title: Antiquity and function of CASTOR and POLLUX, the twin ion channel-encoding genes key to the evolution of root symbioses in plants.
abstract: Root symbioses with arbuscular mycorrhizal fungi and rhizobial bacteria share a common signaling pathway in legumes. Among the common symbiosis genes are CASTOR and POLLUX, the twin homologous genes in Lotus japonicus that encode putative ion channel proteins. Here, we show that the orthologs of CASTOR and POLLUX are ubiquitously present and highly conserved in both legumes and nonlegumes. Using rice (Oryza sativa) as a study system, we employ reverse genetic tools (knockout mutants and RNA interference) to demonstrate that Os-CASTOR and Os-POLLUX are indispensable for mycorrhizal symbiosis in rice. Furthermore, a cross-species complementation test indicates that Os-POLLUX can restore nodulation, but not rhizobial infection, to a Medicago truncatula dmi1 mutant.
authors.affiliation: Department of Plant and Soil Sciences, University of Kentucky, Lexington, Kentucky 40546, USA.
authors.forename: Caiyan
authors.initials: C
authors.lastname: Chen
authors.forename: Cui
authors.initials: C
authors.lastname: Fan
authors.forename: Muqiang
authors.initials: M
authors.lastname: Gao
authors.forename: Hongyan
authors.initials: H
authors.lastname: Zhu
mesh_terms: D000595:Amino Acid Sequence; D004269:DNA, Bacterial / Q000235:genetics; D019143:Evolution, Molecular; D018506:Gene Expression Regulation, Plant; D055786:Gene Knockout Techniques; D017343:Genes, Plant; D005816:Genetic Complementation Test; D046913:Medicago truncatula / Q000235:genetics / Q000378:metabolism / Q000382:microbiology; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D038821:Mycorrhizae / Q000502:physiology; D012275:Oryza / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism / Q000382:microbiology; D034622:RNA Interference; D018749:RNA, Plant / Q000235:genetics; D053204:Root Nodules, Plant / Q000382:microbiology; D016415:Sequence Alignment; D013559:Symbiosis / Q000235:genetics*
chemical_list: D004269:DNA, Bacterial; D010940:Plant Proteins; D018749:RNA, Plant; C036483:T-DNA