RRC ID 30991
Author Takahara M, Magori S, Soyano T, Okamoto S, Yoshida C, Yano K, Sato S, Tabata S, Yamaguchi K, Shigenobu S, Takeda N, Suzaki T, Kawaguchi M.
Title Too much love, a novel Kelch repeat-containing F-box protein, functions in the long-distance regulation of the legume-Rhizobium symbiosis.
Journal Plant Cell Physiol.
Abstract The interaction of legumes with N2-fixing bacteria collectively called rhizobia results in root nodule development. The number of nodules formed is tightly restricted through the systemic negative feedback control by the host called autoregulation of nodulation (AON). Here, we report the characterization and gene identification of TOO MUCH LOVE (TML), a root factor that acts during AON in a model legume Lotus japonicus. In our genetic analyses using another root-regulated hypernodulation mutant, plenty, the tml-1 plenty double mutant showed additive effects on the nodule number, whereas the tml-1 har1-7 double mutant did not, suggesting that TML and PLENTY act in different genetic pathways and that TML and HAR1 act in the same genetic pathway. The systemic suppression of nodule formation by CLE-RS1/RS2 overexpression was not observed in the tml mutant background, indicating that TML acts downstream of CLE-RS1/RS2. The tml-1 Snf2 double mutant developed an excessive number of spontaneous nodules, indicating that TML inhibits nodule organogenesis. Together with the determination of the deleted regions in tml-1/-2/-3, the fine mapping of tml-4 and the next-generation sequencing analysis, we identified a nonsense mutation in the Kelch repeat-containing F-box protein. As the gene knockdown of the candidate drastically increased the number of nodules, we concluded that it should be the causative gene. An expression analysis revealed that TML is a root-specific gene. In addition, the activity of ProTML-GUS was constitutively detected in the root tip and in the nodules/nodule primordia upon rhizobial infection. In conclusion, TML is a root factor acting at the final stage of AON.
Volume 54(4)
Pages 433-47
Published 2013-4
DOI 10.1093/pcp/pct022
PII pct022
PMID 23390201
MeSH F-Box Proteins / genetics F-Box Proteins / metabolism* Fabaceae / metabolism* Fabaceae / microbiology* Loteae / metabolism Loteae / microbiology Plant Proteins / genetics Plant Proteins / metabolism* Plant Root Nodulation / genetics Plant Root Nodulation / physiology Rhizobium / physiology* Root Nodules, Plant / genetics Root Nodules, Plant / metabolism Symbiosis / genetics Symbiosis / physiology
IF 3.929
Times Cited 24
Lotus / Glycine pGWB3 plasmid