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1.
IMA Fungus ; 15(1): 10, 2024 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-38582937

RESUMO

The Apiospora genus comprises filamentous fungi with promising potential, though its full capabilities remain undiscovered. In this study, we present the first genome assembly of an Apiospora arundinis isolate, demonstrating a highly complete and contiguous assembly estimated to 48.8 Mb, with an N99 of 3.0 Mb. Our analysis predicted a total of 15,725 genes, with functional annotations for 13,619 of them, revealing a fungus capable of producing very high amounts of carbohydrate-active enzymes (CAZymes) and secondary metabolites. Through transcriptomic analysis, we observed differential gene expression in response to varying growth media, with several genes related to carbohydrate metabolism showing significant upregulation when the fungus was cultivated on a hay-based medium. Finally, our metabolomic analysis unveiled a fungus capable of producing a diverse array of metabolites.

2.
Front Plant Sci ; 15: 1340189, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38525152

RESUMO

Genomic prediction and genome-wide association studies are becoming widely employed in potato key performance trait QTL identifications and to support potato breeding using genomic selection. Elite cultivars are tetraploid and highly heterozygous but also share many common ancestors and generation-spanning inbreeding events, resulting from the clonal propagation of potatoes through seed potatoes. Consequentially, many SNP markers are not in a 1:1 relationship with a single allele variant but shared over several alleles that might exert varying effects on a given trait. The impact of such redundant "diluted" predictors on the statistical models underpinning genome-wide association studies (GWAS) and genomic prediction has scarcely been evaluated despite the potential impact on model accuracy and performance. We evaluated the impact of marker location, marker type, and marker density on the genomic prediction and GWAS of five key performance traits in tetraploid potato (chipping quality, dry matter content, length/width ratio, senescence, and yield). A 762-offspring panel of a diallel cross of 18 elite cultivars was genotyped by sequencing, and markers were annotated according to a reference genome. Genomic prediction models (GBLUP) were trained on four marker subsets [non-synonymous (29,553 SNPs), synonymous (31,229), non-coding (32,388), and a combination], and robustness to marker reduction was investigated. Single-marker regression GWAS was performed for each trait and marker subset. The best cross-validated prediction correlation coefficients of 0.54, 0.75, 0.49, 0.35, and 0.28 were obtained for chipping quality, dry matter content, length/width ratio, senescence, and yield, respectively. The trait prediction abilities were similar across all marker types, with only non-synonymous variants improving yield predictive ability by 16%. Marker reduction response did not depend on marker type but rather on trait. Traits with high predictive abilities, e.g., dry matter content, reached a plateau using fewer markers than traits with intermediate-low correlations, such as yield. The predictions were unbiased across all traits, marker types, and all marker densities >100 SNPs. Our results suggest that using non-synonymous variants does not enhance the performance of genomic prediction of most traits. The major known QTLs were identified by GWAS and were reproducible across exonic and whole-genome variant sets for dry matter content, length/width ratio, and senescence. In contrast, minor QTL detection was marker type dependent.

3.
Breast Cancer Res ; 25(1): 139, 2023 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-37946261

RESUMO

BACKGROUND: Considering the recent advancements in the treatment of breast cancer with low expression of human epidermal growth factor receptor 2 (HER2), we aimed to examine inter-laboratory variability in the assessment of HER2-low breast cancer across all Danish pathology departments. METHODS: From the Danish Breast Cancer Group, we obtained data on all women diagnosed with primary invasive breast cancer in 2007-2019 who were subsequently assigned for curatively intended treatment. RESULTS: Of 50,714 patients, HER2 score and status were recorded for 48,382, among whom 59.2% belonged to the HER2-low group (score 1+ or 2+ without gene amplification), 26.8% had a HER2 score of 0, and 14.0% were HER2 positive. The proportion of HER2-low cases ranged from 46.3 to 71.8% among pathology departments (P < 0.0001) and from 49.3 to 65.6% over the years (P < 0.0001). In comparison, HER2 positivity rates ranged from 11.8 to 17.2% among departments (P < 0.0001) and from 12.6 to 15.7% over the years (P = 0.005). In the eight departments with the highest number of patients, variability in HER2-low cases increased from 2011 to 2019, although the same immunohistochemical assay was used. By multivariable logistic regression, the examining department was significantly related to both HER2 score 0 and HER2 positivity (P < 0.0001) but showed greater dispersion in odds ratios in the former case (range 0.25-1.41 vs. 0.84-1.27). CONCLUSIONS: Our data showed high inter-laboratory variability in the assessment of HER2-low breast cancer. The findings cast doubt on whether the current test method for HER2 is robust and reliable enough to select HER2-low patients for HER2-targeted treatment in daily clinical practice.


Assuntos
Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/genética , Receptor ErbB-2/genética , Receptor ErbB-2/metabolismo , Sistema de Registros , Dinamarca/epidemiologia
4.
Clin Psychol Psychother ; 30(6): 1264-1278, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37675964

RESUMO

BACKGROUND: Treatment of schizotypal personality disorder is complex. Currently, there are no clear evidence-based recommendations for use of psychotherapy for individuals suffering from this mental illness, and studies are sparse. Our aim in this review is to map and describe the existing research and to answer the research question: What do we know about the use of psychotherapy for people with schizotypal personality disorder? METHODS: We conducted a scoping review using systematic searches in the Embase, MEDLINE and PsycINFO databases. Two reviewers screened possible studies and extracted data on subject samples, type of psychotherapy, outcomes and suggested mechanisms of change. The review is based on the PRISMA checklist for scoping reviews. RESULTS: Twenty-three papers were included, and we found a wide variety of study types, psychotherapeutic orientations and outcomes. Few studies emerged that focused solely on schizotypal personality disorder. CONCLUSION: Psychotherapy as a treatment for schizotypal personality disorder is understudied compared with diagnoses such as schizophrenia and borderline personality disorder. Our results included two randomized controlled studies, as well as mainly smaller studies with different approaches to diagnostic criteria, psychotherapeutic orientation and outcome measures. The findings are too sparse and too diverse to make any evidence-based recommendations. We found some indications that psychotherapy may support and assist individuals with schizotypal personality disorder.


Assuntos
Transtorno da Personalidade Borderline , Esquizofrenia , Transtorno da Personalidade Esquizotípica , Humanos , Transtorno da Personalidade Esquizotípica/terapia , Transtorno da Personalidade Esquizotípica/diagnóstico , Psicoterapia/métodos , Transtorno da Personalidade Borderline/terapia , Avaliação de Resultados em Cuidados de Saúde
5.
J Exp Biol ; 226(11)2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-37283090

RESUMO

Terrestrial arthropods in the Arctic are exposed to highly variable temperatures that frequently reach cold and warm extremes. Yet, ecophysiological studies on arctic insects typically focus on the ability of species to tolerate low temperatures, whereas studies investigating physiological adaptations of species to periodically warm and variable temperatures are few. In this study, we investigated temporal changes in thermal tolerances and the transcriptome in the Greenlandic seed bug Nysius groenlandicus, collected in the field across different times and temperatures in Southern Greenland. We found that plastic changes in heat and cold tolerances occurred rapidly (within hours) and at a daily scale in the field, and that these changes are correlated with diurnal temperature variation. Using RNA sequencing, we provide molecular underpinnings of the rapid adjustments in thermal tolerance across ambient field temperatures and in the laboratory. We show that transcriptional responses are sensitive to daily temperature changes, and days characterized by high temperature variation induced markedly different expression patterns than thermally stable days. Further, genes associated with laboratory-induced heat responses, including expression of heat shock proteins and vitellogenins, were shared across laboratory and field experiments, but induced at time points associated with lower temperatures in the field. Cold stress responses were not manifested at the transcriptomic level.


Assuntos
Aclimatação , Artrópodes , Animais , Aclimatação/fisiologia , Artrópodes/metabolismo , Temperatura Baixa , Temperatura Alta , Insetos/genética , Temperatura , Transcriptoma
6.
IMA Fungus ; 14(1): 3, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36726175

RESUMO

The Penicillia are known to produce a wide range natural products-some with devastating outcome for the agricultural industry and others with unexploited potential in different applications. However, a large-scale overview of the biosynthetic potential of different species has been lacking. In this study, we sequenced 93 Penicillium isolates and, together with eleven published genomes that hold similar assembly characteristics, we established a species phylogeny as well as defining a Penicillium pangenome. A total of 5612 genes were shared between ≥ 98 isolates corresponding to approximately half of the average number of genes a Penicillium genome holds. We further identified 15 lateral gene transfer events that have occurred in this collection of Penicillium isolates, which might have played an important role, such as niche adaption, in the evolution of these fungi. The comprehensive characterization of the genomic diversity in the Penicillium genus supersedes single-reference genomes, which do not necessarily capture the entire genetic variation.

8.
PLoS One ; 17(8): e0273481, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36037153

RESUMO

Dickeya solani is a soft rot bacterium with high virulence. In potato, D. solani, like the other potato-infecting soft rot bacteria, causes rotting and wilting of the stems and rotting of tubers in the field and in storage. Latent, asymptomatic infections of potato tubers are common in harvested tubers, and if the storage conditions are not optimal, the latent infection turns into active rotting. We characterized potato gene expression in artificially inoculated tubers in nonsymptomatic, early infections 1 and 24 hours post-inoculation (hpi) and compared the results to the response in symptomatic tuber tissue 1 week (168 hpi) later with RNA-Seq. In the beginning of the infection, potato tubers expressed genes involved in the detection of the bacterium through pathogen-associated molecular patterns (PAMPs), which induced genes involved in PAMPs-triggered immunity, resistance, production of pathogenesis-related proteins, ROS, secondary metabolites and salicylic acid (SA) and jasmonic acid (JA) biosynthesis and signaling genes. In the symptomatic tuber tissue one week later, the PAMPs-triggered gene expression was downregulated, whereas primary metabolism was affected, most likely leading to free sugars fueling plant defense but possibly also aiding the growth of the pathogen. In the symptomatic tubers, pectic enzymes and cell wall-based defenses were activated. Measurement of hormone production revealed increased SA concentration and almost no JA in the asymptomatic tubers at the beginning of the infection and high level of JA and reduced SA in the symptomatic tubers one week later. These findings suggest that potato tubers rely on different defense strategies in the different phases of D. solani infection even when the infection takes place in fully susceptible plants incubated in conditions leading to rotting. These results support the idea that D. solani is a biotroph rather than a true necrotroph.


Assuntos
Solanum tuberosum , Dickeya , Enterobacteriaceae/genética , Expressão Gênica , Moléculas com Motivos Associados a Patógenos , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Reguladores de Crescimento de Plantas , Ácido Salicílico , Solanum tuberosum/microbiologia
9.
Microb Genom ; 8(4)2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35438621

RESUMO

During the last two decades, whole-genome sequencing has revolutionized genetic research in all kingdoms, including fungi. More than 1000 fungal genomes have been submitted to sequence databases, mostly obtained through second generation short-read DNA sequencing. As a result, highly fragmented genome drafts have typically been obtained. However, with the emergence of third generation long-read DNA sequencing, the assembly challenge can be overcome and highly contiguous assemblies obtained. Such attractive results, however, are extremely dependent on the ability to extract highly purified high molecular weight (HMW) DNA. Extraction of such DNA is currently a significant challenge for all species with cell walls, not least fungi. In this study, four isolates of filamentous ascomycetes (Apiospora pterospermum, Aspergillus sp. (subgen. Cremei), Aspergillus westerdijkiae, and Penicillium aurantiogriseum) were used to develop extraction and purification methods that result in HMW DNA suitable for third generation sequencing. We have tested and propose two straightforward extraction methods based on treatment with either a commercial kit or traditional phenol-chloroform extraction both in combination with a single commercial purification method that result in high quality HMW DNA from filamentous ascomycetes. Our results demonstrated that using these DNA extraction methods and coverage, above 75 x of our haploid filamentous ascomycete fungal genomes result in complete and contiguous assemblies.


Assuntos
Ascomicetos , Sequenciamento por Nanoporos , Ascomicetos/genética , DNA , Genoma Fúngico , Peso Molecular
10.
Int J Lab Hematol ; 44(3): 531-537, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35142436

RESUMO

INTRODUCTION: We performed a single-center study of real-world health data to investigate the direct clinical consequence of targeted next-generation sequencing (NGS) results integrated in the clinicopathological evaluation of patients with cytopenia suspected of myelodysplastic syndrome (MDS). METHODS: The study included 87 newly referred patients, who had a bone marrow examination, which included targeted NGS analysis. NGS was requested at the discretion of either examining pathologist or hematologist. Data were collected retrospectively from patient files including pathology reports with integrated NGS results. RESULTS: The NGS results had a diagnostic impact in 67 cases (77%) when combining both histopathological and final clinical evaluation and provided prognostic value in 19 cases (22%). NGS supported a confident or tentative histopathological diagnosis in 52 cases (60%). Twenty cases (23%) had a final diagnosis of either Clonal Cytopenia of Undetermined Significance (CCUS) or Idiopathic Cytopenia of Undetermined Significance (ICUS). In 4 cases, NGS results affected the choice of principal treatment strategy, including considerations of allotransplantation. Twenty-one patients (24%) could be discharged to primary care physician. CONCLUSION: In a multidisciplinary clinicopathological real-world setting, NGS analysis of bone marrow samples from selected patients contributed substantially to the diagnostic evaluation and management of patients with cytopenia suspected of MDS. Consequently, we have now included NGS analysis in most routine bone marrow examinations from patients with MDS or unexplained cytopenia.


Assuntos
Anemia , Síndromes Mielodisplásicas , Trombocitopenia , Hematopoiese Clonal , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Síndromes Mielodisplásicas/diagnóstico , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/terapia , Estudos Retrospectivos
11.
Genome Biol Evol ; 14(1)2022 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-35104337

RESUMO

The phylogenetic relationship of the Arthrinium genus has changed throughout the years. For many years, the Arthrinium genus included the Apiospora genus as well. New evidence has now showed that these two genera in fact are phylogenetically different and belong to two different clades. Here, we present the first genome draft within the Arthrinium genus. This genome was sequenced using the MinION platform from Oxford Nanopore Technologies and the assembly was contiguous. The assembly comprises ten contigs totaling 39.8 Mb with an N50 length of 7.9. In the assembly, 11,602 genes were predicted whereof 10,784 were functionally annotated. A total of 37 rRNA genes were observed in the assembly and repeat elements spanning 7.39% of the genome were found. A total of 99 secondary metabolite gene clusters were predicted, showing a high potential of novel secondary metabolites. This genome sequence will not only be useful for further investigation of the Arthrinium clade, but also for discovery of novel secondary metabolite compounds that could be of high interest for the food, agricultural, or pharmaceutical industry.


Assuntos
Genoma , Nanoporos , Filogenia
12.
Microb Cell Fact ; 21(1): 9, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-35012550

RESUMO

The biosynthetic pathways for the fungal polyketides bikaverin and bostrycoidin, from Fusarium verticillioides and Fusarium solani respectively, were reconstructed and heterologously expressed in S. cerevisiae alongside seven different phosphopantetheinyl transferases (PPTases) from a variety of origins spanning bacterial, yeast and fungal origins. In order to gauge the efficiency of the interaction between the ACP-domains of the polyketide synthases (PKS) and PPTases, each were co-expressed individually and the resulting production of target polyketides were determined after 48 h of growth. In co-expression with both biosynthetic pathways, the PPTase from Fusarium verticillioides (FvPPT1) proved most efficient at producing both bikaverin and bostrycoidin, at 1.4 mg/L and 5.9 mg/L respectively. Furthermore, the remaining PPTases showed the ability to interact with both PKS's, except for a single PKS-PPTase combination. The results indicate that it is possible to boost the production of a target polyketide, simply by utilizing a more optimal PPTase partner, instead of the commonly used PPTases; NpgA, Gsp and Sfp, from Aspergillus nidulans, Brevibacillus brevis and Bacillus subtilis respectively.


Assuntos
Proteínas de Bactérias/metabolismo , Fusarium/enzimologia , Policetídeo Sintases/metabolismo , Transferases (Outros Grupos de Fosfato Substituídos)/metabolismo , Xantonas/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Vias Biossintéticas , Clonagem Molecular , Fusarium/genética , Isoquinolinas/metabolismo , Modelos Moleculares , Policetídeo Sintases/química , Policetídeo Sintases/genética , Domínios Proteicos , Estrutura Terciária de Proteína , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Transferases (Outros Grupos de Fosfato Substituídos)/química , Transferases (Outros Grupos de Fosfato Substituídos)/genética
13.
PLoS One ; 16(3): e0249172, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33770115

RESUMO

Several shrimp trawl fisheries use a Nordmöre sorting grid to avoid bycatch of fish. However, small fish can pass through the grid. Therefore, the retention of juvenile fish often remains an issue during shrimp trawling. We investigated the vertical distribution of deepwater shrimp (Pandalus borealis) and dominant bycatch species at the point where the Nordmöre grid section is installed. This was achieved using a separator frame which split the net vertically into three compartments of equal entry size. Our results showed that shrimp predominately follow the lower part of the trawl belly, whereas species such as redfish (Sebastes spp.), cod (Gadus morhua), polar cod (Boreogadus saida) and American plaice (Hippoglossoides platessoides) preferred the mid-section in the aft of the trawl. Haddock (Melanogrammus aeglefinus) primarily entered through the upper section of the trawl belly. Using these results, we predict that a vertical separation device installed forward of a 19 mm Nordmöre grid combined with a 35 mm codend would result in a significant reduction in bycatch with only minor loss of shrimp.


Assuntos
Pesqueiros/estatística & dados numéricos , Animais , Alimentos Marinhos
14.
Front Genome Ed ; 3: 795644, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35128523

RESUMO

Potato, Solanum tuberosum is a highly diverse tetraploid crop. Elite cultivars are extremely heterozygous with a high prevalence of small length polymorphisms (indels) and single nucleotide polymorphisms (SNPs) within and between cultivars, which must be considered in CRISPR/Cas gene editing strategies and designs to obtain successful gene editing. In the present study, in-depth sequencing of the gene encoding glucan water dikinase (GWD) 1 and the downy mildew resistant 6 (DMR6-1) genes in the potato cultivars Saturna and Wotan, respectively, revealed both indels and a 1.3-2.8 higher SNP prevalence when compared to the heterozygous diploid RH genome sequence as expected for a tetraploid compared to a diploid. This complicates guide RNA (gRNA) and diagnostic PCR designs. At the same time, high editing efficiencies at the cell pool (protoplast) level are pivotal for achieving full allelic knock-out in tetraploids. Furthermore, high editing efficiencies reduce the downstream cumbersome and delicate ex-plant regeneration. Here, CRISPR/Cas ribonucleoprotein particles (RNPs) were delivered transiently to protoplasts by polyethylene glycol (PEG) mediated transformation. For each of GWD1 and the DMR6-1, 6-10 gRNAs were designed to target regions comprising the 5' and the 3' end of the two genes. Similar to other studies including several organisms, editing efficiency of the individual RNPs varied significantly, and some generated specific indel patterns. RNP's targeting the 5' end of GWD1 yielded significantly higher editing efficiency as compared to targeting the 3' end. For DMR6-1, such an effect was not seen. Simultaneously targeting each of the two target regions with two RNPs (multiplexing) yielded a clear positive synergistic effect on the total editing when targeting the 3' end of the GWD1 gene only. Multiplexing of the two genes, residing on different chromosomes, yielded no or a slightly negative effect on editing from the single or combined gRNA/RNPs. These initial findings may instigate much larger studies needed for facilitating and optimizing precision breeding in plants.

15.
Int J Mol Sci ; 21(20)2020 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-33066643

RESUMO

Through stepwise recreation of the biosynthetic gene cluster containing PKS3 from Fusarium solani, it was possible to produce the core scaffold compound of bostrycoidin, a red aza-anthraquinone pigment in Saccharomyces cerevisiae. This was achieved through sequential transformation associated recombination (TAR) cloning of FvPPT, fsr1, fsr2, and fsr3 into the pESC-vector system, utilizing the inducible bidirectional galactose promoter for heterologous expression in S. cerevisiae. The production of the core metabolite bostrycoidin was investigated through triplicate growth cultures for 1-4 days, where the maximum titer of bostrycoidin was achieved after 2 days of induction, yielding 2.2 mg/L.


Assuntos
Clonagem Molecular , Proteínas Fúngicas/genética , Fusarium/genética , Naftoquinonas/metabolismo , Policetídeo Sintases/genética , Proteínas Fúngicas/metabolismo , Isoquinolinas/metabolismo , Família Multigênica , Policetídeo Sintases/metabolismo , Regiões Promotoras Genéticas , Saccharomyces cerevisiae/genética
16.
Plant Biotechnol J ; 18(10): 2096-2108, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32096588

RESUMO

Solanum tuberosum potato lines with high amylose content were generated by crossing with the wild potato species Solanum sandemanii followed by repeated backcrossing to Solanum tuberosum lines. The trait, termed increased amylose (IAm), was recessive and present after three generations of backcrossing into S. tuberosum lines (6.25% S. sandemanii genes). The tubers of these lines were small, elongated and irregular with small and misshaped starch granules and high sugar content. Additional backcrossing resulted in less irregular tuber morphology, increased starch content (4.3%-9.5%) and increased amylose content (29%-37.9%) but indifferent sugar content. The amylose in the IAm starch granules was mainly located in peripheral spots, and large cavities were found in the granules. Starch pasting was suppressed, and the digestion-resistant starch (RS) content was increased. Comprehensive microarray polymer profiling (CoMPP) analysis revealed specific alterations of major pectic and glycoprotein cell wall components. This complex phenotype led us to search for candidate IAm genes exploiting its recessive trait. Hence, we sequenced genomic DNA of a pool of IAm lines, identified SNPs genome wide against the draft genome sequence of potato and searched for regions of decreased heterozygosity. Three regions, located on chromosomes 3, 7 and 10, respectively, displayed markedly less heterozygosity than average. The only credible starch metabolism-related gene found in these regions encoded the isoamylase-type debranching enzyme Stisa1. Decreased expression of mRNA (>500 fold) and reduced enzyme activity (virtually absent from IAm lines) supported Stisa1 as a candidate gene for IAm.

17.
Sci Rep ; 9(1): 17715, 2019 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-31776399

RESUMO

CRISPR/Cas9 editing efficacies in tetraploid potato were highly improved through the use of endogenous potato U6 promoters. Highly increased editing efficiencies in the Granular Bound Starch Synthase gene at the protoplast level were obtained by replacement of the Arabidopsis U6 promotor, driving expression of the CRISPR component, with endogenous potato U6 promotors. This translated at the ex-plant level into 35% full allelic gene editing. Indel Detection Amplicon Analysis was established as an efficient tool for fast assessment of gene editing in complex genomes, such as potato. Together, this warrants significant reduction of laborious cell culturing, ex-plant regeneration and screening procedures of plants with high complexity genomes.


Assuntos
Sistemas CRISPR-Cas , Edição de Genes/métodos , Melhoramento Vegetal/métodos , Solanum tuberosum/genética , Tetraploidia
18.
BMC Plant Biol ; 19(1): 262, 2019 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-31208336

RESUMO

BACKGROUND: Stored potato (Solanum tuberosum L.) tubers are sensitive to wet conditions that can cause rotting in long-term storage. To study the effect of water on the tuber surface during storage, microarray analysis, RNA-Seq profiling, qRT-PCR and phytohormone measurements were performed to study gene expression and hormone content in wet tubers incubated at two temperatures: 4 °C and 15 °C. The growth of the plants was also observed in a greenhouse after the incubation of tubers in wet conditions. RESULTS: Wet conditions induced a low-oxygen response, suggesting reduced oxygen availability in wet tubers at both temperatures when compared to that in the corresponding dry samples. Wet conditions induced genes coding for heat shock proteins, as well as proteins involved in fermentative energy production and defense against reactive oxygen species (ROS), which are transcripts that have been previously associated with low-oxygen stress in hypoxic or anoxic conditions. Wet treatment also induced senescence-related gene expression and genes involved in cell wall loosening, but downregulated genes encoding protease inhibitors and proteins involved in chloroplast functions and in the biosynthesis of secondary metabolites. Many genes involved in the production of phytohormones and signaling were also affected by wet conditions, suggesting altered regulation of growth by wet conditions. Hormone measurements after incubation showed increased salicylic acid (SA), abscisic acid (ABA) and auxin (IAA) concentrations as well as reduced production of jasmonate 12-oxo-phytodienoic acid (OPDA) in wet tubers. After incubation in wet conditions, the tubers produced fewer stems and more roots compared to controls incubated in dry conditions. CONCLUSIONS: In wet conditions, tubers invest in ROS protection and defense against the abiotic stress caused by reduced oxygen due to excessive water. Changes in ABA, SA and IAA that are antagonistic to jasmonates affect growth and defenses, causing induction of root growth and rendering tubers susceptible to necrotrophic pathogens. Water on the tuber surface may function as a signal for growth, similar to germination of seeds.


Assuntos
Armazenamento de Alimentos , Reguladores de Crescimento de Plantas/metabolismo , Tubérculos/metabolismo , Solanum tuberosum/metabolismo , Metabolismo dos Carboidratos , Parede Celular/metabolismo , Cloroplastos/metabolismo , Regulação da Expressão Gênica de Plantas , Análise de Sequência com Séries de Oligonucleotídeos , Estresse Oxidativo , Tubérculos/crescimento & desenvolvimento , Metabolismo Secundário , Solanum tuberosum/crescimento & desenvolvimento , Transcriptoma , Água
19.
PLoS Genet ; 15(6): e1008205, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31188830

RESUMO

The relationship between population size, inbreeding, loss of genetic variation and evolutionary potential of fitness traits is still unresolved, and large-scale empirical studies testing theoretical expectations are surprisingly scarce. Here we present a highly replicated experimental evolution setup with 120 lines of Drosophila melanogaster having experienced inbreeding caused by low population size for a variable number of generations. Genetic variation in inbred lines and in outbred control lines was assessed by genotyping-by-sequencing (GBS) of pooled samples consisting of 15 males per line. All lines were reared on a novel stressful medium for 10 generations during which body mass, productivity, and extinctions were scored in each generation. In addition, we investigated egg-to-adult viability in the benign and the stressful environments before and after rearing at the stressful conditions for 10 generations. We found strong positive correlations between levels of genetic variation and evolutionary response in all investigated traits, and showed that genomic variation was more informative in predicting evolutionary responses than population history reflected by expected inbreeding levels. We also found that lines with lower genetic diversity were at greater risk of extinction. For viability, the results suggested a trade-off in the costs of adapting to the stressful environments when tested in a benign environment. This work presents convincing support for long-standing evolutionary theory, and it provides novel insights into the association between genetic variation and evolutionary capacity in a gradient of diversity rather than dichotomous inbred/outbred groups.


Assuntos
Variação Genética/genética , Genética Populacional , Genótipo , Endogamia , Animais , Drosophila melanogaster/genética , Feminino , Genômica , Masculino , Fenótipo , Densidade Demográfica , Análise de Sequência de DNA
20.
Front Plant Sci ; 9: 1118, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30131817

RESUMO

Genomic selection (GS) is becoming increasingly applicable to crops as the genotyping costs continue to decrease, which makes it an attractive alternative to traditional selective breeding based on observed phenotypes. With genome-wide molecular markers, selection based on predictions from genotypes can be made in the absence of direct phenotyping. The reliability of predictions depends strongly on the number of individuals used for training the predictive algorithms, particularly in a highly genetically diverse organism such as potatoes; however, the relationship between the individuals also has an enormous impact on prediction accuracy. Here we have studied genomic prediction in three different panels of potato cultivars, varying in size, design, and phenotypic profile. We have developed genomic prediction models for two important agronomic traits of potato, dry matter content and chipping quality. We used genotyping-by-sequencing to genotype 1,146 individuals and generated genomic prediction models from 167,637 markers to calculate genomic estimated breeding values with genomic best linear unbiased prediction. Cross-validated prediction correlations of 0.75-0.83 and 0.39-0.79 were obtained for dry matter content and chipping quality, respectively, when combining the three populations. These prediction accuracies were similar to those obtained when predicting performance within each panel. In contrast, but not unexpectedly, predictions across populations were generally lower, 0.37-0.71 and 0.28-0.48 for dry matter content and chipping quality, respectively. These predictions are not limited by the number of markers included, since similar prediction accuracies could be obtained when using merely 7,800 markers (<5%). Our results suggest that predictions across breeding populations in tetraploid potato are presently unreliable, but that individual prediction models within populations can be combined in an additive fashion to obtain high quality prediction models relevant for several breeding populations.

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