A bioreporter system based on sfYFP, sfCFP, and mScarlet-I in Mesorhizobium japonicum and sfYFP and sfCFP in Rhizobium leguminosarum, driven by nifH consensus promoters was established to monitor occupancy and nitrogen fixation events within legume host nodules. These bioreporter plasmids expand established rhizobium sfGFP system to new hosts and fluorophores.
Senanayake et al. (Mon,) studied this question.