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1.
Bioresour Technol ; 310: 123476, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32402987

RESUMO

The effects of feruloyl esterase-producing Lactobacillus plantarum A1, cellulase, or their combination on the fermentation characteristics, carbohydrate composition, and enzymatic hydrolysis of mixed corn stalk and potato pulp silage were investigated. Two mixture ratios were used: a weight ratio of rehydrated corn stalk to potato pulp of 35:1 (HD) and a weight ratio of dry corn stalk to potato pulp of 5:11 (LD). No advantage was observed with the addition of strain A1 alone for lignocellulosic degradation and cellulose conversion, while its combination with cellulase enhanced the lignocellulosic degradation and preserved more fermentable carbohydrates in co-ensiled corn stalk and potato pulp. The enzymatic hydrolysis results indicated a potential benefit of pretreatment for biogas production, as the co-ensiled HD ratio mixture without additive treatment showed high glucose yield after enzymatic hydrolysis following 60 d of fermentation.


Assuntos
Celulase , Lactobacillus plantarum , Solanum tuberosum , Hidrolases de Éster Carboxílico , Celulose , Fermentação , Hidrólise , Lignina , Silagem , Zea mays
2.
Pestic Biochem Physiol ; 166: 104569, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32448424

RESUMO

In recent years, substantial effort was spent on the exploration and implementation of RNAi technology using double-stranded RNA (dsRNA) for pest management purposes. However, only few studies investigated the geographical variation in RNAi sensitivity present in field-collected populations of the targeted insect pest. In this baseline study, 2nd instar larvae of 14 different European populations of Colorado potato beetle (CPB), Leptinotarsa decemlineata, collected from nine different countries were exposed to a foliarly applied diagnostic dose of dsactin (dsact) to test for possible variations in RNAi response. Only minor variability in RNAi sensitivity was observed between populations. However, the time necessary to trigger a dsRNA-mediated phenotypic response varied significantly among populations, indicated by significant differences in mortality figures obtained five days after treatment. An inbred German laboratory reference strain D01 and a Spanish field strain E02 showed almost 100% mortality after foliar exposure to 30 ng dsactin (equal to 0.96 g/ha), whereas another Spanish strain E01 was least responsive and showed only 30% mortality. Calculated LD50-values for foliarly applied dsact against strains D01 (most sensitive) and E01 (least sensitive) were 9.22 and 68.7 ng/leaf disc, respectively. The variability was not based on target gene sequence divergence or knock-down efficiency. Variability in expression of the core RNAi machinery genes dicer (dcr2a) and argonaute (ago2a) was observed but did not correlate with sensitivity. Interestingly, RT-qPCR data collected for all strains revealed a strong correlation between the expression level of dcr2a and ago2a (r 0.93) as well as ago2a and stauC (r 0.94), a recently described dsRNA binding protein in Coleopterans. Overall, this study demonstrates that sensitivity of CPB to sprayable RNAi slightly varies between strains but also shows that foliar RNAi as a control method works against all tested CPB populations collected across a broad geographic range in Europe. Thus, underpinning the potential of RNAi-based CPB control as a promising component in integrated pest management (IPM) and resistance management programs.


Assuntos
Besouros , Solanum tuberosum , Animais , Larva , Interferência de RNA , RNA de Cadeia Dupla
3.
PLoS One ; 15(3): e0224534, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32231371

RESUMO

Virus resistance genes carried by wild plant species are valuable resources for plant breeding. The Rysto gene, conferring a broad spectrum of durable resistance, originated from Solanum stoloniferum and was introgressed into several commercial potato cultivars, including 'White Lady', by classical breeding. Rysto was mapped to chromosome XII in potato, and markers used for marker-assisted selection in breeding programmes were identified. Nevertheless, there was no information on the identity of the Rysto gene. To begin to reveal the identification of Rysto, fine-scale genetic mapping was performed which, in combination with chromosome walking, narrowed down the locus of the gene to approximately 1 Mb. DNA sequence analysis of the locus identified six full-length NBS-LRR-type (short NLR-type) putative resistance genes. Two of them, designated TMV2 and TMV3, were similar to a TMV resistance gene isolated from tobacco and to Y-1, which co-segregates with Ryadg, the extreme virus resistance gene originated from Solanum andigena and localised to chromosome XI. Furthermore, TMV2 of 'White Lady' was found to be 95% identical at the genomic sequence level with the recently isolated Rysto gene of the potato cultivar 'Alicja'. In addition to the markers identified earlier, this work generated five tightly linked new markers which can serve potato breeding efforts for extreme virus resistance.


Assuntos
Mapeamento Cromossômico , Cromossomos de Plantas/genética , Resistência à Doença/genética , Doenças das Plantas/genética , Solanum tuberosum/genética , Vírus do Mosaico do Tabaco , Doenças das Plantas/virologia , Solanum tuberosum/virologia
4.
Sci Data ; 7(1): 88, 2020 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-32161269

RESUMO

Genome assembly of polyploid plant genomes is a laborious task as they contain more than two copies of the genome, are often highly heterozygous with a high level of repetitive DNA. Next Generation genome sequencing data representing one Chilean and five Peruvian polyploid potato (Solanum spp.) landrace genomes was used to construct genome assemblies comprising five taxa. Third Generation sequencing data (Linked and Long-read data) was used to improve the assembly for one of the genomes. Native landraces are valuable genetic resources for traits such as disease and pest resistance, environmental tolerance and other qualities of interest such as nutrition and fiber for breeding programs. The need for conservation and enhanced understanding of genetic diversity of cultivated potato from South America is also crucial to North American and European cultivars. Here, we report draft genomes from six polyploid potato landraces representing five taxa, illustrating how Third Generation Sequencing can aid in assembling polyploid genomes.


Assuntos
Genoma de Planta , Solanum tuberosum/genética , Variação Genética , Sequenciamento de Nucleotídeos em Larga Escala , Poliploidia , América do Sul
5.
Sheng Wu Gong Cheng Xue Bao ; 36(2): 362-371, 2020 Feb 25.
Artigo em Chinês | MEDLINE | ID: mdl-32148008

RESUMO

Solanum tuberosum Zinc transporter 11 (StZnT11) is very important for maintaining zinc homeostasis in cells. The study on the expression of StZnT11 under abiotic stress and biotic stress laid a foundation for verifying the role of potato StZnT11 in the process of biotic stress of Ralstonia solanacearum species complex. According to the designated EST sequence, the homology of the original sequence was analyzed by using the Blast tool in NCBI, and a homologous object sequence with the highest similarity, coverage and e expectation value was selected. StZnT11 gene is obtained by Silico Cloning. The sequence and coding amino acid composition, physicochemical properties, molecular evolution, phosphorylation site and advanced structure of Solanum tuberosum StZnT11 gene were analyzed by bioinformatics method. The results showed that the cDNA gene is 1 300 bp in length, encoding a protein containing 348 amino acid residues, including 23 phosphorylation sites, one signal peptide and nine transmembrane regions, and is a hydrophobic protein located the plasma membrane. Through amino acid sequence alignment, StZnT11 protein has a high homology with zinc transporter from tobacco, tomato, pepper and other plants. The results of real-time fluorescence quantitative polymerase chain reaction showed that, StZnT11 is up-regulated by different concentrations of exogenous plant hormone abscisic acid (ABA). Tissue localization showed that StZnT11 was mainly expressed in specific tissues (phloem and leaf vascular bundles of stem vascular system). These results provide a theoretical basis for further experimental cloning and functional verification of the gene.


Assuntos
Solanum tuberosum , Sequência de Aminoácidos , Proteínas de Transporte , Clonagem Molecular , Biologia Computacional , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas
6.
Plant Dis ; 104(5): 1492-1499, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32150503

RESUMO

Potato blackleg is caused by a diverse species of pectinolytic bacteria. In Pakistan, approximately 90% of the pathogens involved belong to Pectobacterium atrosepticum. Survey (2014 to 2017), sampling, and isolation from different potato growing areas of Punjab, Pakistan depicted an overall disease incidence of approximately 15%. Thirty-six pectinolytic strains confirmed through biochemical and pathogenicity testing were characterized via gapA gene to identify them at the species level. To further validate the identification, one strain from each species SS26 (P. atrosepticum), SS28 (Pectobacterium polaris), SS70 (Dickeya dianthicola), SS90 (Pectobacterium parmentieri), SS95 (Pectobacterium punjabense), and SS96 (Pectobacterium versatile) were selected for draft genome sequencing and multilocus sequence analysis of 13 housekeeping genes (fusA, rpoD, acnA, purA, gyrB, recA, mdh, mtlD, groEL, secY, glyA, gapA, and rplB). Phylogenetic analysis revealed considerable genetic diversity in the genus Pectobacterium. In silico DNA-DNA hybridization and average nucleotide identity values of the strains selected for genome sequencing were determined with other reference Pectobacterium and Dickeya strains. Moreover, all six representative strains were also phenotypically characterized on the basis of metabolism of different carbon sources. Overall, on the basis of genotypic and phenotypic characteristics, these 36 isolates were grouped into six species: P. atrosepticum, P. versatile, P. parmentieri, P. polaris, P. punjabense, and D. dianthicola.


Assuntos
Pectobacterium , Solanum tuberosum , DNA Bacteriano , Genes Bacterianos , Paquistão , Filogenia , Doenças das Plantas , Análise de Sequência de DNA
7.
Food Chem ; 317: 126431, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32109657

RESUMO

Novel dummy magnetic molecularly imprinted polymers (dex-MMIPs) were prepared for highly selective recognition and fast enrichment of acrylamide (AA) in potato chips. Propionamide (PA) was used as dummy template molecule and the Fe3O4 nanoparticles modified with carboxymethyl dextran were developed as supports. Methacrylic acid (MAA) and ethyleneglycoldimethacrylate (EGDMA) were chosen as the functional monomer and cross-linker, respectively. Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and transmission electron microscopy (TEM) were used to characterize the synthesized dex-MMIPs. The adsorption of dex-MMIPs reached equilibrium within 20 min, and the maximum adsorption quantity (Qm) was 19.28 mg/g with the dissociation constant (Kd) of 35.7 mg/L. Moreover excellent recognition toward acrylamide was achieved compared to analogs, such as N, N'-methylenebisacrylamide (MBA) and nicotinamide (VPP). The satisfactory recoveries of 83.9-96.8% were achieved for selective separation and enrichment of AA in spiked potato chips by dex-MMIPs.


Assuntos
Acrilamida/análise , Análise de Alimentos/métodos , Nanopartículas de Magnetita/química , Impressão Molecular/métodos , Polímeros/química , Solanum tuberosum , Adsorção , Cromatografia Líquida de Alta Pressão , Culinária , Dextranos/química , Contaminação de Alimentos/análise , Magnetismo , Metacrilatos/química , Microscopia Eletrônica de Transmissão , Niacinamida/análise , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria
8.
Food Chem ; 317: 126416, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32087519

RESUMO

T-2 toxin at low concentrations can induce ROS accumulation and modulate host resistance in plants. NOX plays crucial roles in ROS production and is regulated by Ca2+via direct binding to EF-hand motifs. In this study, the effect of EGTA (Ca2+ chelating agent) on the expression and enzymatic activity of NOX, as well as the activities and corresponding gene expressions involved in ROS metabolism and cell membrane integrity, were investigated in treated slices. Results indicated that EGTA treatment significantly affected gene expression and activity of NOX, and reduced ROS accumulation and cell membrane integrity and the enzymatic activities and gene expression involved in ROS metabolism when exposed to treatment. The addition of exogenous Ca2+ restored the initial relative transcript abundance, ROS accumulation and their activities. Results suggest that Ca2+ affected by EGTA plays a crucial role in NOX activity regulation, ultimately affecting ROS metabolism in slices induced by T-2 toxin.


Assuntos
Cálcio/metabolismo , NADPH Oxidases/metabolismo , Proteínas de Plantas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Solanum tuberosum/metabolismo , Toxina T-2/metabolismo , Animais , Cálcio/química , Membrana Celular/metabolismo , Ácido Egtázico/química , Malondialdeído/metabolismo , NADPH Oxidases/genética , Proteínas de Plantas/genética , Tubérculos/metabolismo
9.
Nucleic Acids Res ; 48(6): 3134-3155, 2020 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-32083649

RESUMO

While G/U pairs are present in many RNAs, the lack of molecular studies to characterize the roles of multiple G/U pairs within a single RNA limits our understanding of their biological significance. From known RNA 3D structures, we observed that the probability a G/U will form a Watson-Crick (WC) base pair depends on sequence context. We analyzed 17 G/U pairs in the 359-nucleotide genome of Potato spindle tuber viroid (PSTVd), a circular non-coding RNA that replicates and spreads systemically in host plants. Most putative G/U base pairs were experimentally supported by selective 2'-hydroxyl acylation analyzed by primer extension (SHAPE). Deep sequencing PSTVd genomes from plants inoculated with a cloned master sequence revealed naturally occurring variants, and showed that G/U pairs are maintained to the same extent as canonical WC base pairs. Comprehensive mutational analysis demonstrated that nearly all G/U pairs are critical for replication and/or systemic spread. Two selected G/U pairs were found to be required for PSTVd entry into, but not for exit from, the host vascular system. This study identifies critical roles for G/U pairs in the survival of an infectious RNA, and increases understanding of structure-based regulation of replication and trafficking of pathogen and cellular RNAs.


Assuntos
Vírus de Plantas/genética , RNA não Traduzido/genética , RNA Viral/genética , Viroides/genética , Genoma Viral/genética , Mutação , Conformação de Ácido Nucleico , Vírus de Plantas/patogenicidade , Solanum tuberosum/virologia , Viroides/patogenicidade , Viroses/genética , Viroses/virologia , Replicação Viral/genética
10.
Plant Biol (Stuttg) ; 22(3): 425-432, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32052535

RESUMO

Cyanide-resistant respiration in potato mitochondria is an important pathway for energy dissipation. It can be activated by high light; however, it is unclear what roles cyanide-resistant respiration plays in the response to high light stress in potato. We designed a CRISPR vector for the functional gene StAOX of the potato cyanide-resistant respiratory pathway. Agrobacterium tumefaciens GV3101 was transformed into potato. Hydrogen peroxide level, MDA content, antioxidant activity and cyanide-resistant respiratory capacity of potato leaves under high light stress were determined. Photosynthetic efficiency and chlorophyll content were determined. In addition, the operation of the malate-oxaloacetate shuttle route and transcription level of photorespiration-related enzymes were also examined. The results showed that two base substitutions occurred at the sequencing target site on leaves of the transformed potato. Accumulation of ROS and increased membrane lipid peroxidation were detected in the transformed potato leaves and lower photosynthetic efficiency was observed. The transcription level of the malate-oxaloacetate shuttle route and photorespiration-related enzymes also significantly increased. These results indicate that the cyanide-resistant respiration is an important physiological pathway in potato in response to high light stress. It also suggests that plant cyanide-resistant respiration is closely related to photosynthesis. This implies the unexplored importance of plant cyanide-resistant respiration in plant photosynthesis, energy conversion and carbon skeleton formation.


Assuntos
Respiração Celular , Cianetos , Resistência a Medicamentos , Luz , Folhas de Planta , Solanum tuberosum , Agrobacterium tumefaciens/genética , Respiração Celular/efeitos dos fármacos , Respiração Celular/efeitos da radiação , Clorofila , Cianetos/toxicidade , Oxirredutases/genética , Fotossíntese , Folhas de Planta/metabolismo , Folhas de Planta/efeitos da radiação , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Solanum tuberosum/efeitos da radiação
11.
Sci Total Environ ; 713: 136694, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32019035

RESUMO

The relative ease with which cadmium (Cd) in agricultural soils can transfer to crop plants can pose a potential health risk to consumers. However, efforts to predict and mitigate these risks are often confounded by the various factors that influence metal accumulation in the edible plant parts. The aim of this work was to identify key drivers that determine Cd concentrations in spinach leaves, potato tubers, onion bulbs and wheat grain grown in commercial horticultural operations across New Zealand (NZ). Paired soil and plant samples (n = 147) were collected from farms across different NZ growing regions. Cadmium concentrations in the edible parts were measured and four different tests were used to examine the potential bioavailability of soil Cd: pseudo-total and porewater concentrations, 0.05 M Ca(NO3)2-extraction and diffusive gradients in thin-films (DGT). Information on a range of soil and climatic variables was also collected. The methods' ability to represent Cd concentrations in the plant parts was assessed through single and multiple regression analysis that considered the different variables and the farm locations. Soil Cd concentrations determined by the different tests were positively related to plant concentrations and there were clear regional differences between these relationships. The Ca(NO3)2 extraction predicted over 76% of the variability in Cd concentrations in onion bulbs and spinach leaves, while DGT and porewater Cd provided the best estimates for potato tubers and wheat grains, respectively, once regional differences were considered, along with certain environmental and soil variables. The results show that certain soil and environmental factors can be a key influence for determining Cd accumulation in the edible parts of some plants and that regional differences are important for modulating the extent to which this occurs. These effects should be considered when trying to mitigate the potential risks arising from Cd in agricultural soils.


Assuntos
Solo , Cádmio , Nova Zelândia , Cebolas , Poluentes do Solo , Solanum tuberosum , Spinacia oleracea , Triticum
12.
Microbes Environ ; 35(1)2020.
Artigo em Inglês | MEDLINE | ID: mdl-32101840

RESUMO

The genome of Streptomyces scabies, the predominant causal agent of potato common scab, encodes a potential cutinase, the protein Sub1, which was previously shown to be specifically induced in the presence of suberin. The sub1 gene was expressed in Escherichia coli and the recombinant protein Sub1 was purified and characterized. The enzyme was shown to be versatile because it hydrolyzes a number of natural and synthetic substrates. Sub1 hydrolyzed p-nitrophenyl esters, with the hydrolysis of those harboring short carbon chains being the most effective. The Vmax and Km values of Sub1 for p-nitrophenyl butyrate were 2.36 mol g-1 min-1 and 5.7 10-4 M, respectively. Sub1 hydrolyzed the recalcitrant polymers cutin and suberin because the release of fatty acids from these substrates was observed following the incubation of the enzyme with these polymers. Furthermore, the hydrolyzing activity of the esterase Sub1 on the synthetic polymer polyethylene terephthalate (PET) was demonstrated by the release of terephthalic acid (TA). Sub1 activity on PET was markedly enhanced by the addition of Triton and was shown to be stable at 37°C for at least 20 d.


Assuntos
Proteínas de Bactérias/metabolismo , Hidrolases de Éster Carboxílico/metabolismo , Doenças das Plantas/microbiologia , Polímeros/metabolismo , Streptomyces/enzimologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/isolamento & purificação , Hidrolases de Éster Carboxílico/genética , Hidrolases de Éster Carboxílico/isolamento & purificação , Ácidos Graxos/metabolismo , Hidrólise , Ácidos Ftálicos/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Solanum tuberosum/microbiologia , Streptomyces/genética
13.
J Agric Food Chem ; 68(8): 2467-2476, 2020 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-32031791

RESUMO

Enzymatic browning is a major issue affecting the quality of processed potato (Solanum tuberosum L.). To understand the molecular mechanism of browning, transcriptional analyses were performed by employing potatoes that differed in browning. Coexpression analysis indicated that 9 out of 15 upregulated genes in browning-less groups encoded for potato protease inhibitors (StPIs). In addition, gene otology analysis showed that the enriched terms were mainly involved in protease inhibitors. Overexpression of cysteine StPI 143 and StPI 146 individually reduced browning and lowered protease activities and tyrosine and total free amino acid (FAA) contents, but they could not decrease polyphenol oxidase activity. Moreover, supplementing exogenous tyrosine or total FAAs into transgenic potato mash to wild-type amounts promoted mash browning, browning with total FAAs, more than with tyrosine, resembling wild-type levels. These results implied that cysteine StPIs reduced browning via lowering the accumulation of FAAs in addition to tyrosine. Our findings have enriched the knowledge about the roles and mechanisms of protease inhibitors in regulating enzymatic browning of potato, which provide new ways for controlling potato browning.


Assuntos
Aminoácidos/metabolismo , Proteínas de Plantas/metabolismo , Inibidores de Proteases/metabolismo , Solanum tuberosum/metabolismo , Catecol Oxidase/antagonistas & inibidores , Catecol Oxidase/genética , Catecol Oxidase/metabolismo , Cor , Cisteína Proteases/genética , Cisteína Proteases/metabolismo , Proteínas de Plantas/genética , Solanum tuberosum/enzimologia , Solanum tuberosum/genética
14.
Plant Dis ; 104(3): 688-693, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31940449

RESUMO

Zebra chip (ZC) disease of potato (Solanum tuberosum) is associated with infection by 'Candidatus Liberibacter solanacearum' (Lso). Two haplotypes of Lso-A and B-occur in the United States. Lso haplotype B is more virulent than haplotype A, causing greater disease incidence in tubers, more severe symptoms, and greater loss in tuber yield. This study assessed whether tubers from infected plants generate new infected plants the following year. The effects of both Lso haplotypes A and B on tuber resprout were examined on five potato cultivars. When compared with noninfected tubers, overall plant emergence rate from Lso A- or B-infected tubers was lower, plants emerged slower, and plants generated lower daughter tuber yields in weight and quantity. Plants generally emerged poorly from Lso B-infected tubers and produced lower daughter tuber yields than Lso A-infected tubers. Regardless of Lso treatment, all daughter tubers were asymptomatic, and only 0.3% tested positive for Lso in experiments conducted over 2 years. This suggests that plants generated from Lso A- and Lso B-infected seed potatoes with severe ZC symptoms are likely not a significant source of Lso in potato fields.


Assuntos
Rhizobiaceae , Solanum tuberosum , Haplótipos , Doenças das Plantas , Sementes
15.
Plant Dis ; 104(3): 708-716, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31967506

RESUMO

Phytophthora infestans is the causal agent of potato late blight, a devastating disease of tomato and potato and a threat to global food security. Early detection and intervention is essential for effective management of the pathogen. We developed a loop-mediated isothermal amplification (LAMP) assay for P. infestans and compared this assay to conventional PCR, real-time LAMP, and droplet digital PCR for detection of P. infestans. The LAMP assay was specific for P. infestans on potato and tomato and did not amplify other potato- or tomato-infecting Phytophthora species or other fungal and bacterial pathogens that infect potato and tomato. The detection threshold for SYBR Green LAMP and real-time LAMP read with hydroxynaphthol blue and EvaGreen was 1 pg/µl. In contrast, detection by conventional PCR was 10 pg/µl. Droplet digital PCR had the lowest detection threshold (100 fg/µl). We adapted the LAMP assay using SYBR Green and a mobile reader (mReader) for use in the field. Detection limits were 584 fg/µl for SYBR Green LAMP read on the mReader, which was more sensitive than visualization with the human eye. The mobile platform records geospatial coordinates and data from positive pathogen detections can be directly uploaded to a cloud database. Data can then be integrated into disease surveillance networks. This system will be useful for real-time detection of P. infestans and will improve the timeliness of reports into surveillance systems such as USABlight or EuroBlight.


Assuntos
Lycopersicon esculentum , Phytophthora infestans , Solanum tuberosum , Técnicas de Amplificação de Ácido Nucleico , Reação em Cadeia da Polimerase
16.
World J Microbiol Biotechnol ; 36(1): 18, 2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31912374

RESUMO

In this paper, we report the antimicrobial activity of AMEP412 (a protein elicitor from Bacillus subtilis) against Streptomyces scabiei, which is the potato common scab pathogen. The purified protein samples showed an obvious inhibition zone on an S. scabiei agar plate, and the minimum inhibition concentration detected was 50 µg mL-1. The fluorescence localization assay revealed that AMEP412 could bind to aerial mycelia and spores. The stability test showed that AMEP412 was stable at 60 °C for 30 min and in pH values from 5.0 to 10.0. Its antimicrobial activity was not sensitive to metal cations. However, its activity declined by 23% when treated with Proteinase K, and was completely abrogated with Tween 80 treatment. Three antimicrobial peptides (GS21, GY20 and GY23) were identified from AMEP412, which further verified its antimicrobial activity. This research reveals the antimicrobial function of AMEP412, which not only enriches the function of the protein elicitor, but also provides a candidate for the biocontrol of potato common scab.


Assuntos
Antibacterianos/farmacologia , Bacillus subtilis/metabolismo , Proteínas de Bactérias/farmacologia , Streptomyces/efeitos dos fármacos , Antibacterianos/química , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Proteínas de Bactérias/química , Temperatura Alta , Concentração de Íons de Hidrogênio , Testes de Sensibilidade Microbiana , Micélio/efeitos dos fármacos , Doenças das Plantas/prevenção & controle , Solanum tuberosum/microbiologia , Esporos Bacterianos/efeitos dos fármacos , Streptomyces/crescimento & desenvolvimento
17.
Food Chem ; 313: 126161, 2020 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-31931420

RESUMO

The effects of fermentation on the dynamic state of proton populations, digestibility, and functional properties of potato flours prepared from Atlantic and Kexin No. 1 were investigated. Depending on the changes in moisture content and digestibility of potato flours during fermentation, three proton populations were distinguished. Populations P21 and P22 of fermented potato flours gradually increased during fermentation, resistant starch content, swelling power, and pasting properties also increased, whereas moisture content, digestible starch content, and water solubility index gradually decreased. Correlation analyses showed that populations P21 and P22 had significantly positive correlations with resistant starch content, swelling power, peak viscosity, and breakdown viscosity of fermented potato flours (p < 0.05), while population P23 had significantly positive correlations with moisture content, digestible starch content, and water solubility index (p < 0.001). The results implied that the proton population was an important factor influencing the digestibility and functional properties of fermented potato flours.


Assuntos
Farinha , Prótons , Solanum tuberosum , Digestão , Fermentação , Solubilidade , Amido/química , Amido/metabolismo , Viscosidade
18.
J Agric Food Chem ; 68(8): 2578-2587, 2020 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-31961151

RESUMO

Chlorpropham is a widely used sprouting inhibitor applied on potatoes during their storage. Currently, severe concerns are raised regarding the potential formation of 3-chloroaniline from chlorpropham during heat treatment. The reactions degrading the molecule in the matrix are quite complex under harsh processing conditions, and a molecular investigation is thus challenging. This study aims to decipher the reaction pathways and to discover new metabolites in typical high-temperature food-processing steps. For this purpose, potatoes were treated with 14C-radiolabeled chlorpropham, stored for up to 6 months, and subjected to the traditional preparation steps of boiling, frying, and baking. A quantification method including an acidic hydrolysis was developed for analysis of free and bound analytes. All conducted processing steps led to a substantial mitigation of chlorpropham residues in the consumable products. Of the residues, 17 ± 6% remained in boiled tubers, while 27 ± 3 and 22 ± 3% remained in the fried and baked products, respectively. Chlorpropham was transferred into the surrounding media (boiling water, frying oil, and air, respectively). 3-Chloroaniline was only (raw tubers) or predominantly (processed tubers) present as a bound analyte and was shown to form during storage but not during processing. Additionally, nonextractable and nonquantified residues were detected in the baked and in the long-term-stored tubers after processing. Future studies will have to balance beneficial (mitigating) and potentially hazardous aspects of these results. By transferring the 14C-food-processing approach to a variety of substances, ingredients, and processes, it will be possible to further understand chemical reactions in food processing, finally leading to safer food.


Assuntos
Clorprofam/química , Herbicidas/química , Solanum tuberosum/química , Culinária , Temperatura Alta , Resíduos de Praguicidas/química , Tubérculos/química
19.
PLoS One ; 15(1): e0221604, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31961875

RESUMO

Phytophthora infestans (Mont.) de Bary, a hemibiotrophic oomycete, has caused severe epidemics of late blight in tomato and potato crops around the world since the Irish Potato Famine in the 1840s. Breeding of late blight resistant cultivars is one of the most effective strategies to overcome this disruptive disease. However, P. infestans is able to break down host resistance and acquire resistance to various fungicides, possibly because of the existence of high genetic variability among P. infestans isolates via sexual and asexual reproduction. Therefore, to manage this disease, it is important to understand the genetic divergence of P. infestans isolates. In this study, we analyzed the genomes of P. infestans isolates collected from Egypt and Japan using various molecular approaches including the mating type assay and genotyping simple sequence repeats, mitochondria DNA, and effector genes. We also analyzed genome-wide single nucleotide polymorphisms using double-digest restriction-site associated DNA sequencing and whole genome resequencing (WGRS). The isolates were classified adequately using high-resolution genome-wide approaches. Moreover, these analyses revealed new clusters of P. infestans isolates in the Egyptian population. Monitoring the genetic divergence of P. infestans isolates as well as breeding of resistant cultivars would facilitate the elimination of the late blight disease.


Assuntos
Genes Fúngicos Tipo Acasalamento/genética , Sequenciamento de Nucleotídeos em Larga Escala , Phytophthora infestans/genética , Doenças das Plantas/microbiologia , DNA Mitocondrial/genética , Fungicidas Industriais/farmacologia , Genótipo , Lycopersicon esculentum/microbiologia , Repetições de Microssatélites/genética , Phytophthora infestans/crescimento & desenvolvimento , Doenças das Plantas/genética , Análise de Sequência de DNA , Solanum tuberosum/microbiologia
20.
J Agric Food Chem ; 68(5): 1390-1396, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-31935098

RESUMO

Potato juice is a byproduct of starch processing currently used as feed. However, potato proteins are an untapped source of high-protein food for human nutrition if harmful constituents notably glycoalkaloids (GAs) are detoxified. The two principle GAs found in potato are α-chaconine and α-solanine, both consisting of a solanidine aglycone with a carbohydrate side chain. The first step in the detoxification of these compounds is the removal of the trisaccharide. Whole-genome sequencing of a bacterial isolate, Arthrobacter sp. S41, capable of completely degrading α-chaconine and α-solanine, revealed the presence of a gene cluster possibly involved in the deglycosylation of GAs. Functional characterization confirmed the enzymatic activity of the gene cluster involved in the complete deglycosylation of both α-chaconine and α-solanine. The novel enzymes described here may find value in the bioconversion of feed proteins to food proteins suitable for human nutrition.


Assuntos
Arthrobacter/metabolismo , Proteínas de Bactérias/metabolismo , Família Multigênica , Solanina/análogos & derivados , Solanum tuberosum/toxicidade , Arthrobacter/classificação , Arthrobacter/enzimologia , Arthrobacter/genética , Proteínas de Bactérias/genética , Biotransformação , Glicosilação , Filogenia , Solanina/química , Solanina/metabolismo , Solanina/toxicidade , Solanum tuberosum/metabolismo
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