Open AccessAuxin methylation by IAMT1 , duplicated in the legume lineage, promotes root nodule development in Lotus japonicus
Author(s) -
Takashi Goto,
Takashi Soyano,
Meng Li,
Tomoko Mori,
Masayoshi Kawaguchi
Publication year - 2022
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.2116549119
Subject(s) - lotus japonicus , biology , primordium , epidermis (zoology) , auxin , root nodule , root hair , botany , cortex (anatomy) , nodule (geology) , lateral root , rhizobium , microbiology and biotechnology , arabidopsis , stele , rhizobia , mutant , gene , symbiosis , genetics , bacteria , anatomy , paleontology , neuroscience
Significance IAA carboxyl methyltransferase 1 (IAMT1) converts auxin (IAA) into its methyl ester (MeIAA).IAMT1 is reportedly critical for shoot development of the nonsymbiotic plantArabidopsis . On the other hand, the function ofIAMT1 in roots is unknown. Here, we found thatIAMT1 is duplicated in the legume lineage, which evolved root nodule symbiosis. In the model legumeLotus japonicus , one of two paralogs (namedIAMT1a ) was mainly expressed in root epidermis, but its function is required in the adjacent cell layer, root cortex, where it promotes nodule development. Application of MeIAA, but not IAA, significantly inducedNIN , a master regulator of nodule development, without rhizobia. These findings illuminate our understanding of intertissue communication acquired during evolution of root nodule symbiosis.