title: Deep Sequencing of the Medicago truncatula Root Transcriptome Reveals a Massive and Early Interaction between Nodulation Factor and Ethylene Signals.
abstract: The legume-rhizobium symbiosis is initiated through the activation of the Nodulation (Nod) factor-signaling cascade, leading to a rapid reprogramming of host cell developmental pathways. In this work, we combine transcriptome sequencing with molecular genetics and network analysis to quantify and categorize the transcriptional changes occurring in roots of Medicago truncatula from minutes to days after inoculation with Sinorhizobium medicae. To identify the nature of the inductive and regulatory cues, we employed mutants with absent or decreased Nod factor sensitivities (i.e. Nodulation factor perception and Lysine motif domain-containing receptor-like kinase3, respectively) and an ethylene (ET)-insensitive, Nod factor-hypersensitive mutant (sickle). This unique data set encompasses nine time points, allowing observation of the symbiotic regulation of diverse biological processes with high temporal resolution. Among the many outputs of the study is the early Nod factor-induced, ET-regulated expression of ET signaling and biosynthesis genes. Coupled with the observation of massive transcriptional derepression in the ET-insensitive background, these results suggest that Nod factor signaling activates ET production to attenuate its own signal. Promoter:β-glucuronidase fusions report ET biosynthesis both in root hairs responding to rhizobium as well as in meristematic tissue during nodule organogenesis and growth, indicating that ET signaling functions at multiple developmental stages during symbiosis. In addition, we identified thousands of novel candidate genes undergoing Nod factor-dependent, ET-regulated expression. We leveraged the power of this large data set to model Nod factor- and ET-regulated signaling networks using MERLIN, a regulatory network inference algorithm. These analyses predict key nodes regulating the biological process impacted by Nod factor perception. We have made these results available to the research community through a searchable online resource.
authors.affiliation: Department of Plant Pathology (E.L., B.K.R., N.C.-G., R.V.P., D.R.C) and Plant Biology Graduate Group (A.K.S.), University of California, Davis, California 95616;Korean Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea (S.C.K., N.K.);Catholic University of Korea, Bucheon 420-743, Republic of Korea (H.-J.Y.);Rural Development Administration, Jeonju 560-500, Republic of Korea (H.-J.H., M.O., G.-S.L.);Myongji University, Yongin 449-728, Republic of Korea (G.B.K., J.-H.M.);Wisconsin Institute for Discovery, Madison, Wisconsin 53715 (D.C., S.R.); andDepartment of Computer Sciences (A.F.S.) and Department of Biostatistics and Medical Informatics (S.R.), University of Wisconsin, Madison, Wisconsin 53715.
authors.forename: Estíbaliz
authors.identifier: http://orcid.org/0000-0002-1254-7391
authors.initials: E
authors.lastname: Larrainzar
authors.affiliation: Department of Plant Pathology (E.L., B.K.R., N.C.-G., R.V.P., D.R.C) and Plant Biology Graduate Group (A.K.S.), University of California, Davis, California 95616;Korean Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea (S.C.K., N.K.);Catholic University of Korea, Bucheon 420-743, Republic of Korea (H.-J.Y.);Rural Development Administration, Jeonju 560-500, Republic of Korea (H.-J.H., M.O., G.-S.L.);Myongji University, Yongin 449-728, Republic of Korea (G.B.K., J.-H.M.);Wisconsin Institute for Discovery, Madison, Wisconsin 53715 (D.C., S.R.); andDepartment of Computer Sciences (A.F.S.) and Department of Biostatistics and Medical Informatics (S.R.), University of Wisconsin, Madison, Wisconsin 53715.
authors.forename: Brendan K
authors.initials: BK
authors.lastname: Riely
authors.affiliation: Department of Plant Pathology (E.L., B.K.R., N.C.-G., R.V.P., D.R.C) and Plant Biology Graduate Group (A.K.S.), University of California, Davis, California 95616;Korean Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea (S.C.K., N.K.);Catholic University of Korea, Bucheon 420-743, Republic of Korea (H.-J.Y.);Rural Development Administration, Jeonju 560-500, Republic of Korea (H.-J.H., M.O., G.-S.L.);Myongji University, Yongin 449-728, Republic of Korea (G.B.K., J.-H.M.);Wisconsin Institute for Discovery, Madison, Wisconsin 53715 (D.C., S.R.); andDepartment of Computer Sciences (A.F.S.) and Department of Biostatistics and Medical Informatics (S.R.), University of Wisconsin, Madison, Wisconsin 53715.
authors.forename: Sang Cheol
authors.identifier: http://orcid.org/0000-0003-4389-9178
authors.initials: SC
authors.lastname: Kim
authors.affiliation: Department of Plant Pathology (E.L., B.K.R., N.C.-G., R.V.P., D.R.C) and Plant Biology Graduate Group (A.K.S.), University of California, Davis, California 95616;Korean Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea (S.C.K., N.K.);Catholic University of Korea, Bucheon 420-743, Republic of Korea (H.-J.Y.);Rural Development Administration, Jeonju 560-500, Republic of Korea (H.-J.H., M.O., G.-S.L.);Myongji University, Yongin 449-728, Republic of Korea (G.B.K., J.-H.M.);Wisconsin Institute for Discovery, Madison, Wisconsin 53715 (D.C., S.R.); andDepartment of Computer Sciences (A.F.S.) and Department of Biostatistics and Medical Informatics (S.R.), University of Wisconsin, Madison, Wisconsin 53715.
authors.forename: Noelia
authors.initials: N
authors.lastname: Carrasquilla-Garcia
authors.affiliation: Department of Plant Pathology (E.L., B.K.R., N.C.-G., R.V.P., D.R.C) and Plant Biology Graduate Group (A.K.S.), University of California, Davis, California 95616;Korean Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea (S.C.K., N.K.);Catholic University of Korea, Bucheon 420-743, Republic of Korea (H.-J.Y.);Rural Development Administration, Jeonju 560-500, Republic of Korea (H.-J.H., M.O., G.-S.L.);Myongji University, Yongin 449-728, Republic of Korea (G.B.K., J.-H.M.);Wisconsin Institute for Discovery, Madison, Wisconsin 53715 (D.C., S.R.); andDepartment of Computer Sciences (A.F.S.) and Department of Biostatistics and Medical Informatics (S.R.), University of Wisconsin, Madison, Wisconsin 53715.
authors.forename: Hee-Ju
authors.identifier: http://orcid.org/0000-0002-0123-8665
authors.initials: HJ
authors.lastname: Yu
authors.affiliation: Department of Plant Pathology (E.L., B.K.R., N.C.-G., R.V.P., D.R.C) and Plant Biology Graduate Group (A.K.S.), University of California, Davis, California 95616;Korean Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea (S.C.K., N.K.);Catholic University of Korea, Bucheon 420-743, Republic of Korea (H.-J.Y.);Rural Development Administration, Jeonju 560-500, Republic of Korea (H.-J.H., M.O., G.-S.L.);Myongji University, Yongin 449-728, Republic of Korea (G.B.K., J.-H.M.);Wisconsin Institute for Discovery, Madison, Wisconsin 53715 (D.C., S.R.); andDepartment of Computer Sciences (A.F.S.) and Department of Biostatistics and Medical Informatics (S.R.), University of Wisconsin, Madison, Wisconsin 53715.
authors.forename: Hyun-Ju
authors.initials: HJ
authors.lastname: Hwang
authors.affiliation: Department of Plant Pathology (E.L., B.K.R., N.C.-G., R.V.P., D.R.C) and Plant Biology Graduate Group (A.K.S.), University of California, Davis, California 95616;Korean Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea (S.C.K., N.K.);Catholic University of Korea, Bucheon 420-743, Republic of Korea (H.-J.Y.);Rural Development Administration, Jeonju 560-500, Republic of Korea (H.-J.H., M.O., G.-S.L.);Myongji University, Yongin 449-728, Republic of Korea (G.B.K., J.-H.M.);Wisconsin Institute for Discovery, Madison, Wisconsin 53715 (D.C., S.R.); andDepartment of Computer Sciences (A.F.S.) and Department of Biostatistics and Medical Informatics (S.R.), University of Wisconsin, Madison, Wisconsin 53715.
authors.forename: Mijin
authors.identifier: http://orcid.org/0000-0002-0102-6152
authors.initials: M
authors.lastname: Oh
authors.affiliation: Department of Plant Pathology (E.L., B.K.R., N.C.-G., R.V.P., D.R.C) and Plant Biology Graduate Group (A.K.S.), University of California, Davis, California 95616;Korean Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea (S.C.K., N.K.);Catholic University of Korea, Bucheon 420-743, Republic of Korea (H.-J.Y.);Rural Development Administration, Jeonju 560-500, Republic of Korea (H.-J.H., M.O., G.-S.L.);Myongji University, Yongin 449-728, Republic of Korea (G.B.K., J.-H.M.);Wisconsin Institute for Discovery, Madison, Wisconsin 53715 (D.C., S.R.); andDepartment of Computer Sciences (A.F.S.) and Department of Biostatistics and Medical Informatics (S.R.), University of Wisconsin, Madison, Wisconsin 53715.
authors.forename: Goon Bo
authors.identifier: http://orcid.org/0000-0002-6834-8228
authors.initials: GB
authors.lastname: Kim
authors.affiliation: Department of Plant Pathology (E.L., B.K.R., N.C.-G., R.V.P., D.R.C) and Plant Biology Graduate Group (A.K.S.), University of California, Davis, California 95616;Korean Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea (S.C.K., N.K.);Catholic University of Korea, Bucheon 420-743, Republic of Korea (H.-J.Y.);Rural Development Administration, Jeonju 560-500, Republic of Korea (H.-J.H., M.O., G.-S.L.);Myongji University, Yongin 449-728, Republic of Korea (G.B.K., J.-H.M.);Wisconsin Institute for Discovery, Madison, Wisconsin 53715 (D.C., S.R.); andDepartment of Computer Sciences (A.F.S.) and Department of Biostatistics and Medical Informatics (S.R.), University of Wisconsin, Madison, Wisconsin 53715.
authors.forename: Anandkumar K
authors.identifier: http://orcid.org/0000-0001-9565-2703
authors.initials: AK
authors.lastname: Surendrarao
authors.affiliation: Department of Plant Pathology (E.L., B.K.R., N.C.-G., R.V.P., D.R.C) and Plant Biology Graduate Group (A.K.S.), University of California, Davis, California 95616;Korean Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea (S.C.K., N.K.);Catholic University of Korea, Bucheon 420-743, Republic of Korea (H.-J.Y.);Rural Development Administration, Jeonju 560-500, Republic of Korea (H.-J.H., M.O., G.-S.L.);Myongji University, Yongin 449-728, Republic of Korea (G.B.K., J.-H.M.);Wisconsin Institute for Discovery, Madison, Wisconsin 53715 (D.C., S.R.); andDepartment of Computer Sciences (A.F.S.) and Department of Biostatistics and Medical Informatics (S.R.), University of Wisconsin, Madison, Wisconsin 53715.
authors.forename: Deborah
authors.identifier: http://orcid.org/0000-0002-7324-0131
authors.initials: D
authors.lastname: Chasman
authors.affiliation: Department of Plant Pathology (E.L., B.K.R., N.C.-G., R.V.P., D.R.C) and Plant Biology Graduate Group (A.K.S.), University of California, Davis, California 95616;Korean Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea (S.C.K., N.K.);Catholic University of Korea, Bucheon 420-743, Republic of Korea (H.-J.Y.);Rural Development Administration, Jeonju 560-500, Republic of Korea (H.-J.H., M.O., G.-S.L.);Myongji University, Yongin 449-728, Republic of Korea (G.B.K., J.-H.M.);Wisconsin Institute for Discovery, Madison, Wisconsin 53715 (D.C., S.R.); andDepartment of Computer Sciences (A.F.S.) and Department of Biostatistics and Medical Informatics (S.R.), University of Wisconsin, Madison, Wisconsin 53715.
authors.forename: Alireza F
authors.identifier: http://orcid.org/0000-0002-7804-4084
authors.initials: AF
authors.lastname: Siahpirani
authors.affiliation: Department of Plant Pathology (E.L., B.K.R., N.C.-G., R.V.P., D.R.C) and Plant Biology Graduate Group (A.K.S.), University of California, Davis, California 95616;Korean Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea (S.C.K., N.K.);Catholic University of Korea, Bucheon 420-743, Republic of Korea (H.-J.Y.);Rural Development Administration, Jeonju 560-500, Republic of Korea (H.-J.H., M.O., G.-S.L.);Myongji University, Yongin 449-728, Republic of Korea (G.B.K., J.-H.M.);Wisconsin Institute for Discovery, Madison, Wisconsin 53715 (D.C., S.R.); andDepartment of Computer Sciences (A.F.S.) and Department of Biostatistics and Medical Informatics (S.R.), University of Wisconsin, Madison, Wisconsin 53715.
authors.forename: Ramachandra V
authors.initials: RV
authors.lastname: Penmetsa
authors.affiliation: Department of Plant Pathology (E.L., B.K.R., N.C.-G., R.V.P., D.R.C) and Plant Biology Graduate Group (A.K.S.), University of California, Davis, California 95616;Korean Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea (S.C.K., N.K.);Catholic University of Korea, Bucheon 420-743, Republic of Korea (H.-J.Y.);Rural Development Administration, Jeonju 560-500, Republic of Korea (H.-J.H., M.O., G.-S.L.);Myongji University, Yongin 449-728, Republic of Korea (G.B.K., J.-H.M.);Wisconsin Institute for Discovery, Madison, Wisconsin 53715 (D.C., S.R.); andDepartment of Computer Sciences (A.F.S.) and Department of Biostatistics and Medical Informatics (S.R.), University of Wisconsin, Madison, Wisconsin 53715.
authors.forename: Gang-Seob
authors.initials: GS
authors.lastname: Lee
authors.affiliation: Department of Plant Pathology (E.L., B.K.R., N.C.-G., R.V.P., D.R.C) and Plant Biology Graduate Group (A.K.S.), University of California, Davis, California 95616;Korean Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea (S.C.K., N.K.);Catholic University of Korea, Bucheon 420-743, Republic of Korea (H.-J.Y.);Rural Development Administration, Jeonju 560-500, Republic of Korea (H.-J.H., M.O., G.-S.L.);Myongji University, Yongin 449-728, Republic of Korea (G.B.K., J.-H.M.);Wisconsin Institute for Discovery, Madison, Wisconsin 53715 (D.C., S.R.); andDepartment of Computer Sciences (A.F.S.) and Department of Biostatistics and Medical Informatics (S.R.), University of Wisconsin, Madison, Wisconsin 53715.
authors.forename: Namshin
authors.identifier: http://orcid.org/0000-0001-6361-274X
authors.initials: N
authors.lastname: Kim
authors.affiliation: Department of Plant Pathology (E.L., B.K.R., N.C.-G., R.V.P., D.R.C) and Plant Biology Graduate Group (A.K.S.), University of California, Davis, California 95616;Korean Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea (S.C.K., N.K.);Catholic University of Korea, Bucheon 420-743, Republic of Korea (H.-J.Y.);Rural Development Administration, Jeonju 560-500, Republic of Korea (H.-J.H., M.O., G.-S.L.);Myongji University, Yongin 449-728, Republic of Korea (G.B.K., J.-H.M.);Wisconsin Institute for Discovery, Madison, Wisconsin 53715 (D.C., S.R.); andDepartment of Computer Sciences (A.F.S.) and Department of Biostatistics and Medical Informatics (S.R.), University of Wisconsin, Madison, Wisconsin 53715.
authors.forename: Sushmita
authors.initials: S
authors.lastname: Roy
authors.affiliation: Department of Plant Pathology (E.L., B.K.R., N.C.-G., R.V.P., D.R.C) and Plant Biology Graduate Group (A.K.S.), University of California, Davis, California 95616;Korean Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea (S.C.K., N.K.);Catholic University of Korea, Bucheon 420-743, Republic of Korea (H.-J.Y.);Rural Development Administration, Jeonju 560-500, Republic of Korea (H.-J.H., M.O., G.-S.L.);Myongji University, Yongin 449-728, Republic of Korea (G.B.K., J.-H.M.);Wisconsin Institute for Discovery, Madison, Wisconsin 53715 (D.C., S.R.); andDepartment of Computer Sciences (A.F.S.) and Department of Biostatistics and Medical Informatics (S.R.), University of Wisconsin, Madison, Wisconsin 53715 munjh@mju.ac.kr drcook@ucdavis.edu.
authors.forename: Jeong-Hwan
authors.initials: JH
authors.lastname: Mun
authors.affiliation: Department of Plant Pathology (E.L., B.K.R., N.C.-G., R.V.P., D.R.C) and Plant Biology Graduate Group (A.K.S.), University of California, Davis, California 95616;Korean Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea (S.C.K., N.K.);Catholic University of Korea, Bucheon 420-743, Republic of Korea (H.-J.Y.);Rural Development Administration, Jeonju 560-500, Republic of Korea (H.-J.H., M.O., G.-S.L.);Myongji University, Yongin 449-728, Republic of Korea (G.B.K., J.-H.M.);Wisconsin Institute for Discovery, Madison, Wisconsin 53715 (D.C., S.R.); andDepartment of Computer Sciences (A.F.S.) and Department of Biostatistics and Medical Informatics (S.R.), University of Wisconsin, Madison, Wisconsin 53715 munjh@mju.ac.kr drcook@ucdavis.edu.
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Cook
mesh_terms: D053898:Biosynthetic Pathways / Q000187:drug effects / Q000235:genetics; D016000:Cluster Analysis; D005030:Ethylenes / Q000378:metabolism* / Q000494:pharmacology; D025461:Feedback, Physiological; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D063990:Gene Ontology; D053263:Gene Regulatory Networks; D017343:Genes, Plant; D059014:High-Throughput Nucleotide Sequencing / Q000379:methods*; D046913:Medicago truncatula / Q000187:drug effects / Q000235:genetics* / Q000382:microbiology*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development / Q000382:microbiology; D012231:Rhizobium / Q000187:drug effects / Q000502:physiology; D015398:Signal Transduction / Q000187:drug effects* / Q000235:genetics; D013559:Symbiosis / Q000235:genetics; D013997:Time Factors; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects; D059467:Transcriptome / Q000187:drug effects / Q000235:genetics*
chemical_list: D005030:Ethylenes; D010940:Plant Proteins; D014157:Transcription Factors; C036216:ethylene