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2.
Braz. j. biol ; 84: e253451, 2024. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1345553

RESUMO

Abstract Root-knot nematode Meloidogyne incognita is among the biotic factors which has greatly affected both the yield and the quality of the tomato crop. The egg parasitic nematode, Purpureocillium lilacinum (Pl) is considered as one of the most promising agents in controlling and overcoming this plant pathogen. The nematicidal effect of the native isolate Pl AUMC 10149 on second stage juvenile's survival and egg hatching of M. incognita at different times of exposure was tested in vitro. The obtained data showed that Pl gave a maximum percentage of J2 mortality (97.6%) and egg hatching inhibition (79.8%) after 72 hours of exposure. The potentiality of Pl as well as Bio-Nematon to control M. incognita infecting tomato was conducted using different times of application in vivo. Nine treatments with five replicates were used for such bioagents compared with the nematicide Oxamyl. Each seedling was inoculated with 1000 J2s of nematode/pot and 10 mL of Pl (1x1010 CFU/mL) or Bio-Nematon spore suspension (1x108 CFU/mL) 10mL/pot. The results indicated that the most effective treatments in reducing nematode population, number of galls and egg masses of M. incognita in plant roots was performed with treatment by Pl pre-planting and post-infection with Pl (Rf 1.9) giving a significant enhancement in plant length (64.9%), fresh weight (72.52%) and shoot dry weight (163.41%) without negatively impacting environment. Therefore, the present study confirmed that using P. lilacinum AUMC 10149 can be used as a practical supplement to environmentally friendly disease management of root-knot nematodes in Egypt.


Resumo O nematoide-das-galhas Meloidogyne incognita está entre os fatores bióticos que afetaram enormemente a produção e a qualidade da cultura do tomate. O nematoide parasita de ovos, Purpureocillium lilacinum (Pl), é considerado um dos mais promissores agentes no controle e superação desse fitopatógeno. O efeito nematicida do isolado nativo Pl AUMC 10149 na sobrevivência de juvenis de segundo estágio e na eclosão dos ovos de M. incognita em diferentes momentos de exposição foi testado in vitro. Os dados obtidos mostraram que o Pl deu um percentual máximo de mortalidade de J2 (97.6%) e inibição da eclosão dos ovos (79.8%) após 72 horas de exposição. A potencialidade de Pl e de Bio-Nematon para controlar M. incognita infectando tomate foi conduzida em diferentes tempos de aplicação in vivo. Nove tratamentos com cinco repetições foram usados ​​para tais bioagentes em comparação com o nematicida Oxamyl. Cada muda foi inoculada com 1.000 J2s de nematoide / vaso e 10 mL de Pl (1×1010 CFU/mL). Ou suspensão de esporos Bio-Nematon (1×108 CFU/mL) 10mL/pot. Os resultados indicaram que os tratamentos mais eficazes na redução da população de nematoides, número de galhas e desovas de M. incognita nas raízes das plantas foram realizados com Pl pré-plantio e pós-infecção com Pl (Rf 1.9), dando um aumento significativo no comprimento da planta (64.9%), massa fresca (72.52%) e massa seca da parte aérea (163.41%) sem impactar negativamente o meio ambiente. Portanto, o presente estudo confirmou que o uso de P. lilacinum AUMC 10149 pode ser usado como um suplemento prático para o manejo ecologicamente correto de nematoides-das-galhas no Egito.


Assuntos
Animais , Tylenchoidea/patogenicidade , Lycopersicon esculentum/parasitologia , Agentes de Controle Biológico , Hypocreales
3.
Dokl Biochem Biophys ; 506(1): 191-194, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36303050

RESUMO

The effect of silicon nanoparticles (1 µg/mL) on the activity of lipid peroxidation, peroxidase, superoxide dismutase, and catalase in tomato roots invaded by root-knot nematode Meloidogyne incognita was studied. It was shown that, at the early stages of parasitization in the plants treated with Si-NPs, a low activity of PO and SOD, as well as an increased level of lipid peroxidation, are observed, which indicates the formation of free radicals (reactive oxygen species, ROS) that can inhibit nematodes and limit the formation of giant cells. During the sedentary stage, at the stages of nutrition, development, and egg production, the roots of the treated plants showed an increased activity of PO, CAT, and SOD, as well as a low activity of LPO as compared to the infested untreated plants. This makes it possible to maintain a balance between the formation and neutralization of ROS and is important not only in the protection of plant tissues from oxidative processes but also in the preservation of giant cells that feed the parasite. The presented data for the first time show the mechanism of action of Si-NPs in the development of resistance and adaptation of plants to biogenic stress, associated with the effect on various components of the antioxidant system and their functional interaction.


Assuntos
Antioxidantes , Lycopersicon esculentum , Nanopartículas , Raízes de Plantas , Silício , Tylenchoidea , Animais , Antioxidantes/metabolismo , Lycopersicon esculentum/enzimologia , Lycopersicon esculentum/parasitologia , Raízes de Plantas/enzimologia , Raízes de Plantas/parasitologia , Espécies Reativas de Oxigênio , Silício/farmacologia , Superóxido Dismutase
4.
Exp Parasitol ; 241: 108359, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35998723

RESUMO

To contribute to the development of new fumigant nematicides for the control of the plant-parasitic nematode Meloidogyne incognita, this study started with 31 volatile organic compounds reported as toxic to nematodes. At 500 µg/mL, α-ionone, (S)-carvone, (R)-carvone, 2-methylpropyl acetate, undecan-2-one, decan-2-one, and dodecan-2-one caused mortalities to M. incognita second-stage juveniles (J2) that were similar to those obtained with the commercial nematicides carbofuran (170 µg/mL) and fluensulfone (42.2 µg/mL). (R)-carvone, with a lethal concentration to 50% J2 (LC50) equal to 524 µg/mL, was selected for subsequent studies. When J2 were exposed to the (R)-carvone solution, the infectivity and reproduction on tomato were reduced. In the M. incognita egg hatching assay, (R)-carvone behaved like a true ovicide. When employed as a fumigant, (R)-carvone (3.9 g/L) was as efficient as the soil fumigant dazomet (0.245 g/L) in eliminating eggs of the nematode in a substrate to be used for tomato planting. According to in silico studies employing pharmacophoric searches and molecular docking, acetylcholinesterases are the target of (R)-carvone in the nematode.


Assuntos
Lycopersicon esculentum , Tylenchoidea , Acetilcolinesterase , Animais , Antinematódeos/química , Antinematódeos/farmacologia , Monoterpenos Cicloexânicos , Lycopersicon esculentum/parasitologia , Simulação de Acoplamento Molecular , Solo
5.
ISME J ; 16(9): 2230-2241, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35760884

RESUMO

In-depth understanding of metabolite-mediated plant-nematode interactions can guide us towards novel nematode management strategies. To improve our understanding of the effects of secondary metabolites on soil nematode communities, we grew Arabidopsis thaliana genetically altered in glucosinolate, camalexin, or flavonoid synthesis pathways, and analyzed their root-associated nematode communities using metabarcoding. To test for any modulating effects of the associated microbiota on the nematode responses, we characterized the bacterial and fungal communities. Finally, as a proxy of microbiome-modulating effects on nematode invasion, we isolated the root-associated microbiomes from the mutants and tested their effect on the ability of the plant parasitic nematode Meloidogyne incognita to penetrate tomato roots. Most mutants had altered relative abundances of several nematode taxa with stronger effects on the plant parasitic Meloidogyne hapla than on other root feeding taxa. This probably reflects that M. hapla invades and remains embedded within root tissues and is thus intimately associated with the host. When transferred to tomato, microbiomes from the flavonoid over-producing pap1-D enhanced M. incognita root-invasion, whereas microbiomes from flavonoid-deficient mutants reduced invasion. This suggests microbiome-mediated effect of flavonoids on Meloidogyne infectivity plausibly mediated by the alteration of the abundances of specific microbial taxa in the transferred microbiomes, although we could not conclusively pinpoint such causative microbial taxa.


Assuntos
Arabidopsis , Lycopersicon esculentum , Microbiota , Tylenchoidea , Animais , Arabidopsis/genética , Flavonoides , Lycopersicon esculentum/genética , Lycopersicon esculentum/microbiologia , Lycopersicon esculentum/parasitologia , Raízes de Plantas/genética , Tylenchoidea/genética
6.
J Agric Food Chem ; 70(22): 6658-6669, 2022 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-35613461

RESUMO

Plant parasitic nematodes (PPNs) develop through three major stages in their life cycle: hatching, infection, and reproduction. Interruption of any of these stages can affect their growth and survival. We used screenhouse pot experiments, laboratory in vitro hatching and mortality assays, and chemical analysis to test the hypothesis that the non-host Asteraceae plant vegetable black-jack (Bidens pilosa) suppresses infection of the PPN Meloidogyne incognita in two susceptible Solanaceae host plants, tomato (Solanum lycopersicum) and black nightshade (S. nigrum). In intercrop and drip pot experiments, B. pilosa significantly reduced the number of galls and egg masses in root-knot nematode (RKN)-susceptible host plants by 3-9-fold compared to controls. Chemical analysis of the most bioactive fraction from the root exudates of B. pilosa identified several classes of compounds, including vitamins, a dicarboxylic acid, amino acids, aromatic acids, and a flavonoid. In in vitro assays, the vitamins and aromatic acids elicited the highest inhibition in egg hatching, whereas ascorbic acid (vitamin) and 2-hydroxybenzoic acid (aromatic acid) elicited strong nematicidal activity against M. incognita, with LC50/48 h values of 12 and 300 ng/µL, respectively. Our results provide insights into how certain non-host plants can be used as companion crops to disrupt PPN infestation.


Assuntos
Lycopersicon esculentum , Tylenchoidea , Animais , Produtos Agrícolas , Lycopersicon esculentum/parasitologia , Doenças das Plantas/parasitologia , Doenças das Plantas/prevenção & controle , Raízes de Plantas/parasitologia , Verduras , Vitaminas
7.
Gene ; 821: 146335, 2022 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-35182672

RESUMO

Late blight caused by Phytophthora infestans brings huge economic losses to the production of tomato (Solanum lycopersicum) every year. F-box proteins participate in plants response to phytohormones and biotic stress, whereas as the largest subfamily of F-box superfamily, the detailed information about F-box associated (SlFBA) family in tomato has been rarely reported. In this study, a total of 46 tomato FBA genes were identified based on the latest genome annotation. Phylogenetic analysis revealed that the FBA proteins from tomato and 6 different plant species were clustered into 7 distinct clades. The SlFBA genes were unevenly distributed on 11 chromosomes of tomato, mainly concentrated in the regions with high gene density. Tandem duplications and purification selection contribute to the expansion and evolution of the SlFBA gene family. Transcriptome analysis revealed that the SlFBA genes were differentially expressed in different tissues with obvious tissue-specific expression patterns. There were 18 SlFBA genes differentially expressed in P. infestans-resistant and -susceptible tomato, among which, 3 SlFBA genes might play positive roles in tomato resistance to P. infestans. Taken together, this study systematically analyzed the SlFBA genes family for the first time and identified the candidate SlFBA genes that affect tomato resistance to P. infestans, which provided important genetic and breeding resources for improving tomato resistance to pathogens.


Assuntos
Resistência à Doença , Perfilação da Expressão Gênica/métodos , Lycopersicon esculentum/crescimento & desenvolvimento , Phytophthora infestans/patogenicidade , Proteínas de Plantas/genética , Análise de Sequência de DNA/métodos , Mapeamento Cromossômico , Motivos F-Box , Regulação da Expressão Gênica de Plantas , Interações Hospedeiro-Patógeno , Lycopersicon esculentum/genética , Lycopersicon esculentum/parasitologia , Anotação de Sequência Molecular , Especificidade de Órgãos , Filogenia , Proteínas de Plantas/química , Alinhamento de Sequência
8.
Sci Rep ; 12(1): 2915, 2022 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-35190634

RESUMO

The root-knot nematode, Meloidogyne javanica is a devastating pest affecting tomato production worldwide. Entomopathogenic nematodes (EPNs) are considered very promising biocontrol agents that could be used to effectively manage plant-parasitic nematode. The antagonistic activity of five EPN strains isolated from different fields in Morocco was evaluated against juvenile (J2s) antagonism in soil, the number of egg masses, and the galling index of M. javanica and J2s reproduction in the root. In greenhouse experiments, Steinernema feltiae strains (EL45 and SF-MOR9), Steinernema sp. (EL30), and those of Heterorhabditis bacteriophora (HB-MOR7 and EL27) were applied to the soil alongside RKN J2s. There was a significant reduction in M. javanica densities in the soil and roots by EPNs treatments when compared to the positive control. The EPNs decreased both egg masses formation and galling index by 80% compared to the positive control. The application of EPNs at a rate of 50 and 75 infective juveniles (IJs) cm-2 gave significant control of all studied nematological parameters compared to the positive control, which confirmed the importance of the doses applied. The applied dose was significantly correlated with M. javanica parameters according to polynomial regression models. The results also showed that S. feltiae strain (EL45) significantly increased plant height and root length, while H. bacteriophora strain (HB-MOR7) only enhanced root fresh weight. Therefore, both indigenous EPN strains; EL45 and SF-MOR9 have eco-friendly biological potential against M. javanica in vegetable crops.


Assuntos
Agricultura/métodos , Antibiose/fisiologia , Produtos Agrícolas/parasitologia , Lycopersicon esculentum/parasitologia , Nematoides/fisiologia , Doenças das Plantas/prevenção & controle , Doenças das Plantas/parasitologia , Tylenchoidea/fisiologia , Tylenchoidea/patogenicidade , Animais , Marrocos , Controle Biológico de Vetores/métodos , Reprodução , Solo/parasitologia
9.
J Biol Chem ; 298(3): 101637, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35085555

RESUMO

Adaptation to nutrient deprivation depends on the activation of metabolic programs to use reserves of energy. When outside a host plant, second-stage juveniles (J2) of the root-knot nematode (Meloidogyne spp.), an important group of pests responsible for severe losses in the production of crops (e.g., rice, wheat, and tomato), are unable to acquire food. Although lipid hydrolysis has been observed in J2 nematodes, its role in fitness and the underlying mechanisms remain unknown. Using RNA-seq analysis, here, we demonstrated that in the absence of host plants, the pathway for the biosynthesis of polyunsaturated fatty acids was upregulated, thereby increasing the production of arachidonic acid in middle-stage J2 Meloidogyne incognita worms. We also found that arachidonic acid upregulated the expression of the transcription factor hlh-30b, which in turn induced lysosomal biogenesis. Lysosomes promoted lipid hydrolysis via a lysosomal lipase, LIPL-1. Furthermore, our data demonstrated that blockage of lysosomal lipolysis reduced both lifespan and locomotion of J2 worms. Strikingly, disturbance of lysosomal lipolysis resulted in a decline in infectivity of these juveniles on tomato roots. Our findings not only reveal the molecular mechanism of lipolysis in J2 worms but also suggest potential novel strategies for the management of root-knot nematode pests.


Assuntos
Lycopersicon esculentum , Tylenchoidea , Animais , Ácidos Araquidônicos/metabolismo , Metabolismo dos Lipídeos , Lipólise , Lycopersicon esculentum/parasitologia , Lisossomos , Tylenchoidea/metabolismo , Tylenchoidea/fisiologia
10.
Plant Sci ; 314: 111120, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34895549

RESUMO

Little is known about how different plant-based diets influence the insect herbivores' oral secretion (OS) composition and eventually the plant defense responses. We analyzed the OS composition of the generalist Lepidopteran insect, Helicoverpa armigera feeding on the host plant tomato (OSH), non-host plant capsicum (OSNH), and artificial diet (OSAD) using Liquid Chromatography-Quadrupole Time of Flight Mass Spectrometry. Higher numbers and levels of alkaloids and terpenoids were observed in OSH and OSNH, respectively while OSAD was rich in phospholipids. Interestingly, treatment of H. armigera OSAD, OSH and OSNH on wounded tomato leaves showed differential expression of (i) genes involved in JA and SA biosynthesis and their responsive genes, and (ii) biosynthetic pathway genes of chlorogenic acid (CGA) and trehalose, which exhibited increased accumulation along with several other plant defensive metabolites. Specifically, high levels of CGA were detected after OSH and OSNH treatments in tomato leaves. There was higher expression of the genes involved in phenylpropanoid biosynthesis, which may lead to the increased accumulation of CGA and related metabolites. In the insect bioassay, CGA significantly inhibited H. armigera larval growth. Our results underline the differential accumulation of plant and insect OS metabolites and identified potential plant metabolite(s) affecting insect growth and development.


Assuntos
Secreções Corporais/química , Dieta , Herbivoria/fisiologia , Interações Hospedeiro-Parasita/fisiologia , Lepidópteros/fisiologia , Lycopersicon esculentum/parasitologia , Defesa das Plantas contra Herbivoria/fisiologia , Animais
11.
Sci Rep ; 11(1): 23346, 2021 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-34857835

RESUMO

Tuta absoluta is one of the most devastating pests of Solanaceae crops in Africa. We previously demonstrated the efficacy of Metarhizium anisopliae isolates ICIPE 18, ICIPE 20 and ICIPE 665 against adult T. absoluta. However, adequate strain selection and accurate spatial prediction are fundamental to optimize their efficacy and formulations before field deployment. This study therefore assessed the thermotolerance, conidial yield and virulence (between 15 and 35 °C) of these potent isolates. Over 90% of conidia germinated at 20, 25 and 30 °C while no germination occurred at 15 °C. Growth of the three isolates occurred at all temperatures, but was slower at 15, 33 and 35 °C as compared to 20, 25 and 30 °C. Optimum temperatures for mycelial growth and spore production were 30 and 25 °C, respectively. Furthermore, ICIPE 18 produced higher amount of spores than ICIPE 20 and ICIPE 665. The highest mortality occurred at 30 °C for all the three isolates, while the LT50 values of ICIPE 18 and ICIPE 20 were significantly lower at 25 and 30 °C compared to those of ICIPE 665. Subsequently, several nonlinear equations were fitted to the mortality data to model the virulence of ICIPE 18 and ICIPE 20 against adult T. absoluta using the Entomopathogenic Fungi Application (EPFA) software. Spatial prediction revealed suitable locations for ICIPE 18 and ICIPE 20 deployment against T. absoluta in Kenya, Tanzania and Uganda. Our findings suggest that ICIPE 18 and ICIPE 20 could be considered as effective candidate biopesticides for an improved T. absoluta management based on temperature and location-specific approach.


Assuntos
Agentes de Controle Biológico , Interações Hospedeiro-Parasita , Lycopersicon esculentum/parasitologia , Metarhizium/fisiologia , Mariposas/microbiologia , Controle Biológico de Vetores , Temperatura , Animais , Metarhizium/isolamento & purificação , Mariposas/parasitologia , Análise Espacial
12.
Braz J Biol ; 84: e253451, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34730701

RESUMO

Root-knot nematode Meloidogyne incognita is among the biotic factors which has greatly affected both the yield and the quality of the tomato crop. The egg parasitic nematode, Purpureocillium lilacinum (Pl) is considered as one of the most promising agents in controlling and overcoming this plant pathogen. The nematicidal effect of the native isolate Pl AUMC 10149 on second stage juvenile's survival and egg hatching of M. incognita at different times of exposure was tested in vitro. The obtained data showed that Pl gave a maximum percentage of J2 mortality (97.6%) and egg hatching inhibition (79.8%) after 72 hours of exposure. The potentiality of Pl as well as Bio-Nematon to control M. incognita infecting tomato was conducted using different times of application in vivo. Nine treatments with five replicates were used for such bioagents compared with the nematicide Oxamyl. Each seedling was inoculated with 1000 J2s of nematode/pot and 10 mL of Pl (1x1010 CFU/mL) or Bio-Nematon spore suspension (1x108 CFU/mL) 10mL/pot. The results indicated that the most effective treatments in reducing nematode population, number of galls and egg masses of M. incognita in plant roots was performed with treatment by Pl pre-planting and post-infection with Pl (Rf 1.9) giving a significant enhancement in plant length (64.9%), fresh weight (72.52%) and shoot dry weight (163.41%) without negatively impacting environment. Therefore, the present study confirmed that using P. lilacinum AUMC 10149 can be used as a practical supplement to environmentally friendly disease management of root-knot nematodes in Egypt.


Assuntos
Agentes de Controle Biológico , Hypocreales , Lycopersicon esculentum , Tylenchoidea , Animais , Lycopersicon esculentum/parasitologia , Tylenchoidea/patogenicidade
13.
Int J Mol Sci ; 22(22)2021 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-34830029

RESUMO

Cyst nematodes are important herbivorous pests in agriculture that obtain nutrients through specialized root structures termed syncytia. Syncytium initiation, development, and functioning are a research focus because syncytia are the primary interface for molecular interactions between the host plant and parasite. The small size and complex development (over approximately two weeks) of syncytia hinder precise analyses, therefore most studies have analyzed the transcriptome of infested whole-root systems or syncytia-containing root segments. Here, we describe an effective procedure to microdissect syncytia induced by Globodera rostochiensis from tomato roots and to analyze the syncytial proteome using mass spectrometry. As little as 15 mm2 of 10-µm-thick sections dissected from 30 syncytia enabled the identification of 100-200 proteins in each sample, indicating that mass-spectrometric methods currently in use achieved acceptable sensitivity for proteome profiling of microscopic samples of plant tissues (approximately 100 µg). Among the identified proteins, 48 were specifically detected in syncytia and 7 in uninfected roots. The occurrence of approximately 50% of these proteins in syncytia was not correlated with transcript abundance estimated by quantitative reverse-transcription PCR analysis. The functional categories of these proteins confirmed that protein turnover, stress responses, and intracellular trafficking are important components of the proteome dynamics of developing syncytia.


Assuntos
Cromadoria , Células Gigantes/metabolismo , Lycopersicon esculentum , Proteínas de Plantas/metabolismo , Raízes de Plantas , Proteoma/metabolismo , Animais , Lycopersicon esculentum/metabolismo , Lycopersicon esculentum/parasitologia , Raízes de Plantas/metabolismo , Raízes de Plantas/parasitologia
14.
Int J Mol Sci ; 22(21)2021 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-34768853

RESUMO

Phytophthora infestans (P. infestans) recently caused epidemics of tomato late blight. Our study aimed to identify the function of the SlMYBS2 gene in response to tomato late blight. To further investigate the function of SlMYBS2 in tomato resistance to P. infestans, we studied the effects of SlMYBS2 gene knock out. The SlMYBS2 gene was knocked out by CRISPR-Cas9, and the resulting plants (SlMYBS2 gene knockout, slmybs2-c) showed reduced resistance to P. infestans, accompanied by increases in the number of necrotic cells, lesion sizes, and disease index. Furthermore, after P. infestans infection, the expression levels of pathogenesis-related (PR) genes in slmybs2-c plants were significantly lower than those in wild-type (AC) plants, while the number of necrotic cells and the accumulation of reactive oxygen species (ROS) were higher than those in wild-type plants. Taken together, these results indicate that SlMYBS2 acts as a positive regulator of tomato resistance to P. infestans infection by regulating the ROS level and the expression level of PR genes.


Assuntos
Resistência à Doença/genética , Lycopersicon esculentum/parasitologia , Phytophthora infestans/patogenicidade , Doenças das Plantas/parasitologia , Fatores de Transcrição/genética , Sistemas CRISPR-Cas , Regulação da Expressão Gênica de Plantas/genética , Lycopersicon esculentum/genética , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/genética , Espécies Reativas de Oxigênio/metabolismo
15.
PLoS One ; 16(9): e0257925, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34591899

RESUMO

Tuta absoluta is one of the most damaging pests of tomato crops worldwide. Damage due to larvae may cause up to 100% loss of tomato production. Use of natural enemies to control the pest, notably predatory mirids such as Nesidiocoris tenuis and Macrolophus pygmaeus, is increasingly being promoted. However, considering the potential damage caused to tomatoes by these omnivorous predators in the absence of T. absoluta, an alternative solution could be required to reduce tomato damage and improve the predators' performance. The use of companion plants can be an innovative solution to cope with these issues. The present study aimed to determine the influence of companion plants and alternative preys on the predators' performance in controlling T. absoluta and protecting tomato plants. We evaluated the effect of predators (alone or combined) and a companion plant (sesame (Sesamum indicum)) on T. absoluta egg predation and crop damage caused by N. tenuis. The influence of an alternative prey (Ephestia kuehniella eggs) on the spatial distribution of predators was also evaluated by caging them in the prey presence or absence, either on tomato or sesame plants or on both. We found that the presence of sesame did not reduce the efficacy of N. tenuis or M. pygmaeus in consuming T. absoluta eggs; hatched egg proportion decreased when N. tenuis, M. pygmaeus, or both predators were present. More specifically, this proportion was more strongly reduced when both predators were combined. Sesame presence also reduced necrotic rings caused by N. tenuis on tomato plants. Nesidiocoris tenuis preferred sesame over tomato plants (except when food was provided only on the tomato plant) and the upper part of the plants, whereas M. pygmaeus preferred tomato to sesame plants (except when food was provided only on the sesame plant) and had no preference for a plant part. Combination of predators N. tenuis and M. pygmaeus allows for better coverage of cultivated plants in terms of occupation of different plant parts and better regulation of T. absoluta populations. Sesamum indicum is a potential companion plant that can be used to significantly reduce N. tenuis damage to tomatoes.


Assuntos
Heterópteros/fisiologia , Lepidópteros/patogenicidade , Lycopersicon esculentum/crescimento & desenvolvimento , Sesamum/crescimento & desenvolvimento , Animais , Produtos Agrícolas/crescimento & desenvolvimento , Produtos Agrícolas/parasitologia , Larva/fisiologia , Lepidópteros/parasitologia , Lycopersicon esculentum/parasitologia , Controle Biológico de Vetores , Componentes Aéreos da Planta/crescimento & desenvolvimento , Componentes Aéreos da Planta/parasitologia , Comportamento Predatório , Sesamum/parasitologia
16.
BMC Complement Med Ther ; 21(1): 229, 2021 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-34517859

RESUMO

BACKGROUND: We previously reported that the tomato glycoalkaloid tomatine inhibited the growth of Trichomonas vaginalis strain G3, Tritrichomonas foetus strain D1, and Tritrichomonas foetus-like strain C1 that cause disease in humans and farm and domesticated animals. The increasing prevalence of antibiotic resistance requires development of new tools to enhance or replace medicinal antibiotics. METHODS: Wild tomato plants were harvested and divided into leaves, stems, and fruit of different colors: green, yellow, and red. Samples were freeze dried and ground with a handheld mill. The resulting powders were evaluated for their potential anti-microbial effects on protozoan parasites, bacteria, and fungi. A concentration of 0.02% (w/v) was used for the inhibition of protozoan parasites. A high concentration of 10% (w/v) solution was tested for bacteria and fungi as an initial screen to evaluate potential anti-microbial activity and results using this high concentration limits its clinical relevance. RESULTS: Natural powders derived from various parts of tomato plants were all effective in inhibiting the growth of the three trichomonads to varying degrees. Test samples from leaves, stems, and immature 'green' tomato peels and fruit, all containing tomatine, were more effective as an inhibitor of the D1 strain than those prepared from yellow and red tomato peels which lack tomatine. Chlorogenic acid and quercetin glycosides were present in all parts of the plant and fruit, while caffeic acid was only found in the fruit peels. Any correlation between plant components and inhibition of the G3 and C1 strains was not apparent, although all the powders were variably effective. Tomato leaf was the most effective powder in all strains, and was also the highest in tomatine. S. enterica showed a minor susceptibility while B. cereus and C. albicans fungi both showed a significant growth inhibition with some of the test powders. The powders inhibited growth of the pathogens without affecting beneficial lactobacilli found in the normal flora of the vagina. CONCLUSIONS: The results suggest that powders prepared from tomato leaves, stems, and green tomato peels and to a lesser extent from peels from yellow and red tomatoes offer potential multiple health benefits against infections caused by pathogenic protozoa, bacteria, and fungi, without affecting beneficial lactobacilli that also reside in the normal flora of the vagina.


Assuntos
Antitricômonas/farmacologia , Antitricômonas/uso terapêutico , Lycopersicon esculentum/química , Lycopersicon esculentum/parasitologia , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Tricomoníase/tratamento farmacológico , Animais , California , Gatos/parasitologia , Bovinos/parasitologia , Feminino , Frutas/química , Humanos , Masculino , Folhas de Planta/química , Caules de Planta/química , Trichomonas/efeitos dos fármacos
17.
Plant Cell Rep ; 40(12): 2287-2302, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34387737

RESUMO

KEY MESSAGE: This study establishes possibility of combinatorial silencing of more than one functional gene for their efficacy against root-knot nematode, M. incognita. Root-knot nematodes (RKN) of the genus Meloidogyne are the key important plant parasitic nematodes (PPNs) in agricultural and horticultural crops worldwide. Among RKNs, M. incognita is the most notorious that demand exploration of novel strategies for their management. Due to its sustainable and target-specific nature, RNA interference (RNAi) has gained unprecedented importance to combat RKNs. However, based on the available genomic information and interaction studies, it can be presumed that RKNs are dynamic and not dependent on single genes for accomplishing a particular function. Therefore, it becomes extremely important to consider silencing of more than one gene to establish any synergistic or additive effect on nematode parasitism. In this direction, we have combined three effectors specific to subventral gland cells of M. incognita, Mi-msp1, Mi-msp16, Mi-msp20 as fusion cassettes-1 and two FMRFamide-like peptides, Mi-flp14, Mi-flp18, and Mi-msp20 as fusion cassettes-2 to establish their possible utility for M. incognita management. In vitro RNAi assay in tomato and adzuki bean using these two fusion gene negatively altered nematode behavior in terms of reduced attraction, invasion, development, and reproduction. Subsequently, Nicotiana tabacum plants were transformed with these two fusion gene hairpin RNA-expressing vectors (hpRNA), and characterized via PCR, qRT-PCR, and Southern blot hybridization. Production of siRNAs specific to Mi-flp18 and Mi-msp1 was also confirmed by Northern hybridization. Further, transgenic events expressing single copy insertions of hpRNA constructs of fusion 1 and fusion-2 conferred up to 85% reduction in M. incognita multiplication. Besides, expression quantification revealed a significant reduction in mRNA abundance of target genes (up to 1.8-fold) in M. incognita females extracted from transgenic plants, and provided additional evidence for successful gene silencing.


Assuntos
Proteínas de Helminto/genética , Interações Hospedeiro-Parasita/genética , Interferência de RNA , Tabaco/genética , Tylenchoidea/genética , Animais , Feminino , Inativação Gênica , Lycopersicon esculentum/genética , Lycopersicon esculentum/parasitologia , Plantas Geneticamente Modificadas/genética , RNA Interferente Pequeno/genética , Proteínas Recombinantes de Fusão/genética , Reprodutibilidade dos Testes , Tabaco/parasitologia , Tylenchoidea/patogenicidade , Vigna/genética , Vigna/parasitologia
18.
Science ; 373(6556): 774-779, 2021 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-34385392

RESUMO

The oomycete Phytophthora infestans is a damaging crop pathogen and a model organism to study plant-pathogen interactions. We report the discovery of a family of copper-dependent lytic polysaccharide monooxygenases (LPMOs) in plant pathogenic oomycetes and its role in plant infection by P. infestans We show that LPMO-encoding genes are up-regulated early during infection and that the secreted enzymes oxidatively cleave the backbone of pectin, a charged polysaccharide in the plant cell wall. The crystal structure of the most abundant of these LPMOs sheds light on its ability to recognize and degrade pectin, and silencing the encoding gene in P. infestans inhibits infection of potato, indicating a role in host penetration. The identification of LPMOs as virulence factors in pathogenic oomycetes opens up opportunities in crop protection and food security.


Assuntos
Lycopersicon esculentum/parasitologia , Oxigenases de Função Mista/metabolismo , Pectinas/metabolismo , Phytophthora infestans/enzimologia , Doenças das Plantas/parasitologia , Solanum tuberosum/parasitologia , Cobre , Oxigenases de Função Mista/química , Oxigenases de Função Mista/genética , Modelos Moleculares , Oxirredução , Phytophthora infestans/genética , Phytophthora infestans/patogenicidade , Folhas de Planta/parasitologia , Polissacarídeos/metabolismo , Conformação Proteica , Domínios Proteicos , Fatores de Virulência/química , Fatores de Virulência/genética , Fatores de Virulência/metabolismo
19.
BMC Plant Biol ; 21(1): 358, 2021 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-34348650

RESUMO

BACKGROUND: The South America pinworm, Tuta absoluta, is a destructive pest of tomato that causes important losses worldwide. Breeding of resistant/tolerant tomato cultivars could be an effective strategy for T. absoluta management but, despite the economic importance of tomato, very limited information is available about its response to this treat. To elucidate the defense mechanisms to herbivore feeding a comparative analysis was performed between a tolerant and susceptible cultivated tomato at both morphological and transcriptome level to highlight constitutive leaf barriers, molecular and biochemical mechanisms to counter the effect of T. absoluta attack. RESULTS: The tolerant genotype showed an enhanced constitutive barrier possibly as result of the higher density of trichomes and increased inducible reactions upon mild infestation thanks to the activation/repression of key transcription factors regulating genes involved in cuticle formation and cell wall strength as well as of antinutritive enzymes, and genes involved in the production of chemical toxins and bioactive secondary metabolites. CONCLUSIONS: Overall, our findings suggest that tomato resilience to the South America pinworm is achieved by a combined strategy between constitutive and induced defense system. A well-orchestrated modulation of plant transcription regulation could ensure a trade-off between defense needs and fitness costs. Our finding can be further exploited for developing T. absoluta tolerant cultivars, acting as important component of integrated pest management strategy for more sustainable production.


Assuntos
Regulação da Expressão Gênica de Plantas , Lycopersicon esculentum/genética , Doenças das Plantas/genética , Folhas de Planta/genética , Transcriptoma , Animais , Perfilação da Expressão Gênica/métodos , Ontologia Genética , Interações Hospedeiro-Parasita , Larva/fisiologia , Lycopersicon esculentum/metabolismo , Lycopersicon esculentum/parasitologia , Mariposas/fisiologia , Doenças das Plantas/parasitologia , Folhas de Planta/metabolismo , Folhas de Planta/parasitologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , RNA-Seq/métodos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Tricomas/genética , Tricomas/metabolismo , Tricomas/parasitologia
20.
Genes (Basel) ; 12(8)2021 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-34440427

RESUMO

Tuta absoluta is one of the most significant invasive pests affecting tomato plants worldwide. RT-qPCR has emerged as one of the most sensitive and accurate methods for detecting gene expression data. The screening of stable internal reference genes is the most critical step for studying the molecular mechanisms of environmental adaptability. The stable reference genes expressed in T. absoluta under specific experimental conditions have not yet been clarified. In this study, seven candidate reference genes (RPL27, RPS13, RPS15, EF1-α, TUB, TBP, and ß-actin) and their optimal numbers were evaluated under biotic (developmental stages and adult tissues) and abiotic (insecticide, temperature, and plant VOC) conditions using four software programs. Our results identified the following reference genes and numbers as optimal: three genes (EF1-α, RPS13, and RPL27) for different developmental stages (egg, larva, pupa, unmated adult), two genes (RPS13 and TBP) for adult tissues (antenna, head, thorax, abdomen, leg), two genes (TBP and RPS13) for insecticides (Bacillus thuringiensis, chlorpyrifos, abamectin-aminomethyl, and chlorantraniliprole), two genes (RPL27 and TUB) for temperature-induced stresses (0, 25, and 40 °C), and two genes (RPS13 and TUB) for VOC-induced stresses (nonanal, α-phellandrene, and tomato leaves). Our results provide a reference for selecting appropriate reference genes for further study of the functional genes of T. absoluta under different experimental conditions.


Assuntos
Genes de Insetos/genética , Lepidópteros/genética , Lycopersicon esculentum/parasitologia , Reação em Cadeia da Polimerase em Tempo Real/normas , Animais , Inseticidas/farmacologia , Larva/genética , Larva/patogenicidade , Lepidópteros/patogenicidade , Lycopersicon esculentum/genética , Lycopersicon esculentum/crescimento & desenvolvimento , Mariposas/genética , Mariposas/patogenicidade , Controle Biológico de Vetores , Padrões de Referência
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