• Aucun résultat trouvé

Natural multiplicity of infection of plant cells by genomes of Cauliflower mosaic virus populations

N/A
N/A
Protected

Academic year: 2021

Partager "Natural multiplicity of infection of plant cells by genomes of Cauliflower mosaic virus populations"

Copied!
2
0
0

Texte intégral

(1)

HAL Id: hal-02755736

https://hal.inrae.fr/hal-02755736

Submitted on 3 Jun 2020

HAL is a multi-disciplinary open access

archive for the deposit and dissemination of sci-entific research documents, whether they are pub-lished or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers.

L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Natural multiplicity of infection of plant cells by

genomes of Cauliflower mosaic virus populations

Serafín Gutiérrez, Michel Yvon, Baptiste Monsion, Gael Thébaud, Yannis

Michalakis, Stéphane Blanc

To cite this version:

Serafín Gutiérrez, Michel Yvon, Baptiste Monsion, Gael Thébaud, Yannis Michalakis, et al.. Natu-ral multiplicity of infection of plant cells by genomes of Cauliflower mosaic virus populations. 12è Rencontres de Virologie Végétale (RVV), Jan 2009, Aussois, France. �hal-02755736�

(2)

Résumés communications orales RVV Aussois 2009

10

Natural multiplicity of infection of plant cells by genomes of Cauliflower

mosaic virus populations

Gutierrez1 S., Yvon1 M., Monsion1 B., Thébaud1 G., Michalakis2 Y., and Blanc1 S.

1-UMR BGPI 385 INRA-CIRAD-AgroM, TA A54/K Campus International de Baillarguet, Montpellier cedex 05, France.

2-GEMI, UMR CNRS Ŕ IRD 2724, IRD, 911 Avenue Agropolis, B.P. 64501, 34394 Montpellier Cedex 5. France

The number of viral genomes co-infecting host cells during the course of a systemic infection (the multiplicity of cellular infection, MOI) is a parameter of foremost importance for several aspects of the biology of viruses. While a low MOI may reduce the intra-cellular competition between genetic variants, it also greatly limits the extent of possible complementation, and de

facto reduces the recombination frequency. In contrast, a high MOI would augment the

possibility of trans-complementation between variants, and the recombination frequency, but potentially also enhance accumulation of defective genomes and increase competition for replication. These simple examples illustrate the predicted contrasted effects of MOI on viral genomes and populations, which open the possibility for important trade-offs on this particular trait.

Despite its importance, very little information is available on the MOI of viruses infecting eukaryotic hosts. A mean MOI value of 4 has been previously determined only for a baculovirus infecting insects. Also, an average value of 3 proviruses has been estimated in the HIV-infected spleen cells of two patients, suggesting an MOI above this value. In plants, the MOI has not been directly investigated at the cellular level for any virus species.

Using Cauliflower mosaic virus infecting turnip host plants, we measured both the ratio of two co-infecting genetic variants, and the rate of cellular co-infection within single leaves. A statistical model, based on maximum likelihood, allowed the calculation of mean MOI values from these data at different stages of the systemic infection. Indeed, under the hypothesis that the probability of cellular infection by a given variant depends on its relative frequency within the leaf, and that infection by one and/or the other variant are independent, the cellular co-infection rate for a given ratio of the two variants directly depends on the number of viral genomes infecting each cell.

This experiment yielded several remarkable results. The CaMV infects host cells at a very elevated MOI reaching values around 10, largely exceeding the rare estimates cited above. The MOI is not a constant; it greatly increases from leaf to leaf during the course of host invasion to drop late in infection close to initial values. This drop seems induced by flowering. Finally, at a given time point, different MOI values are measurable in different leaves.

Références

Documents relatifs

In plant cane, the first detection of the pathogen on the leaf canopy varied according to proximity of other sugarcane fields and climatic conditions.. Additionally, once the

ﺎﺳدﺎﺳ : ﻴﺒﻟا ﻖﻴﻗﺪﺘﻟا : ﻋ ظﺎﻔ او ﺔﺴﺳﺆﳌا ﮫﺟاﻮﻳ نأ ﻦﻜﻤﻳ ﺎﻣو ثﻮﻠﺘﻟاو ﺔﺌ ﺒﻟﺎﺑ ﺔﺻﺎ ا ﺔﻤﻈﻧﻷﺎﺑ ما ﻟ ىﺪﻣ سﺎﻴﻗ ﮫﻨﻣ فﺪ ﻟا اﻮﻣو ﺔﻴ ﻴﺒﻟا ﺔﻤﻈﻧ رﻮ ﺪﺗ إ يدﺆﺗ ﻟا ردﺎﺼﳌا

A module to check manual annotation, called the inspector, was integrated in the implementation of Chado, with database triggers that calls SQL functions for monitored events..

A part les grandes psychopathologies connues, Binswanger a individualisé des vécus faisant ainsi apparaître la classification en elle- même comme « l’égarement », la « fuite

As already described, European soft ticks (Ornithodoros erraticus and Ornithodoros verrucosus) were not able to transmit African swine fever virus by biting pigs although these

RNA from isolates of West Nile Virus (WNV), Yellow Fever Virus (YFV), Japanese Encephalitis Virus (JEV), Dengue Viruses (DENV1-4) and Tick borne Encephalitis Virus (TBEV) as well as

The multiplicity of cellular infection (MOI) is the number of virus genomes of a given virus species that infect individual cells.. This parameter chiefly impacts the severity

Our approach unveils how some distinctive features of the kinetics of cement hydration can be related to changes in the mor- phology of the gels and elucidates the role of