Mal de Río Cuarto Virus Infection Triggers the Production of Distinctive Viral-Derived siRNA Profiles in Wheat and Its Planthopper Vector

DE HARO, LUIS A.; DUMÓN, ANALÍA D.; MATTIO, MARÍA F.; ARGÜELLO CARO, EVANGELINA BEATRIZ; LLAUGER, GABRIELA; ZAVALLO, DIEGO; BLANC, HERVÉ; MONGELLI, VANESA C.; TRUOL, GRACIELA; SALEH, MARÍA-CARLA; ASURMENDI, SEBASTIÁN; DEL VAS, MARIANA

Frontiers in Plant Science

Frontiers Media SA

Año: 2017 vol. 8

Plant reoviruses are able to multiply in gramineae plants and delphacid vectorsencountering different defense strategies with unique features. This study aims to comparatively assess alterations of small RNA (sRNA) populations in both hosts upon virus infection. For this purpose, we characterized the sRNA profiles of wheat and planthopper vectors infected by Mal de Río Cuarto virus (MRCV, Fijivirus, Reoviridae)and quantified virus genome segments by quantitative reverse transcription PCR Weprovide evidence that plant and insect silencing machineries differentially recognize the viral genome, thus giving rise to distinct profiles of virus-derived small interfering RNAs(vsiRNAs). In plants, most of the virus genome segments were targeted preferentiallywithin their upstream sequences and vsiRNAs mapped with higher density to the smallergenome segments than to the medium or larger ones. This tendency, however, wasnot observed in insects. In both hosts, vsiRNAs were equally derived from sense andantisense RNA strands and the differences in vsiRNAs accumulation did not correlatewith mRNAs accumulation. We also established that the piwi-interacting RNA (piRNA)pathway was active in the delphacid vector but, contrary to what is observed in virusinfectedmosquitoes, virus-specific piRNAs were not detected. This work contributes tothe understanding of the silencing response in insect and plant hosts.