RRC ID 52759
Author Fukudome M, Calvo-Begueria L, Kado T, Osuki K, Rubio MC, Murakami E, Nagata M, Kucho K, Sandal N, Stougaard J, Becana M, Uchiumi T.
Title Hemoglobin LjGlb1-1 is involved in nodulation and regulates the level of nitric oxide in the Lotus japonicus-Mesorhizobium loti symbiosis.
Journal J. Exp. Bot.
Abstract Leghemoglobins transport and deliver O2 to the symbiosomes inside legume nodules and are essential for nitrogen fixation. However, the roles of other hemoglobins (Hbs) in the rhizobia-legume symbiosis are unclear. Several Lotus japonicus mutants affecting LjGlb1-1, a non-symbiotic class 1 Hb, have been used to study the function of this protein in symbiosis. Two TILLING alleles with single amino acid substitutions (A102V and E127K) and a LORE1 null allele with a retrotransposon insertion in the 5'-untranslated region (96642) were selected for phenotyping nodulation. Plants of all three mutant lines showed a decrease in long infection threads and nodules, and an increase in incipient infection threads. About 4h after inoculation, the roots of mutant plants exhibited a greater transient accumulation of nitric oxide (NO) than did the wild-type roots; nevertheless, in vitro NO dioxygenase activities of the wild-type, A102V, and E127K proteins were similar, suggesting that the mutated proteins are not fully functional in vivo The expression of LjGlb1-1, but not of the other class 1 Hb of L. japonicus (LjGlb1-2), was affected during infection of wild-type roots, further supporting a specific role for LjGlb1-1. In conclusion, the LjGlb1-1 mutants reveal that this protein is required during rhizobial infection and regulates NO levels.
Volume 67(17)
Pages 5275-83
Published 2016-9
DOI 10.1093/jxb/erw290
PII erw290
PMID 27443280
PMC PMC5014168
MeSH Hemoglobins / metabolism Hemoglobins / physiology* Loteae / growth & development Loteae / metabolism Loteae / microbiology Loteae / physiology* Mesorhizobium / metabolism Mesorhizobium / physiology* Nitric Oxide / metabolism* Plant Proteins / metabolism Plant Proteins / physiology* Plant Root Nodulation / physiology* Plant Roots / growth & development Plant Roots / microbiology Plant Roots / physiology Real-Time Polymerase Chain Reaction Symbiosis / physiology
IF 5.36
Lotus / Glycine Gifu B-129