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 2016-9-1
DOI 10.1093/jxb/erw290
PII erw290
PMID 27443280
PMC PMC5014168
MeSH Hemoglobins / metabolism Hemoglobins / physiology* Lotus / growth & development Lotus / metabolism Lotus / microbiology Lotus / 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 5.908
Times Cited 16
Lotus / Glycine Gifu B-129