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1.
Proc Natl Acad Sci U S A ; 120(10): e2216922120, 2023 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-36848561

RESUMO

Plants generate energy flows through natural food webs, driven by competition for resources among organisms, which are part of a complex network of multitrophic interactions. Here, we demonstrate that the interaction between tomato plants and a phytophagous insect is driven by a hidden interplay between their respective microbiotas. Tomato plants colonized by the soil fungus Trichoderma afroharzianum, a beneficial microorganism widely used in agriculture as a biocontrol agent, negatively affects the development and survival of the lepidopteran pest Spodoptera littoralis by altering the larval gut microbiota and its nutritional support to the host. Indeed, experiments aimed to restore the functional microbial community in the gut allow a complete rescue. Our results shed light on a novel role played by a soil microorganism in the modulation of plant-insect interaction, setting the stage for a more comprehensive analysis of the impact that biocontrol agents may have on ecological sustainability of agricultural systems.


Assuntos
Microbioma Gastrointestinal , Microbiota , Solanum lycopersicum , Animais , Solo , Insetos , Agricultura
2.
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 , Solanum lycopersicum/metabolismo , Solanum lycopersicum/parasitologia , Animais , Afídeos/fisiologia , Interações Hospedeiro-Parasita , Spodoptera/fisiologia , Compostos Orgânicos Voláteis/metabolismo , Vespas/fisiologia
3.
Biotechnol Lett ; 39(7): 1049-1058, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28365881

RESUMO

OBJECTIVES: To engineer broad spectrum resistance in potato using different expression strategies. RESULTS: The previously identified Ribosome-Inactivating Protein from Phytolacca heterotepala was expressed in potato under a constitutive or a wound-inducible promoter. Leaves and tubers of the plants constitutively expressing the transgene were resistant to Botrytis cinerea and Rhizoctonia solani, respectively. The wound-inducible promoter was useful in driving the expression upon wounding and fungal damage, and conferred resistance to B. cinerea. The observed differences between the expression strategies are discussed considering the benefits and features offered by the two systems. CONCLUSIONS: Evidence is provided of the possible impact of promoter sequences to engineer BSR in plants, highlighting that the selection of a suitable expression strategy has to balance specific needs and target species.


Assuntos
Resistência à Doença , Expressão Gênica , Organismos Geneticamente Modificados/imunologia , Doenças das Plantas/prevenção & controle , Proteínas Recombinantes/metabolismo , Proteínas Inativadoras de Ribossomos/metabolismo , Solanum tuberosum/imunologia , Botrytis/imunologia , Botrytis/patogenicidade , Regulação da Expressão Gênica de Plantas , Organismos Geneticamente Modificados/genética , Phytolacca/enzimologia , Phytolacca/genética , Doenças das Plantas/microbiologia , Proteínas Recombinantes/genética , Rhizoctonia/imunologia , Rhizoctonia/patogenicidade , Proteínas Inativadoras de Ribossomos/genética , Solanum tuberosum/genética
4.
J Integr Plant Biol ; 58(4): 413-25, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25727685

RESUMO

Olive fly (Bactrocera oleae R.) is the most harmful insect pest of olive (Olea europaea L.) which strongly affects fruits and oil production. Despite the expanding economic importance of olive cultivation, up to now, only limited information on plant responses to B. oleae is available. Here, we demonstrate that olive fruits respond to B. oleae attack by producing changes in an array of different defensive compounds including phytohormones, volatile organic compounds (VOCs), and defense proteins. Bactrocera oleae-infested fruits induced a strong ethylene burst and transcript levels of several putative ethylene-responsive transcription factors became significantly upregulated. Moreover, infested fruits induced significant changes in the levels of 12-oxo-phytodienoic acid and C12 derivatives of the hydroperoxide lyase. The emission of VOCs was also changed quantitatively and qualitatively in insect-damaged fruits, indicating that B. oleae larval feeding can specifically affect the volatile blend of fruits. Finally, we show that larval infestation maintained high levels of trypsin protease inhibitors in ripe fruits, probably by affecting post-transcriptional mechanisms. Our results provide novel and important information to understand the response of the olive fruit to B. oleae attack; information that can shed light onto potential new strategies to combat this pest.


Assuntos
Etilenos/metabolismo , Frutas/parasitologia , Olea/parasitologia , Doenças das Plantas/parasitologia , Tephritidae/fisiologia , Compostos Orgânicos Voláteis/metabolismo , Animais , Comportamento Alimentar , Flores/genética , Frutas/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Larva , Modelos Biológicos , Olea/genética , Doenças das Plantas/genética , Reguladores de Crescimento de Plantas/metabolismo , Inibidores de Proteases/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transdução de Sinais/genética
5.
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.

6.
Plant Sci ; 340: 111969, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38159610

RESUMO

The in-depth studies over the years on the defence barriers by tomato plants have shown that the Systemin peptide controls the response to a wealth of environmental stress agents. This multifaceted stress reaction seems to be related to the intrinsic disorder of its precursor protein, Prosystemin (ProSys). Since latest findings show that ProSys has biological functions besides Systemin sequence, here we wanted to assess if this precursor includes peptide motifs able to trigger stress-related pathways. Candidate peptides were identified in silico and synthesized to test their capacity to trigger defence responses in tomato plants against different biotic stressors. Our results demonstrated that ProSys harbours several repeat motifs which triggered plant immune reactions against pathogens and pest insects. Three of these peptides were detected by mass spectrometry in plants expressing ProSys, demonstrating their effective presence in vivo. These experimental data shed light on unrecognized functions of ProSys, mediated by multiple biologically active sequences which may partly account for the capacity of ProSys to induce defense responses to different stress agents.


Assuntos
Peptídeos , Proteínas de Plantas , Peptídeos/metabolismo , Proteínas de Plantas/metabolismo
7.
BMC Genomics ; 14: 835, 2013 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-24279304

RESUMO

BACKGROUND: The tomato (Solanum lycopersium L.) is the most widely grown vegetable in the world. It was domesticated in Latin America and Italy and Spain are considered secondary centers of diversification. This food crop has experienced severe genetic bottlenecks and modern breeding activities have been characterized by trait introgression from wild species and divergence in different market classes. RESULTS: With the aim to examine patterns of polymorphism, characterize population structure and identify putative loci under positive selection, we genotyped 214 tomato accessions (which include cultivated landraces, commercial varieties and wild relatives) using a custom-made Illumina SNP-panel. Most of the 175 successfully scored SNP loci were found to be polymorphic. Population structure analysis and estimates of genetic differentiation indicated that landraces constitute distinct sub-populations. Furthermore, contemporary varieties could be separated in groups (processing, fresh and cherry) that are consistent with the recent breeding aimed at market-class specialization. In addition, at the 95% confidence level, we identified 30, 34 and 37 loci under positive selection between landraces and each of the groups of commercial variety (cherry, processing and fresh market, respectively). Their number and genomic locations imply the presence of some extended regions with high genetic variation between landraces and contemporary varieties. CONCLUSIONS: Our work provides knowledge concerning the level and distribution of genetic variation within cultivated tomato landraces and increases our understanding of the genetic subdivision of contemporary varieties. The data indicate that adaptation and selection have led to a genomic signature in cultivated landraces and that the subpopulation structure of contemporary varieties is shaped by directed breeding and largely of recent origin. The genomic characterization presented here is an essential step towards a future exploitation of the available tomato genetic resources in research and breeding programs.


Assuntos
Polimorfismo de Nucleotídeo Único , Solanum lycopersicum/genética , Cruzamento , Evolução Molecular , Genes de Plantas , Loci Gênicos , Modelos Genéticos , Seleção Genética , Análise de Sequência de DNA
8.
BMC Genomics ; 14: 515, 2013 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-23895395

RESUMO

BACKGROUND: Aphids are among the most destructive pests in temperate climates, causing significant damage on several crops including tomato. We carried out a transcriptomic and proteomic study to get insights into the molecular mechanisms and dynamics of the tomato response to the Macrosyphum euphorbiae aphid. RESULTS: The time course analysis of aphid infestation indicated a complex, dynamic pattern of gene expression. Several biological functions were affected and genes related to the stress and defence response were the most represented. The Gene Ontology categories of the differentially expressed genes (899) and identified proteins (57) indicated that the tomato response is characterized by an increased oxidative stress accompanied by the production of proteins involved in the detoxification of oxygen radicals. Aphids elicit a defense reaction based on the cross-communication of different hormone-related signaling pathways such as those related to the salicylic acid (SA), jasmonic acid (JA), ethylene and brassinosteroids. Among them, the SA-signaling pathway and stress-responsive SA-dependent genes play a dominant role. Furthermore, tomato response is characterized by a reduced accumulation of photosynthetic proteins and a modification of the expression of various cell wall related genes. CONCLUSIONS: Our work allowed a more comprehensive understanding of the signaling events and the defense dynamics of the tomato response to aphids in a compatible interaction and, based on experimental data, a model of the tomato-aphid molecular interaction was proposed. Considering the rapid advancement of tomato genomics, this information will be important for the development of new protection strategies.


Assuntos
Afídeos/fisiologia , Proteômica , Ácido Salicílico/metabolismo , Solanum lycopersicum/parasitologia , Transcriptoma , Animais , Perfilação da Expressão Gênica , Solanum lycopersicum/genética , Reação em Cadeia da Polimerase
9.
Comput Struct Biotechnol J ; 21: 212-223, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36544481

RESUMO

Tomato Prosystemin (ProSys), the precursor of Systemin, a small peptidic hormone, is produced at very low concentration in unchallenged plants, while its expression greatly increases in response to several different stressors triggering an array of defence responses. The molecular mechanisms that underpin such a wide array of defence barriers are not fully understood and are likely correlated with the intrinsically disordered (ID) structure of the protein. ID proteins interact with different protein partners forming complexes involved in the modulation of different biological mechanisms. Here we describe the ProSys-protein network that shed light on the molecular mechanisms underpinning ProSys associated defence responses. Three different approaches were used. In silico prediction resulted in 98 direct interactors, most clustering in phytohormone biosynthesis, transcription factors and signal transduction gene classes. The network shows the central role of ProSys during defence responses, that reflects its role as central hub. In vitro ProSys interactors, identified by Affinity Purification-Mass Spectrometry (AP-MS), revealed over three hundred protein partners, while Bimolecular Fluorescent Complementation (BiFC) experiments validated in vivo some interactors predicted in silico and in vitro. Our results demonstrate that ProSys interacts with several proteins and reveal new key molecular events in the ProSys-dependent defence response of tomato plant.

11.
BMC Plant Biol ; 12: 86, 2012 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-22694925

RESUMO

BACKGROUND: The fruit fly Bactrocera oleae is the primary biotic stressor of cultivated olives, causing direct and indirect damages that significantly reduce both the yield and the quality of olive oil. To study the olive-B. oleae interaction, we conducted transcriptomic and proteomic investigations of the molecular response of the drupe. The identifications of genes and proteins involved in the fruit response were performed using a Suppression Subtractive Hybridisation technique and a combined bi-dimensional electrophoresis/nanoLC-ESI-LIT-MS/MS approach, respectively. RESULTS: We identified 196 ESTs and 26 protein spots as differentially expressed in olives with larval feeding tunnels. A bioinformatic analysis of the identified non-redundant EST and protein collection indicated that different molecular processes were affected, such as stress response, phytohormone signalling, transcriptional control and primary metabolism, and that a considerable proportion of the ESTs could not be classified. The altered expression of 20 transcripts was also analysed by real-time PCR, and the most striking differences were further confirmed in the fruit of a different olive variety. We also cloned the full-length coding sequences of two genes, Oe-chitinase I and Oe-PR27, and showed that these are wound-inducible genes and activated by B. oleae punctures. CONCLUSIONS: This study represents the first report that reveals the molecular players and signalling pathways involved in the interaction between the olive fruit and its most damaging biotic stressor. Drupe response is complex, involving genes and proteins involved in photosynthesis as well as in the production of ROS, the activation of different stress response pathways and the production of compounds involved in direct defence against phytophagous larvae. Among the latter, trypsin inhibitors should play a major role in drupe resistance reaction.


Assuntos
Olea/fisiologia , Transdução de Sinais , Estresse Fisiológico , Tephritidae/fisiologia , Sequência de Aminoácidos , Animais , Biologia Computacional , Etiquetas de Sequências Expressas/metabolismo , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Herbivoria , Dados de Sequência Molecular , Olea/genética , Olea/metabolismo , Fotossíntese , Proteoma/análise , Espécies Reativas de Oxigênio/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Alinhamento de Sequência , Transcriptoma
12.
BMC Plant Biol ; 12: 162, 2012 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-22963618

RESUMO

BACKGROUND: Olive (Olea europaea L.) fruits contain numerous secondary metabolites, primarily phenolics, terpenes and sterols, some of which are particularly interesting for their nutraceutical properties. This study will attempt to provide further insight into the profile of olive phenolic compounds during fruit development and to identify the major genetic determinants of phenolic metabolism. RESULTS: The concentration of the major phenolic compounds, such as oleuropein, demethyloleuropein, 3-4 DHPEA-EDA, ligstroside, tyrosol, hydroxytyrosol, verbascoside and lignans, were measured in the developing fruits of 12 olive cultivars. The content of these compounds varied significantly among the cultivars and decreased during fruit development and maturation, with some compounds showing specificity for certain cultivars. Thirty-five olive transcripts homologous to genes involved in the pathways of the main secondary metabolites were identified from the massive sequencing data of the olive fruit transcriptome or from cDNA-AFLP analysis. Their mRNA levels were determined using RT-qPCR analysis on fruits of high- and low-phenolic varieties (Coratina and Dolce d'Andria, respectively) during three different fruit developmental stages. A strong correlation was observed between phenolic compound concentrations and transcripts putatively involved in their biosynthesis, suggesting a transcriptional regulation of the corresponding pathways. OeDXS, OeGES, OeGE10H and OeADH, encoding putative 1-deoxy-D-xylulose-5-P synthase, geraniol synthase, geraniol 10-hydroxylase and arogenate dehydrogenase, respectively, were almost exclusively present at 45 days after flowering (DAF), suggesting that these compounds might play a key role in regulating secoiridoid accumulation during fruit development. CONCLUSIONS: Metabolic and transcriptional profiling led to the identification of some major players putatively involved in biosynthesis of secondary compounds in the olive tree. Our data represent the first step towards the functional characterisation of important genes for the determination of olive fruit quality.


Assuntos
Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Olea/metabolismo , Fenóis/metabolismo , Transcriptoma , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Vias Biossintéticas , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Frutas/genética , Perfilação da Expressão Gênica , Genes de Plantas , Glucosídeos/genética , Glucosídeos/metabolismo , Glucosídeos Iridoides/metabolismo , Iridoides , Metabolômica/métodos , Olea/genética , Olea/crescimento & desenvolvimento , Álcool Feniletílico/análogos & derivados , Álcool Feniletílico/metabolismo , Óleos de Plantas/análise , Óleos de Plantas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Prefenato Desidrogenase/genética , Prefenato Desidrogenase/metabolismo , Piranos/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Especificidade da Espécie
13.
Meat Sci ; 183: 108662, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34469806

RESUMO

This work investigated the effects of feeding ensiled bergamot pulp to pigs on meat and salami quality. Eighteen pigs were assigned to two experimental treatments and fed a cereal-based concentrate diet (control) or the same diet in which ensiled bergamot pulp replaced 15% dry matter of the diet fed (BP). The BP treatment increased α-linolenic acid (+250%; P < 0.05), docosapentaenoic acid (+62%; P < 0.05), docosahexaenoic acid (+43%; P < 0.05) and consequently n-3 PUFA (+15%; P < 0.01) in meat. In salami, the content of α-linolenic acid, total PUFA and n-3 PUFA increased (+320%, +25% and + 258%, respectively) by feeding the BP diet (P < 0.001). The inclusion of bergamot pulp in the diet did not alter the oxidative stability in raw and cooked meat and colour descriptors. In salami, TBARS values were lower after 5 days of storage (P < 0.001) in BP group (1.54 vs 2.96). Finally, dietary supplementation with ensiled bergamot pulp to pigs improved the nutritional value of meat and meat products.


Assuntos
Ração Animal , Citrus , Produtos da Carne/análise , Carne de Porco/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Dieta/veterinária , Ácidos Graxos Insaturados/análise , Silagem , Suínos
14.
Animals (Basel) ; 12(6)2022 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-35327154

RESUMO

An investigation was carried out on the effect in pig diet of supplementation with exhausted bergamot by-product, stemming from pharmaceutical industry after extraction of phenolic compounds, on growth performance and on the quality of meat and meat products. Twenty pigs were assigned to two dietary treatments and fed a conventional concentrate (control) or a concentrate including exhausted bergamot by-product at the level of 15% on a DM basis (EB). No significant differences between dietary treatments were found for final weight (p = 0.243), carcass weight (p = 0.679), dry matter intake (p = 0.321). In EB pork, the proportion of docosapentaenoic acid was significantly increased (p < 0.05); it tended to have a greater proportion of n-3 PUFA (p = 0.09), and the n-6/n-3 PUFA ratio was lower in EB treatment (p = 0.01). In salami from EB pigs fed, the proportion of α-linolenic acid and the total n-3 PUFA were higher than in the control group (p < 0.001). In salami, the TBARS value was lower after 5 days of storage (p < 0.001) in the EB group. Therefore, the present results suggest that the inclusion of exhausted bergamot by-product in pig diet resulted in a qualitative improvement of meat and meat products.

15.
Biology (Basel) ; 11(1)2022 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-35053122

RESUMO

Systemin (Sys) is an octadecapeptide, which upon wounding, is released from the carboxy terminus of its precursor, Prosystemin (ProSys), to promote plant defenses. Recent findings on the disordered structure of ProSys prompted us to investigate a putative biological role of the whole precursor deprived of the Sys peptide. We produced transgenic tomato plants expressing a truncated ProSys gene in which the exon coding for Sys was removed and compared their defense response with that induced by the exogenous application of the recombinant truncated ProSys (ProSys(1-178), the Prosystemin sequence devoid of Sys region). By combining protein structure analyses, transcriptomic analysis, gene expression profiling and bioassays with different pests, we demonstrate that truncated ProSys promotes defense barriers in tomato plants through a hormone-independent defense pathway, likely associated with the production of oligogalacturonides (OGs). Both transgenic and plants treated with the recombinant protein showed the modulation of the expression of genes linked with defense responses and resulted in protection against the lepidopteran pest Spodoptera littoralis and the fungus Botrytis cinerea. Our results suggest that the overall function of the wild-type ProSys is more complex than previously shown, as it might activate at least two tomato defense pathways: the well-known Sys-dependent pathway connected with the induction of jasmonic acid biosynthesis and the successive activation of a set of defense-related genes, and the ProSys(1-178)-dependent pathway associated with OGs production leading to the OGs mediate plant immunity.

16.
Front Plant Sci ; 13: 887674, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35685017

RESUMO

Prosystemin is a 200-amino acid precursor expressed in Solanaceae plants which releases at the C-terminal part a peptidic hormone called Systemin in response to wounding and herbivore attack. We recently showed that Prosystemin is not only a mere scaffold of Systemin but, even when deprived of Systemin, is biologically active. These results, combined with recent discoveries that Prosystemin is an intrinsically disordered protein containing disordered regions within its sequence, prompted us to investigate the N-terminal portions of the precursor, which contribute to the greatest disorder within the sequence. To this aim, PS1-70 and PS1-120 were designed, produced, and structurally and functionally characterized. Both the fragments, which maintained their intrinsic disorder, were able to induce defense-related genes and to protect tomato plants against Botrytis cinerea and Spodoptera littoralis larvae. Intriguingly, the biological activity of each of the two N-terminal fragments and of Systemin is similar but not quite the same and does not show any toxicity on experimental non-targets considered. These regions account for different anti-stress activities conferred to tomato plants by their overexpression. The two N-terminal fragments identified in this study may represent new promising tools for sustainable crop protection.

17.
Plants (Basel) ; 10(7)2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34209307

RESUMO

Apricot (Prunus armeniaca L.) is an economically important tree species globally cultivated in temperate areas. Italy has an ample number of traditional varieties, but numerous landraces are abandoned and at risk of extinction because of increasing urbanization, agricultural intensification, and varietal renewal. In this work, we investigated the morphological and genetic diversity present in an ex-situ collection of 28 neglected varieties belonging to the so-called "Vesuvian apricot". Our aim was to understand the level of diversity and the possible link between the promotion of specific fruit types (e.g., by public policies) and the intraspecific variation in apricot. The combination of five continuous and seven categorical traits allowed us to phenotypically distinguish the varieties; while fruit quality-related attributes displayed high variation, both apricot size and skin colour were more uniform. The twelve fluorescent-based Simple Sequence Repeats (SSRs) markers identified cultivar-specific molecular profiles and revealed a high molecular diversity, which poorly correlated with that described by the morphological analysis. Our results highlighted the complementary information provided by the two sets of descriptors and that DNA markers are necessary to separate morphologically related apricot landraces. The observed morphological and genetic differences suggest a loss of diversity influenced by maintenance breeding of specific pomological traits (e.g., skin colour and size). Finally, our study provided evidence to recommend complementary strategies to avoid the loss of diversity in apricot. Actions should pivot on both the promotion of easily identified premium products and more inclusive biodiversity-centred on-farm strategies.

18.
Front Plant Sci ; 12: 678830, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34177994

RESUMO

Species of the ecological opportunistic, avirulent fungus, Trichoderma are widely used in agriculture for their ability to protect crops from the attack of pathogenic fungi and for plant growth promotion activity. Recently, it has been shown that they may also have complementary properties that enhance plant defense barriers against insects. However, the use of these fungi is somewhat undermined by their variable level of biocontrol activity, which is influenced by environmental conditions. Understanding the source of this variability is essential for its profitable and wide use in plant protection. Here, we focus on the impact of temperature on Trichoderma afroharzianum T22, Trichoderma atroviride P1, and the defense response induced in tomato by insects. The in vitro development of these two strains was differentially influenced by temperature, and the observed pattern was consistent with temperature-dependent levels of resistance induced by them in tomato plants against the aphid, Macrosiphum euphorbiae, and the noctuid moth, Spodoptera littoralis. Tomato plants treated with T. afroharzianum T22 exhibited enhanced resistance toward both insect pests at 25°C, while T. atroviride P1 proved to be more effective at 20°C. The comparison of plant transcriptomic profiles generated by the two Trichoderma species allowed the identification of specific defense genes involved in the observed response, and a selected group was used to assess, by real-time quantitative reverse transcription PCR (qRT-PCR), the differential gene expression in Trichoderma-treated tomato plants subjected to the two temperature regimens that significantly affected fungal biological performance. These results will help pave the way toward a rational selection of the most suitable Trichoderma isolates for field applications, in order to best face the challenges imposed by local environmental conditions and by extreme climatic shifts due to global warming.

19.
New Phytol ; 187(4): 1089-1101, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20546139

RESUMO

*An integrated approach has been used to obtain an understanding of the molecular and chemical mechanisms underlying resistance to aphids in cherry-like tomato (Solanum lycopersicum) landraces from the Campania region (southern Italy). The aphid-parasitoid system Macrosiphum euphorbiae-Aphidius ervi was used to describe the levels of resistance against aphids in two tomato accessions (AN5, AN7) exhibiting high yield and quality traits and lacking the tomato Mi gene. *Aphid development and reproduction, flight response by the aphid parasitoid A. ervi, gas chromatography-mass spectrometry headspace analysis of plant volatile organic compounds and transcriptional analysis of aphid responsive genes were performed on selected tomato accessions and on a susceptible commercial variety (M82). *When compared with the cultivated variety, M82, AN5 and AN7 showed a significant reduction of M. euphorbiae fitness, the release of larger amounts of specific volatile organic compounds that are attractive to the aphid parasitoid A. ervi, a constitutively higher level of expression of plant defence genes and differential enhancement of plant indirect resistance induced by aphid feeding. *These results provide new insights on how local selection can offer the possibility of the development of innovative genetic strategies to increase tomato resistance against aphids.


Assuntos
Afídeos , Expressão Gênica , Genes de Plantas , Interações Hospedeiro-Parasita/genética , Doenças das Plantas , Imunidade Vegetal/genética , Solanum lycopersicum/genética , Animais , Solanum lycopersicum/química , Solanum lycopersicum/metabolismo , Compostos Orgânicos Voláteis/metabolismo
20.
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
Peptídeos/genética , Plantas Tolerantes a Sal/fisiologia , Solanum lycopersicum/fisiologia , Ácido Abscísico/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Solanum lycopersicum/genética , Solanum lycopersicum/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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