Tollenaere Charlotte auteur aut IRD Lacombe Séverine auteur aut IRD Wonni I. auteur aut IRD Barro M. auteur aut IRD Ndougonna C. auteur aut IRD Gnacko F. auteur aut IRD Sérémé D. auteur aut IRD Jacobs J.M. auteur aut IRD Hébrard Eugénie auteur aut IRD Cunnac Sébastien auteur aut IRD Brugidou Christophe auteur aut IRD text journalArticle eng text/pdf reformatted digital access 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. specialized AFRIQUE SUBSAHARIENNE BURKINA FASO TANZANIE MADAGASCAR 076 8 645 [13 en ligne] 2017 1664-462X https://www.documentation.ird.fr/hor/fdi:010069662 10.3389/fpls.2017.00645 1664-462X [F B010069662] https://www.documentation.ird.fr/hor/fdi:010069662 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers17-05/010069662.pdf IRD - Base Horizon / Pleins textes 2017-05-16 2023-07-11 fdi:010069662 fre