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Publications

NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.

2024

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Abstract

Background Potato virus Y (PVY) is among the economically most damaging viral pathogen in production of potato (Solanum tuberosum) worldwide. The gene Rysto derived from the wild potato relative Solanum stoloniferum confers extreme resistance to PVY. Results The presence and diversity of Rysto were investigated in wild relatives of potato (298 genotypes representing 29 accessions of 26 tuber-bearing Solanum species) using PacBio amplicon sequencing. A total of 55 unique Rysto-like sequences were identified in 72 genotypes representing 12 accessions of 10 Solanum species and six resistant controls (potato cultivars Alicja, Bzura, Hinga, Nimfy, White Lady and breeding line PW363). The 55 Rysto-like sequences showed 89.87 to 99.98% nucleotide identity to the Rysto reference gene, and these encoded in total 45 unique protein sequences. While Rysto-like26 identified in Alicja, Bzura, White Lady and Rysto-like16 in PW363 encode a protein identical to the Rysto reference, the remaining 44 predicted Rysto-like proteins were 65.93 to 99.92% identical to the reference. Higher levels of diversity of the Rysto-like sequences were found in the wild relatives of potato than in the resistant control cultivars. The TIR and NB-ARC domains were the most conserved within the Rysto-like proteins, while the LRR and C-JID domains were more variable. Several Solanum species, including S. antipoviczii and S. hougasii, showed resistance to PVY. This study demonstrated Hyoscyamus niger, a Solanaceae species distantly related to Solanum, as a host of PVY. Conclusions The new Rysto-like variants and the identified PVY resistant potato genotypes are potential resistance sources against PVY in potato breeding. Identification of H. niger as a host for PVY is important for cultivation of this plant, studies on the PVY management, its ecology, and migrations. The amplicon sequencing based on PacBio SMRT and the following data analysis pipeline described in our work may be applied to obtain the nucleotide sequences and analyze any full-length genes from any, even polyploid, organisms.

Abstract

Background The order Lepidoptera has an abundance of species, including both agriculturally beneficial and detrimental insects. Molecular data has been used to investigate the phylogenetic relationships of major subdivisions in Lepidoptera, which has enhanced our understanding of the evolutionary relationships at the family and superfamily levels. However, the phylogenetic placement of many superfamilies and/or families in this order is still unknown. In this study, we determine the systematic status of the family Argyresthiidae within Lepidoptera and explore its phylogenetic affinities and implications for the evolution of the order. We describe the first mitochondrial (mt) genome from a member of Argyresthiidae, the apple fruit moth Argyresthia conjugella. The insect is an important pest on apples in Fennoscandia, as it switches hosts when the main host fails to produce crops. Results The mt genome of A. conjugella contains 16,044 bp and encodes all 37 genes commonly found in insect mt genomes, including 13 protein-coding genes (PCGs), two ribosomal RNAs, 22 transfer RNAs, and a large control region (1101 bp). The nucleotide composition was extremely AT-rich (82%). All detected PCGs (13) began with an ATN codon and terminated with a TAA stop codon, except the start codon in cox1 is ATT. All 22 tRNAs had cloverleaf secondary structures, except trnS1, where one of the dihydrouridine (DHU) arms is missing, reflecting potential differences in gene expression. When compared to the mt genomes of 507 other Lepidoptera representing 18 superfamilies and 42 families, phylogenomic analyses found that A. conjugella had the closest relationship with the Plutellidae family (Yponomeutoidea-super family). We also detected a sister relationship between Yponomeutoidea and the superfamily Tineidae. Conclusions Our results underline the potential importance of mt genomes in comparative genomic analyses of Lepidoptera species and provide valuable evolutionary insight across the tree of Lepidoptera species.

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Abstract

Phytophthora cactorum is a plant pathogenic oomycete that causes crown rot in strawberry leading to significant economic losses every year. To invade the host, P. cactorum secretes an arsenal of effectors that can manipulate host physiology and impair its defense system promoting infection. A transcriptome analysis was conducted on a susceptible wild strawberry genotype (Fragaria vesca) 48 hours post inoculation with P. cactorum to identify effectors expressed during the early infection stage. The analysis revealed 4,668 P. cactorum genes expressed during infection of F. vesca. A total of 539 secreted proteins encoded by transcripts were identified, including 120 carbohydrate-active enzymes, 40 RXLRs, 23 proteolytic enzymes, nine elicitins, seven cysteine rich proteins, seven necrosis inducing proteins and 216 hypothetical proteins with unknown function. Twenty of the 40 RXLR effector candidates were transiently expressed in Nicotiana benthamiana using agroinfiltration and five previously unreported RXLR effector genes (Pc741, Pc8318, Pc10890, Pc20813, and Pc22290) triggered cell death when transiently expressed. The identified cell death inducing RXLR effectors showed 31–66% identity to known RXLR effectors in different Phytophthora species having roles in pathogenicity including both activation and suppression of defense response in the host. Furthermore, homology analysis revealed that these cell death inducing RXLR effectors were highly conserved (82 - 100% identity) across 23 different strains of P. cactorum originating from apple or strawberry.

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Abstract

Helse- og miljørisiko ved bruk av bakterien Psychrobacter sp. i plantevernmiddelet Nemaslug® Helserisikoen for mennesker ved bruk av Nemaslug® anses som lav, men man kan ikke utelukke risiko for svært infeksjonsutsatte pasientgrupper. Det er ingen bevis for helseproblemer som oppstår ved inntak av matvarer behandlet med Nemaslug®. Vitenskapskomiteen for mat og miljø (VKM) har, på oppdrag fra Mattilsynet, utført en risikovurdering av bakterien Psychrobacter sp. som inngår i plantevernmiddelet Nemaslug®. Plantevernmiddelet Nemaslug®, som er godkjent for bruk i Norge siden 2005, inneholder nematoden Phasmarhabditis hermaphrodita. Nematoden bærer en symbiotisk bakterie som fungerer som den aktive biokontrollorganismen ved å produsere giftstoffer som dreper snegler ved infeksjon. Bakgrunnen for oppdraget er at det ble avdekket at bakterien i Nemaslug® ikke er Moraxella osloensis, som den tidligere godkjenningen er basert på. Den er i stedet blitt identifisert som en art i bakterieslekten Psychrobacter, mest sannsynlig Psychrobacter faecalis, alternativt Psychrobacter pulmonis. Denne vurderingen skal danne grunnlag for Mattilsynets beslutning om hvorvidt Nemaslug® skal beholde sin godkjenning for bruk i Norge eller ei. Resultater Det er begrenset informasjon om helsefarene ved Psychrobacter sp. hos mennesker. Kunnskap om antibiotikaresistens og patogenisitet i slekten Psychrobacter er i stor grad mangelfull. Det er lite informasjon om forekomsten av Psychrobacter sp. i Norge. Potensialet for spredning og etablering av Psychrobacter sp. i miljøet under norske forhold vurderes som lavt. Risikoen Nemaslug® utgjør for ikke-målorganismer, spesielt bløtdyr, er usikker og krever videre forskning. Videre taksonomisk analyse og fullstendig genomsekvensering er nødvendig for å bekrefte artstilhørigheten til bakterien i Nemaslug®. Konklusjoner Selv om informasjonen om helsefarene knyttet til Psychrobacter sp. hos mennesker er begrenset, betraktes den generelt som et lavrisikopatogen. Helserisikoen for mennesker ved bruk av Nemaslug® anses derfor som lav, men risiko for pasientgrupper som er svært mottakelige for infeksjoner kan ikke utelukkes. Det er ingen bevis for helseproblemer som oppstår ved inntak av matvarer behandlet med Nemaslug®. Metode VKM har hentet data og informasjon fra søkeren via Mattilsynet og VKMs forrige rapport om Nemaslug®. Et grundig litteratursøk ble gjennomført for å innhente ytterligere relevant informasjon. ​Vurderingen er godkjent av VKMs faggruppe for plantehelse.

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Abstract

Ascospores discharged at rainfall and dispersed by wind can provide long-distance spread of the European canker fungus, Neonectria ditissima. Ascospores are produced by perithecia which are the sexual reproductive stage. Diffuse knowledge exists on the seasonal pattern of perithecium formation under different climatic conditions. Therefore, the development of perithecia was observed for several successive seasons at five sites in three Northern European countries. In Norway and Finland, ripe perithecia were commonly recorded throughout the year, and on individual cankers continuously for up to 28 months. In contrast, asexual reproductive structures (sporodochia) were confined to the growing season in both countries. In Northern Germany an average of 51% of cankers developed ripe perithecia by late winter, and perithecial senescence ensued in late spring. On average, ripe perithecia were present on cankers for 22 weeks. In contrast, sporodochia were observed all year round. The timing of perithecium maturation correlated with the number of days with > 2 mm rainfall in July–September. The presence of mature perithecia and sporodochia for different lengths of time in different countries has implications for regional disease management strategies.