title: Aphid vector population density determines the emergence of necrogenic satellite RNAs in populations of cucumber mosaic virus.
abstract: The satellite RNAs of cucumber mosaic virus (CMV) that induce systemic necrosis in tomato plants (N-satRNA) multiply to high levels in the infected host while severely depressing CMV accumulation and, hence, its aphid transmission efficiency. As N-satRNAs are transmitted into CMV particles, the conditions for N-satRNA emergence are not obvious. Model analyses with realistic parameter values have predicted that N-satRNAs would invade CMV populations only when transmission rates are high. Here, we tested this hypothesis experimentally by passaging CMV or CMV+N-satRNAs at low or high aphid densities (2 or 8 aphids/plant). As predicted, high aphid densities were required for N-satRNA emergence. The results showed that at low aphid densities, random effects due to population bottlenecks during transmission dominate the epidemiological dynamics of CMV/CMV+N-satRNA. The results suggest that maintaining aphid populations at low density will prevent the emergence of highly virulent CMV+N-satRNA isolates.
authors.affiliation: Centro de Biotecnología y Genómica de Plantas UPM-INIA and ETSI Agrónomos, Universidad Politécnica de Madrid, Campus de Montegancedo. 28223 Pozuelo de Alarcón, Madrid, Spain.
authors.forename: Mónica
authors.initials: M
authors.lastname: Betancourt
authors.affiliation: Centro de Biotecnología y Genómica de Plantas UPM-INIA and ETSI Agrónomos, Universidad Politécnica de Madrid, Campus de Montegancedo. 28223 Pozuelo de Alarcón, Madrid, Spain.
authors.forename: Aurora
authors.initials: A
authors.lastname: Fraile
authors.affiliation: Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant, Science, Cornell University, Ithaca, NY 14853, USA.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Milgroom
authors.affiliation: Centro de Biotecnología y Genómica de Plantas UPM-INIA and ETSI Agrónomos, Universidad Politécnica de Madrid, Campus de Montegancedo. 28223 Pozuelo de Alarcón, Madrid, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: García-Arenal
mesh_terms: D000818:Animals; D001042:Aphids / Q000254:growth & development* / Q000821:virology*; D017799:Cucumovirus / Q000254:growth & development*; D007303:Insect Vectors; D018551:Solanum lycopersicum / Q000821:virology; D010935:Plant Diseases / Q000821:virology; D011156:Population Density; D019244:RNA, Satellite / Q000378:metabolism*
chemical_list: D019244:RNA, Satellite