The role of allelopathy in host-virus relations

1
The role of allelopathy in host-virus relations

• G.Kazinczi1, J.Horvath2, A.Takacs1, I.Béres2,
  R.Gáborjányi2, M.Nádasy2
• 1Office for Academy Research Groups Attached to
  Universities and Other Institutions, University
  of Veszprém, Georgikon Faculty of Agricultural
  Sciences
• 2University of Veszprém, Georgikon Faculty of
  Agricultural Sciences

2
Allelopathy (Molish 1937)

• A type of interference among higher plants, where
  products of secondary metabolism inhibit (less
  promote) the development of neighbourhood plant
• Earlier only plant-plant, today
  plant-microorganism interactions
• It is considered as a new alternative way for
  biological control

3
Plant viruses make up about 15-30 out of the
whole plant diseasesVirus particles create close
biologial unit with the plant cellChemical plant
protection against viruses is unsuccesfull in
vivoSome natural substances are known to inhibit
replication and cell- to cell movement of viruses
and reduce virus concentration
4
Mode of action

• It is not yet known exactly, but it can be
  presumed that natural inhibitors may modify
  special receptor places on the plant cell
  surface, therefore adhesion of virus particles
  can not be happened

5
The aim of the study

• To examine the effect of allelopathic weed
  extracts on some host-virus relations

6
MATERIALS AND METHODS
7
DONOR SPECIES
Cirsium arvense
Asclepias syriaca
Convolvulus arvensis
Abutilon theophrasti
Chelidonium majus
Fresh plant parts were collected and grinding
8

• Plant water extracts were made using 25 g fress
  biomass/100 ml distilled water
• Extracts were used to spray daily test plants
  from their 2-4 leaf stages until the end of
  experiments

9
Host-virus relations (recipient species)
10
Chenopodium amaranticolor-Alfalfa mosaic virus
11
Chenopodium quinoa-Sowbane mosaic virus
12
Cucumis sativusDelicatesse -Zucchini yellow
mosaic virus
13
Solanum nigrum- Obuda pepper virus
14

• Virus infection (DAS ELISA)
• From the extinction values we can conclude from
  the virus concentration samples are considered
  resistant to virus infection if extinction
  values do not exceed two times those of the
  negative control
• Fresh weight
• (five weeks after inoculations)

15
RESULTS
16

• The effect of C. majus extracts on the virus
  concentration in test plants (a, C. majus root
  extract b, C. majus shoot extract c, positive
  control d, negative control)
• Slight, significant reduction in AMV
  concentration due to C. majus root extract
• Enhanced virus concentration in S. nigrum
• No difference in virus concentration in C. quinoa
  and C. sativus

17

• The effect of C. majus extracts on the fresh
  weight of test plants (a, C. majus root extract
  b, C. majus shoot extract c, positive control
  d, negative control)
• 1st column, C. majus root extract 2nd, C. majus
  shoot extract 3rd, positive control 4th, LSD5)

18
The effect of water extract on the ObPV
concentration in S. nigrum (1, A. syriaca root
2, A. syriaca shoot 3, C. arvense shoot 4, C.
arvensis shoot 5, A. theophrasti shoot 6,
positive control 7, negative control)
19
The effect of water extracts on the fresh weight
of S. nigrum 1, A. syriaca root 2, A. syriaca
shoot 3, C. arvense shoot 4, C. arvensis shoot
5, A. theophrasti shoot 6, positive control
20
Conclusions

• Sprayed plant extracts did not inhibit virus
  infection
• Allelopathic plant extracts have different effect
  on the development and virus concentration in
  hosts
• One exception was in case of C. majus root
  extracts, which reduced significantly not only
  AMV concentration but also fresh weight of C.
  amaranticolor
• It seems that there is no relation between
  allelopathic inhibitory effect of weeds on the
  development of test plants and virus inhibitory
  effect in the hosts

21
Thank you for the attention!