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1.
Sci Rep ; 10(1): 3114, 2020 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-32080275

RESUMO

The meadow spittlebug, Philaenus spumarius, is a highly polyphagous widespread species, playing a major role in the transmission of the bacterium Xylella fastidiosa subspecies pauca, the agent of the "Olive Quick Decline Syndrome". Essential oils (EOs) are an important source of bio-active volatile compounds that could interfere with basic metabolic, biochemical, physiological, and behavioural functions of insects. Here, we report the electrophysiological and behavioural responses of adult P. spumarius towards some EOs and related plants. Electroantennographic tests demonstrated that the peripheral olfactory system of P. spumarius females and males perceives volatile organic compounds present in the EOs of Pelargonium graveolens, Cymbopogon nardus and Lavandula officinalis in a dose-dependent manner. In behavioral bioassays, evaluating the adult responses towards EOs and related plants, both at close (Y-tube) and long range (wind tunnel), males and females responded differently to the same odorant. Using EOs, a clear attraction was noted only for males towards lavender EO. Conversely, plants elicited responses that varied upon the plant species, testing device and adult sex. Both lavender and geranium repelled females at any distance range. On the contrary, males were attracted by geranium and repelled by citronella. Finally, at close distance, lavender and citronella were repellent for females and males, respectively. Our results contribute to the development of innovative tools and approaches, alternative to the use of synthetic pesticides, for the sustainable control of P. spumarius aiming to contrasting the expansion of X. fastidiosa.


Assuntos
Comportamento Animal , Fenômenos Eletrofisiológicos , Hemípteros/efeitos dos fármacos , Óleos Voláteis/farmacologia , Animais , Infecções Bacterianas/microbiologia , Bioensaio , Feminino , Repelentes de Insetos , Insetos Vetores/microbiologia , Masculino , Odorantes , Doenças das Plantas/microbiologia , Olfato , Compostos Orgânicos Voláteis/farmacologia , Xylella
2.
Plants (Basel) ; 8(10)2019 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-31623335

RESUMO

Plant defense peptides represent an important class of compounds active against pathogens and insects. These molecules controlling immune barriers can potentially be used as novel tools for plant protection, which mimic natural defense mechanisms against invaders. The constitutive expression in tomato plants of the precursor of the defense peptide systemin was previously demonstrated to increase tolerance against moth larvae and aphids and to hamper the colonization by phytopathogenic fungi, through the expression of a wealth of defense-related genes. In this work we studied the impact of the exogenous supply of systemin to tomato plants on pests to evaluate the use of the peptide as a tool for crop protection in non-transgenic approaches. By combining gene expression studies and bioassays with different pests we demonstrate that the exogenous supply of systemin to tomato plants enhances both direct and indirect defense barriers. Experimental plants, exposed to this peptide by foliar spotting or root uptake through hydroponic culture, impaired larval growth and development of the noctuid moth Spodoptera littoralis, even across generations, reduced the leaf colonization by the fungal pathogen Botrytis cinerea and were more attractive towards natural herbivore antagonists. The induction of these defense responses was found to be associated with molecular and biochemical changes under control of the systemin signalling cascade. Our results indicate that the direct delivery of systemin, likely characterized by a null effect on non-target organisms, represents an interesting tool for the sustainable protection of tomato plants.

3.
Front Physiol ; 10: 813, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31333483

RESUMO

Numerous microbial root symbionts are known to induce different levels of enhanced plant protection against a variety of pathogens. However, more recent studies have demonstrated that beneficial microbes are able to induce plant systemic resistance that confers some degree of protection against insects. Here, we report how treatments with the fungal biocontrol agent Trichoderma atroviride strain P1 in tomato plants induce responses that affect pest insects with different feeding habits: the noctuid moth Spodoptera littoralis (Boisduval) and the aphid Macrosiphum euphorbiae (Thomas). We observed that the tomato plant-Trichoderma P1 interaction had a negative impact on the development of moth larvae and on aphid longevity. These effects were attributed to a plant response induced by Trichoderma that was associated with transcriptional changes of a wide array of defense-related genes. While the impact on aphids could be related to the up-regulation of genes involved in the oxidative burst reaction, which occur early in the defense reaction, the negative performance of moth larvae was associated with the enhanced expression of genes encoding for protective enzymes (i.e., Proteinase inhibitor I (PI), Threonine deaminase, Leucine aminopeptidase A1, Arginase 2, and Polyphenol oxidase) that are activated downstream in the defense cascade. In addition, Trichoderma P1 produced alterations in plant metabolic pathways leading to the production and release of volatile organic compounds (VOCs) that are involved in the attraction of the aphid parasitoid Aphidius ervi, thus reinforcing the indirect plant defense barriers. Our findings, along with the evidence available in the literature, indicate that the outcome of the tripartite interaction among plant, Trichoderma, and pests is highly specific and only a comprehensive approach, integrating both insect phenotypic changes and plant transcriptomic alterations, can allow a reliable prediction of its potential for plant protection.

4.
PLoS One ; 13(11): e0205245, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30403678

RESUMO

Ooencyrtus spp. (Hymenoptera, Chalcidoidea, Encyrtidae) are important natural enemies of agricultural and forest insect pests, and are distributed worldwide. Their reduced dimensions, highly variable morphological characters and possible effect of wide host range and abiotic factors, make correct identification at the species level particularly difficult. This paper combined molecular, morphological, and biological data to characterize a group of Ooencyrtus spp. emerging from the eggs of the variegated caper bug, Stenozygum coloratum in the east Mediterranean area. COI and ITS2 sequencing revealed the presence of six and five divergent clades, respectively. Three clades were identified as Ooencyrtus telenomicida, Ooencyrtus pityocampae and O. pistaciae. Two clades represent new species which are here described and named Ooencyrtus zoeae and Ooencyrtus mevalbelus. These features were combined with reliable morphological characters to facilitate the separation of these species. A dichotomous key and a new synonymy are proposed. Ooencyrtus pistaciae had two distinct COI clades but only one ITS2 clade. Crossbreeding trials that included Ooencyrtus telenomicida, Ooencyrtus melvabelus sp. nov. and Ooencyrtus zoeae sp. nov. confirmed their reproductive isolation. COI sequences showed 0-0.8% and 4-9% within and between-species genetic differences, respectively. ITS2 showed 0.4-5.9% genetic differences between species, with no genetic differences within species. Haplotype diversity of Israeli and Turkish populations of the various species was 0-0.98 and was particularly low in Ooencyrtus pityocampae, whose Israeli population showed no diversity. The discovery of the Ooencyrtus spp. on the eggs of the caper bug, and their abundance support the idea that the bug can be used as an alternative host for augmentation of populations of these parasitoids in agricultural and forestry systems.


Assuntos
Biodiversidade , Hemípteros , Himenópteros , Animais , Cruzamento , Cruzamentos Genéticos , Ovos , Genes Mitocondriais , Variação Genética , Haplótipos , Hemípteros/anatomia & histologia , Hemípteros/classificação , Hemípteros/genética , Himenópteros/anatomia & histologia , Himenópteros/classificação , Himenópteros/genética , Filogenia
5.
Front Plant Sci ; 9: 1480, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30356724

RESUMO

Arbuscular mycorrhizal (AM) fungi are very widespread, forming symbiotic associations with ∼80% of land plant species, including almost all crop plants. These fungi are considered of great interest for their use as biofertilizer in low-input and organic agriculture. In addition to an improvement in plant nutrition, AM fungi have been reported to enhance plant tolerance to important abiotic and biotic environmental conditions, especially to a reduced availability of resources. These features, to be exploited and applied in the field, require a thorough identification of mechanisms involved in nutrient transfer, metabolic pathways induced by single and multiple stresses, physiological and eco-physiological mechanisms resulting in improved tolerance. However, cooperation between host plants and AM fungi is often related to the specificity of symbiotic partners, the environmental conditions and the availability of resources. In this study, the impact of two AM fungal species (Funneliformis mosseae and Rhizophagus intraradices) on the water stress tolerance of a commercial tomato cultivar (San Marzano nano) has been evaluated in pots. Biometric and eco-physiological parameters have been recorded and gene expression analyses in tomato roots have been focused on plant and fungal genes involved in inorganic phosphate (Pi) uptake and transport. R. intraradices, which resulted to be more efficient than F. mosseae to improve physiological performances, was selected to assess the role of AM symbiosis on tomato plants subjected to combined stresses (moderate water stress and aphid infestation) in controlled conditions. A positive effect on the tomato indirect defense toward aphids in terms of enhanced attraction of their natural enemies was observed, in agreement with the characterization of volatile organic compound (VOC) released. In conclusion, our results offer new insights for understanding the molecular and physiological mechanisms involved in the tolerance toward water deficit as mediated by a specific AM fungus. Moreover, they open new perspectives for the exploitation of AM symbiosis to enhance crop tolerance to abiotic and biotic stresses in a scenario of global change.

6.
Int J Mol Sci ; 19(9)2018 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-30217050

RESUMO

Following herbivore attacks, plants modify a blend of volatiles organic compounds (VOCs) released, resulting in the attraction of their antagonists. However, volatiles released constitutively may affect herbivores and natural enemies' fitness too. In tomato there is still a lack of information on the genetic bases responsible for the constitutive release of VOC involved in direct and indirect defenses. Here we studied the constitutive emissions related to the two most abundant sesquiterpene synthase genes expressed in tomato and their functional role in plant defense. Using an RNA interference approach, we silenced the expression of TPS9 and TPS12 genes and assessed the effect of this transformation on herbivores and parasitoids. We found that silenced plants displayed a different constitutive volatiles emission from controls, resulting in reduced attractiveness for the aphid parasitoid Aphidius ervi and in an impaired development of Spodoptera exigua larvae. We discussed these data considering the transcriptional regulation of key-genes involved in the pathway of VOC metabolism. We provide several lines of evidence on the metabolic flux from terpenoids to phenylpropanoids. Our results shed more light on constitutive defenses mediated by plant volatiles and on the molecular mechanisms involved in their metabolic regulation.


Assuntos
Herbivoria/fisiologia , Lycopersicon esculentum/metabolismo , Lycopersicon esculentum/parasitologia , Animais , Afídeos/fisiologia , Interações Hospedeiro-Parasita , Spodoptera/fisiologia , Compostos Orgânicos Voláteis/metabolismo , Vespas/fisiologia
7.
Zootaxa ; 4531(3): 374-382, 2018 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-30647395

RESUMO

Delottococcus aberiae is an invasive mealybug native to South Africa that has been accidentally introduced into Spain. A survey of natural enemies in its native area to potentially be used for biological control of this pest resulted in a number of species, among which four belonged to the genus Anagyrus. Following an integrative approach using morphological and molecular data, two species new to science are here described and compared with closely related ones: Anagyrus aberiae sp.n. and Anagyrus antoniae sp.n. A dichotomous key to separate the species of Anagyrus attacking D. aberiae in South Africa is provided. [Zoobank LSID: Anagyrus aberiae Guerrieri sp. nov. (Fig. 1-7): LSID urn:lsid:zoobank.org:pub:8CF8983B-93DC-4ECF-A8FB-CF76E94319B3 Anagyrus antoniae Guerrieri sp. nov. (Fig. 8-12): LSID urn:lsid:zoobank.org:pub:8CF8983B-93DC-4ECF-A8FB-CF76E94319B3].


Assuntos
Hemípteros , Himenópteros , Animais , África do Sul , Espanha
8.
Sci Rep ; 7(1): 15522, 2017 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-29138416

RESUMO

Plants actively respond to herbivory by inducing various defense mechanisms in both damaged (locally) and non-damaged tissues (systemically). In addition, it is currently widely accepted that plant-to-plant communication allows specific neighbors to be warned of likely incoming stress (defense priming). Systemin is a plant peptide hormone promoting the systemic response to herbivory in tomato. This 18-aa peptide is also able to induce the release of bioactive Volatile Organic Compounds, thus also promoting the interaction between the tomato and the third trophic level (e.g. predators and parasitoids of insect pests). In this work, using a combination of gene expression (RNA-Seq and qRT-PCR), behavioral and chemical approaches, we demonstrate that systemin triggers metabolic changes of the plant that are capable of inducing a primed state in neighboring unchallenged plants. At the molecular level, the primed state is mainly associated with an elevated transcription of pattern -recognition receptors, signaling enzymes and transcription factors. Compared to naïve plants, systemin-primed plants were significantly more resistant to herbivorous pests, more attractive to parasitoids and showed an increased response to wounding. Small peptides are nowadays considered fundamental signaling molecules in many plant processes and this work extends the range of downstream effects of this class of molecules to intraspecific plant-to-plant communication.


Assuntos
Comunicação Autócrina/genética , Regulação da Expressão Gênica de Plantas/imunologia , Lycopersicon esculentum/metabolismo , Peptídeos/genética , Imunidade Vegetal/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Sequência de Aminoácidos , Animais , Comunicação Autócrina/imunologia , Ontologia Genética , Herbivoria/fisiologia , Larva/fisiologia , Lycopersicon esculentum/genética , Lycopersicon esculentum/imunologia , Lycopersicon esculentum/parasitologia , Anotação de Sequência Molecular , Peptídeos/síntese química , Peptídeos/imunologia , Folhas de Planta/genética , Folhas de Planta/imunologia , Folhas de Planta/parasitologia , Proteínas de Plantas/classificação , Proteínas de Plantas/imunologia , Receptores de Reconhecimento de Padrão/genética , Transdução de Sinais , Spodoptera/fisiologia , Fatores de Transcrição/genética , Fatores de Transcrição/imunologia , Transcrição Genética , Compostos Orgânicos Voláteis/imunologia , Compostos Orgânicos Voláteis/metabolismo
9.
Insect Sci ; 24(6): 1025-1033, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28475289

RESUMO

Many fungal root symbionts of the genus Trichoderma are well-known for their beneficial effects on agronomic performance and protection against plant pathogens; moreover, they may enhance protection from insect pests, by triggering plant resistance mechanisms. Defense barriers against insects are induced by the activation of metabolic pathways involved in the production of defense-related plant compounds, either directly active against herbivore insects, or exerting an indirect effect, by increasing the attraction of herbivore natural enemies. In a model system composed of the tomato plant, the aphid Macrosiphum euphorbiae and the parasitoid Aphidius ervi, plant metabolic changes induced by Trichoderma harzianum and their effects on higher trophic levels have been assessed. T. harzianum T22 treatments induce a primed state that upon aphid attacks leads to an increased attraction of aphid parasitoids, mediated by the enhanced production of volatile organic compounds (VOCs) that are known to induce Aphidius ervi flight. Transcriptome sequencing of T22-treated plants infested by aphids showed a remarkable upregulation of genes involved in terpenoids biosynthesis and salicylic acid pathway, which are consistent with the observed flight response of A. ervi and the VOC bouquet profile underlying this behavioral response.


Assuntos
Afídeos/fisiologia , Lycopersicon esculentum/microbiologia , Trichoderma/fisiologia , Compostos Orgânicos Voláteis , Vespas/fisiologia , Animais , Afídeos/parasitologia , Feminino , Voo Animal , Herbivoria , Interações Hospedeiro-Parasita , Lycopersicon esculentum/genética , Simbiose
10.
Plant Physiol ; 171(2): 1009-23, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27208301

RESUMO

Arbuscular mycorrhizal (AM) fungi, which form symbioses with the roots of the most important crop species, are usually considered biofertilizers, whose exploitation could represent a promising avenue for the development in the future of a more sustainable next-generation agriculture. The best understood function in symbiosis is an improvement in plant mineral nutrient acquisition, as exchange for carbon compounds derived from the photosynthetic process: this can enhance host growth and tolerance to environmental stresses, such as water stress (WS). However, physiological and molecular mechanisms occurring in arbuscular mycorrhiza-colonized plants and directly involved in the mitigation of WS effects need to be further investigated. The main goal of this work is to verify the potential impact of AM symbiosis on the plant response to WS To this aim, the effect of two AM fungi (Funneliformis mosseae and Rhizophagus intraradices) on tomato (Solanum lycopersicum) under the WS condition was studied. A combined approach, involving ecophysiological, morphometric, biochemical, and molecular analyses, has been used to highlight the mechanisms involved in plant response to WS during AM symbiosis. Gene expression analyses focused on a set of target genes putatively involved in the plant response to drought, and in parallel, we considered the expression changes induced by the imposed stress on a group of fungal genes playing a key role in the water-transport process. Taken together, the results show that AM symbiosis positively affects the tolerance to WS in tomato, with a different plant response depending on the AM fungi species involved.


Assuntos
Glomeromycota/fisiologia , Lycopersicon esculentum/microbiologia , Micorrizas/fisiologia , Simbiose , Água/fisiologia , Desidratação , Lycopersicon esculentum/fisiologia , Raízes de Plantas/microbiologia , Raízes de Plantas/fisiologia , Estresse Fisiológico
11.
PLoS One ; 11(2): e0147382, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26840953

RESUMO

Drosophila suzukii (Matsumura), commonly known as Spotted Wing Drosophila (SWD), is a worldwide serious economic threat to the production of berries and stone fruits. The chemical control widely used against this pest is often not able to preventing yield losses because wild flora offers an abundance of fruits to D. suzukii where the pest is able to reproduce and from where it recolonizes neighbouring cultivated fields. Alternatively, within Integrated Pest Management protocols for D. suzukii, biological control could play a key role by reducing its populations particularly in non-cultivated habitats, thus increasing the effectiveness and reducing the side negative effects of other management strategies. Because of the scarcity and of the low efficiency of autochthonous parasitoids in the new invaded territories, in the last few years, a number of surveys started in the native area of D. suzukii to find parasitoid species to be evaluated in quarantine structures and eventually released in the field, following a classical biological control approach. This paper reports the results of these surveys carried out in South Korea and for the first time in China. Among the parasitoids collected, those belonging to the genus Asobara Foerster resulted dominant both by number and species diversity. By combining morphological characters and the mitochondrial COI gene as a molecular marker, we identified seven species of Asobara, of which two associated with D. suzukii, namely A. japonica and A leveri, and five new to science, namely Asobara brevicauda, A. elongata, A mesocauda, A unicolorata, A. triangulata. Our findings offer new opportunity to find effective parasitoids to be introduced in classical biological control programmes in the territories recently invaded by D. suzukii.


Assuntos
Agentes de Controle Biológico , Drosophila/classificação , Himenópteros/classificação , Controle de Insetos/métodos , Comportamento Predatório/fisiologia , Animais , Biodiversidade , China , Produtos Agrícolas , Drosophila/genética , Cadeia Alimentar , Himenópteros/genética , Filogenia
12.
Plant Mol Biol Report ; 33(5): 1270-1285, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26339120

RESUMO

Systemin is a signal peptide that promotes the response to wounding and herbivore attack in tomato. This 18-amino acid peptide is released from a larger precursor, prosystemin. To study the role of systemin as a modulator of defense signaling, we generated tomato (Solanum lycopersicum) transgenic plants that overexpress the prosystemin cDNA. We carried out a transcriptomic analysis comparing two different transgenic events with the untransformed control. The Gene Ontology categories of the 503 differentially expressed genes indicated that several biological functions were affected. Systemin promotes the expression of an array of defense genes that are dependent on different signaling pathways and it downregulates genes connected with carbon fixation and carbohydrate metabolism. These alterations present a degree of overlap with the response programs that are classically associated to pathogen defense or abiotic stress protection, implying that end products of the systemin signaling pathway may be more diverse than expected. We show also that the observed transcriptional modifications have a relevant functional outcome, since transgenic lines were more resistant against very different biotic stressors such as aphids (Macrosiphum euphorbiae), phytopathogenic fungi (Botrytis cinerea and Alternaria alternata) and phytophagous larvae (Spodoptera littoralis). Our work demonstrated that in tomato the modulation of a single gene is sufficient to provide a wide resistance against stress by boosting endogenous defense pathways. Overall, the data provided evidence that the systemin peptide might serve as DAMP signal in tomato, acting as a broad indicator of tissue integrity.

13.
J Plant Physiol ; 173: 28-32, 2015 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-25462075

RESUMO

In the last decade plant-to-plant communication has received an increasing attention, particularly for the role of Volatile Organic Compounds as possible elicitors of plant defense. The role of ß-ocimene as an interspecific elicitor of plant defense has been recently assessed in multitrophic systems including different plant species (Solanaceae, Poaceae, legumes) and different pest species including chewer insects and phytophagous mites. Both chewer insects and phytophagous mites are known to elicit specific plant defensive pathways which are different (at least in part) from those elicited by sap feeders. The aim of this research was to fill this gap of knowledge and to assess the role of ß-ocimene as an elicitor of plant defense against aphid pests, which are sap feeders. For this purpose we used as transgenic tobacco plant releasing an odour plume enriched in this compound as emitter and a tomato plant as receiver. We selected the aphid Macrosiphum euphorbiae and its natural enemy, the parasitoid Aphidius ervi, as the targets of plant induced defense. Tomato plant defense induced by ß-ocimene was assessed by characterizing the aphid performance in terms of fixing behaviour, development and reproduction (direct plant defense) and the parasitoid performance in terms of attraction towards tomato plants (indirect plant defense). The characterization of tomato response to ß-ocimene was completed by the identification of Volatile Organic Compounds as released by conditioned tomato plants. Tomato plants that were exposed to the volatiles of transgenic tobacco enriched in ß-ocimene resulted in less suitable for the aphids in respect to control ones (direct defense). On tomato plants "elicited" by ß-ocimene we recorded: a significant lower number of aphids settled; a significant lower number newborn nymphs; a significant lower weight of aphids feeding. In addition, tomato plants "elicited" by ß-ocimene resulted became more attractive towards the parasitoid A. ervi than control ones. These results could be explained at least in part by examining the composition of the Volatile Organic Compounds released by tomato plants "elicited" by ß-ocimene. Indeed, we found a significantly higher release of several compounds including methyl salicylate and cis-3-hexen-1-ol. These two compounds have been demonstrated to impair aphid development and reproduction and to be involved in the attraction of the aphid parasitoid A. ervi. By considering the ubiquity of ß-ocimene and its ability to regulate the communication of plants belonging 30 to different species (if not families), we concluded that this compound is an ideal candidate for new 31 strategies of sustainable control of agricultural pests.


Assuntos
Alcenos/metabolismo , Afídeos/fisiologia , Interações Hospedeiro-Parasita , Lycopersicon esculentum/imunologia , Imunidade Vegetal , Tabaco/química , Monoterpenos Acíclicos , Animais , Expressão Gênica , Hexanóis/metabolismo , Lycopersicon esculentum/efeitos dos fármacos , Lycopersicon esculentum/genética , Plantas Geneticamente Modificadas , Salicilatos/metabolismo , Tabaco/genética , Compostos Orgânicos Voláteis/metabolismo
14.
Mol Plant Microbe Interact ; 26(10): 1249-56, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23718124

RESUMO

Below ground and above ground plant-insect-microorganism interactions are complex and regulate most of the developmental responses of important crop plants such as tomato. We investigated the influence of root colonization by a nonmycorrhizal plant-growth-promoting fungus on direct and indirect defenses of tomato plant against aphids. The multitrophic system included the plant Solanum lycopersicum ('San Marzano nano'), the root-associated biocontrol fungus Trichoderma longibrachiatum strain MK1, the aphid Macrosiphum euphorbiae (a tomato pest), the aphid parasitoid Aphidius ervi, and the aphid predator Macrolophus pygmaeus. Laboratory bioassays were performed to assess the effect of T. longibrachiatum MK1, interacting with the tomato plant, on quantity and quality of volatile organic compounds (VOC) released by tomato plant, aphid development and reproduction, parasitoid behavior, and predator behavior and development. When compared with the uncolonized controls, plants whose roots were colonized by T. longibrachiatum MK1 showed quantitative differences in the release of specific VOC, better aphid population growth indices, a higher attractiveness toward the aphid parasitoid and the aphid predator, and a quicker development of aphid predator. These findings support the development of novel strategies of integrated control of aphid pests. The species-specific or strain-specific characteristics of these below ground-above ground interactions remain to be assessed.


Assuntos
Afídeos/fisiologia , Himenópteros/fisiologia , Lycopersicon esculentum/microbiologia , Controle Biológico de Vetores , Doenças das Plantas/microbiologia , Trichoderma/fisiologia , Animais , Interações Hospedeiro-Patógeno , Lycopersicon esculentum/química , Lycopersicon esculentum/parasitologia , Doenças das Plantas/parasitologia , Raízes de Plantas/química , Raízes de Plantas/microbiologia , Raízes de Plantas/parasitologia , Especificidade da Espécie , Compostos Orgânicos Voláteis/metabolismo
15.
Physiol Plant ; 138(1): 10-21, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19843237

RESUMO

Plants have evolved complex mechanisms to perceive environmental cues and develop appropriate and coordinated responses to abiotic and biotic stresses. Considerable progress has been made towards a better understanding of the molecular mechanisms of plant response to a single stress. However, the existence of cross-tolerance to different stressors has proved to have great relevance in the control and regulation of organismal adaptation. Evidence for the involvement of the signal peptide systemin and jasmonic acid in wound-induced salt stress adaptation in tomato has been provided. To further unravel the functional link between plant responses to salt stress and mechanical damage, transgenic tomato (Lycopersicon esculentum Mill.) plants constitutively expressing the prosystemin cDNA have been exposed to a moderate salt stress. Prosystemin over-expression caused a reduction in stomatal conductance. However, in response to salt stress, prosystemin transgenic plants maintained a higher stomatal conductance compared with the wild-type control. Leaf concentrations of abscissic acid (ABA) and proline were lower in stressed transgenic plants compared with their wild-type control, implying that either the former perceived a less stressful environment or they adapted more efficiently to it. Consistently, under salt stress, transgenic plants produced a higher biomass, indicating that a constitutive activation of wound responses is advantageous in saline environment. Comparative gene expression profiling of stress-induced genes suggested that the partial stomatal closure was not mediated by ABA and/or components of the ABA signal transduction pathway. Possible cross-talks between genes involved in wounding and osmotic stress adaptation pathways in tomato are discussed.


Assuntos
Lycopersicon esculentum/fisiologia , Peptídeos/genética , Plantas Tolerantes a Sal/fisiologia , Ácido Abscísico/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Lycopersicon esculentum/genética , Lycopersicon esculentum/crescimento & desenvolvimento , Estômatos de Plantas/fisiologia , Transpiração Vegetal , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/fisiologia , Prolina/metabolismo , RNA de Plantas/genética , Plantas Tolerantes a Sal/genética , Plantas Tolerantes a Sal/crescimento & desenvolvimento , Cloreto de Sódio/farmacologia
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