title: A thaumatin-like protein, Rj4, controls nodule symbiotic specificity in soybean.
abstract: Soybeans exhibit a nitrogen-fixing symbiosis with soil bacteria of the genera Bradyrhizobium and Ensifer/Sinorhizobium in a unique organ, the root nodule. It is well known that nodulation of soybean is controlled by several host genes referred to as Rj (rj) genes. Among these genes, a dominant allele, Rj4, restricts nodulation with specific bacterial strains such as B. elkanii USDA61 and B. japonicum Is-34. These incompatible strains fail to invade the host epidermal cells as revealed by observations using DsRed-labeled bacteria. Here, we describe the molecular identification of the Rj4 gene by using map-based cloning with several mapping populations. The Rj4 gene encoded a thaumatin-like protein (TLP) that belongs to pathogenesis-related (PR) protein family 5. In rj4/rj4 genotype soybeans and wild soybeans, we found six missense mutations and two consecutive amino acid deletions in the rj4 gene as compared with the Rj4 allele. We also found, using hairy root transformation, that the rj4/rj4 genotype soybeans were fully complemented by the expression of the Rj4 gene. Whereas the expression of many TLPs and other PR proteins is induced by biotic/abiotic stress, Rj4 gene expression appears to be constitutive in roots including root nodules.
authors: National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki, 305-8602 Japan.
authors: Masaki
authors: M
authors: Hayashi
authors: Faculty of Agriculture, University of Miyazaki, 1-1 Gakuen Kibanadai-Nishi, Miyazaki, Miyazaki, 889-2192 Japan Department of Agriculture and Forest Sciences, Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu-cho, Matsue, Shimane, 690-8504 Japan.
authors: Sokichi
authors: S
authors: Shiro
authors: National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki, 305-8602 Japan.
authors: Hiroyuki
authors: H
authors: Kanamori
authors: National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki, 305-8602 Japan.
authors: Satomi
authors: S
authors: Mori-Hosokawa
authors: National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki, 305-8602 Japan.
authors: Harumi
authors: H
authors: Sasaki-Yamagata
authors: National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki, 305-8602 Japan.
authors: Takashi
authors: T
authors: Sayama
authors: National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki, 305-8602 Japan.
authors: Miki
authors: M
authors: Nishioka
authors: National Agriculture and Food Research Organization, Kyushu Okinawa Agricultural Research Center, 2421 Suya, Koshi, Kumamoto, 861-1192 Japan.
authors: Masakazu
authors: M
authors: Takahashi
authors: National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki, 305-8602 Japan.
authors: Masao
authors: M
authors: Ishimoto
authors: National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki, 305-8602 Japan.
authors: Yuichi
authors: Y
authors: Katayose
authors: National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki, 305-8602 Japan.
authors: Akito
authors: A
authors: Kaga
authors: National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki, 305-8602 Japan.
authors: Kyuya
authors: K
authors: Harada
authors: National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki, 305-8602 Japan Department of Life Science, International Christian University, 3-10-2, Osawa, Mitaka, Tokyo, 181-8585 Japan.
authors: Hiroshi
authors: H
authors: Kouchi
authors: Faculty of Agriculture, University of Miyazaki, 1-1 Gakuen Kibanadai-Nishi, Miyazaki, Miyazaki, 889-2192 Japan.
authors: Yuichi
authors: Y
authors: Saeki
authors: National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki, 305-8602 Japan umehara@affrc.go.jp.
authors: Yosuke
authors: Y
authors: Umehara
mesh_terms: D001483:Base Sequence; D020369:Bradyrhizobium / Q000235:genetics / Q000502:physiology; D002874:Chromosome Mapping; D018506:Gene Expression Regulation, Plant; D056426:Genetic Loci / Q000235:genetics; D005838:Genotype; D008969:Molecular Sequence Data; D009586:Nitrogen Fixation; D010641:Phenotype; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D055170:Plant Root Nodulation; D018517:Plant Roots / Q000235:genetics / Q000502:physiology; D053204:Root Nodules, Plant / Q000235:genetics / Q000502:physiology; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013025:Glycine max / Q000235:genetics* / Q000502:physiology; D013045:Species Specificity; D013559:Symbiosis
chemical_list: D010940:Plant Proteins; C003427:thaumatin protein, plant
keywords: Host restriction of nodulation; Nodule symbiotic specificity; Rj gene; Root nodule symbiosis; Soybean; Thaumatin-like protein (TLP)