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BMC Microbiol ; 18(1): 136, 2018 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-30336787


BACKGROUND: Dickeya zeae is the causal agent of maize and rice foot rot diseases, but recently it was also found to infect banana and cause severe losses in China. Strains from different sources showed significant diversity in nature, implying complicated evolution history and pathogenic mechanisms. RESULTS: D. zeae strains were isolated from soft rot banana plants and ornamental monocotyledonous Clivia miniata. Compared with D. zeae strain EC1 isolated from rice, clivia isolates did not show any antimicrobial activity, produced less extracellular enzymes, had a much narrow host ranges, but released higher amount of extracellular polysaccharides (EPS). In contrast, the banana isolates in general produced more extracellular enzymes and EPS than strain EC1. Furthermore, we provided evidence that the banana D. zeae isolate MS2 produces a new antibiotic/phytotoxin(s), which differs from the zeamine toxins produced by rice pathogen D. zeae strain EC1 genetically and in its antimicrobial potency. CONCLUSIONS: The findings from this study expanded the natural host range of D. zeae and highlighted the genetic and phenotypic divergence of D. zeae strains. Conclusions can be drawn from a series of tests that at least two types of D. zeae strains could cause the soft rot disease of banana, with one producing antimicrobial compound while the other producing none, and the D. zeae clivia strains could only infect monocot hosts. D. zeae strains isolated from different sources have diverse virulence characteristics.

Amaryllidaceae/microbiologia , Enterobacteriaceae/genética , Enterobacteriaceae/patogenicidade , Musa/microbiologia , Oryza/microbiologia , Doenças das Plantas/microbiologia , Proteínas de Bactérias/genética , China , Variação Genética , Filogenia , Virulência
Planta ; 248(6): 1443-1453, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30128603


MAIN CONCLUSION: An interesting AMF colonization microcosm has been detected in the roots of Pancratium maritimum (sea daffodil). Both sequencing techniques (Sanger and NGS) have been used for AMF characterisation, showing a balanced trade-off between pros and cons. By Sanger and next generation sequencing of rRNA nuclear molecular markers (SSU-ITS-LSU and ITS2, respectively), the presence of AMF communities in the roots of P. maritimum was evaluated. Our results shed light on the presence of AMF in sea daffodil and the diversity of assemblages of AMF detected after Sanger sequencing of the SSU-ITS-LSU marker is much higher than that determined following NGS sequencing of ITS2 alone.

Amaryllidaceae/microbiologia , Fungos/genética , Micorrizas/genética , Código de Barras de DNA Taxonômico , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Fungos/isolamento & purificação , Sequenciamento de Nucleotídeos em Larga Escala , Micorrizas/isolamento & purificação , Raízes de Plantas/microbiologia , Análise de Sequência de DNA
World J Microbiol Biotechnol ; 34(9): 132, 2018 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-30105532


Actinomycetes, a Gram positive bacteria, well reported as a source of antibiotics, also possess potential to control various plant pathogens, besides acting as plant growth promoting agent. Chemicals in different forms are extensively being used in vegetable farming, adversely affecting the environment and consumer health. Microbial agent like actinomycetes can substantially replace these harmful chemicals, and have now started finding a place as an important input in to farming practices. Only selected vegetable crops belonging to 11 different families have been explored with use of actinomycetes as biocontrol and plant growth promoting agent till now. It provides ample opportunities to vegetable researchers, to further explore with use of this very important group of microorganisms, in order to achieve even higher production level of safe vegetables. Mycostop and Actinovate are two actinomycetes based formulations globally available for use in vegetable farming as a substitute for chemical formulations. Present review article has summarized the literature available on use of actinomycetes in vegetable farming. Existing wide gap in knowledge, and potential thrust areas for future research have also been projected.

Actinobacteria/fisiologia , Produtos Agrícolas/crescimento & desenvolvimento , Produtos Agrícolas/microbiologia , Desenvolvimento Vegetal , Verduras/crescimento & desenvolvimento , Verduras/microbiologia , Agricultura , Amaranthaceae/crescimento & desenvolvimento , Amaranthaceae/microbiologia , Amaryllidaceae/crescimento & desenvolvimento , Amaryllidaceae/microbiologia , Antibiose , Apiaceae/crescimento & desenvolvimento , Apiaceae/microbiologia , Asparagaceae/crescimento & desenvolvimento , Asparagaceae/microbiologia , Asteraceae/crescimento & desenvolvimento , Asteraceae/microbiologia , Agentes de Controle Biológico , Brassicaceae/crescimento & desenvolvimento , Brassicaceae/microbiologia , Cucurbitaceae/crescimento & desenvolvimento , Cucurbitaceae/microbiologia , Fabaceae/crescimento & desenvolvimento , Fabaceae/microbiologia , Doenças das Plantas/prevenção & controle , Solanaceae/crescimento & desenvolvimento , Solanaceae/microbiologia , Zingiberaceae/crescimento & desenvolvimento , Zingiberaceae/microbiologia
J Plant Physiol ; 216: 100-107, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28609666


It is generally known that cyclic GMP widespread in prokaryotic and eukaryotic cells, is involved in essential cellular processes and stress signal transduction. However, in contrast to animals the knowledge about plant guanylyl cyclases (GCs) which catalyze the formation of cGMP from GTP is still quite obscure. Recent studies of plant GCs are focused on identification and functional analysis of a new family of membrane proteins called "moonlighting kinases with GC activity" with guanylyl cyclase catalytic center encapsulated within intracellular kinase domain. Here we report identification and characterization of plasma membrane receptor of peptide signaling molecules - HpPepR1 in Hippeastrum hybridum. Both bioinformatic analysis of amimo acid sequence and in vitro studies revealed that the protein can act as guanylyl cyclase. The predicted amino acid sequence contains highly conserved 14 aa-long search motif in the catalytic center of GCs from lower and higher eukaryotes. Here, we provide experimental evidence to show that the intracellular domain of HpPepR1 can generate cGMP in vitro. Moreover, it was shown that the accumulation of HpPepR1 transcript was sharply increased after Peyronellaea curtisii (=Phoma narcissi) fungal infection, whereas mechanical wounding has no influence on expression profile of studied gene. These results may indicate the participation of cGMP-dependent pathway in rapid, alarm plant reactions induced by pathogen infection.

Amaryllidaceae/enzimologia , Amaryllidaceae/microbiologia , Ascomicetos/fisiologia , Genes de Plantas , Guanilato Ciclase/genética , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Amaryllidaceae/genética , Sequência de Aminoácidos , Sequência de Bases , DNA Complementar/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Guanilato Ciclase/química , Guanilato Ciclase/metabolismo , Doenças das Plantas/genética , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Domínios Proteicos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Recombinantes/isolamento & purificação , Sesquiterpenos/isolamento & purificação , Sesquiterpenos/metabolismo
Mycologia ; 108(5): 981-992, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27474520


This study was conducted to characterize a novel Fusarium species that caused leaf and stem spot on Agapanthus praecox (Agapanthus, African lily) in northern Italy and leaf rot and spot on the same host in Melbourne, Australia. Formally described as Fusarium agapanthi, this pathogen was analyzed using phenotypic, phytopathogenic, secondary metabolite, molecular phylogenetic and genomic data. Five strains were characterized, including one isolated in 1999 from symptomatic A. praecox in Saluzzo, Italy, and four in 2010 from diseased leaf tissue from the same host exhibiting leaf rot and spot symptoms in the Melbourne Gardens, Royal Botanic Gardens Victoria, Australia. Maximum parsimony and maximum likelihood molecular phylogenetic analyses of portions of six individual genes and the combined dataset all strongly supported F. agapanthi either as the earliest diverging genealogically exclusive lineage in the American Clade of the F. fujikuroi species complex, or alternatively a novel monotypic lineage sister to the American Clade. Koch's postulates were completed on dwarf blue- and large white-flowering varieties of A. praecox, where two isolates of F. agapanthi produced slowly spreading necrotic lesions when inoculated onto leaves and flower stems. Fusarium agapanthi is distinguished from other fusaria by the production of densely branched aerial conidiophores with polyphialides throughout the aerial mycelium on synthetic nutrient-poor agar. BLASTn searches of the F. agapanthi NRRL 31653 and NRRL 54464 (= VPRI 41787) genome sequences were conducted to predict sexual reproductive mode and mycotoxin potential. Results indicated that they possessed MAT1-2 and MAT1-1 idiomorphs, respectively, indicating that this species might be heterothallic. Furthermore, based on the presence of homologs of the bikaverin and fusarubin biosynthetic gene clusters in the F. agapanthi genomes, liquid chromatography-mass spectrometry analysis was conducted and confirmed production of these secondary metabolites in rice and corn kernel cultures of the fungus.

Amaryllidaceae/microbiologia , Fusarium/classificação , Fusarium/isolamento & purificação , Naftoquinonas/metabolismo , Doenças das Plantas/microbiologia , Xantonas/metabolismo , Austrália , Vias Biossintéticas/genética , Análise por Conglomerados , Fusarium/genética , Fusarium/metabolismo , Genes Fúngicos Tipo Acasalamento , Itália , Filogenia , Folhas de Planta/microbiologia , Caules de Planta/microbiologia , Análise de Sequência de DNA