widespread endogenization of genome sequences of non-retroviral rna viruses into plant genomes广泛endogenization non-retroviral rna病毒的基因组序列到植物基因组中.pdf

Widespread Endogenization of Genome Sequences of Non-Retroviral RNA Viruses into Plant Genomes 1. 1. 1 1 1 2 Sotaro Chiba , Hideki Kondo , Akio Tani , Daisuke Saisho , Wataru Sakamoto , Satoko Kanematsu , Nobuhiro Suzuki1* 1 Institute of Plant Science and Resources, Okayama University, Kurashiki, Japan, 2 National Institute of Fruit Tree Science, National Agricultural Research Organization (NARO), Morioka, Japan Abstract Non-retroviral RNA virus sequences (NRVSs) have been found in the chromosomes of vertebrates and fungi, but not plants. Here we report similarly endogenized NRVSs derived from plus-, negative-, and double-stranded RNA viruses in plant chromosomes. These sequences were found by searching public genomic sequence databases, and, importantly, most NRVSs were subsequently detected by direct molecular analyses of plant DNAs. The most widespread NRVSs were related to the coat protein (CP) genes of the family Partitiviridae which have bisegmented dsRNA genomes, and included plant- and fungus-infecting members. The CP of a novel fungal virus (Rosellinia necatrix partitivirus 2, RnPV2) had the greatest sequence similarity to Arabidopsis thaliana ILR2, which is thought to regulate the activities of the phytohormone auxin, indole-3-acetic acid (IAA). Furthermore, partitivirus CP-like sequences much more closely related to plant partitiviruses than to RnPV2 were identified in a wide range of plant species. In addition, the nucleocapsid protein genes of cytorhabdoviruses and varicosaviruses were found in species of over 9 plant families, including Brassicaceae and Solanaceae. A replicase-like sequence of a betaflexivirus was identified in th