Objectives. 1. Distribution of PMTV in Norway 2. Variability of PMTV in Norway 3. Resistance to PMTV

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3 Objectives 1. Distribution of PMTV in Norway 2. Variability of PMTV in Norway 3. Resistance to PMTV

4 Distribution of PMTV Finnmark Potatoes grown all over the country How to map the distribution of PMTV? How to test for PMTV? Nordland Troms Nord Trøndelag Sør Trøndelag Møre og Romsdal Sogn og Fjordane Hordaland Rogaland Vest Agder Aust Agder Hedmark Oppland Buskerud Akershus Østfold Vestfold Telemark

5 (2) Finnmark (9) Troms (9) Nordland (4) (37) Nord Trøndelag Sør Trøndelag 345 soil samples (4) Møre og Romsdal (3) Sogn og Fjordane Hedmark (112) (1) Hordaland Oppland (41) (21) Rogaland (2) Vest Agder (8) Aust Agder Buskerud (6) Akershus (12) Østfold (21) Vestfold (46) Telemark (7)

6 % PMTV in the largest potato producing areas 57 % Nord Trøndelag 100% Rogaland Hedmark Oppland 67 % 66 % Østfold Vestfold 76 % 78 %

7 Finnmark Troms Nordland Nord Trøndelag Sør Trøndelag Møre og Romsdal PMTV found in at least one field of each county Sogn og Fjordane Hordaland Rogaland Vest Agder Aust Agder Hedmark Oppland Buskerud Akershus Østfold Vestfold Telemark

8 Variability of PMTV in Norway Do we have different strains of PMTV?

9 Finnmark Troms Nordland Nord Trøndelag Sør Trøndelag Choose isolates Møre og Romsdal Sogn og Fjordane Hordaland Rogaland Vest Agder Aust Agder Hedmark Oppland Buskerud Akershus Østfold Vestfold Telemark

10 Propagate the isolates

11 Inoculate to a set of test plants Nicotiana debneyi Nicotiana tabacum Nicotiana rustica Nicotiana glutinosa Capsicum annum Chenopodium quinoa Chenopodium amaranticolor Lycopersicon esculentum

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13 Systemic infection

14 Symptomatology

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16 Temperature Low temperature (16-18 C ) High temperature (22-25 C ) Increase in symptom intensity Attenuation of symptoms Delay in systemic infection Enhanced systemic infection

17 How about genetic variability? % similarity

18 Conclusions Distribution of PMTV? Troms Finnmark Why? o Movement of planting material o Resistant varieties o Symptomless infection o Seed potato testing Sør Trøndelag Møre og Romsdal Nord Trøndelag Nordland Sogn og Fjordane Hordaland Rogaland Vest Agder Aust Agder Hedmark Oppland Buskerud Akershus Østfold Vestfold Telemark

19 Variability of PMTV in Norway Conclusions According to test plant assays (Yes) However, little variability in the 8K Does this explain why sometimes we can have symptomless infections? Is it worth it to start giving strain names to these PMTV isolates?

20 Resistance to PMTV Berle Bruse Dorado Gladiator Jupiter Kerrs Pink N NCT Oleva Saturna (control)

21 Finnmark Three fields chosen Different climatic conditions Troms Berle Bruse Dorado Gladiator Jupiter Kerrs Pink N NCT Oleva Saturna (control) Nordland Nord Trøndelag Sør Trøndelag Møre og Romsdal Sogn og Fjordane Hordaland Rogaland Vest Agder Hedmark Oppland Buskerud Akershus Østfold Vestfold Aust Agder Telemark

22 Finnmark Troms Take soil fields And do test in Graminor Nord Trøndelag Nordland Sør Trøndelag Møre og Romsdal Sogn og Fjordane Hordaland Rogaland Vest Agder Aust Agder Hedmark Oppland Buskerud Akershus Østfold Vestfold Telemark

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24 % tubers with spraing % of tubers showing spraing Is any variety resistant? Spraing in tubers on the 3 locations Jæ ren Stjørdal Vestfold

25 All varieties can be infected by PMTV

26 % tubers with spraing Spraing in tubers on the 3 locations Jæ ren Stjørdal Vestfold % tubers with spraing from pot-trial % tubers with Spraing40 Jæ ren Stjørdal Vestfold

27 % tubers with spraing Strain of PMTV? Spraing in tubers on the 3 locations Jæ ren Stjørdal Vestfold

28 Incidence of spraing? Some varieties seem to be more succeptible to spraing, But does not correlate with resistance Climatic conditions Doesn t seem to be due to a specific strain

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30 PVY Théâtre de l'absurde

31 PVY makeup and diagnostics ELISA 4C3 ELIS A 1F5 5 NTR P1 HC- Pro P3 C1 PVY O NI a NI b CP 3 NTR 5 NTR P1 HC- Pro P3 C1 PVY N NI a NI b CP 3 NTR + 5 NTR P1 HC- Pro P3 C1 PVY N:O NI a NI b CP 3 NTR 5 NTR P1 HC- Pro P3 C1 PVY NTN RT-PCR Primers based on P1 or NI a NI b CP 3 NTR + +

32 PVY NTN It can be PVY N It can be PVY C It can be PVY O It can be a recombinant! PVY N-NA PVY C-O, Ext.

33 What is really PVY NTN? Is a phisiological response to PVY (in general) in: Specific potato varieties under specific evironmental conditions Var. Atlantic (summer) Necrotic ringspots PVY NTN SB- 32

34 Potato mop top virus PMTV Genetic strains We also have strains Not useful to Use the «strain concept» Biological strains All can generate rings Depends on the climatic Conditions and/or variety!

35 Plant virus elimination by inducing RNA silencing in vivo

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37 Silencing-based resistance to PnMV Degradation of viral RNA

38 TG susceptible to PnMV did not express sirna Transcription and processing of the transgene is required

39 Detection of PnMV in the inoculated leaves (ELISA)

40 Detection of PnMV in the inoculated leaves hprna-based resistance to PnMV Prevents replication of the virus in the inoculated leaves

41 Using a viral vector to induce silencing Virus A Virus B Virus A

42 Killing a virus with another virus? Tales of a suicidal virus SPFMV CMV SPFMV CMV

43 SPFMV CMV + SPFMV SPFMV CMV SPFMV

44 SPFMV CMV-SP Inverted repeat

45 CMV-SP SPFMV CMV-SP SPFMV CMV-SP SPFMV

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48 Screening for TRV

49 Wait some weeks and evaluate symptoms Huge task! 60 fields

50 Detection of TRV in weed roots

51 Why not trying to detect TRV from weeds fround in the field? Farmers ar very efficeint in removing weeds How about the roots?

52 PCR detection is not so difficult RNA extraction PCR amplification RNA

53 3. Third step: device how to collect samples

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55 Select a number of samples to test

56 RNA 1. First step: RNA extraction for roots

57 2. Second step: PCR from RNA extracted from the roots TRV Kontrol

58 TRV