to perceived gender norms? METHODS: We conducted 22 semi-structured interviews with people of Congolese descent currently living in Belgium. Participants were selected using both snowball sampling and purposive sampling. Plant use in the context of sexual health was recorded through freelisting. Data on narratives, ideas, and perceptions of this plant use in the context of sexual health were collected. Interview transcripts were analyzed using thematic analysis. RESULTS: We identified 17 plant species used for sexual health. Three overarching themes emerged from our data. Plants were used with a notable gender bias favoring male sexual potency enhancement. Men used these plants for both remedying potency issues and enhancing sexual prowess. In contrast, knowledge about plants for female sexual health was limited. Gender norms reinforced the importance of male sexual potency, while stigmatizing open discussions of female sexuality. CONCLUSIONS: The use of medicinal plants for sexual health raises health, social, and conservation concerns, underscoring the need for further research in this area. This study contributes to understanding medicinal plant use within the Congolese community in Belgium and highlights the necessity for future research on herbal practices for female sexual health in this context.


Assuntos
Plantas Medicinais , Saúde Sexual , Humanos , Masculino , Feminino , Etnobotânica , Bélgica , Sexismo , Extratos Vegetais , Fitoterapia
8.
Neotrop Entomol ; 52(2): 273-282, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35729313

RESUMO

In recent years, Liorhyssus hyalinus (Fabricius) (Hemiptera: Rhopalidae) and Nysius simulans Stål (Hemiptera: Lygaeidae) have emerged as important pests of quinoa in Peru, when the crop started to be cultivated at relatively low elevations. The potential of the native lacewing Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae) was evaluated as a biological control agent of these two pest species. Prey consumption on all immature stages of L. hyalinus and N. simulans was assessed, as well as development on first instars of these heteropterans and eggs of Sitotroga cerealella (Olivier) (Lepidoptera: Pyralidae) as a factitious prey. In addition, prey preference was examined in the absence and presence of a preferred prey, Macrosiphum euphorbiae (Thomas) (Hemiptera: Aphididae). Larvae of the predator were not able to feed on L. hyalinus eggs, but they effectively did on N. simulans eggs as well as on all nymphal instars of both species. Nymphs of L. hyalinus were less suitable prey for larval development of C. externa than eggs of S. cerealella, whereas N. simulans was overall an unsuitable prey. There was a clear prey preference of C. externa for aphids over the two heteropteran species, as well as a preference for N. simulans over L. hyalinus. The predation rates in this study indicate the potential of C. externa as a predator of these heteropteran pests that can play a role in both conservation and augmentation biological control programs.


Assuntos
Afídeos , Chenopodium quinoa , Heterópteros , Animais , Insetos , Comportamento Predatório , Larva , Ninfa
9.
Sci Rep ; 12(1): 9227, 2022 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-35680943

RESUMO

Examining why human populations used specific technologies in the Final Pleistocene is critical to understanding our evolutionary path. A key Final Pleistocene techno-tradition is the Howiesons Poort, which is marked by an increase in behavioral complexity and technological innovation. Central to this techno-tradition is the production of backed artifacts-small, sharp blades likely used as insets in composite tools. Although backed artifacts were manufactured for thousands of years before the Howiesons Poort, this period is marked by a phenomenal increase in their production. In this paper we test both social and environmental hypotheses to explain this phenomenon. We correlate environmental data with changing frequencies of backed artifact production at Sibudu and assess morphological similarity across seven sites in southern Africa. We find that these artifacts are made to a similar template across different regions and that their increased production correlates with multiple paleo-environmental proxies. When compared to an Australian outgroup, the backed artifacts from the seven southern African sites cluster within the larger shape space described by the Australian group. This leads us to argue that the observed standardized across southern Africa is related to cultural similarities and marks a strengthening of long-distance social ties during the MIS4.


Assuntos
Arqueologia , Evolução Biológica , África Austral , Austrália , Humanos , África do Sul , Tecnologia
10.
J Ethnobiol Ethnomed ; 18(1): 29, 2022 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-35392948

RESUMO

BACKGROUND: As a hard-hit area during the COVID-19 pandemic, Belgium knew the highest mortality among people from sub-Saharan African descent, compared to any other group living in the country. After migration, people often maintain traditional perceptions and habits regarding health and healthcare, resulting in a high prevalence of traditional, complementary and alternative medicine use among different migrant communities in northern urban settings. Despite being the largest community of sub-Saharan African descent in Belgium, little is known on ethnobotanical practices of the Belgian Congolese community. We therefore conducted an exploratory study on the use of medicinal plants in the context of COVID-19 and perceptions on this new disease among members of the Congolese community in Belgium. METHODS: We conducted 16 in-depth semi-structured interviews with people of Congolese descent currently living in Belgium. Participants were selected using purposive sampling. Medicinal plant use in the context of COVID-19 was recorded through free-listing. Data on narratives, ideas and perceptions on the origin, cause/aetiology and overall measures against COVID-19 (including vaccination) were collected. Interview transcripts were analysed using thematic analysis. RESULTS: Four overarching themes emerged from our data. Firstly, participants perceived the representation of the severity of COVID-19 by the Belgian media and government-and by extend by all governmental agencies in the global north-as exaggerated. As a result, traditional and complementary treatments were seen as feasible options to treat symptoms of the disease. Fifteen forms of traditional, complementary and alternative medicine were documented, of which thirteen were plants. Participants seem to fold back on their Congolese identity and traditional knowledge in seeking coping strategies to deal with the COVID-19 pandemic. Finally, institutional postcolonial distrust did not only seem to lead to distrust in official messages on the COVID-19 pandemic but also to feelings of vaccination hesitancy. CONCLUSION: In the context of the COVID-19 pandemic, participants in our study retreated to, reshaped and adapted traditional and culture-bound knowledge. This study suggests that the fragile and sensitive relationship between sub-Saharan African migrant groups and other social/ethnic groups in Belgium might play a role in their sensitivity to health-threatening situations, such as the COVID-19 pandemic.


Assuntos
COVID-19 , Terapias Complementares , Plantas Medicinais , Bélgica , Etnobotânica , Humanos , Pandemias
11.
Sci Rep ; 12(1): 20154, 2022 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-36418431

RESUMO

Understanding the responses of insect herbivores to plant chemical defences is pivotal for the management of crops and pests. However, the mechanisms of interaction are not entirely understood. In this study, we compared the whole transcriptome gene expression of the aphid Macrosiphum euphorbiae grown on two different varieties of tomato that differ in their inducible chemical defences. We used two isogenic lines of tomato with a shared genetic background that only differ in the presence of type IV glandular trichomes and their associated acylsucrose excretions. This works also reports a de novo transcriptome of the aphid M. euphorbiae. Subsequently, we identified a unique and distinct gene expression profile for the first time corresponding to aphid´s exposure to type IV glandular trichomes and acylsugars. The analysis of the aphid transcriptome shows that tomato glandular trichomes and their associated secretions are highly efficient in triggering stress-related responses in the aphid, and demonstrating that their role in plant defence goes beyond the physical impediment of herbivore activity. Some of the differentially expressed genes were associated with carbohydrate, lipid and xenobiotic metabolisms, immune system, oxidative stress response and hormone biosynthesis pathways. Also, the observed responses are compatible with a starvation syndrome. The transcriptome analysis puts forward a wide range of genes involved in the synthesis and regulation of detoxification enzymes that reveal important underlying mechanisms in the interaction of the aphid with its host plant and provides a valuable genomic resource for future study of biological processes at the molecular level using this aphid.


Assuntos
Afídeos , Solanum lycopersicum , Animais , Afídeos/genética , Solanum lycopersicum/genética , Solanum lycopersicum/metabolismo , Tricomas/genética , Perfilação da Expressão Gênica , Herbivoria
12.
EFSA J ; 20(6): e07391, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35774585

RESUMO

The European Commission requested the EFSA Panel on Plant Health to prepare and deliver risk assessments for commodities listed in Commission Implementing Regulation (EU) 2018/2019 as 'High risk plants, plant products and other objects'. This Scientific Opinion covers plant health risks posed by plants of Prunus domestica grafted on Prunus cerasifera imported from Ukraine, taking into account the available scientific information, including the technical information provided by Ukraine. All pests associated with the commodity were evaluated against specific criteria for their relevance for this opinion. One quarantine pest (Lopholeucaspis japonica), two protected zone quarantine pests (Erwinia amylovora and Xanthomonas arboricola pv. pruni) and one non-regulated pest (Eotetranychus prunicola) that fulfilled all relevant criteria were selected for further evaluation. For these four pests, the risk mitigation measures proposed in the technical dossier from Ukraine were evaluated taking into account the possible limiting factors. For the selected pests, an expert judgement is given on the likelihood of pest freedom taking into consideration the risk mitigation measures acting on the pest, including uncertainties associated with the assessment. The degree of pest freedom varies among the pests evaluated, with Xanthomonas arboricola pv. pruni being the pest most frequently expected on the imported plants. The Expert Knowledge Elicitation indicated with 95% certainty that between 9,870 and 10,000 bundles (consisting of 10 plants each) per 10,000 would be free from Xanthomonas arboricola pv. pruni.

13.
EFSA J ; 20(3): e07201, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35356478

RESUMO

The European Commission requested the EFSA Panel on Plant Health to prepare and deliver risk assessments for commodities listed in Commission Implementing Regulation (EU) 2018/2019 as 'High risk plants, plant products and other objects'. This Scientific Opinion covers plant health risks posed by defoliated and in dormant phase, grafted bare rooted plants for planting of Malus domestica imported from Moldova, taking into account the available scientific information, including the technical information provided by the applicant country. A list of 1,118 pests potentially associated with the commodity species was compiled. The relevance of these pests was assessed following defined criteria and based on evidence. The EU-quarantine pest Xiphinema rivesi non-EU populations fulfilled these criteria and was selected for further evaluation. For this pest, the risk mitigation measures proposed in the technical dossier from Moldova were evaluated taking into account the possible limiting factors. For this pest, an expert judgement is given on the likelihood of pest freedom taking into consideration the risk mitigation measures acting on it, including uncertainties associated with the assessment. The Expert Knowledge Elicitation indicated, with 95% certainty, that between 9,991 and 10,000 plants per 10,000 would be free of X. rivesi.

14.
J Anim Ecol ; 80(1): 148-58, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20964685

RESUMO

1. Invertebrate species generally do not respond independently to genotypic variation in plants, giving rise to clusters of species that naturally associate with or avoid certain genotypes. This covariation causes coevolution to be diffuse rather than pairwise. Studies on this topic, however, have never considered the belowground invertebrate community, leaving a critical gap in our understanding. 2. We investigated the covariation among naturally colonising above- and belowground invertebrate species across six genetically distinct populations of the dune grass Ammophila arenaria. After having grown from seed in a common garden, plants were randomised in a single field site to exclude all but broad-sense genetic variation. 3. Strong positive covariation across genotypes among both above- and belowground invertebrates was detected, while correlations between these two groups were negative. This clustering of above- and belowground species matched well with order level taxonomy. Host range, trophic level and food type on the other hand did not correspond well with the clusters. Within the cluster of aboveground fauna, subsequent groupings were not related to any phylogenetic or ecological characteristic, although correlations within these subgroups were very high. We furthermore demonstrated significant differences in multiple invertebrate species occurrence between plant genotypes, in general as well as at the above- and belowground level. 4. The observed strong covariation suggests diffuse coevolution between A. arenaria and its associated invertebrate species. The trade-off between root and shoot invertebrates could however hamper directional selection on resistance to either group. 5. Our results clearly demonstrate the need for studies of plant-animal interactions to include the belowground fauna, as this might drastically alter our general conception of how plants and their associated animal communities interact and how these interactions shape the process of evolution.


Assuntos
Genótipo , Invertebrados/fisiologia , Poaceae/genética , Solo , Animais , Ecossistema
15.
Plants (Basel) ; 10(9)2021 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-34579320

RESUMO

During the last few years, quinoa, a traditional Andean crop, has been cultivated at low elevations where pest pressure is high and farmers resort to intensive use of insecticides. This field study investigated the impact of four insecticides (cypermethrin, imidacloprid, teflubenzuron and emamectin benzoate) on insect pests of quinoa and their side effects on the arthropod community at the coastal level of Peru, by analysing the species composition, species diversity and population density. The arthropod community was examined with pitfall traps (for ground dwelling species), plant samplings (for pests and their natural enemies that inhabit the crop), and yellow pan traps (to catch flying insects). The results demonstrated that Macrosiphum euphorbiae, Frankliniella occidentalis and Spoladea recurvalis were efficiently controlled by cypermethrin and imidacloprid; the latter compound also showed long-term effects on Nysius simulans. Teflubenzuron and emamectin benzoate proved to be efficient to control S. recurvalis. Imidacloprid had the strongest adverse effects on the arthropod community in terms of species diversity, species composition and natural enemy density as compared to the other insecticides. Findings of this study may assist farmers intending to grow quinoa at the coastal level in selecting the most appropriate insecticides under an integrated pest management approach.

16.
Plants (Basel) ; 10(9)2021 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-34579474

RESUMO

While it has been well evidenced that plant domestication affects the structure of the root-associated microbiome, there is a poor understanding of how domestication-mediated differences between rhizosphere microorganisms functionally affect microbial ecosystem services. In this study, we explore how domestication influenced functional assembly patterns of bacterial communities in the root-associated soil of 27 tomato accessions through a transect of evolution, from plant ancestors to landraces to modern cultivars. Based on molecular analysis, functional profiles were predicted and co-occurrence networks were constructed based on the identification of co-presences of functional units in the tomato root-associated microbiome. The results revealed differences in eight metabolic pathway categories and highlighted the influence of the host genotype on the potential functions of soil bacterial communities. In general, wild tomatoes differed from modern cultivars and tomato landraces which showed similar values, although all ancestral functional characteristics have been conserved across time. We also found that certain functional groups tended to be more evolutionarily conserved in bacterial communities associated with tomato landraces than those of modern varieties. We hypothesize that the capacity of soil bacteria to provide ecosystem services is affected by agronomic practices linked to the domestication process, particularly those related to the preservation of soil organic matter.

17.
Plants (Basel) ; 11(1)2021 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-35009046

RESUMO

Soil bacterial communities are involved in multiple ecosystem services, key in determining plant productivity. Crop domestication and intensive agricultural practices often disrupt species interactions with unknown consequences for rhizosphere microbiomes. This study evaluates whether variation in plant traits along a domestication gradient determines the composition of root-associated bacterial communities; and whether these changes are related to targeted plant traits (e.g., fruit traits) or are side effects of less-often-targeted traits (e.g., resistance) during crop breeding. For this purpose, 18 tomato varieties (wild and modern species) differing in fruit and resistance traits were grown in a field experiment, and their root-associated bacterial communities were characterised. Root-associated bacterial community composition was influenced by plant resistance traits and genotype relatedness. When only considering domesticated tomatoes, the effect of resistance on bacterial OTU composition increases, while the effect due to phylogenetic relatedness decreases. Furthermore, bacterial diversity positively correlated with plant resistance traits. These results suggest that resistance traits not selected during domestication are related to the capacity of tomato varieties to associate with different bacterial groups. Taken together, these results evidence the relationship between plant traits and bacterial communities, pointing out the potential of breeding to affect plant microbiomes.

18.
Pest Manag Sci ; 77(9): 4117-4127, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33914389

RESUMO

BACKGROUND: Glandular trichomes are essential in plants' defence against pests however, the mechanisms of action are not completely understood. While there is considerable evidence of feeding and movement impairment by trichomes, the effect on other traits is less clear. We combined laboratory and greenhouse experiments with molecular analysis to understand how glandular trichomes affect the behavior, population growth, and the expression of biomarkers involved in detoxification, primary metabolism, and developmental pathways of the aphid Macrosiphum euphorbiae. We used two isogenic tomato lines that differ in the presence of type IV glandular trichomes and production of acylsucroses; i.e.,Solanum lycopersicum cv. 'Moneymaker' and an introgressed line from Solanum pimpinellifolium (with trichomes type IV). RESULTS: Type IV glandular trichomes affected host selection and aphid proliferation with aphids avoiding, and showing impaired multiplication on the genotype with trichomes. The exposure to type IV glandular trichomes resulted in the overexpression of detoxication markers (i.e., Hsp70, Hsp17, Hsp10); the repression of the energetic metabolism (GAPDH), and the activation of the ecdysone pathway; all these, underlying the key adaptations and metabolic trade-offs in aphids exposed to glandular trichomes. CONCLUSION: Our results demonstrate the detrimental effect of glandular trichomes (type IV) on the aphid and put forward their mode of action. Given the prevalence of glandular trichomes in wild and cultivated Solanaceae; and of the investigated molecular biomarkers in insects in general, our results provide relevant mechanisms to understand the effect of trichomes not only on herbivorous insects but also on other trophic levels.


Assuntos
Afídeos , Solanum lycopersicum , Solanum , Animais , Afídeos/genética , Genótipo , Solanum lycopersicum/genética , Tricomas
19.
EFSA J ; 19(8): e06799, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34457073

RESUMO

The European Commission requested to the EFSA Panel on Plant Health to evaluate a dossier from South Africa where the application of the systems approach to mitigate the risk of entry of the false codling moth, Thaumatotibia leucotreta (Lepidoptera: Tortricidae), into the EU when trading citrus fruits is explained. After collecting additional evidence from the Department of Agriculture, Land Reform and Rural Development of South Africa, and reviewing the published literature, the Panel performed an assessment on the likelihood of pest freedom for T. leucotreta on citrus fruits at the point of entry in the EU considering the proposed systems approach. An expert judgement is given on the likelihood of pest freedom following the evaluation of the risk mitigation measures on T. leucotreta, including any uncertainties. There are three options (i.e. A, B and C) within the systems approach followed in South Africa that differentiate mainly in the sampling intensity in the field and the packing house as well as in temperature conditions during shipment. Therefore, three independent elicitations were conducted, one for each option. The main uncertainties were: (1) whether sampling once per orchard is representative for subsequent harvests (within 4 weeks) from the same orchard; (2) the correct implementation of the temperature regimes during shipment; (3) the mortality rate in fruit estimated for the different temperature regimes. The Expert Knowledge Elicitation indicated with 95% certainty that 9,182 out of 10,000 pallets for option A, 8,478 out of 10,000 pallets for option B, and 9,743 out of 10,000 pallets for option C will be free from T. leucotreta. In light of the additional information provided by South Africa once the elicitations were performed, it became apparent that the setting temperature during shipment was not achieved in 12 out of 14 cases of interceptions. Therefore, there is increased uncertainty on pest freedom. The Panel identified the weaknesses associated with the risk mitigation measures in the systems approach and made recommendations that could increase its effectiveness.

20.
EFSA J ; 19(3): e06428, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33732391

RESUMO

The European Commission requested the EFSA Panel on Plant Health to prepare and deliver risk assessments for commodities listed in Commission Implementing Regulation (EU) 2018/2019 as 'High risk plants, plant products and other objects. This Scientific Opinion covers plant health risks posed by tubers of Ullucus tuberosus imported from Peru, taking into account the available scientific information, including the technical information provided by Peru. The relevance of an EU quarantine pest for this opinion was based on evidence that: (i) the pest is present in Peru, (ii) U. tuberosus is a host of the pest and (iii) the pest can be associated with the commodity. The relevance of any other pest, not regulated in the EU, was based on evidence that: (i) the pest is present in Peru (ii) the pest is absent in the EU; (iii) U. tuberosus is a host of the pest; (iv) the pest can be associated with the commodity and (v) the pest may have an impact and can pose a potential risk for the EU territory. There are five pests i.e. one insect (Amathynetoides nitidiventris), two nematodes (Atalodera andina and Nacobbus aberrans) and two viruses (the Andean potato latent virus (APLV) and the potato virus T (PVT)) that fulfilled all relevant criteria were selected for further evaluation. For the five pests, the risk mitigation measures proposed in the technical dossier from Peru were evaluated taking into account the possible limiting factors. For each of the five pests, an expert judgement is given on the likelihood of pest freedom taking into consideration the risk mitigation measures acting on the pest, including uncertainties associated with the assessment. The degree of pest freedom varies among the pests evaluated, with PVT being the pest most frequently expected on the imported commodities. The Expert Knowledge Elicitation indicated, with 95% certainty, that between 9,157 and 10,000 tubers out of 10,000 would be free of PVT.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA