title: NODULES WITH ACTIVATED DEFENSE 1 is required for maintenance of rhizobial endosymbiosis in Medicago truncatula.
abstract: The symbiotic interaction between legume plants and rhizobia results in the formation of root nodules, in which symbiotic plant cells host and harbor thousands of nitrogen-fixing rhizobia. Here, a Medicago truncatula nodules with activated defense 1 (nad1) mutant was identified using reverse genetics methods. The mutant phenotype was characterized using cell and molecular biology approaches. An RNA-sequencing technique was used to analyze the transcriptomic reprogramming of nad1 mutant nodules. In the nad1 mutant plants, rhizobial infection and propagation in infection threads are normal, whereas rhizobia and their symbiotic plant cells become necrotic immediately after rhizobia are released from infection threads into symbiotic cells of nodules. Defense-associated responses were detected in nad1 nodules. NAD1 is specifically present in root nodule symbiosis plants with the exception of Morus notabilis, and the transcript is highly induced in nodules. NAD1 encodes a small uncharacterized protein with two predicted transmembrane helices and is localized at the endoplasmic reticulum. Our data demonstrate a positive role for NAD1 in the maintenance of rhizobial endosymbiosis during nodulation.
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: Haixiang
authors.initials: H
authors.lastname: Yu
authors.affiliation: Shanghai Key Lab of Bio-energy Crops, School of Life Sciences, Shanghai University, Shanghai, 200444, China.
authors.forename: Li
authors.initials: L
authors.lastname: Luo
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: Liujian
authors.initials: L
authors.lastname: Duan
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, College of Informatics, Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: Liuyang
authors.initials: L
authors.lastname: Cai
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: Xinxing
authors.initials: X
authors.lastname: He
authors.affiliation: Plant Biology Division, The Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, OK, 73401, USA.
authors.forename: Jiangqi
authors.initials: J
authors.lastname: Wen
authors.affiliation: Plant Biology Division, The Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, OK, 73401, USA.
authors.forename: Kirankumar S
authors.initials: KS
authors.lastname: Mysore
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, College of Informatics, Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: Guoliang
authors.initials: G
authors.lastname: Li
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: Aifang
authors.initials: A
authors.lastname: Xiao
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: Deqiang
authors.initials: D
authors.lastname: Duanmu
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: Yangrong
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Department of Plant, Soil and Entomological Sciences and Program of Microbiology, Molecular Biology and Biochemistry, University of Idaho, Moscow, ID, 83844, USA.
authors.forename: Zonglie
authors.initials: Z
authors.lastname: Hong
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: Zhongming
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D065150:Cellular Reprogramming / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005816:Genetic Complementation Test; D046913:Medicago truncatula / Q000235:genetics / Q000382:microbiology* / Q000648:ultrastructure; D009154:Mutation / Q000235:genetics; D009586:Nitrogen Fixation / Q000235:genetics; D009928:Organ Specificity / Q000235:genetics; D010636:Phenols / Q000378:metabolism; D010641:Phenotype; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D021381:Protein Transport; D012231:Rhizobium / Q000502:physiology*; D053204:Root Nodules, Plant / Q000382:microbiology / Q000648:ultrastructure; D016415:Sequence Alignment; D013559:Symbiosis / Q000502:physiology*; D059467:Transcriptome / Q000235:genetics
chemical_list: D010636:Phenols; D010940:Plant Proteins
keywords: Medicago truncatula; Tnt-insertion mutant; defense-like responses; legume; necrosis; nitrogen fixation; nodules; rhizobial endosymbiosis