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1.
Plants (Basel) ; 13(13)2024 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-38999712

RESUMO

Phosphite (Phi) has gained attention in agriculture due to its biostimulant effect on crops. This molecule has been found to benefit plant performance by providing protection against pathogens, improving yield and fruit quality as well as nutrient and water use efficiency. It is still unclear how Phi enhances plant growth and protects against multiple stresses. It has been hypothesized that Phi acts by directly affecting the pathogens and interacting with the plant cellular components and molecular machinery to elicit defense responses. This study elucidates the mechanisms underlying Phi's beneficial effects on plants, revealing their complex interplay with fundamental signaling pathways. An RNA-seq study of Arabidopsis seedlings under optimal and limiting phosphate conditions helped us unveil Phi's role in promoting plant growth by activating the expression of the genes involved in the biosynthesis and signaling pathways associated with abscisic acid (ABA), salicylic acid (SA), and jasmonic acid (JA). The expression of ABA-related genes, known for their involvement in stress response and development regulation, is triggered by Phi treatment, contributing to enhanced resilience and growth. Simultaneously, the activation of the SA pathway, associated with defense responses, suggests Phi's potential in bolstering plant immunity. Moreover, Phi influences JA biosynthesis and signaling, which are crucial for defense against herbivores and pathogens, thereby strengthening plants' defenses. Our findings reveal a multifaceted mechanism through which Phi benefits Arabidopsis development. Understanding its intricate interplay with key signaling pathways opens avenues for leveraging Phi as a strategic tool to enhance plant resilience, immunity, and growth in agricultural and ecological contexts.

2.
Life (Basel) ; 14(6)2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38929736

RESUMO

Pomegranate fruit dry rot is caused by Coniella granati, also referred as Pilidiella granati. In order to decipher the induced responses of mature pomegranates inoculated with the pathogen, an RNA-seq analysis was employed. A high number of differentially expressed genes (DEGs) were observed through a three-time series inoculation period. The transcriptional reprogramming was time-dependent, whereas the majority of DEGs were suppressed and the expression patterns of specific genes may facilitate the pathogen colonization at 1 day after inoculation (dai). In contrast, at 2 dai and mainly thereafter at 3 dai, defense responses were partially triggered in delay. Particularly, DEGs were mainly upregulated at the latest time point. Among them, specific DEGs involved in cell wall modification and degradation processes, pathogen recognition and signaling transduction cascades, activation of specific defense and metabolite biosynthesis-related genes, as well in induction of particular families of transcriptional factors, may constitute crucial components of a defense recruiting strategy employed by pomegranate fruit upon C. granati challenge. Overall, our findings provide novel insights to the compatible interaction of pomegranates-C. granati and lay the foundations for establishing integrated pest management (IPM) strategies involving advanced approaches, such as gene editing or molecular breeding programs for disease resistance, according to European Union (EU) goals.

3.
J Fungi (Basel) ; 10(6)2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38921400

RESUMO

Phytopathogenic Ganoderma species pose a significant threat to global plant health, resulting in estimated annual economic losses exceeding USD (US Dollars) 68 billion in the agriculture and forestry sectors worldwide. To combat this pervasive menace effectively, a comprehensive understanding of the biology, ecology, and plant infection mechanisms of these pathogens is imperative. This comprehensive review critically examines various aspects of Ganoderma spp., including their intricate life cycle, their disease mechanisms, and the multifaceted environmental factors influencing their spread. Recent studies have quantified the economic impact of Ganoderma infections, revealing staggering yield losses ranging from 20% to 80% across various crops. In particular, oil palm plantations suffer devastating losses, with an estimated annual reduction in yield exceeding 50 million metric tons. Moreover, this review elucidates the dynamic interactions between Ganoderma and host plants, delineating the pathogen's colonization strategies and its elicitation of intricate plant defense responses. This comprehensive analysis underscores the imperative for adopting an integrated approach to Ganoderma disease management. By synergistically harnessing cultural practices, biological control, and chemical treatments and by deploying resistant plant varieties, substantial strides can be made in mitigating Ganoderma infestations. Furthermore, a collaborative effort involving scientists, breeders, and growers is paramount in the development and implementation of sustainable strategies against this pernicious plant pathogen. Through rigorous scientific inquiry and evidence-based practices, we can strive towards safeguarding global plant health and mitigating the dire economic consequences inflicted by Ganoderma infections.

4.
Food Chem ; 453: 139669, 2024 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-38781900

RESUMO

Green mold is a common postharvest disease infected by Penicillium digitatum that causes citrus fruit decay, and severely affects fruit storage quality. This work aimed to investigate the antifungal activity of Sanxiapeptin against P. digitatum, and elucidate the possible mechanisms involved. Sanxiapeptin was capable of inhibiting spore germination, germ tube length and mycelial growth. The SYTOX green staining assay revealed that Sanxiapeptin targeted the fungal membrane, and changed the membrane permeability, leading to the leakage of cell constituents. Meanwhile, Sanxiapeptin could influence the cell wall permeability and integrity by increasing the activities of chitinase and glucanase, resulting in abnormal chitin consumption and the decrease of glucan. Intriguingly, Sanxiapeptin could effectively control postharvest decay in citrus fruits, and activate the host resistance responses by regulating the phenylpropanoid pathway. In conclusion, Sanxiapeptin exhibits multiphasic antifungal mechanisms of action to control green mold in citrus fruits, shows great potential as novel food preservatives.


Assuntos
Citrus , Conservantes de Alimentos , Frutas , Penicillium , Doenças das Plantas , Citrus/microbiologia , Citrus/química , Penicillium/crescimento & desenvolvimento , Penicillium/efeitos dos fármacos , Doenças das Plantas/microbiologia , Frutas/microbiologia , Frutas/química , Frutas/crescimento & desenvolvimento , Frutas/efeitos dos fármacos , Conservantes de Alimentos/farmacologia , Antifúngicos/farmacologia , Antifúngicos/química , Conservação de Alimentos/métodos , Fungicidas Industriais/farmacologia , Fungicidas Industriais/química
5.
Cell ; 187(12): 3024-3038.e14, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38781969

RESUMO

Plants frequently encounter wounding and have evolved an extraordinary regenerative capacity to heal the wounds. However, the wound signal that triggers regenerative responses has not been identified. Here, through characterization of a tomato mutant defective in both wound-induced defense and regeneration, we demonstrate that in tomato, a plant elicitor peptide (Pep), REGENERATION FACTOR1 (REF1), acts as a systemin-independent local wound signal that primarily regulates local defense responses and regenerative responses in response to wounding. We further identified PEPR1/2 ORTHOLOG RECEPTOR-LIKE KINASE1 (PORK1) as the receptor perceiving REF1 signal for plant regeneration. REF1-PORK1-mediated signaling promotes regeneration via activating WOUND-INDUCED DEDIFFERENTIATION 1 (WIND1), a master regulator of wound-induced cellular reprogramming in plants. Thus, REF1-PORK1 signaling represents a conserved phytocytokine pathway to initiate, amplify, and stabilize a signaling cascade that orchestrates wound-triggered organ regeneration. Application of REF1 provides a simple method to boost the regeneration and transformation efficiency of recalcitrant crops.


Assuntos
Proteínas de Plantas , Regeneração , Transdução de Sinais , Solanum lycopersicum , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Solanum lycopersicum/metabolismo , Regulação da Expressão Gênica de Plantas , Peptídeos/metabolismo
6.
Front Plant Sci ; 15: 1376917, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38645389

RESUMO

Plants have evolved distinct defense strategies in response to a diverse range of chewing and sucking insect herbivory. While chewing insect herbivores, exemplified by caterpillars and beetles, cause visible tissue damage and induce jasmonic acid (JA)-mediated defense responses, sucking insects, such as aphids and whiteflies, delicately tap into the phloem sap and elicit salicylic acid (SA)-mediated defense responses. This review aims to highlight the specificity of defense strategies in Brassica plants and associated underlying molecular mechanisms when challenged by herbivorous insects from different feeding guilds (i.e., chewing and sucking insects). To establish such an understanding in Brassica plants, the typical defense responses were categorized into physical, chemical, and metabolic adjustments. Further, the impact of contrasting feeding patterns on Brassica is discussed in context to unique biochemical and molecular modus operandi that governs the resistance against chewing and sucking insect pests. Grasping these interactions is crucial to developing innovative and targeted pest management approaches to ensure ecosystem sustainability and Brassica productivity.

7.
Sheng Wu Gong Cheng Xue Bao ; 40(4): 1050-1064, 2024 Apr 25.
Artigo em Chinês | MEDLINE | ID: mdl-38658148

RESUMO

Heterotrimeric GTP-binding protein (G-proteins) complex, which consists of Gα, Gß and Gγ subunits, plays critical roles in defense signaling. Arabidopsis genome contains only a single Gß-encoding gene, AGB1. Loss function of AGB1 in Arabidopsis results in enhanced susceptibility to a wide range of pathogens. However, the function of soybean AGB1 in immunity has not been previously interrogated. Bioinformatic analysis indicated that there are four GmAGB1 homologous genes in soybean genome, sharing homology of 86%-97%. To overcome the functional redundancy of these GmAGB1 homologs, virus-induced gene silencing (VIGS) mediated by the bean pod mottle virus (BPMV) was used to silence these four genes simultaneously. As expected, these four GmAGB1 homologous genes were indeed silenced by a single BPMV-VIGS vector carrying a conserved fragments among these four genes. A dwarfed phenotype was observed in GmAGB1s-silenced soybean plants, suggesting that GmAGB1s play a crucial role in growth and development. Disease resistance analysis indicated that silencing GmAGB1s significantly compromised the resistance of soybean plants against Xanthomonas campestris pv. glycinea (Xag). This reduced resistance was correlated with the decreased accumulation of pathogen-induced reactive oxygen species (ROS) and the reduced activation of GmMPK3 in response to flg22, a conserved N-terminal peptide of flagellin protein. These results indicate that GmAGB1 functions as a positive regulator in disease resistance and GmAGB1 is indispensable for the ROS production and GmMPK3 activation induced by pathogen infection. Yeast two hybrid assay showed that GmAGB1 interacted with GmAGG1, suggesting that an evolutionary conserved heterotrimeric G protein complex similarly functions in soybean.


Assuntos
Resistência à Doença , Inativação Gênica , Glycine max , Doenças das Plantas , Glycine max/genética , Glycine max/imunologia , Glycine max/microbiologia , Doenças das Plantas/imunologia , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Resistência à Doença/genética , Comovirus/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteínas de Plantas/imunologia , Regulação da Expressão Gênica de Plantas , Subunidades beta da Proteína de Ligação ao GTP/genética , Subunidades beta da Proteína de Ligação ao GTP/metabolismo , Subunidades beta da Proteína de Ligação ao GTP/imunologia , Xanthomonas , Espécies Reativas de Oxigênio/metabolismo
8.
Int J Mol Sci ; 25(7)2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38612510

RESUMO

The ATP-dependent caseinolytic protease (Clp) system has been reported to play an important role in plant growth, development, and defense against pathogens. However, whether the Clp system is involved in plant defense against herbivores remains largely unclear. We explore the role of the Clp system in rice defenses against brown planthopper (BPH) Nilaparvata lugens by combining chemical analysis, transcriptome, and molecular analyses, as well as insect bioassays. We found the expression of a rice Clp proteolytic subunit gene, OsClpP6, was suppressed by infestation of BPH gravid females and mechanical wounding. Silencing OsClpP6 enhanced the level of BPH-induced jasmonic acid (JA), JA-isoleucine (JA-Ile), and ABA, which in turn promoted the production of BPH-elicited rice volatiles and increased the resistance of rice to BPH. Field trials showed that silencing OsClpP6 decreased the population densities of BPH and WBPH. We also observed that silencing OsClpP6 decreased chlorophyll content in rice leaves at early developmental stages and impaired rice root growth and seed setting rate. These findings demonstrate that an OsClpP6-mediated Clp system in rice was involved in plant growth-defense trade-offs by affecting the biosynthesis of defense-related signaling molecules in chloroplasts. Moreover, rice plants, after recognizing BPH infestation, can enhance rice resistance to BPH by decreasing the Clp system activity. The work might provide a new way to breed rice varieties that are resistant to herbivores.


Assuntos
Ciclopentanos , Hemípteros , Oryza , Oxilipinas , Feminino , Animais , Proteases Dependentes de ATP , Oryza/genética , Melhoramento Vegetal , Peptídeo Hidrolases , Isoleucina , Hemípteros/genética , Trifosfato de Adenosina
9.
Adv Virus Res ; 118: 77-212, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38461031

RESUMO

Resistance to infection by plant viruses involves proteins encoded by plant resistance (R) genes, viz., nucleotide-binding leucine-rich repeats (NLRs), immune receptors. These sensor NLRs are activated either directly or indirectly by viral protein effectors, in effector-triggered immunity, leading to induction of defense signaling pathways, resulting in the synthesis of numerous downstream plant effector molecules that inhibit different stages of the infection cycle, as well as the induction of cell death responses mediated by helper NLRs. Early events in this process involve recognition of the activation of the R gene response by various chaperones and the transport of these complexes to the sites of subsequent events. These events include activation of several kinase cascade pathways, and the syntheses of two master transcriptional regulators, EDS1 and NPR1, as well as the phytohormones salicylic acid, jasmonic acid, and ethylene. The phytohormones, which transit from a primed, resting states to active states, regulate the remainder of the defense signaling pathways, both directly and by crosstalk with each other. This regulation results in the turnover of various suppressors of downstream events and the synthesis of various transcription factors that cooperate and/or compete to induce or suppress transcription of either other regulatory proteins, or plant effector molecules. This network of interactions results in the production of defense effectors acting alone or together with cell death in the infected region, with or without the further activation of non-specific, long-distance resistance. Here, we review the current state of knowledge regarding these processes and the components of the local responses, their interactions, regulation, and crosstalk.


Assuntos
Reguladores de Crescimento de Plantas , Imunidade Vegetal , Imunidade Vegetal/genética , Reguladores de Crescimento de Plantas/metabolismo , Plantas , Transdução de Sinais , Doenças das Plantas/genética
10.
Plant Cell Rep ; 43(3): 80, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38411713

RESUMO

The escalating challenges posed by metal(loid) toxicity in agricultural ecosystems, exacerbated by rapid climate change and anthropogenic pressures, demand urgent attention. Soil contamination is a critical issue because it significantly impacts crop productivity. The widespread threat of metal(loid) toxicity can jeopardize global food security due to contaminated food supplies and pose environmental risks, contributing to soil and water pollution and thus impacting the whole ecosystem. In this context, plants have evolved complex mechanisms to combat metal(loid) stress. Amid the array of innovative approaches, omics, notably transcriptomics, proteomics, and metabolomics, have emerged as transformative tools, shedding light on the genes, proteins, and key metabolites involved in metal(loid) stress responses and tolerance mechanisms. These identified candidates hold promise for developing high-yielding crops with desirable agronomic traits. Computational biology tools like bioinformatics, biological databases, and analytical pipelines support these omics approaches by harnessing diverse information and facilitating the mapping of genotype-to-phenotype relationships under stress conditions. This review explores: (1) the multifaceted strategies that plants use to adapt to metal(loid) toxicity in their environment; (2) the latest findings in metal(loid)-mediated transcriptomics, proteomics, and metabolomics studies across various plant species; (3) the integration of omics data with artificial intelligence and high-throughput phenotyping; (4) the latest bioinformatics databases, tools and pipelines for single and/or multi-omics data integration; (5) the latest insights into stress adaptations and tolerance mechanisms for future outlooks; and (6) the capacity of omics advances for creating sustainable and resilient crop plants that can thrive in metal(loid)-contaminated environments.


Assuntos
Ecossistema , Proteômica , Inteligência Artificial , Perfilação da Expressão Gênica , Metais/toxicidade , Solo
11.
Stress Biol ; 4(1): 2, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38163824

RESUMO

Plants have evolved a complex and elaborate signaling network to respond appropriately to the pathogen invasion by regulating expression of defensive genes through certain transcription factors. The APETALA2/ethylene response factor (AP2/ERF) family members have been determined as key regulators in growth, development, and stress responses in plants. Moreover, a growing body of evidence has demonstrated the critical roles of AP2/ERFs in plant disease resistance. In this review, we describe recent advances for the function of AP2/ERFs in defense responses against microbial pathogens. We summarize that AP2/ERFs are involved in plant disease resistance by acting downstream of mitogen activated protein kinase (MAPK) cascades, and regulating expression of genes associated with hormonal signaling pathways, biosynthesis of secondary metabolites, and formation of physical barriers in an MAPK-dependent or -independent manner. The present review provides a multidimensional perspective on the functions of AP2/ERFs in plant disease resistance, which will facilitate the understanding and future investigation on the roles of AP2/ERFs in plant immunity.

12.
Planta ; 259(3): 53, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38294549

RESUMO

MAIN CONCLUSION: The biostimulant Hanseniaspora opuntiae regulates Arabidopsis thaliana root development and resistance to Botrytis cinerea. Beneficial microbes can increase plant nutrient accessibility and uptake, promote abiotic stress tolerance, and enhance disease resistance, while pathogenic microorganisms cause plant disease, affecting cellular homeostasis and leading to cell death in the most critical cases. Commonly, plants use specialized pattern recognition receptors to perceive beneficial or pathogen microorganisms. Although bacteria have been the most studied plant-associated beneficial microbes, the analysis of yeasts is receiving less attention. This study assessed the role of Hanseniaspora opuntiae, a fermentative yeast isolated from cacao musts, during Arabidopsis thaliana growth, development, and defense response to fungal pathogens. We evaluated the A. thaliana-H. opuntiae interaction using direct and indirect in vitro systems. Arabidopsis growth was significantly increased seven days post-inoculation with H. opuntiae during indirect interaction. Moreover, we observed that H. opuntiae cells had a strong auxin-like effect in A. thaliana root development during in vitro interaction. We show that 3-methyl-1-butanol and ethanol are the main volatile compounds produced by H. opuntiae. Subsequently, it was determined that A. thaliana plants inoculated with H. opuntiae have a long-lasting and systemic effect against Botrytis cinerea infection, but independently of auxin, ethylene, salicylic acid, or jasmonic acid pathways. Our results demonstrate that H. opuntiae is an important biostimulant that acts by regulating plant development and pathogen resistance through different hormone-related responses.


Assuntos
Arabidopsis , Botrytis , Hanseniaspora , Ácidos Indolacéticos
13.
Plant Dis ; : PDIS09231880RE, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-37858967

RESUMO

The fungus Coleosporium zanthoxyli causes leaf rust in Chinese pepper (Zanthoxylum armatum). To investigate the control effect of elicitor treatment on leaf rust in this species, the impact of salicylic acid (SA) on the spores and growth of C. zanthoxyli and the induced resistance to leaf rust by Z. armatum were analyzed, and the possible defense mechanisms involved in SA induction were evaluated. The results showed that SA had no effect on C. zanthoxyli spore germination and growth; however, rust resistance was induced in Z. armatum. The optimal SA treatment concentration was 0.4 mg/ml, and the relative cure effect reached 44.56%. SA-induced disease resistance was evident for up to 10 days, while the optimal induction interval was 48 h after stimulation. Consistent with the induced resistance, H2O2, total protein, total phenol, and lignin concentrations and polyphenol oxidase (PPO), peroxidase (POD), phenylalanine ammonia lyase (PAL), superoxide dismutase (SOD), and catalase (CAT) activities were significantly increased with the SA treatment, whereas the malondialdehyde content was significantly decreased. In addition, exogenous SA promoted defense-related enzyme activities, including those of POD, CAT, and PAL, and increased H2O2, lignin, and endogenous SA contents. Furthermore, SA induced the expression of SA signaling pathway genes such as ZaPR1 and ZaNPR1, and silencing ZaPR1 enhanced the sensitivity of Z. armatum to leaf rust. Our results demonstrated that 0.4 mg/ml SA priming increased the activities of CAT, POD, and PAL, elevated the contents of H2O2, lignin, and endogenous SA, and upregulated the expression of the SA-related gene ZaPR1, thereby enhancing the resistance of Z. armatum to leaf rust.

14.
Phytopathology ; 114(2): 418-426, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37665321

RESUMO

Our previous research showed that a powdery mildew resistant barley line (MvHV07-17) maintains its resistance to Blumeria hordei (Bh) even if plants are exposed to a long-term high temperature of 35°C for 120 h before Bh inoculation, whereas such high temperature pretreatment further increases susceptibility to infection in the susceptible barley line MvHV118-17. In the present study, we extended this approach using short-term high-temperature water treatment (49°C for 30 s) to determine how it affects powdery mildew resistance in these barley lines. We found that this short-term heat shock (HS) impaired plant defense responses, as reflected by development of Bh colonies and visible necrotic spots on leaves of MvHV07-17, which does not develop visible symptoms upon Bh inoculation under optimal growth conditions. In contrast, both HS and long-term heat stress enhanced susceptibility to Bh in MvHV118-17 plants. These results were supported by the measurement of Bh biomass using a qPCR method. Furthermore, microscopic examinations showed that HS elevated the rate of successful Bh penetration events and the spread of cell death in the surrounding mesophyll area and allowed for colony formation and sporulation in resistant barley, whereas early and effective plant defense responses, such as papilla formation and single-cell epidermal hypersensitive response, were significantly reduced. Furthermore, we found that the accumulation of hydrogen peroxide in both resistant and susceptible barley was correlated with susceptibility induced by HS and long-term heat-stress. This study may contribute to a better understanding of plant defense responses to Bh in barley exposed to heat. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.


Assuntos
Hordeum , Temperatura , Doenças das Plantas , Biomassa , Morte Celular , Erysiphe
15.
Int J Mol Sci ; 24(23)2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-38069282

RESUMO

Rice (Oryza sativa L.) is the staple food of more than half of Earth's population. Brown planthopper (Nilaparvata lugens Stål, BPH) is a host-specific pest of rice responsible for inducing major losses in rice production. Utilizing host resistance to control N. lugens is considered to be the most cost-effective method. Therefore, the exploration of resistance genes and resistance mechanisms has become the focus of breeders' attention. During the long-term co-evolution process, rice has evolved multiple mechanisms to defend against BPH infection, and BPHs have evolved various mechanisms to overcome the defenses of rice plants. More than 49 BPH-resistance genes/QTLs have been reported to date, and the responses of rice to BPH feeding activity involve various processes, including MAPK activation, plant hormone production, Ca2+ flux, etc. Several secretory proteins of BPHs have been identified and are involved in activating or suppressing a series of defense responses in rice. Here, we review some recent advances in our understanding of rice-BPH interactions. We also discuss research progress in controlling methods of brown planthoppers, including cultural management, trap cropping, and biological control. These studies contribute to the establishment of green integrated management systems for brown planthoppers.


Assuntos
Hemípteros , Oryza , Animais , Oryza/metabolismo , Locos de Características Quantitativas , Reguladores de Crescimento de Plantas/metabolismo , Hemípteros/genética
16.
BMC Biol ; 21(1): 247, 2023 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-37936151

RESUMO

BACKGROUND: Leptosphaeria maculans "brassicae" (Lmb) and Leptosphaeria biglobosa "brassicae" (Lbb) make up a species complex involved in the stem canker (blackleg) disease of rapeseed (Brassica napus). They coinfect rapeseed together, from the early stage of infection on leaves to the final necrotic stage at the stem base, and both perform sexual crossings on plant residues. L. biglobosa is suggested to be a potential biocontrol agent against Lmb, but there has been no mechanistic investigation of the different types of interactions that may occur between the plant and the two fungal species. RESULTS: We investigated the bi- or tripartite interaction mechanisms by (i) confronting Lmb and Lbb in culture conditions or during cotyledon infection, with different timing and/or spore concentration regimes, (ii) performing RNA-Seq experiments in vitro or on the kinetics of infection of cotyledons infected by Lmb and/or Lbb to evaluate the transcriptomic activity and the plant response when both fungal species are inoculated together. Lbb infection of B. napus cotyledons was typical of a necrotrophic behavior, with a very early setup of one pathogenicity program and very limited colonization of tissues. This contrasted with the complex succession of pathogenicity programs of the hemibiotroph Lmb. During simultaneous co-infection by both species, Lmb was strongly impacted in its growth and transcriptomic dynamics both in vitro and in planta, while Lbb was unaffected by the presence of Lmb. However, the drastic inhibition of Lmb growth by Lbb was ineffective in the case of delayed inoculation with Lbb or a lower amount of spores of Lbb compared to Lmb. CONCLUSIONS: Our data suggest that Lmb growth inhibition by Lbb is the result of a combination of factors that may include competition for trophic resources, the generation by Lbb of an environment unsuitable for the lifecycle of Lmb or/and the effect on Lmb of plant defense responses induced by Lbb. It indicates that growth inhibition occurs in very specific conditions (i.e., co-inoculation at the same place of an equal amount of inoculum) that are unlikely to occur in the field where their coexistence does not prevent any species from completing their life cycle.


Assuntos
Ascomicetos , Brassica napus , Ascomicetos/genética , Brassica napus/microbiologia , Perfilação da Expressão Gênica , Transcriptoma , Cotilédone/microbiologia , Doenças das Plantas/microbiologia
17.
BMC Genomics ; 24(1): 553, 2023 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-37723458

RESUMO

BACKGROUND: Black spot disease caused by the necrotrophic fungus Alternaria spp. is one of the most devastating diseases affecting Chrysanthemum morifolium. There is currently no effective way to prevent chrysanthemum black spot. RESULTS: We revealed that pre-treatment of chrysanthemum leaves with the methy jasmonate (MeJA) significantly reduces their susceptibility to Alternaria alternata. To understand how MeJA treatment induces resistance, we monitored the dynamics of metabolites and the transcriptome in leaves after MeJA treatment following A. alternata infection. JA signaling affected the resistance of plants to pathogens through cell wall modification, Ca2+ regulation, reactive oxygen species (ROS) regulation, mitogen-activated protein kinase cascade and hormonal signaling processes, and the accumulation of anti-fungal and anti-oxidant metabolites. Furthermore, the expression of genes associated with these functions was verified by reverse transcription quantitative PCR and transgenic assays. CONCLUSION: Our findings indicate that MeJA pre-treatment could be a potential orchestrator of a broad-spectrum defense response that may help establish an ecologically friendly pest control strategy and offer a promising way of priming plants to induce defense responses against A. alternata.


Assuntos
Alternaria , Chrysanthemum , Antioxidantes , Chrysanthemum/genética
18.
Plant Commun ; 4(5): 100676, 2023 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-37644724

RESUMO

Plant defense responses involve several biological processes that allow plants to fight against pathogenic attacks. How these different processes are orchestrated within organs and depend on specific cell types is poorly known. Here, using single-cell RNA sequencing (scRNA-seq) technology on three independent biological replicates, we identified several cell populations representing the core transcriptional responses of wild-type Arabidopsis leaves inoculated with the bacterial pathogen Pseudomonas syringae DC3000. Among these populations, we retrieved major cell types of the leaves (mesophyll, guard, epidermal, companion, and vascular S cells) with which we could associate characteristic transcriptional reprogramming and regulators, thereby specifying different cell-type responses to the pathogen. Further analyses of transcriptional dynamics, on the basis of inference of cell trajectories, indicated that the different cell types, in addition to their characteristic defense responses, can also share similar modules of gene reprogramming, uncovering a ubiquitous antagonism between immune and susceptible processes. Moreover, it appears that the defense responses of vascular S cells, epidermal cells, and mesophyll cells can evolve along two separate paths, one converging toward an identical cell fate, characterized mostly by lignification and detoxification functions. As this divergence does not correspond to the differentiation between immune and susceptible cells, we speculate that this might reflect the discrimination between cell-autonomous and non-cell-autonomous responses. Altogether our data provide an upgraded framework to describe, explore, and explain the specialization and the coordination of plant cell responses upon pathogenic challenge.


Assuntos
Arabidopsis , Arabidopsis/genética , Análise da Expressão Gênica de Célula Única , Folhas de Planta/genética , Diferenciação Celular , Células Vegetais
19.
Neurosci Bull ; 2023 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-37477800

RESUMO

Panic disorder is a psychiatric disorder characterized by recurrent panic attacks, with a prevalence of ~ 4% in the general population, causing heavy personal and socioeconomic burdens. The similarities of animal defense responses to clinical panic attack symptoms in humans make it possible to translate neuroanatomical pathways identified in animal studies to panic disorder in humans. Therefore, in this review we first present a basic overview of panic disorder in humans including the main subtypes, models commonly used to trigger panic attacks, related hypotheses, the neurotransmitter systems that may be involved, and the current clinical treatments to give the reader a comprehensive understanding of panic disorder. The animal section introduces the models that trigger panic-like behavior in animals and the brain regions that may be involved, providing insights for future elucidation of the neural circuit mechanisms behind panic attacks.

20.
Front Plant Sci ; 14: 1176048, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37404545

RESUMO

Diverse molecular processes regulate the interactions between insect herbivores and their host plants. When plants are exposed to insects, elicitors induce plant defenses, and complex physiological and biochemical processes are triggered, such as the activation of the jasmonic acid (JA) and salicylic acid (SA) pathways, Ca2+ flux, reactive oxygen species (ROS) burst, mitogen-activated protein kinase (MAPK) activation, and other responses. For better adaptation, insects secrete a large number of effectors to interfere with plant defenses on multiple levels. In plants, resistance (R) proteins have evolved to recognize effectors and trigger stronger defense responses. However, only a few effectors recognized by R proteins have been identified until now. Multi-omics approaches for high-throughput elicitor/effector identification and functional characterization have been developed. In this review, we mainly highlight the recent advances in the identification of the elicitors and effectors secreted by insects and their target proteins in plants and discuss their underlying molecular mechanisms, which will provide new inspiration for controlling these insect pests.

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