Tollenaere Charlotte, Lacombe Séverine, Wonni I., Barro M., Ndougonna C., Gnacko F., Sérémé D., Jacobs J.M., Hébrard Eugénie, Cunnac Sébastien, Brugidou Christophe. (2017). Virus-bacteria rice co-infection in Africa : field estimation, reciprocal effects, molecular mechanisms, and evolutionary implications. Frontiers in Plant Sciences, 8, 645 [13 p. en ligne]. ISSN 1664-462X.
Titre du document
Virus-bacteria rice co-infection in Africa : field estimation, reciprocal effects, molecular mechanisms, and evolutionary implications
Année de publication
2017
Auteurs
Tollenaere Charlotte, Lacombe Séverine, Wonni I., Barro M., Ndougonna C., Gnacko F., Sérémé D., Jacobs J.M., Hébrard Eugénie, Cunnac Sébastien, Brugidou Christophe
Source
Frontiers in Plant Sciences, 2017,
8, 645 [13 p. en ligne] ISSN 1664-462X
Simultaneous infection of a single plant by various pathogen species is increasingly recognized as an important modulator of host resistance and a driver of pathogen evolution. Because plants in agro-ecosystems are the target of a multitude of pathogenic microbes, co-infection could be frequent, and consequently important to consider. This is particularly true for rapidly intensifying crops, such as rice in Africa. This study investigated potential interactions between pathogens causing two of the major rice diseases in Africa: the Rice yellow mottle virus (RYMV) and the bacterium Xanthomonas oryzae pathovar oryzicola (Xoc) in order to: 1/ document virus-bacteria co-infection in rice in the field, 2/ explore experimentally their consequences in terms of symptom development and pathogen multiplication, 3/ test the hypothesis of underlying molecular mechanisms of interactions and 4/ explore potential evolutionary consequences. Field surveys in Burkina Faso revealed that a significant proportion of rice fields were simultaneously affected by the two diseases. Co-infection leads to an increase in bacterial specific symptoms, while a decrease in viral load is observed compared to the mono-infected mock. The lack of effect found when using a bacterial mutant for an effector specifically inducing expression of a small RNA regulatory protein, HEN1, as well as a viral genotype-specific effect, both suggest a role for gene silencing mechanisms mediating the within-plant interaction between RYMV and Xoc. Potential implications for pathogen evolution could not be inferred because genotype-specific effects were found only for pathogens originating from different countries, and consequently not meeting in the agrosystem. We argue that pathogen-pathogen-host interactions certainly deserve more attention, both from a theoretical and applied point of view.
Plan de classement
Sciences du monde végétal [076]
Localisation
Fonds IRD [F B010069662]
Identifiant IRD
fdi:010069662
