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1.
Int J Mol Sci ; 22(15)2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34360726

RESUMO

Fungal diseases pose a major threat to ornamental plants, with an increasing percentage of pathogen-driven host losses. In ornamental plants, management of the majority of fungal diseases primarily depends upon chemical control methods that are often non-specific. Host basal resistance, which is deficient in many ornamental plants, plays a key role in combating diseases. Despite their economic importance, conventional and molecular breeding approaches in ornamental plants to facilitate disease resistance are lagging, and this is predominantly due to their complex genomes, limited availability of gene pools, and degree of heterozygosity. Although genetic engineering in ornamental plants offers feasible methods to overcome the intrinsic barriers of classical breeding, achievements have mainly been reported only in regard to the modification of floral attributes in ornamentals. The unavailability of transformation protocols and candidate gene resources for several ornamental crops presents an obstacle for tackling the functional studies on disease resistance. Recently, multiomics technologies, in combination with genome editing tools, have provided shortcuts to examine the molecular and genetic regulatory mechanisms underlying fungal disease resistance, ultimately leading to the subsequent advances in the development of novel cultivars with desired fungal disease-resistant traits, in ornamental crops. Although fungal diseases constitute the majority of ornamental plant diseases, a comprehensive overview of this highly important fungal disease resistance seems to be insufficient in the field of ornamental horticulture. Hence, in this review, we highlight the representative mechanisms of the fungal infection-related resistance to pathogens in plants, with a focus on ornamental crops. Recent progress in molecular breeding, genetic engineering strategies, and RNAi technologies, such as HIGS and SIGS for the enhancement of fungal disease resistance in various important ornamental crops, is also described.


Assuntos
Resistência à Doença/genética , Fungos Mitospóricos/crescimento & desenvolvimento , Melhoramento Vegetal , Doenças das Plantas , Plantas Geneticamente Modificadas , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/microbiologia
2.
Int J Mol Sci ; 22(11)2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-34200345

RESUMO

Efficient accumulation of flavonoids is important for increased tolerance to biotic stress. Although several plant defense mechanisms are known, the roles of many pathways, proteins, and secondary metabolites in stress tolerance are unknown. We generated a flavanone 3-hydroxylase (F3H) overexpressor rice line and inoculated Xanthomonas Oryzae pv. oryzae and compared the control and wildtype inoculated plants. In addition to promoting plant growth and developmental maintenance, the overexpression of F3H increased the accumulation of flavonoids and increased tolerance to bacterial leaf blight (BLB) stress. Moreover, leaf lesion length was higher in the infected wildtype plants compared with infected transgenics. Kaempferol and quercetin, which scavenge reactive oxygen species, overaccumulated in transgenic lines compared with wildtypes in response to pathogenic infection, detected by scanning electron microscopy and spectrophotometry. The induction of F3H altered the antioxidant system and reduced the levels of glutathione peroxidase activity and malondialdehyde (MDA) contents in the transgenic lines compared with the wildtypes. Downstream gene regulation analysis showed that the expression of F3H increased the regulation of flavonol synthase (FLS), dihydroflavonol 4-reductase (DFR), and slender rice mutant (SLR1) during BLB stress. The analysis of SA and JA signaling revealed an antagonistic interaction between both hormones and that F3H induction significantly promoted SA and inhibited JA accumulation in the transgenic lines. SA-dependent nonexpressor pathogenesis-related (NPR1) and Xa1 showed significant upregulation in the infected transgenic lines compared with the infected control and wildtype lines. Thus, the overexpression of F3H was essential for increasing BLB stress tolerance.


Assuntos
Antioxidantes/metabolismo , Resistência à Doença/imunologia , Flavonoides/metabolismo , Hormônios/metabolismo , Oxigenases de Função Mista/metabolismo , Oryza/imunologia , Doenças das Plantas/imunologia , Resistência à Doença/genética , Regulação da Expressão Gênica de Plantas , Oxigenases de Função Mista/genética , Oryza/genética , Oryza/metabolismo , Oryza/microbiologia , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Folhas de Planta/genética , Folhas de Planta/imunologia , Folhas de Planta/metabolismo , Folhas de Planta/microbiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/imunologia , Plantas Geneticamente Modificadas/metabolismo , Plantas Geneticamente Modificadas/microbiologia , Estresse Fisiológico , Xanthomonas/fisiologia
3.
Nat Commun ; 12(1): 3378, 2021 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-34099713

RESUMO

The re-emergence of stem rust on wheat in Europe and Africa is reinforcing the ongoing need for durable resistance gene deployment. Here, we isolate from wheat, Sr26 and Sr61, with both genes independently introduced as alien chromosome introgressions from tall wheat grass (Thinopyrum ponticum). Mutational genomics and targeted exome capture identify Sr26 and Sr61 as separate single genes that encode unrelated (34.8%) nucleotide binding site leucine rich repeat proteins. Sr26 and Sr61 are each validated by transgenic complementation using endogenous and/or heterologous promoter sequences. Sr61 orthologs are absent from current Thinopyrum elongatum and wheat pan genome sequences, contrasting with Sr26 where homologues are present. Using gene-specific markers, we validate the presence of both genes on a single recombinant alien segment developed in wheat. The co-location of these genes on a small non-recombinogenic segment simplifies their deployment as a gene stack and potentially enhances their resistance durability.


Assuntos
Resistência à Doença/genética , Proteínas NLR/genética , Plantas Geneticamente Modificadas/microbiologia , Puccinia/patogenicidade , Triticum/microbiologia , Cromossomos de Plantas/genética , Genes de Plantas , Engenharia Genética , Marcadores Genéticos , Melhoramento Vegetal/métodos , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Caules de Planta/microbiologia , Plantas Geneticamente Modificadas/genética , Puccinia/isolamento & purificação , Triticum/genética
4.
PLoS One ; 16(4): e0249699, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33831084

RESUMO

Plants have developed various mechanisms to respond specifically to each biotrophic attack. It has been shown that the electrical signals emitted by plants are associated with herbivory stress responses and can lead to the activation of multiple defences. Bt cotton is a genetically modified pest-resistant plant that produces an insecticide from Bacillus thuringiensis (Bt) to control Lepidopteran species. Surprisingly, there is no study-yet, that characterizes the signalling mechanisms in transgenic cotton plants attacked by non-target insects, such as aphids. In this study, we characterized the production of electrical signals on Bt and non-Bt cotton plants infested with Aphis gossypii and, in addition, we characterized the dispersal behaviour of aphids to correlate this behaviour to plant signalling responses. Electrical signalling of the plants was recorded with an extracellular measurement technique. Impressively, our results showed that both Bt and non-Bt cotton varieties, when attacked by A. gossypii, emitted potential variation-type electrical signals and clearly showed the presence of distinct responses regarding their perception and the behaviour of aphids, with evidence of delay, in terms of signal amount, and almost twice the amount of Cry1F protein was observed on Bt cotton plants at the highest density of insects/plant. We present in our article some hypotheses that are based on plant physiology and insect behaviour to explain the responses found on Bt cotton plants under aphid stress.


Assuntos
Afídeos/microbiologia , Bacillus thuringiensis/metabolismo , Gossypium/microbiologia , Gossypium/parasitologia , Estresse Fisiológico/fisiologia , Animais , Gossypium/genética , Herbivoria/fisiologia , Insetos/microbiologia , Inseticidas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/microbiologia , Plantas Geneticamente Modificadas/parasitologia , Transdução de Sinais/genética , Estresse Fisiológico/genética
5.
Toxins (Basel) ; 13(3)2021 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-33801997

RESUMO

Seeking useful biological agents for mycotoxin detoxification has achieved success in the last twenty years thanks to the participation of many multidisciplinary teams. We have recently witnessed discoveries in the fields of bacterial genetics (inclusive of next-generation sequencing), protein encoding, and bioinformatics that have helped to shape the latest perception of how microorganisms/mycotoxins/environmental factors intertwine and interact, so the road is opened for new breakthroughs. Analysis of literature data related to the biological control of mycotoxins indicates the ability of yeast, bacteria, fungi and enzymes to degrade or adsorb mycotoxins, which increases the safety and quality of susceptible crops, animal feed and, ultimately, food of animal origin (milk, meat and eggs) by preventing the presence of residues. Microbial detoxification (transformation and adsorption) is becoming a trustworthy strategy that leaves no or less toxic compounds and contributes to food security. This review summarizes the data and highlights the importance and prospects of these methods.


Assuntos
Ração Animal/microbiologia , Proteção de Cultivos , Produtos Agrícolas/microbiologia , Contaminação de Alimentos/prevenção & controle , Fungos/metabolismo , Micotoxinas/metabolismo , Controle Biológico de Vetores , Adsorção , Animais , Produtos Agrícolas/genética , Produtos Agrícolas/crescimento & desenvolvimento , Abastecimento de Alimentos , Humanos , Inativação Metabólica , Micotoxinas/toxicidade , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/microbiologia
6.
Int J Mol Sci ; 22(4)2021 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-33668636

RESUMO

Tomato is one of the major vegetable crops consumed worldwide. Tomato yellow leaf curl virus (TYLCV) and fungal Oidium sp. are devastating pathogens causing yellow leaf curl disease and powdery mildew. Such viral and fungal pathogens reduce tomato crop yields and cause substantial economic losses every year. Several commercial tomato varieties include Ty-5 (SlPelo) and Mildew resistance locus o 1 (SlMlo1) locus that carries the susceptibility (S-gene) factors for TYLCV and powdery mildew, respectively. The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas) is a valuable genome editing tool to develop disease-resistant crop varieties. In this regard, targeting susceptibility factors encoded by the host plant genome instead of the viral genome is a promising approach to achieve pathogen resistance without the need for stable inheritance of CRISPR components. In this study, the CRISPR/Cas9 system was employed to target the SlPelo and SlMlo1 for trait introgression in elite tomato cultivar BN-86 to confer host-mediated immunity against pathogens. SlPelo-knockout lines were successfully generated, carrying the biallelic indel mutations. The pathogen resistance assays in SlPelo mutant lines confirmed the suppressed accumulation of TYLCV and restricted the spread to non-inoculated plant parts. Generated knockout lines for the SlMlo1 showed complete resistance to powdery mildew fungus. Overall, our results demonstrate the efficiency of the CRISPR/Cas9 system to introduce targeted mutagenesis for the rapid development of pathogen-resistant varieties in tomato.


Assuntos
Begomovirus/metabolismo , Sistemas CRISPR-Cas , Resistência à Doença/genética , Edição de Genes , Lycopersicon esculentum , Doenças das Plantas , Plantas Geneticamente Modificadas , Genoma de Planta , Lycopersicon esculentum/genética , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/microbiologia , Lycopersicon esculentum/virologia , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Doenças das Plantas/virologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/microbiologia , Plantas Geneticamente Modificadas/virologia
7.
Int J Mol Sci ; 22(4)2021 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-33670294

RESUMO

Verticillium wilt is threatening the world's cotton production. The pathogenic fungus Verticillium dahliae can survive in the soil in the form of microsclerotia for a long time, colonize through the root of cotton, and invade into vascular bundles, causing yellowing and wilting of cotton leaves, and in serious cases, leading to plant death. Breeding resistant varieties is the most economical and effective method to control Verticillium wilt. In previous studies, proteomic analysis was carried out on different cotton varieties inoculated with V. dahliae strain Vd080. It was found that GhRPS6 was phosphorylated after inoculation, and the phosphorylation level in resistant cultivars was 1.5 times than that in susceptible cultivars. In this study, knockdown of GhRPS6 expression results in the reduction of SA and JA content, and suppresses a series of defensive response, enhancing cotton plants susceptibility to V. dahliae. Overexpression in Arabidopsis thaliana transgenic plants was found to be more resistant to V. dahliae. Further, serines at 237 and 240 were mutated to phenylalanine, respectively and jointly. The transgenic Arabidopsis plants demonstrated that seri-237 compromised the plant resistance to V. dahliae. Subcellular localization in Nicotiana benthamiana showed that GhRPS6 was localized in the nucleus. Additionally, the pathogen inoculation and phosphorylation site mutation did not change its localization. These results indicate that GhRPS6 is a potential molecular target for improving resistance to Verticillium wilt in cotton. This lays a foundation for breeding disease-resistant varieties.


Assuntos
Ascomicetos/crescimento & desenvolvimento , Resistência à Doença , Regulação da Expressão Gênica de Plantas , Gossypium , Doenças das Plantas , Proteínas de Plantas , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/microbiologia , Estudo de Associação Genômica Ampla , Gossypium/genética , Gossypium/metabolismo , Gossypium/microbiologia , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Proteínas de Plantas/biossíntese , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Plantas Geneticamente Modificadas/microbiologia
8.
Toxins (Basel) ; 13(2)2021 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-33670470

RESUMO

For 30 years, forage ryegrass breeding has known that the germplasm may contain a maternally inherited symbiotic Epichloë endophyte. These endophytes produce a suite of secondary alkaloid compounds, dependent upon strain. Many produce ergot and other alkaloids, which are associated with both insect deterrence and livestock health issues. The levels of alkaloids and other endophyte characteristics are influenced by strain, host germplasm, and environmental conditions. Some strains in the right host germplasm can confer an advantage over biotic and abiotic stressors, thus acting as a maternally inherited desirable 'trait'. Through seed production, these mutualistic endophytes do not transmit into 100% of the crop seed and are less vigorous than the grass seed itself. This causes stability and longevity issues for seed production and storage should the 'trait' be desired in the germplasm. This makes understanding the precise nature of the relationship vitally important to the plant breeder. These Epichloë endophytes cannot be 'bred' in the conventional sense, as they are asexual. Instead, the breeder may modulate endophyte characteristics through selection of host germplasm, a sort of breeding by proxy. This article explores, from a forage seed company perspective, the issues that endophyte characteristics and breeding them by proxy have on ryegrass breeding, and outlines the methods used to assess the 'trait', and the application of these through the breeding, production, and deployment processes. Finally, this article investigates opportunities for enhancing the utilisation of alkaloid-producing endophytes within pastures, with a focus on balancing alkaloid levels to further enhance pest deterrence and improving livestock outcomes.


Assuntos
Alcaloides/metabolismo , Endófitos/metabolismo , Epichloe/metabolismo , Herbivoria , Gado , Lolium/microbiologia , Plantas Geneticamente Modificadas/microbiologia , Sementes/microbiologia , Alcaloides/genética , Alcaloides/toxicidade , Ração Animal , Animais , Endófitos/genética , Epichloe/genética , Regulação Fúngica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Lolium/genética , Lolium/crescimento & desenvolvimento , Nova Zelândia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Reprodução Assexuada , Metabolismo Secundário , Sementes/genética , Sementes/crescimento & desenvolvimento , Simbiose
9.
Commun Biol ; 4(1): 372, 2021 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-33742112

RESUMO

Phytophthora sojae is a pathogen that causes stem and root rot in soybean (Glycine max [L.] Merr.). We previously demonstrated that GmBTB/POZ, a BTB/POZ domain-containing nuclear protein, enhances resistance to P. sojae in soybean, via a process that depends on salicylic acid (SA). Here, we demonstrate that GmBTB/POZ associates directly with soybean LIKE HETEROCHROMATIN PROTEIN1 (GmLHP1) in vitro and in vivo and promotes its ubiquitination and degradation. Both overexpression and RNA interference analysis of transgenic lines demonstrate that GmLHP1 negatively regulates the response of soybean to P. sojae by reducing SA levels and repressing GmPR1 expression. The WRKY transcription factor gene, GmWRKY40, a SA-induced gene in the SA signaling pathway, is targeted by GmLHP1, which represses its expression via at least two mechanisms (directly binding to its promoter and impairing SA accumulation). Furthermore, the nuclear localization of GmLHP1 is required for the GmLHP1-mediated negative regulation of immunity, SA levels and the suppression of GmWRKY40 expression. Finally, GmBTB/POZ releases GmLHP1-regulated GmWRKY40 suppression and increases resistance to P. sojae in GmLHP1-OE hairy roots. These findings uncover a regulatory mechanism by which GmBTB/POZ-GmLHP1 modulates resistance to P. sojae in soybean, likely by regulating the expression of downstream target gene GmWRKY40.


Assuntos
Proteínas Cromossômicas não Histona/metabolismo , Phytophthora/patogenicidade , Raízes de Plantas/microbiologia , Plantas Geneticamente Modificadas/microbiologia , Proteínas de Soja/metabolismo , Soja/microbiologia , Domínio BTB-POZ , Proteínas Cromossômicas não Histona/genética , Regulação da Expressão Gênica de Plantas , Interações Hospedeiro-Patógeno , Phytophthora/imunologia , Raízes de Plantas/genética , Raízes de Plantas/imunologia , Raízes de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/imunologia , Plantas Geneticamente Modificadas/metabolismo , Proteólise , Proteínas de Soja/genética , Soja/genética , Soja/imunologia , Soja/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Ubiquitinação
10.
Methods Mol Biol ; 2238: 3-17, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33471321

RESUMO

Plant biotechnology provides a means for the rapid genetic improvement of crops including the enhancement of complex traits like yield and nutritional quality through the introduction and coordinated expression of multiple genes. GAANTRY (gene assembly in Agrobacterium by nucleic acid transfer using recombinase technology) is a flexible and effective system for stably stacking multiple genes within an Agrobacterium virulence plasmid transfer DNA (T-DNA) region. The system provides a simple and efficient method for assembling and stably maintaining large stacked constructs within the GAANTRY ArPORT1 Agrobacterium rhizogenes strain. The assembly process utilizes unidirectional site-specific recombinases in vivo and an alternating bacterial selection scheme to sequentially assemble multiple genes into a single transformation construct. A detailed description of the procedures used for bacterial transformation, selection, counter selection, and genomic PCR validation with the GAANTRY system are presented. The methods described facilitate the efficient assembly and validation of large GAANTRY T-DNA constructs. This powerful, yet simple to use, technology will be a convenient tool for transgene stacking and plant genetic engineering of rice and other crop plants.


Assuntos
Agrobacterium/genética , Produtos Agrícolas/genética , DNA Nucleotidiltransferases/metabolismo , Técnicas de Transferência de Genes , Engenharia Genética/métodos , Ácidos Nucleicos/genética , Plantas Geneticamente Modificadas/genética , Agrobacterium/patogenicidade , Produtos Agrícolas/microbiologia , DNA Nucleotidiltransferases/genética , Vetores Genéticos/administração & dosagem , Plantas Geneticamente Modificadas/microbiologia , Plasmídeos/administração & dosagem , Plasmídeos/genética , Recombinação Genética , Transgenes/fisiologia
11.
Methods Mol Biol ; 2238: 19-35, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33471322

RESUMO

Efficient stacking of multiple genes is a critical element in metabolic engineering of complex pathways, synthetic biology, and genetic improvement of complex agronomic traits in plants. Here we present a high-efficiency multigene assembly and transformation vector system, TransGene Stacking II (TGS II), for these purposes. The operation process is described in detail, and the successful operation mainly depends on effective reagents, special Escherichia coli strains, and basic molecular biological means without other specific equipments.


Assuntos
Agrobacterium/genética , Produtos Agrícolas/metabolismo , Engenharia Metabólica/métodos , Plantas Geneticamente Modificadas/metabolismo , Biologia Sintética/métodos , Transformação Genética , Transgenes/fisiologia , Agrobacterium/patogenicidade , Produtos Agrícolas/genética , Produtos Agrícolas/microbiologia , Vetores Genéticos/administração & dosagem , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/microbiologia , Plasmídeos/administração & dosagem , Plasmídeos/genética , Recombinases/genética , Recombinases/metabolismo , Recombinação Genética
12.
Nat Commun ; 12(1): 433, 2021 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-33469010

RESUMO

The poverty of disease resistance gene reservoirs limits the breeding of crops for durable resistance against evolutionary dynamic pathogens. Zymoseptoria tritici which causes Septoria tritici blotch (STB), represents one of the most genetically diverse and devastating wheat pathogens worldwide. No fully virulent Z. tritici isolates against synthetic wheats carrying the major resistant gene Stb16q have been identified. Here, we use comparative genomics, mutagenesis and complementation to identify Stb16q, which confers broad-spectrum resistance against Z. tritici. The Stb16q gene encodes a plasma membrane cysteine-rich receptor-like kinase that was recently introduced into cultivated wheat and which considerably slows penetration and intercellular growth of the pathogen.


Assuntos
Produtos Agrícolas/genética , Resistência à Doença/genética , Proteínas de Plantas/genética , Proteínas Serina-Treonina Quinases/genética , Triticum/genética , Alelos , Ascomicetos/patogenicidade , Membrana Celular/enzimologia , Produtos Agrícolas/microbiologia , Genes de Plantas/genética , Melhoramento Vegetal/métodos , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/microbiologia , Sementes/genética , Triticum/enzimologia , Triticum/microbiologia
13.
Plant Cell Rep ; 40(3): 529-541, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33386424

RESUMO

KEY MESSAGE: Overexpression of CiNPR4 enhanced resistance of transgenic citrus plants to Huanglongbing by perceiving the salicylic acid and jasmonic acid signals and up-regulating the transcriptional activities of plant-pathogen interaction genes. Developing transgenic citrus plants with enhanced immunity is an efficient strategy to control citrus Huanglongbing (HLB). Here, a nonexpressor of pathogenesis-related gene 1 (NPR1) like gene from HLB-tolerant 'Jackson' grapefruit (Citrus paradisi Macf.), CiNPR4, was introduced into 'Wanjincheng' orange (Citrus sinensis Obseck). CiNPR4 expression was determined in transgenic citrus plants using quantitative real-time PCR analyses. The Candidatus Liberibacter asiaticus (CLas) pathogen of HLB was successfully transmitted to transgenic citrus plants by grafting infected buds. HLB symptoms developed in transgenic and wild-type (WT) plants by 9 months after inoculation. A CLas population analysis showed that 26.9% of transgenic lines exhibited significantly lower CLas titer levels compared with the CLas-infected WT plants at 21 months after inoculation. Lower starch contents and anatomical aberration levels in the phloem were observed in transgenic lines having enhanced resistance compared with CLas-infected WT plants. CiNPR4 overexpression changed the jasmonic acid, but not salicylic acid, level. Additionally, the jasmonic acid and salicylic acid levels increased after CLas infection. Transcriptome analyses revealed that the enhanced resistance of transgenic plants to HLB resulted from the up-regulated transcriptional activities of plant-pathogen interaction-related genes.


Assuntos
Citrus paradisi/genética , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/microbiologia , Citrus paradisi/microbiologia , Ciclopentanos/metabolismo , Resistência à Doença/genética , Regulação da Expressão Gênica de Plantas , Liberibacter/patogenicidade , Oxilipinas/metabolismo , Floema/anatomia & histologia , Floema/genética , Filogenia , Reprodutibilidade dos Testes , Ácido Salicílico/metabolismo , Análise de Sequência de RNA , Amido/genética , Amido/metabolismo
14.
Mol Plant ; 14(4): 620-632, 2021 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-33450368

RESUMO

Mitogen-activated protein kinase (MAPK) cascades regulate a myriad of plant biological processes, including disease resistance. Plant genomes encode a large number of MAPK kinase kinases (MAPKKKs) that can be divided into two subfamilies, namely MEKK-like kinases and Raf-like kinases. Thus far, the functions of MEKK-like MAPKKKs have been relatively well characterized, but the roles of Raf-like MAPKKKs in plant MAPK cascades remain less understood. Here, we report the role of OsEDR1, a Raf-like MAPKKK, in the regulation of the MAPK cascade in rice response to the bacterial pathogen Xanthomonas oryzae pv. oryzicola (Xoc). We found that OsEDR1 inhibits OsMPKK10.2 (a MAPK kinase) activity through physical interaction. Upon Xoc infection, OsMPKK10.2 is phosphorylated at S304 to activate OsMPK6 (a MAPK). Interestingly, activated OsMPK6 phosphorylates OsEDR1 at S861, which destabilizes OsEDR1 and thus releases the inhibition of OsMPKK10.2, leading to increased OsMPKK10.2 activity and enhanced resistance of rice plants to Xoc. Taken together, these results provide new insights into the functions of Raf-like kinases in the regulation of the MAPK cascade in plant immunity.


Assuntos
Oryza/microbiologia , Doenças das Plantas/microbiologia , Plantas Geneticamente Modificadas/microbiologia , Resistência à Doença/genética , Regulação da Expressão Gênica de Plantas , Fosforilação/genética , Imunidade Vegetal/genética , Imunidade Vegetal/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Xanthomonas/patogenicidade
15.
Can J Microbiol ; 67(1): 85-97, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32721220

RESUMO

Agroinfiltration is used to treat plants with modified strains of Agrobacterium tumefaciens for the purpose of transient in planta expression of genes transferred from the bacterium. These genes encode valuable recombinant proteins for therapeutic or industrial applications. Treatment of large quantities of plants for industrial-scale protein production exposes bacteria (harboring genes of interest) to agroinfiltration medium that is devoid of nutrients and carbon sources for prolonged periods of time (possibly upwards of 24 h). Such conditions may negatively influence bacterial viability, infectivity of plant cells, and target protein production. Here, we explored the role of timing in bacterial culture preparation for agroinfiltration using mass spectrometry-based proteomics to define changes in cellular processes. We observed distinct profiles associated with bacterial treatment conditions and exposure timing, including significant changes in proteins involved in pathogenesis, motility, and nutrient acquisition systems as the bacteria adapt to the new environment. These data suggest a progression towards increased cellular remodelling over time. In addition, we described changes in growth- and environment-specific processes over time, underscoring the interconnectivity of pathogenesis and chemotaxis-associated proteins with transport and metabolism. Overall, our results have important implications for the production of transiently expressed target protein products, as prolonged exposure to agroinfiltration medium suggests remodelling of the bacterial proteins towards enhanced infection of plant cells.


Assuntos
Adaptação Fisiológica/efeitos dos fármacos , Inoculantes Agrícolas/efeitos dos fármacos , Agrobacterium tumefaciens/efeitos dos fármacos , Meios de Cultura/farmacologia , Agricultura Molecular , Inoculantes Agrícolas/fisiologia , Agrobacterium tumefaciens/fisiologia , Proteínas de Bactérias/metabolismo , Meios de Cultura/metabolismo , Plantas Geneticamente Modificadas/microbiologia , Proteômica , Proteínas Recombinantes/genética
16.
Int J Mol Sci ; 21(24)2020 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-33322321

RESUMO

The present study was designed to serve as a comprehensive analysis of Citrus sinensis (C. sinensis) pectin acetylesterases (CsPAEs), and to assess the roles of these PAEs involved in the development of citrus bacterial canker (CBC) caused by Xanthomonas citri subsp. citri (Xcc) infection. A total of six CsPAEs were identified in the genome of C. sinensis, with these genes being unevenly distributed across chromosomes 3, 6, and 9, and the unassembled scaffolds. A subset of CsPAEs were found to be involved in responses to Xcc infection. In particular, CsPAE2 was identified to be associated with such infections, as it was upregulated in CBC-susceptible variety Wanjincheng and inversely in CBC-resistant variety Calamondin. Transgenic citrus plants overexpressing CsPAE2 were found to be more susceptible to CBC, whereas the silencing of this gene was sufficient to confer CBC resistance. Together, these findings provide evolutionary insights into and functional information about the CsPAE family. This study also suggests that CsPAE2 is a potential candidate gene that negatively contributes to bacterial canker disease and can be used to breed CBC-resistant citrus plants.


Assuntos
Esterases/metabolismo , Plantas Geneticamente Modificadas/microbiologia , Xanthomonas/patogenicidade , Esterases/genética , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Doenças das Plantas/microbiologia , Plantas Geneticamente Modificadas/enzimologia
17.
Sci Rep ; 10(1): 19439, 2020 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-33173096

RESUMO

Bacterial leaf steak (BLS) caused by Xanthomonas oryzae pv. oryzicola (Xoc) is a devastating disease in rice production. The resistance to BLS in rice is a quantitatively inherited trait, of which the molecular mechanism is still unclear. It has been proved that xa5, a recessive bacterial blast resistance gene, is the most possible candidate gene of the QTL qBlsr5a for BLS resistance. To study the molecular mechanism of xa5 function in BLS resistance, we created transgenic lines with RNAi of Xa5 (LOC_Os05g01710) and used RNA-seq to analyze the transcriptomes of a Xa5-RNAi line and the wild-type line at 9 h after inoculation with Xoc, with the mock inoculation as control. We found that Xa5-RNAi could (1) increase the resistance to BLS as expected from xa5; (2) alter (mainly up-regulate) the expression of hundreds of genes, most of which were related to disease resistance; and (3) greatly enhance the response of thousands of genes to Xoc infection, especially of the genes involved in cell death pathways. The results suggest that xa5 is the cause of BLS-resistance of QTL qBlsr5a and it displays BLS resistance effect probably mainly because of the enhanced response of the cell death-related genes to Xoc infection.


Assuntos
Perfilação da Expressão Gênica/métodos , Oryza/genética , Oryza/microbiologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/microbiologia , Xanthomonas/patogenicidade , Resistência à Doença/genética , Regulação da Expressão Gênica de Plantas , Interferência de RNA , Análise de Sequência de RNA
18.
Microbes Environ ; 35(4)2020.
Artigo em Inglês | MEDLINE | ID: mdl-33162465

RESUMO

In the past thirty years, the biosafety of the aboveground part of crops, including horizontal gene transferal through pollen dispersal and hybridization, has been the focus of research; however, microbial communities in the underground part are attracting increasing attention. In the present study, the soybean root-associated bacterial communities of the G2-EPSPS plus GAT transgenic soybean line Z106, its recipient variety ZH10, and Z106 treated with glyphosate (Z106J) were compared at the seedling, flowering, and seed filling stages by high-throughput sequencing of the V4 hypervariable regions of 16S rRNA gene amplicons using Illumina MiSeq. The results obtained showed no significant differences in the alpha/beta diversities of root-associated bacterial communities at the three stages among ZH10, Z106, and Z106J under field growth conditions; however, the relative abundance of four main nitrogen-fixing bacterial genera significantly differed among ZH10, Z106, and Z106J. Ternary plot results indicated that in the root compartment, the proportional contributions of rhizobial nitrogen-fixing Ensifer fredii and Bradyrhizobium elkanii, which exhibit an extremely broad nodulation host range, markedly differed among the three treatments at the three stages. Thus, the present results indicate that transgenic G2-EPSPS and GAT soybean may induce different changes in functional bacterial species in soil, such as E. fredii and B. elkanii, from ZH10, which were compensated for/enriched at the flowering and seed filling stages, respectively, to some extent through as of yet unknown mechanisms by transgenic soybean treated with glyphosate.


Assuntos
Bactérias/isolamento & purificação , Glicina/análogos & derivados , Resistência a Herbicidas , Herbicidas/farmacologia , Microbiologia do Solo , Soja/efeitos dos fármacos , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/genética , Glicina/farmacologia , Microbiota/efeitos dos fármacos , Filogenia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/microbiologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/metabolismo , Plantas Geneticamente Modificadas/microbiologia , Soja/genética , Soja/crescimento & desenvolvimento , Soja/microbiologia
19.
Int J Mol Sci ; 21(22)2020 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-33233855

RESUMO

A class of proteins that were discovered to bind the immunosuppressant drug FK506, called FK506-binding proteins (FKBPs), are members of a sub-family of immunophilins. Although they were first identified in human, FKBPs exist in all three domains of life. In this report, a rice FKBP12 homolog was first identified as a biotic stress-related gene through suppression subtractive hybridization screening. By ectopically expressing OsFKBP12 in the heterologous model plant system, Arabidopsis thaliana, for functional characterization, OsFKBP12 was found to increase susceptibility of the plant to the pathogen, Pseudomonas syringae pv. tomato DC3000 (Pst DC3000). This negative regulatory role of FKBP12 in biotic stress responses was also demonstrated in the AtFKBP12-knockout mutant, which exhibited higher resistance towards Pst DC3000. Furthermore, this higher-plant FKBP12 homolog was also shown to be a negative regulator of salt tolerance. Using yeast two-hybrid tests, an ancient unconventional G-protein, OsYchF1, was identified as an interacting partner of OsFKBP12. OsYchF1 was previously reported as a negative regulator of both biotic and abiotic stresses. Therefore, OsFKBP12 probably also plays negative regulatory roles at the convergence of biotic and abiotic stress response pathways in higher plants.


Assuntos
Oryza/genética , Proteínas de Plantas/fisiologia , Serina-Treonina Quinases TOR/fisiologia , Arabidopsis/genética , Arabidopsis/microbiologia , Resistência à Doença/genética , Regulação da Expressão Gênica de Plantas , Técnicas de Inativação de Genes , Oryza/fisiologia , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/microbiologia , Pseudomonas syringae/patogenicidade , Tolerância ao Sal/genética , Serina-Treonina Quinases TOR/genética , Técnicas do Sistema de Duplo-Híbrido
20.
Sci Rep ; 10(1): 17294, 2020 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-33057018

RESUMO

Insecticidal proteins encoded by the truncated genes from Bacillus thuringiensis (Bt) in transgenic crops are released into soil mainly through root exudate and crop residues. In the present study, Bt Cry1Ac protein was hydrolyzed by pronase that was secreted by the soil bacterium Streptomyces griseus. Six peptides were identified as the products of enzymatic hydrolysis by nano liquid chromatography tandem mass spectrometry (LC-MS/MS). One of the six peptides was labeled with radioactive isotope iodine-125 and then purified. The 125I-peptide solution was irrigated to the rhizosphere soil of watermelon seedlings (Citrullus lanatus L.) and wheat seedlings (Triticum aestivum L.), which the two crops usually intercrop with cotton in China. Detection of radioactivity in both plant tissues within one hour proved adsorption, uptake and translocation of the peptide into watermelon and wheat seedlings. Three of the identified peptides were sprayed onto the seedling leaves of watermelon, wheat and maize (Zea mays L.) in the field or the growth chamber. No significant effects on plant growth were observed. These peptides also did not affect growth of organic phosphate-dissolving, nitrogen-fixing, and potassium-dissolving bacteria in the culture. This study provides a new view of GMO risk assessment methodology.


Assuntos
Toxinas de Bacillus thuringiensis/metabolismo , Bacillus thuringiensis/genética , Endotoxinas/metabolismo , Gossypium/metabolismo , Gossypium/microbiologia , Proteínas Hemolisinas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Plantas Geneticamente Modificadas/microbiologia , Microbiologia do Solo , China , Produtos Agrícolas/crescimento & desenvolvimento , Produtos Agrícolas/metabolismo , Hidrólise , Fixação de Nitrogênio , Organofosfatos/metabolismo , Streptomyces griseus/metabolismo
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