title: Additional cause for reduced JA-Ile in the root of a Lotus japonicus phyB mutant.
abstract: Light is critical for supplying carbon for use in the energetically expensive process of nitrogen-fixing symbiosis between legumes and rhizobia. We recently showed that root nodule formation in phyB mutants [which have a constitutive shade avoidance syndrome (SAS) phenotype] was suppressed in white light, and that nodulation in wild-type is controlled by sensing the R/FR ratio through jasmonic acid (JA) signaling. We concluded that the cause of reduced root nodule formation in phyB mutants was the inhibition of JA-Ile production in root. Here we show that the shoot JA-Ile level of phyB mutants is higher than that of the wild-type strain MG20, suggesting that translocation of JA-Ile from shoot to root is impeded in the mutant. These results indicate that root nodule formation in phyB mutants is suppressed both by decreased JA-Ile production, caused by reduced JAR1 activity in root, and by reduced JA-Ile translocation from shoot to root.
authors: Department of Environmental Sciences, Faculty of Agriculture, Saga University, Honjyo-machi, Saga, Japan.
authors: Tamaki
authors: T
authors: Shigeyama
authors: Akiyoshi
authors: A
authors: Tominaga
authors: Susumu
authors: S
authors: Arima
authors: Tatsuya
authors: T
authors: Sakai
authors: Sayaka
authors: S
authors: Inada
authors: Yusuke
authors: Y
authors: Jikumaru
authors: Yuji
authors: Y
authors: Kamiya
authors: Toshiki
authors: T
authors: Uchiumi
authors: Mikiko
authors: M
authors: Abe
authors: Masatsugu
authors: M
authors: Hashiguchi
authors: Ryo
authors: R
authors: Akashi
authors: Ann M
authors: AM
authors: Hirsch
authors: Akihiro
authors: A
authors: Suzuki
mesh_terms: D003517:Cyclopentanes / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics; D007532:Isoleucine / Q000031:analogs & derivatives* / Q000378:metabolism; D008027:Light; D000070116:Lotus / Q000235:genetics / Q000254:growth & development / Q000378:metabolism* / Q000528:radiation effects; D009154:Mutation / Q000235:genetics*; D054883:Oxylipins / Q000378:metabolism; D051939:Phytochrome B / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism* / Q000528:radiation effects; D018520:Plant Shoots / Q000378:metabolism / Q000528:radiation effects
chemical_list: D003517:Cyclopentanes; D054883:Oxylipins; D010940:Plant Proteins; C532883:jasmonoyl-isoleucine; D007532:Isoleucine; D051939:Phytochrome B; C011006:jasmonic acid