title: The REL3-mediated TAS3 ta-siRNA pathway integrates auxin and ethylene signaling to regulate nodulation in Lotus japonicus.
abstract: The ta-siRNA pathway is required for lateral organ development, including leaf patterning, flower differentiation and lateral root growth. Legumes can develop novel lateral root organs--nodules--resulting from symbiotic interactions with rhizobia. However, ta-siRNA regulation in nodule formation remains unknown. To explore ta-siRNA regulation in nodule formation, we investigated the roles of REL3, a key component of TAS3 ta-siRNA biogenesis, during nodulation in Lotus japonicus. We characterized the symbiotic phenotypes of the TAS3 ta-siRNA defective rel3 mutant, and analyzed the responses of the rel3 mutant to auxin and ethylene in order to gain insight into TAS3 ta-siRNA regulation of nodulation. The rel3 mutant produced fewer pink nitrogen-fixing nodules, with substantially decreased infection frequency and nodule initiation. Moreover, the rel3 mutant was more resistant than wild-type to 1-naphthaleneacetic acid (NAA) and N-1-naphthylphthalamic acid (NPA) in root growth, and exhibited insensitivity to auxins but greater sensitivity to auxin transport inhibitors during nodulation. Furthermore, the rel3 mutant has enhanced root-specific ethylene sensitivity and altered responses to ethylene during nodulation; the low-nodulating phenotype of the rel3 mutant can be restored by ethylene synthesis inhibitor L-α-(2-aminoethoxyvinyl)-glycine (AVG) or action inhibitor Ag(+). The REL3-mediated TAS3 ta-siRNA pathway regulates nodulation by integrating ethylene and auxin signaling.
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology & Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China.
authors.forename: Xiaolin
authors.initials: X
authors.lastname: Li
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology & Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China.
authors.forename: Mingjuan
authors.initials: M
authors.lastname: Lei
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology & Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China.
authors.forename: Zhongyuan
authors.initials: Z
authors.lastname: Yan
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology & Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Wang
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology & Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China.
authors.forename: Aimin
authors.initials: A
authors.lastname: Chen
authors.affiliation: The key Laboratory of Oasis Eco-agriculture, Agriculture College of Shihezi University, Shihezi, 832003, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Sun
authors.affiliation: School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, China.
authors.forename: Da
authors.initials: D
authors.lastname: Luo
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology & Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China.
authors.forename: Yanzhang
authors.initials: Y
authors.lastname: Wang
mesh_terms: D005030:Ethylenes / Q000378:metabolism*; D007210:Indoleacetic Acids / Q000378:metabolism*; D000070116:Lotus / Q000378:metabolism*; D059128:Mesorhizobium / Q000502:physiology; D010641:Phenotype; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D055170:Plant Root Nodulation / Q000235:genetics*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D015398:Signal Transduction; D013559:Symbiosis / Q000235:genetics
chemical_list: D005030:Ethylenes; D007210:Indoleacetic Acids; D010940:Plant Proteins; D034741:RNA, Small Interfering; C036216:ethylene
keywords: TAS3 ta-siRNA biogenesis; auxin; auxin response regulator (ARF); ethylene; nodulation; rel3 mutant