coevolution and hierarchical interactions of tomato mosaic virus and the resistance gene tm-1共同进化和层次交互抗性基因番茄花叶病毒和tm-1.pdfVIP

Coevolution and Hierarchical Interactions of Tomato mosaic virus and the Resistance Gene Tm-1 1 1 1,2 3 1 Kazuhiro Ishibashi *, Natsuki Mawatari , Shuhei Miyashita , Hirohisa Kishino , Tetsuo Meshi , Masayuki Ishikawa1 1 Division of Plant Sciences, National Institute of Agrobiological Sciences, Tsukuba, Japan, 2 Japan Science and Technology Agency (JST), Precursory Research for Embryonic Science and Technology (PRESTO), Kawaguchi, Japan, 3 Graduate School of Agricultural and Life Sciences, University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan Abstract During antagonistic coevolution between viruses and their hosts, viruses have a major advantage by evolving more rapidly. Nevertheless, viruses and their hosts coexist and have coevolved, although the processes remain largely unknown. We previously identified Tm-1 that confers resistance to Tomato mosaic virus (ToMV), and revealed that it encodes a protein that binds ToMV replication proteins and inhibits RNA replication. Tm-1 was introgressed from a wild tomato species Solanum habrochaites into the cultivated tomato species Solanum lycopersicum. In this study, we analyzed Tm-1 alleles in S. habrochaites. Although most part of this gene was under purifying selection, a cluster of nonsynonymous substitutions in a small region important for inhibitory activity was identified, suggesting that the region is under positive selection. We then examined the resistance of S. habrochaites plants to ToMV. Approximately 60% of 149 individuals from 24 accessions were resistant to ToMV, while the others accumulated detectable levels of coat protein after inoculation. Unexpectedly, many S. habrochaites plants w