Research Projects

Leghemoglobin (LegH) in leguminous plants sequesters oxygen molecules to protect rhizobial nitrogenase, an oxygen-labile enzyme that catalyzes NH3 formation during symbiotic nitrogen fixation (sNF). sNF requires a balance between oxygen sequestration by LegH and rhizobial respiration. A previous project funded by sERB investigated the spatio-temporal status of phosphorylated LegH using anti-phospho-peptide antibodies. The results showed that P-LegH became detectable primarily in the infected cell membrane from 14dpi onwards, while the non-phospho counterpart was seen as early as 9dpi. P-LegH gradually dispersed in the cytosol of infected cells towards later dpi with the increase of rhizobial load. The study hypothesizes that the subcellular localization of LegH during sNF in L.japonicus is partly regulated by its phosphorylation at serine residues and its interaction with Nlj16. The project aims to elucidate the molecular regulation of the subcellular localization of LegH during sNF in L.japonicus to understand how pO2 is maintained in symbiotic tissue for optimal N2 fixation.