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1.
J Integr Plant Biol ; 2021 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-34825772

RESUMO

Phytophthora capsici is one of the most harmful pathogens in agriculture, which threatens the safe production of multiple crops and causes serious economic losses worldwide. Here, we identified a P. capsici expansin-like protein, PcEXLX1, by liquid chromatography-tandem mass spectrometry from Nicotiana benthamiana apoplastic fluid infected with P. capsici. Clustered regularly interspaced short palindromic repeat/caspase 9 (CRISPR/Cas9)-mediated PcEXLX1 knockout mutants exhibited significantly enhanced virulence, while the overexpression of PcEXLX1 impaired the virulence. Prokaryotically expressed PcEXLX1 activated multiple plant immune responses, which were BRI1-associated kinase 1 (BAK1)- and suppressor of BIR1-1 (SOBIR1)-dependent. Furthermore, overexpression of PcEXLX1 homologs in N. benthamiana could also increase plant resistance to P. capsici. A G-type lectin receptor-like kinase from N. benthamiana, expansin-regulating kinase 1 (ERK1), was shown to regulate the perception of PcEXLX1 and positively mediate the plant resistance to P. capsici. These results reveal that the expansin-like protein, PcEXLX1, is a novel apoplastic effector with plant immunity-inducing activity of oomycetes, perception of which is regulated by the receptor-like kinase, ERK1. This article is protected by copyright. All rights reserved.

2.
PLoS Pathog ; 17(10): e1010001, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34648596

RESUMO

Sexual reproduction is an essential stage of the oomycete life cycle. However, the functions of critical regulators in this biological process remain unclear due to a lack of genome editing technologies and functional genomic studies in oomycetes. The notorious oomycete pathogen Pythium ultimum is responsible for a variety of diseases in a broad range of plant species. In this study, we revealed the mechanism through which PuM90, a stage-specific Puf family RNA-binding protein, regulates oospore formation in P. ultimum. We developed the first CRISPR/Cas9 system-mediated gene knockout and in situ complementation methods for Pythium. PuM90-knockout mutants were significantly defective in oospore formation, with empty oogonia or oospores larger in size with thinner oospore walls compared with the wild type. A tripartite recognition motif (TRM) in the Puf domain of PuM90 could specifically bind to a UGUACAUA motif in the mRNA 3' untranslated region (UTR) of PuFLP, which encodes a flavodoxin-like protein, and thereby repress PuFLP mRNA level to facilitate oospore formation. Phenotypes similar to PuM90-knockout mutants were observed with overexpression of PuFLP, mutation of key amino acids in the TRM of PuM90, or mutation of the 3'-UTR binding site in PuFLP. The results demonstrated that a specific interaction of the RNA-binding protein PuM90 with the 3'-UTR of PuFLP mRNA at the post-transcriptional regulation level is critical for the sexual reproduction of P. ultimum.


Assuntos
Pythium/fisiologia , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/metabolismo , Regiões 3' não Traduzidas , Doenças das Plantas/microbiologia , Reprodução
3.
Int J Mol Sci ; 22(20)2021 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-34681661

RESUMO

Three Solanaceae hosts (TSHs), S. tuberosum, N. benthamiana and S. lycopersicum, represent the three major phylogenetic clades of Solanaceae plants infected by Phytophthora infestans, which causes late blight, one of the most devastating diseases seriously affecting crop production. However, details regarding how different Solanaceae hosts respond to P. infestans are lacking. Here, we conducted RNA-seq to analyze the transcriptomic data from the TSHs at 12 and 24 h post P. infestans inoculation to capture early expression effects. Macroscopic and microscopic observations showed faster infection processes in S. tuberosum than in N. benthamiana and S. lycopersicum under the same conditions. Analysis of the number of genes and their level of expression indicated that distinct response models were adopted by the TSHs in response to P. infestans. The host-specific infection process led to overlapping but distinct in GO terms and KEGG pathways enriched for differentially expressed genes; many were tightly linked to the immune response in the TSHs. S. tuberosum showed the fastest response and strongest accumulation of reactive oxygen species compared with N. benthamiana and S. lycopersicum, which also had similarities and differences in hormone regulation. Collectively, our study provides an important reference for a better understanding of late blight response mechanisms of different Solanaceae host interactions.

4.
Plant J ; 108(1): 67-80, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34374485

RESUMO

Plants deploy various immune receptors to recognize pathogen-derived extracellular signals and subsequently activate the downstream defense response. Recently, increasing evidence indicates that the endoplasmic reticulum (ER) plays a part in the plant defense response, known as ER stress-mediated immunity (ERSI), that halts pathogen infection. However, the mechanism for the ER stress response to signals of pathogen infection remains unclear. Here, we characterized the ER stress response regulator NAC089, which was previously reported to positively regulate programed cell death (PCD), functioning as an ERSI regulator. NAC089 translocated from the ER to the nucleus via the Golgi in response to Phytophthora capsici culture filtrate (CF), which is a mixture of pathogen-associated molecular patterns (PAMPs). Plasma membrane localized co-receptor BRASSINOSTEROID INSENSITIVE 1-associated receptor kinase 1 (BAK1) was required for the CF-mediated translocation of NAC089. The nuclear localization of NAC089, determined by the NAC domain, was essential for immune activation and PCD. Furthermore, NAC089 positively contributed to host resistance against the oomycete pathogen P. capsici and the bacteria pathogen Pseudomonas syringae pv. tomato (Pst) DC3000. We also proved that NAC089-mediated immunity is conserved in Nicotiana benthamiana. Together, we found that PAMP signaling induces the activation of ER stress in plants, and that NAC089 is required for ERSI and plant resistance against pathogens.

5.
Mol Plant Pathol ; 22(11): 1358-1369, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34382319

RESUMO

Carbohydrate-binding module family 1 (CBM1) is a cellulose-binding domain that is almost exclusively found in fungi and oomycetes. CBM1-containing proteins (CBPs) have diverse domain architectures and play pivotal roles in the plant-microbe interaction. However, only a few CBPs have been functionally investigated. In this study, we identified PcCBP3 in an oomycete pathogen, Phytophthora capsici. PcCBP3 contains two tandem CBM1 domains and its orthologs from other Phytophthora species exhibit diversity including gene loss, pseudogenization, variations in sequences, and domain structures. PcCBP3 is upregulated during infection and knockout of PcCBP3 results in significantly decreased virulence. Moreover, PcCBP3 requires signal peptide to induce BAK1-dependent cell death in Nicotiana benthamiana. Further studies indicate that PcCBP3-triggered cell death and plant immunity require its N-terminal region, which is conserved in CBM1-containing proteins and other small, secreted, cysteine-rich protein from oomycetes. These results suggest that PcCBP3 is an apoplastic effector and could be perceived by the plant immune system.

6.
J Fungi (Basel) ; 7(7)2021 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-34206578

RESUMO

As a non-pathogenic oomycete, the biocontrol agent Pythium oligandrum is able to control plant diseases through direct mycoparasite activity and boosting plant immune responses. Several P. oligandrum elicitors have been found to activate plant immunity as microbe-associated molecular patterns (MAMPs). Necrosis- and ethylene-inducing peptide 1 (Nep1)-like proteins (NLPs) are a group of MAMPs widely distributed in eukaryotic and prokaryotic plant pathogens. However, little is known about their distribution and functions in P. oligandrum and its sister species Pythium periplocum. Here, we identified a total of 25 NLPs from P. oligandrum (PyolNLPs) and P. periplocum (PypeNLPs). Meanwhile, we found that PyolNLPs/PypeNLPs genes cluster in two chromosomal segments, and our analysis suggests that they expand by duplication and share a common origin totally different from that of pathogenic oomycetes. Nine PyolNLPs/PypeNLPs induced necrosis in Nicotiana benthamiana by agroinfiltration. Eight partially purified PyolNLPs/PypeNLPs were tested for their potential biocontrol activity. PyolNLP5 and PyolNLP7 showed necrosis-inducing activity in N. benthamiana via direct protein infiltration. At sufficient concentrations, they both significantly reduced disease severity and suppressed the in planta growth of Phytophthora capsici in solanaceous plants including N. benthamiana (tobacco), Solanum lycopersicum (tomato) and Capsicum annuum (pepper). Our assays suggest that the Phytophthora suppression effect of PyolNLP5 and PyolNLP7 is irrelevant to reactive oxygen species (ROS) accumulation. Instead, they induce the expression of antimicrobial plant defensin genes, and the induction depends on their conserved nlp24-like peptide pattern. This work demonstrates the biocontrol role of two P. oligandrum NLPs for solanaceous plants, which uncovers a novel approach of utilizing NLPs to develop bioactive formulae for oomycete pathogen control with no ROS-caused injury to plants.

7.
Front Microbiol ; 12: 702632, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34305870

RESUMO

Golgi reassembly stacking proteins (GRASPs) play important roles in Golgi structure formation, ER stress response, and unconventional secretion in eukaryotic cells. However, GRASP functions in oomycetes haven't been adequately characterized. Here, we report the identification and functional analysis of PsGRASP, a GRASP-encoding gene from the soybean-infecting oomycete Phytophthora sojae. Transcriptional profiling showed that PsGRASP expression is up-regulated at the infection stages. PsGRASP knockout mutants were created using the CRISPR/Cas9 system. These mutants exhibited impaired vegetative growth, zoospore release and virulence. PsGRASP was involved ER stress responses and altered laccase activity. Our work suggests that PsGRASP is crucial for P. sojae development and pathogenicity.

8.
iScience ; 24(7): 102725, 2021 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-34258557

RESUMO

Leucine-rich repeat receptor-like kinases (LRR-RLKs) are critical signal receptors in plant development and defense. Like plants, oomycete pathogen genomes also harbor LRR-RLKs, but their functions remain largely unknown. Here, we systematically characterize all the 24 LRR-RLK genes (PsRLKs) from Phytophthora sojae, which is a model of oomycete pathogens. Although none of them was required for vegetative growth, the specific PsRLKs are important for stress responses, zoospore production, zoospores chemotaxis, and pathogenicity. Interestingly, the Gα subunit PsGPA1 interacts with the five chemotaxis-related PsRLKs via their intracellular kinase domains, and expression of PsGPA1 gene is downregulated in the three mutants (ΔPsRLK17/22/24). Moreover, we generated the PsRLK-PsRLK interaction network of P. sojae and found that PsRLK21, together with PsRLK10 or PsRLK17, regulate virulence by direct association. Taken together, our results reveal the diverse roles of LRR-RLKs in modulating P. sojae development, interaction with soybean, and responses to diverse environmental factors.

9.
New Phytol ; 232(2): 802-817, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34260062

RESUMO

Vitellogenin (Vg) is a well-known nutritious protein involved in reproduction in nearly all oviparous animals, including insects. Recently, Vg has been detected in saliva proteomes of several piercing-sucking herbivorous arthropods, including the small brown planthopper (Laodelphax striatellus, SBPH). Its function, however, remains unexplored. We investigated the molecular mechanism underlying SBPH orally secreted Vg-mediated manipulation of plant-insect interaction by RNA interference, phytohormone and H2 O2 profiling, protein-protein interaction studies and herbivore bioassays. A C-terminal polypeptide of Vg (VgC) in SBPH, when secreted into rice plants, acted as a novel effector to attenuate host rice defenses, which in turn improved insect feeding performance. Silencing Vg reduced insect feeding and survival on rice. Vg-silenced SBPH nymphs consistently elicited higher H2 O2 production, a well-established defense mechanism in rice, whereas expression of VgC in planta significantly hindered hydrogen peroxide (H2 O2 ) accumulation and promoted insect performance. VgC interacted directly with the rice transcription factor OsWRKY71, a protein which is involved in induction of H2 O2 accumulation and plant resistance to SBPH. These findings indicate a novel effector function of Vg: when secreted into host rice plants, this protein effectively weakened H2 O2 -mediated plant defense through its association with a plant immunity regulator.


Assuntos
Líquidos Corporais , Hemípteros , Oryza , Animais , Oryza/genética , Interferência de RNA , Vitelogeninas
10.
J Exp Bot ; 72(15): 5751-5765, 2021 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-34195821

RESUMO

Due to their sessile nature, plants must respond to various environmental assaults in a coordinated manner. The endoplasmic reticulum is a central hub for plant responses to various stresses. We previously showed that Phytophthora utilizes effector PsAvh262-mediated binding immunoglobulin protein (BiP) accumulation for suppressing endoplasmic reticulum stress-triggered cell death. As a BiP binding partner, Bcl-2-associated athanogene 7 (BAG7) plays a crucial role in the maintenance of the unfolded protein response, but little is known about its role in plant immunity. In this work, we reveal a double-faced role of BAG7 in Arabidopsis-Phytophthora interaction in which it regulates endoplasmic reticulum stress-mediated immunity oppositely in different cellular compartments. In detail, it acts as a susceptibility factor in the endoplasmic reticulum, but plays a resistance role in the nucleus against Phytophthora. Phytophthora infection triggers the endoplasmic reticulum-to-nucleus translocation of BAG7, the same as abiotic heat stress; however, this process can be prevented by PsAvh262-mediated BiP accumulation. Moreover, the immunoglobulin/albumin-binding domain in PsAvh262 is essential for both pathogen virulence and BiP accumulation. Taken together, our study uncovers a double-faced role of BAG7; Phytophthora advances its colonization in planta by utilizing an effector to detain BAG7 in the endoplasmic reticulum.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Phytophthora , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Estresse do Retículo Endoplasmático , Doenças das Plantas , Imunidade Vegetal/genética
11.
Phytopathol Res ; 3(1): 12, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34127941

RESUMO

Phytophthora cactorum is a devastating pathogen that infects a wide range of plants and causes Phytophthora rot disease, which has resulted in great economic losses in crop production. Therefore, the rapid and practicable detection of P. cactorum is important for disease monitoring and forecasting. In this study, we developed a lateral flow recombinase polymerase amplification (LF-RPA) assay for the sensitive visual detection of P. cactorum. Specific primers for P. cactorum were designed based on the ras-related protein gene Ypt1; all 10 P. cactorum isolates yielded positive detection results, whereas no cross-reaction occurred in related oomycete or fungal species. The detection limit for the LF-RPA assay was 100 fg of genomic DNA under optimized conditions. Combined with a simplified alkaline lysis method for plant DNA extraction, the LF-RPA assay successfully detected P. cactorum in naturally diseased strawberry samples without specialized equipment within 40 min. Thus, the LF-RPA assay developed in this study is a rapid, simple, and accurate method for the detection of P. cactorum, with the potential for further application in resource-limited laboratories. Supplementary Information: The online version contains supplementary material available at 10.1186/s42483-021-00089-8.

12.
New Phytol ; 232(1): 264-278, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34157161

RESUMO

Receptor-like cytoplasmic kinase subfamily VII (RLCK-VII) proteins are the central immune kinases in plant pattern-recognition receptor (PRR) complexes, and they orchestrate a complex array of defense responses against bacterial and fungal pathogens. However, the role of RLCK-VII in plant-oomycete pathogen interactions has not been established. Phytophthora capsici is a notorious oomycete pathogen that infects many agriculturally important vegetables. Here, we report the identification of RXLR25, an RXLR effector that is required for the virulence of P. capsici. In planta expression of RXLR25 significantly enhanced plants' susceptibility to Phytophthora pathogens. Microbial pattern-induced immune activation in Arabidopsis was severely impaired by RXLR25. We further showed that RXLR25 interacts with RLCK-VII proteins. Using nine rlck-vii high-order mutants, we observed that RLCK-VII-6 and RLCK-VII-8 members are required for resistance to P. capsici. The RLCK-VII-6 members are specifically required for Phytophthora culture filtrate (CF)-induced immune responses. RXLR25 directly targets RLCK-VII proteins such as BIK1, PBL8, and PBL17 and inhibits pattern-induced phosphorylation of RLCK-VIIs to suppress downstream immune responses. This study identified a key virulence factor for P. capsici, and the results revealed the importance of RLCK-VII proteins in plant-oomycete interactions.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Phytophthora infestans , Proteínas de Arabidopsis/genética , Doenças das Plantas , Imunidade Vegetal , Proteínas Serina-Treonina Quinases
13.
Int J Biol Macromol ; 182: 1670-1680, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34022316

RESUMO

Late blight, caused by the oomycete Phytophthora infestans, is one of the most devastating diseases that results in huge losses of potato crops worldwide. Chitosan as a defence elicitor can induce plant innate immunity against pathogen infection, but the efficiency and specific defence mechanism of chitosan against late blight in potato have not been elaborated. In this study, we demonstrated that the application of chitosan significantly enhanced potato resistance and reduced P. infestans infection in potted potato and in the field. Large-scale transcriptomic analysis suggested that chitosan preferentially activated several important pathways related to the plant defence response. Notably, we revealed that chitosan triggered pattern-triggered immunity responses in potato. Chitosan could trigger pattern recognition receptors to initiate intracellular signalling, and gradually amplify the immune signal. qRT-PCR verification showed that chitosan induced the expression of defence-related genes in potato. Moreover, treatment with chitosan result in Induced Systemic Resistance (ISR) in potato, including an accumulation of plant hormone salicylic acid, increase in the level of phenylalanine ammonia lyase activity and a content decrease of malondialdehyde. These findings help elucidate chitosan-mediated activation of the immune system in potato and provide a potential ecofriendly strategy to control potato late blight in the field.


Assuntos
Quitosana/farmacologia , Phytophthora infestans/efeitos dos fármacos , Solanum tuberosum/microbiologia , Doenças das Plantas/prevenção & controle , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
14.
Mol Plant ; 14(8): 1391-1403, 2021 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-33965632

RESUMO

Phytophthora pathogens are a persistent threat to the world's commercially important agricultural crops, including potato and soybean. Current strategies aim at reducing crop losses rely mostly on disease-resistance breeding and chemical pesticides, which can be frequently overcome by the rapid adaptive evolution of pathogens. Transgenic crops with intrinsic disease resistance offer a promising alternative and continue to be developed. Here, we explored Phytophthora-derived PI3P (phosphatidylinositol 3-phosphate) as a novel control target, using proteins that bind this lipid to direct secreted anti-microbial peptides and proteins (AMPs) to the surface of Phytophthora pathogens. In transgenic Nicotiana benthamiana, soybean, and potato plants, significantly enhanced resistance to different pathogen isolates was achieved by expression of two AMPs (GAFP1 or GAFP3 from the Chinese medicinal herb Gastrodia elata) fused with a PI3P-specific binding domain (FYVE). Using the soybean pathogen P. sojae as an example, we demonstrated that the FYVE domain could boost the activities of GAFPs in multiple independent assays, including those performed in vitro, in vivo, and in planta. Mutational analysis of P. sojae PI3K1 and PI3K2 genes of this pathogen confirmed that the enhanced activities of the targeted GAFPs were correlated with PI3P levels in the pathogen. Collectively, our study provides a new strategy that could be used to confer resistance not only to Phytophthora pathogens in many plants but also potentially to many other kinds of plant pathogens with unique targets.

15.
Nat Commun ; 12(1): 2451, 2021 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-33907187

RESUMO

Many pathogens infect hosts through specific organs, such as Ustilaginoidea virens, which infects rice panicles. Here, we show that a microbe-associated molecular pattern (MAMP), Ser-Thr-rich Glycosyl-phosphatidyl-inositol-anchored protein (SGP1) from U. virens, induces immune responses in rice leaves but not panicles. SGP1 is widely distributed among fungi and acts as a proteinaceous, thermostable elicitor of BAK1-dependent defense responses in N. benthamiana. Plants specifically recognize a 22 amino acid peptide (SGP1 N terminus peptide 22, SNP22) in its N-terminus that induces cell death, oxidative burst, and defense-related gene expression. Exposure to SNP22 enhances rice immunity signaling and resistance to infection by multiple fungal and bacterial pathogens. Interestingly, while SGP1 can activate immune responses in leaves, SGP1 is required for U. virens infection of rice panicles in vivo, showing it contributes to the virulence of a panicle adapted pathogen.


Assuntos
Proteínas Fúngicas/imunologia , Hypocreales/patogenicidade , Oryza/imunologia , Doenças das Plantas/imunologia , Folhas de Planta/imunologia , Proteínas de Plantas/imunologia , Sequência de Aminoácidos , Morte Celular/genética , Morte Celular/imunologia , Proteínas Fúngicas/genética , Regulação da Expressão Gênica , Glicosilfosfatidilinositóis/química , Glicosilfosfatidilinositóis/metabolismo , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Hypocreales/genética , Hypocreales/crescimento & desenvolvimento , Hypocreales/imunologia , Inflorescência/genética , Inflorescência/imunologia , Inflorescência/microbiologia , Oryza/genética , Oryza/microbiologia , Padrões Moleculares Associados a Patógenos/imunologia , Padrões Moleculares Associados a Patógenos/metabolismo , Peptídeos/genética , Peptídeos/imunologia , Células Vegetais/imunologia , Células Vegetais/patologia , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Imunidade Vegetal/genética , Folhas de Planta/genética , Folhas de Planta/microbiologia , Proteínas de Plantas/genética , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Transdução de Sinais , Virulência
16.
PLoS Pathog ; 17(3): e1009388, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33711077

RESUMO

Phytophthora genomes encode a myriad of Crinkler (CRN) effectors, some of which contain putative kinase domains. Little is known about the host targets of these kinase-domain-containing CRNs and their infection-promoting mechanisms. Here, we report the host target and functional mechanism of a conserved kinase CRN effector named CRN78 in a notorious oomycete pathogen, Phytophthora sojae. CRN78 promotes Phytophthora capsici infection in Nicotiana benthamiana and enhances P. sojae virulence on the host plant Glycine max by inhibiting plant H2O2 accumulation and immunity-related gene expression. Further investigation reveals that CRN78 interacts with PIP2-family aquaporin proteins including NbPIP2;2 from N. benthamiana and GmPIP2-13 from soybean on the plant plasma membrane, and membrane localization is necessary for virulence of CRN78. Next, CRN78 promotes phosphorylation of NbPIP2;2 or GmPIP2-13 using its kinase domain in vivo, leading to their subsequent protein degradation in a 26S-dependent pathway. Our data also demonstrates that NbPIP2;2 acts as a H2O2 transporter to positively regulate plant immunity and reactive oxygen species (ROS) accumulation. Phylogenetic analysis suggests that the phosphorylation sites of PIP2 proteins and the kinase domains of CRN78 homologs are highly conserved among higher plants and oomycete pathogens, respectively. Therefore, this study elucidates a conserved and novel pathway used by effector proteins to inhibit host cellular defenses by targeting and hijacking phosphorylation of plant aquaporin proteins.


Assuntos
Phytophthora/patogenicidade , Doenças das Plantas/imunologia , Imunidade Vegetal/fisiologia , Proteínas de Plantas/metabolismo , Fatores de Virulência/metabolismo , Fosforilação , Transdução de Sinais/fisiologia
17.
Ecotoxicol Environ Saf ; 213: 112061, 2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33636466

RESUMO

Maize seed treatment with chemicals to control underground pests is a common agricultural practice, but inappropriate use of insecticides poses a considerable threat to plant development and soil nontarget organisms. In this study, the availability of tetraniliprole seed dressing to control the black cutworm Agrotis ipsilon (Lepidoptera: Noctuidae) in the maize seeding stage and its safety to earthworms (Eisenia fetida) were investigated. The selective toxicity (ST) of tetraniliprole between E. fetida and A. ipsilon was greater than 4000. No significant adverse effect of tetraniliprole seed treatment on the germination of maize seeds was observed at concentrations of 2.4-9.6 g a.i. /kg seed. Compared with the untreated control, seed treatment with tetraniliprole at 9.6 g a.i. /kg seed greatly reduced the percentage of damaged plants from 88.73% to 26.67%, and achieved the highest control effect of 69.91%. Tetraniliprole of 2.4 g a.i. /kg seed can effectively inhibit A. ipsilon until 14 days after seed germination, with the lowest mortality rate of 44.44%. During the entire exposure period, the maximum residual concentration of tetraniliprole detected in the soil (5.86 mg/kg) was considerably lower than the LC50 value of tetraniliprole to E. fetida (>4000 mg/kg). According to the low-tier risk assessment, the highest risk quotient (RQ) of tetraniliprole seed treatment to earthworms at test concentrations was 2.8 × 10-3, which was evaluated as acceptable. This study provided data support for tetraniliprole seed treatment to control underground pests in maize fields.


Assuntos
Inseticidas/toxicidade , Pirazóis/toxicidade , Piridinas/toxicidade , Poluentes do Solo/toxicidade , Tetrazóis/toxicidade , Animais , Inseticidas/análise , Mariposas , Oligoquetos , Pirazóis/análise , Piridinas/análise , Medição de Risco , Sementes/química , Solo/química , Poluentes do Solo/análise , Tetrazóis/análise , Zea mays
18.
J Integr Plant Biol ; 63(2): 305-311, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33095498

RESUMO

The development of durable and broad-spectrum resistance is an economical and eco-friendly approach to control crop diseases for sustainable agricultural production. Emerging knowledge of the molecular basis of pathogenesis and plant-pathogen interactions has contributed to the development of novel pathogen-informed breeding strategies beyond the limits imposed by conventional breeding. Here, we review the current status of pathogen-assisted resistance-related gene cloning. We also describe how pathogen effector proteins can be used to identify resistance resources and to inform cultivar deployment. Finally, we summarize the main approaches for pathogen-directed plant improvement, including transgenesis and genome editing. Thus, we describe the emerging role of pathogen-related studies in the breeding of disease-resistant varieties, and propose innovative pathogen-informed strategies for future applications.


Assuntos
Produtos Agrícolas/imunologia , Produtos Agrícolas/microbiologia , Resistência à Doença/imunologia , Interações Hospedeiro-Patógeno , Melhoramento Vegetal , Doenças das Plantas/microbiologia , Edição de Genes
19.
Mol Plant Microbe Interact ; 34(2): 157-167, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33103962

RESUMO

Diseases caused by the notorious Phytophthora spp. result in enormous economic losses to crops and forests. Increasing evidence suggests that small open reading frame-encoded polypeptides (SEPs) participate in environmental responses of animals, plants, and fungi. However, it remains largely unknown whether Phytophthora pathogens produce SEPs. Here, we systematically predicted and identified 96 SEP candidates in P. capsici. Among them, three may induce stable cell death in Nicotiana benthamiana. Phytophthora-specific and conserved SEP1 facilitated P. capsici infection. PcSEP1-induced cell death is BAK1 and SOBIR1 independent and is correlated with its virulence function. Finally, PcSEP1 may be targeted to the apoplast for carrying out its functions, for which the C terminus is indispensable. Together, our results demonstrated that SEP1 is a new virulence factor, and previously unknown SEPs may act as effector proteins in Phytophthora pathogens.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.


Assuntos
Genes de Protozoários , Phytophthora , Fatores de Virulência , Genes de Protozoários/genética , Phytophthora/genética , Phytophthora/patogenicidade , Doenças das Plantas/parasitologia , Tabaco/parasitologia , Fatores de Virulência/genética
20.
Trends Plant Sci ; 26(1): 2-4, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32972847

RESUMO

Botrytis-Induced Kinase 1 (BIK1) is a convergent and central signaling component in plant immunity. Recent studies in Arabidopsis thaliana by Wang et al. and Ma et al. have revealed that polyubiquitination and monoubiquitination of BIK1 lead to the attenuation or activation of immune signaling, respectively.


Assuntos
Proteínas de Arabidopsis , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Botrytis , Homeostase , Fosforilação , Imunidade Vegetal/genética , Proteínas Serina-Treonina Quinases/genética , Ubiquitinação
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