scholarly journals Genetic and physiological characterization of sunflower resistance provided by the wild-derived OrDeb2 gene against highly virulent races of Orobanche cumana Wallr

2021 ◽  
Author(s):  
Mónica Fernández-Aparicio ◽  
Lidia del Moral ◽  
Stéphane Muños ◽  
Leonardo Velasco ◽  
Begoña Pérez-Vich
Keyword(s):  
Genetic Resistance ◽  
Resistance Mechanism ◽  
Kinase Domain ◽  
Genomic Region ◽  
Snp Markers ◽  
Resistance Response ◽  
Physiological Characterization ◽  
Orobanche Cumana ◽  
Genes Encoding ◽  
Highly Virulent

Abstract Key message OrDeb2 confers post-attachment resistance to Orobanche cumana and is located in a 1.38 Mbp genomic interval containing a cluster of receptor-like kinase and receptor-like protein genes with nine high-confidence candidates. Abstract Sunflower broomrape is a holoparasitic angiosperm that parasitizes on sunflower roots, severely constraining crop yield. Breeding for resistance is the most effective method of control. OrDeb2 is a dominant resistance gene introgressed into cultivated sunflower from a wild-related species that confers resistance to highly virulent broomrape races. The objectives of this study were as follows: (i) locate OrDeb2 into the sunflower genome and determine putative candidate genes and (ii) characterize its underlying resistance mechanism. A segregating population from a cross between the sunflower resistant line DEB2, carrying OrDeb2, and a susceptible line was phenotyped for broomrape resistance in four experiments, including different environments and two broomrape races (FGV and GTK). This population was also densely genotyped with microsatellite and SNP markers, which allowed locating OrDeb2 within a 0.9 cM interval in the upper half of Chromosome 4. This interval corresponded to a 1.38 Mbp genomic region of the sunflower reference genome that contained a cluster of genes encoding LRR (leucine-rich repeat) receptor-like proteins lacking a cytoplasmic kinase domain and receptor-like kinases with one or two kinase domains and lacking an extracellular LRR region, which were valuable candidates for OrDeb2. Rhizotron and histological studies showed that OrDeb2 determines a post-attachment resistance response that blocks O. cumana development mainly at the cortex before the establishment of host-parasite vascular connections. This study will contribute to understand the interaction between crops and parasitic weeds, to establish durable breeding strategies based on genetic resistance and provide useful tools for marker-assisted selection and OrDeb2 map-based cloning.

scholarly journals Resistance of European Spring 2-Row Barley Cultivars to Pyrenophora graminea and Detection of Associated Loci

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 374
Author(s):  
Nadia Faccini ◽  
Stefano Delbono ◽  
Arzu Çelik Oğuz ◽  
Luigi Cattivelli ◽  
Giampiero Valè ◽  
...  
Keyword(s):  
Molecular Data ◽  
Kinase Domain ◽  
Snp Markers ◽  
Barley Cultivars ◽  
Genome Wide ◽  
Genes Encoding ◽  
Pyrenophora Graminea ◽  
Barley Leaf ◽  
Barley Resistance ◽  
Highly Virulent

Pyrenophora graminea is the seed-borne pathogen causal agent of barley leaf stripe disease. In this work, we screened a collection of 206 spring two-row barley cultivars from Europe for their resistance to the fungal pathogen. Artificial inoculation with the highly virulent isolate Dg2 revealed a continuous variation for the incidence of infection, with few highly resistant or highly susceptible genotypes. On average, old cultivars showed higher resistance than the more modern ones. Genome-Wide Association Scan was performed by exploiting available molecular data for >4000 SNP markers and revealed a single, highly significant association on the short arm of chromosome 6H, in a genomic position where quantitative trait loci (QTL) for barley resistance to P. graminea were not detected before. Based on the last version of the reference barley genome, genes encoding for proteins with a kinase domain were suggested as candidates for the locus.

scholarly journals Comparative Transcriptome Profiling Reveals Defense-Related Genes against Meloidogyne incognita Invasion in Tobacco

Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 2081 ◽  
Author(s):  
Xiaohui Li ◽  
Xuexia Xing ◽  
Pei Tian ◽  
Mingzhen Zhang ◽  
Zhaoguang Huo ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Meloidogyne Incognita ◽  
Resistance Mechanism ◽  
Transcriptome Profiling ◽  
Ethylene Response Factor ◽  
Sequencing Analysis ◽  
Cell Wall Modification ◽  
Resistance Response ◽  
Helix Loop Helix ◽  
Genes Encoding

Root-knot nematodes Meloidogyne incognita are one of the most destructive pathogens, causing severe losses to tobacco productivity and quality. However, the underlying resistance mechanism of tobacco to M. incognita is not clear. In this study, two tobacco genotypes, K326 and Changbohuang, which are resistant and susceptible to M. incognita, respectively, were used for RNA-sequencing analysis. An average of 35 million clean reads were obtained. Compared with their expression levels in non-infected plants of the same genotype, 4354 and 545 differentially expressed genes (DEGs) were detected in the resistant and susceptible genotype, respectively, after M. incognita invasion. Overall, 291 DEGs, involved in diverse biological processes, were common between the two genotypes. Genes encoding toxic compound synthesis, cell wall modification, reactive oxygen species and the oxidative burst, salicylic acid signal transduction, and production of some other metabolites were putatively associated with tobacco resistance to M. incognita. In particular, the complex resistance response needed to overcome M. incognita invasion may be regulated by several transcription factors, such as the ethylene response factor, MYB, basic helix–loop–helix transcription factor, and indole acetic acid–leucine-resistant transcription factor. These results may aid in the identification of potential genes of resistance to M. incognita for tobacco cultivar improvement.

scholarly journals Updated Characterization of Races of Plasmopara halstedii and Entomopathogenic Fungi as Endophytes of Sunflower Plants in Axenic Culture

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 268
Author(s):  
Pedro Miranda-Fuentes ◽  
Ana B. García-Carneros ◽  
Leire Molinero-Ruiz
Keyword(s):  
Plant Growth ◽  
Downy Mildew ◽  
Entomopathogenic Fungi ◽  
Genetic Resistance ◽  
Axenic Culture ◽  
Plasmopara Halstedii ◽  
Successful Establishment ◽  
Axenic Conditions ◽  
Highly Virulent

The management of downy mildew (Plasmopara halstedii) in sunflower, is heavily dependent on genetic resistance, whilst entomopathogenic fungi (EF) can reduce other sunflower diseases. In this work, we characterized P. halstedii from Spain and other countries collected in the past few years. Twenty-three races were identified (the most frequent in Spain being 310, 304, 705 and 715), with an increasing proportion of highly virulent races. Five isolates from countries other than Spain overcame the resistance in RHA-340. In addition, we assessed the efficacy of five EF against downy mildew and their effects on sunflower growth in axenic conditions. None of the entomopathogens reduced disease severity, nor did they have any effect on plant growth when applied together with P. halstedii. In contrast, three EF reduced some of the plant growth variables in the absence of the pathogen. Microbiological and molecular diagnostics suggest that the axenic system and the short experimental time used in this study did not favor the successful establishment of EF in the plants or their potential biocontrol effect. Our results show a shift in P. halstedii racial patterns and suggest that soil as a growth substrate and long infection times are needed for EF effectiveness against downy mildew.

scholarly journals Inheritance of resistance to a highly virulent race F of Orobanche cumana Wallr. in a sunflower line derived from interspecific amphiploids

Helia ◽  
2002 ◽  
Vol 25 (36) ◽  
pp. 137-143 ◽  
Author(s):  
B. Pérez-Vich ◽  
B. Akhtouch ◽  
J. Munoz-Ruz ◽  
J.M. Fernandez-Martinez ◽  
C.C. Jan
Keyword(s):  
Inheritance Of Resistance ◽  
Orobanche Cumana ◽  
Sunflower Line ◽  
Highly Virulent

scholarly journals Efflux-Related Resistance to Norfloxacin, Dyes, and Biocides in Bloodstream Isolates of Staphylococcus aureus

2007 ◽  
Vol 51 (9) ◽  
pp. 3235-3239 ◽  
Author(s):  
Carmen E. DeMarco ◽  
Laurel A. Cushing ◽  
Emmanuel Frempong-Manso ◽  
Susan M. Seo ◽  
Tinevimbo A. A. Jaravaza ◽  
...  
Keyword(s):  
Gene Expression ◽  
Staphylococcus Aureus ◽  
Efflux Pump ◽  
Resistance Mechanism ◽  
Efflux Pump Inhibitor ◽  
Qrt Pcr ◽  
Reverse Transcription Pcr ◽  
Environmental Surfaces ◽  
Genes Encoding ◽  
High Level

ABSTRACT Efflux is an important resistance mechanism in Staphylococcus aureus, but its frequency in patients with bacteremia is unknown. Nonreplicate bloodstream isolates were collected over an 8-month period, and MICs of four common efflux pump substrates, with and without the broad-spectrum efflux pump inhibitor reserpine, were determined (n = 232). A reserpine-associated fourfold decrease in MIC was considered indicative of efflux. Strains exhibiting efflux of at least two of the four substrates were identified (“effluxing strains” [n = 114]). For these strains, MICs with or without reserpine for an array of typical substrates and the expression of mepA, mdeA, norA, norB, norC, and qacA/B were determined using quantitative real-time reverse transcription-PCR (qRT-PCR). A fourfold or greater increase in gene expression was considered significant. The most commonly effluxed substrates were ethidium bromide and chlorhexidine (100 and 96% of effluxing strains, respectively). qRT-PCR identified strains overexpressing mepA (5 [4.4%]), mdeA (13 [11.4%]), norA (26 [22.8%]), norB (29 [25.4%]), and norC (19 [16.7%]); 23 strains overexpressed two or more genes. Mutations probably associated with increased gene expression included a MepR-inactivating substitution and norA promoter region insertions or deletions. Mutations possibly associated with increased expression of the other analyzed genes were also observed. Effluxing strains comprised 49% of all strains studied (114/232 strains), with nearly half of these overexpressing genes encoding MepA, MdeA, and/or NorABC (54/114 strains). Reduced susceptibility to biocides may contribute to persistence on environmental surfaces, and efflux of drugs such as fluoroquinolones may predispose strains to high-level target-based resistance.

scholarly journals Field-based screening identifies resistance to Sunn pest (Eurygaster integriceps) feeding at vegetative stage in elite wheat genotypes

2017 ◽  
Vol 68 (2) ◽  
pp. 126 ◽  
Author(s):  
Livinus Emebiri ◽  
Mustapha El Bousshini ◽  
Mui-Keng Tan ◽  
Francis C. Ogbonnaya
Keyword(s):  
Strong Association ◽  
Genetic Resistance ◽  
Pest Resistance ◽  
Snp Markers ◽  
Vegetative Stage ◽  
Sunn Pest ◽  
Wheat Varieties ◽  
Wheat Germplasm ◽  
Eurygaster Integriceps ◽  
A Genome

Sunn pest (Eurygaster integriceps Puton) is currently widely distributed in West and Central Asia and Eastern Europe, but has not been found in Australia, Western Europe or North America. Climate warming is known to promote the expansion of its range of distribution, and it is expected that the insect could spread into new territories. Varieties of wheat (Triticum aestivum) carrying resistance remain an important component of managing the biosecurity risk of any potential incursion. Previous studies have identified sources of Sunn pest resistance in wheat, but there is little information on the genes that confer the resistance. This research used field-based, artificial infestation cages to evaluate 204 elite wheat varieties for Sunn pest resistance, at Terbol, Lebanon. A significant (P < 0.001) difference in resistance was observed among the wheat germplasm, with 19 varieties rated as resistant to moderately resistant and 17 as highly susceptible. Three of the elite varieties showed very little damage, a status similar to that of the resistant check, ICBW-209273. In parallel, the research carried out a genome-wide scan with single-nucleotide polymorphism (SNP) markers to identify chromosome regions and putative genes associated with resistance. Association mapping identified SNP markers with significant associations on chromosomes 2D, 4B and 5B. When these markers were projected onto the wheat population sequencing-based (POPSEQ) reference map, they tended to map close to the location of wheat height-reducing genes. The phenotypic variation explained by the identified markers ranged from 7% to 11%, and collectively, they explained 23.9% of the variation or 45% of the generalised heritability. Marker-trait association was confirmed in two independent, doubled-haploid wheat populations, derived from crosses involving wheat landraces from Afghanistan, where Sunn pest is recognised as an endemic problem. In the two wheat populations, the analyses validated the strong association between wsnp_BF483640B_Ta_2_2 and resistance to Sunn pest damage at the vegetative stage. This study demonstrates existence of genetic resistance to Sunn pest feeding at the vegetative stage in elite wheat germplasm. The study also identified and validated SNP markers that could be useful tools for transfer of resistance into new wheat cultivars.

scholarly journals Minimization of energy transduction confers resistance to phosphine in the rice weevil, Sitophilus oryzae

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Kyeongnam Kim ◽  
Jeong Oh Yang ◽  
Jae-Yoon Sung ◽  
Ji-Young Lee ◽  
Jeong Sun Park ◽  
...  
Keyword(s):  
Cancer Metabolism ◽  
Insect Pests ◽  
Sitophilus Oryzae ◽  
Resistance Mechanism ◽  
Energy Transduction ◽  
Metabolic Reprogramming ◽  
Rice Weevil ◽  
Altered Expression ◽  
Synonymous Mutations ◽  
Genes Encoding

Abstract Infestation of phosphine (PH3) resistant insects threatens global grain reserves. PH3 fumigation controls rice weevil (Sitophilus oryzae) but not highly resistant insect pests. Here, we investigated naturally occurring strains of S. oryzae that were moderately resistant (MR), strongly resistant (SR), or susceptible (wild-type; WT) to PH3 using global proteome analysis and mitochondrial DNA sequencing. Both PH3 resistant (PH3–R) strains exhibited higher susceptibility to ethyl formate-mediated inhibition of cytochrome c oxidase than the WT strain, whereas the disinfectant PH3 concentration time of the SR strain was much longer than that of the MR strain. Unlike the MR strain, which showed altered expression levels of genes encoding metabolic enzymes involved in catabolic pathways that minimize metabolic burden, the SR strain showed changes in the mitochondrial respiratory chain. Our results suggest that the acquisition of strong PH3 resistance necessitates the avoidance of oxidative phosphorylation through the accumulation of a few non-synonymous mutations in mitochondrial genes encoding complex I subunits as well as nuclear genes encoding dihydrolipoamide dehydrogenase, concomitant with metabolic reprogramming, a recognized hallmark of cancer metabolism. Taken together, our data suggest that reprogrammed metabolism represents a survival strategy of SR insect pests for the compensation of minimized energy transduction under anoxic conditions. Therefore, understanding the resistance mechanism of PH3–R strains will support the development of new strategies to control insect pests.

scholarly journals Gut–Liver Immune Response and Gut Microbiota Profiling Reveal the Pathogenic Mechanisms of Vibrio harveyi in Pearl Gentian Grouper (Epinephelus lanceolatus♂ × E. fuscoguttatus♀)

2020 ◽  
Vol 11 ◽  
Author(s):  
Yiqin Deng ◽  
Yaqiu Zhang ◽  
Haoxiang Chen ◽  
Liwen Xu ◽  
Qian Wang ◽  
...  
Keyword(s):  
Immune Response ◽  
Bacterial Community ◽  
Gut Microbiota ◽  
Vibrio Harveyi ◽  
Virulent Strain ◽  
Interspecies Interactions ◽  
Genes Encoding ◽  
Genetic Information Processing ◽  
Cellular Immune ◽  
Highly Virulent

Vibrio harveyi causes vibriosis in nearly 70% of grouper (Epinephelus sp.), seriously limiting grouper culture. As well as directly inhibiting pathogens, the gut microbiota plays critical roles in immune homeostasis and provides essential health benefits to its host. However, there is still little information about the variations in the immune response to V. harveyi infection and the gut microbiota of grouper. To understand the virulence mechanism of V. harveyi in the pearl gentian grouper, we investigated the variations in the pathological changes, immune responses, and gut bacterial communities of pearl gentian grouper after exposure to differently virulent V. harveyi strains. Obvious histopathological changes were detected in heart, kidney, and liver. In particular, nodules appeared and huge numbers of V. harveyi cells colonized the liver at 12 h postinfection (hpi) with highly virulent V. harveyi. Although no V. harveyi was detected in the gut, the infection simultaneously induced a gut-liver immune response. In particular, the expression of 8 genes associated with cellular immune processes, including genes encoding inflammatory cytokines and receptors, and pattern recognition proteins, was markedly induced by V. harveyi infection, especially with the highly virulent V. harveyi strain. V. harveyi infection also induced significant changes in gut bacterial community, in which Vibrio and Photobacterium increased but Bradyrhizobium, Lactobacillus, Blautia, and Faecalibaculum decreased in the group infected with the highly virulent strain, with accounting for 82.01% dissimilarity. Correspondingly, four bacterial functions related to bacterial pathogenesis were increased by infection with highly virulent V. harveyi, whereas functions involving metabolism and genetic information processing were reduced. These findings indicate that V. harveyi colonizes the liver and induces a gut-liver immune response that substantially disrupts the composition of and interspecies interactions in the bacterial community in fish gut, thereby altering the gut-microbiota-mediated functions and inducing fish death.

scholarly journals De Novo Transcriptomic Resources in the Brain of Vespa velutina for Invasion Control

Insects ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 101
Author(s):  
Miao Wang ◽  
Hanyu Li ◽  
Huoqing Zheng ◽  
Liuwei Zhao ◽  
Xiaofeng Xue ◽  
...  
Keyword(s):  
Large Scale ◽  
Target Genes ◽  
De Novo ◽  
Transcriptome Profiling ◽  
Molecular Study ◽  
Snp Markers ◽  
Nucleotide Polymorphisms ◽  
Illumina Hiseq ◽  
Vespa Velutina ◽  
Genes Encoding

The invasion of Vespa velutina presents a great threat to the agriculture economy, the ecological environment, and human health. An effective strategy for this hornet control is urgently required, but the limited genome information of Vespa velutina restricts the application of molecular-genomic tools for targeted hornet management. Therefore, we conducted large-scale transcriptome profiling of the hornet brain to obtain functional target genes and molecular markers. Using an Illumina HiSeq platform, more than 41 million clean reads were obtained and de novo assembled into 182,087 meaningful unigenes. A total of 56,400 unigenes were annotated against publicly available protein sequence databases and a set of reliable Simple Sequence Repeats (SSRs) and Single Nucleotide Polymorphisms (SNP) markers were developed. The homologous genes encoding crucial behavior regulation factors, odorant binding proteins (OBPs), and vitellogenin, were also identified from highly expressed transcripts. This study provides abundant molecular targets and markers for invasive hornet control and further promotes the genetic and molecular study of Vespa velutina.

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