Sissel Haugslien
Senioringeniør
Forfattere
Zhibo Hamborg Ada Konstanse Kristensen Xiaoyan Ma Sissel Haugslien Carl-Henrik Lensjø Alvin Peter van der Ende Øyvor Stensbøl Qiaochun Wang Jana Fránová Dag-Ragnar BlystadSammendrag
Background of the study – Cryopreservation is considered to be a valuable method for long-term preservation of plant germplasm and recently it has been shown to be a reliable method for preserving obligate pathogens including plant viruses. Objectives – (1) Droplet-vitrification cryopreservation of strawberry genotypes in Norway; (2) Preservation efficiency of aphid-transmitted strawberry mild yellow edge virus (SMYEV) and strawberry vein banding virus (SVBV) following cryopreservation. Methods – Excised shoot tips of cv. ‘Korona’ were cryopreserved with different durations of PVS2 varying from 10 to 60 min, whereas virus-infected shoot tips were cryopreserved using either 10, 40 or 60 min of PVS2. Results – The results showed that 40–60 minutes of PVS2 treatment was more efficient for preserving strawberry germplasm than lower duration times (10–30 min). Thirty-two strawberry genotypes have been successfully cryopreserved through droplet-vitrification with regeneration rates ranging from 45% to 100% with 40 min PVS2 treatment. Cryopreserved viruses were quantitatively analyzed by Reverse Transcription-quantitative polymerase chain reaction (RT-qPCR). SVBV was successfully cryopreserved in all the regenerated shoots following cryopreservation with all the three durations of PVS2 examined. SMYEV, however, was more efficiently preserved in shoot tips exposed to 40 min (90%) of PVS2, in comparison to 60 min (33%). Conclusion – This demonstrates that SMYEV and SVBV can be successfully cryopreserved in living cells of Fragaria ssp. by droplet vitrification. The results indicate that cryopreservation has great potential for long-time preservation of both strawberry germplasm and aphid-transmitted strawberry-infecting viruses.
Sammendrag
Sharkavirus (Plum pox virus, PPV) er en karanteneskadegjører som har blitt funnet i plomme, fersken og aprikos i Norge. Første påvisning var i 1998. Fra 1998 til 2013 ble det utført kartleggings- og utryddingsprogram flere av årene med det mål å utrydde sharkavirus fra frukthager med kommersiell plommedyrking i Norge. Kartleggingen i 2023 ble planlagt for å oppdatere og dokumentere smittestatus i Norge, samt få grunnlag for framtidig regulering/kategorisering av sharkavirus i revidert plantehelseforskrift. Programmet hadde som ønske å sjekke status for sharkavirus i Norge 10 år etter forrige kartlegging i 2013. Det ble testet 2463 prøver for sharkavirus i 2023. Alle disse prøvene var bladprøver. I alt 139 lokaliteter i 11 fylker ble kartlagt. På i 33 av disse lokalitetene ble det funn av sharkavirus. Litt under halvparten av disse, 15 steder var nye funnsteder. Vestland fylke hadde flest kartlagte lokaliteter (65), hvorav 19 hadde funn av sharkavirus, inkludert 10 nye funnsteder. Plommesortene med flest påvisninger var Mallard, Jubileum og Valor. Siden 1998 har det blitt testet mer enn 90 000 trær på i overkant av tusen lokaliteter (frukthager, privathager, planteskoler og hagesentre). Det har blitt påvist sharkavirus på 111 lokaliteter når vi regner inn 2023-funnene.
Forfattere
Ana-Maria Madalina Pantazica Andre van Eerde Mihaela-Olivia Dobrica Iuliana Caras Irina Ionescu Adriana Costache Catalin Tucureanu Hege Særvold Steen Catalin Lazar Inger Heldal Sissel Haugslien Adrian Onu Crina Stavaru Norica Branza-Nichita Jihong Liu ClarkeSammendrag
The recent SARS-CoV-2 pandemic has taught the world a costly lesson about the devastating consequences of viral disease outbreaks but also, the remarkable impact of vaccination in limiting life and economic losses. Vaccination against human Hepatitis B Virus (HBV), a major human pathogen affecting 290 million people worldwide, remains a key action towards viral hepatitis elimination by 2030. To meet this goal, the development of improved HBV antigens is critical to overcome non-responsiveness to standard vaccines based on the yeast-produced, small (S) envelope protein. We have recently shown that combining relevant immunogenic determinants of S and large (L) HBV proteins in chimeric antigens markedly enhances the anti-HBV immune response. However, the demand for cost-efficient, high-quality antigens remains challenging. This issue could be addressed by using plants as versatile and rapidly scalable protein production platforms. Moreover, the recent generation of plants lacking β-1,2-xylosyltransferase and α-1,3-fucosyltransferase activities (FX-KO), by CRISPR/Cas9 genome editing, enables production of proteins with “humanized” N-glycosylation. In this study, we investigated the impact of plant N-glycosylation on the immunogenic properties of a chimeric HBV S/L vaccine candidate produced in wild-type and FX-KO Nicotiana benthamiana. Prevention of β-1,2-xylose and α-1,3-fucose attachment to the HBV antigen significantly increased the immune response in mice, as compared with the wild-type plant-produced counterpart. Notably, the antibodies triggered by the FX-KO-made antigen neutralized more efficiently both wild-type HBV and a clinically relevant vaccine escape mutant. Our study validates in premiere the glyco-engineered Nicotiana benthamiana as a substantially improved host for plant production of glycoprotein vaccines.