This time, the research group of the University of Tsukuba et al. Used the Lotus japonicus, which is a model plant of the legume family, to screen for mutants that cannot normally perform nodule symbiosis, and lan (lack of symbiont accommodation) new mutants. I named it. The lan mutant has significantly reduced formation of structures called infectious threads for uptake of rhizobia into the roots, and even when infected with mycorrhizal fungi, it is a dendritic organ that is a symbiotic organ with mycorrhizal fungi. It was found that little body formation was observed.This suggests that the LAN gene, which is the cause of the mutation, is a factor that works to accept symbiotic microorganisms into the roots.

　Subsequently, we found that the LAN gene encodes a component of a protein complex called a mediator, which is responsible for the gene expression regulatory function.In fact, it is said that the lan mutant suppressed the expression of genes whose expression should be induced in the process of nodule symbiosis and mycorrhizal symbiosis, and LAN is an indispensable protein for symbiosis with rhizobia and mycorrhizal fungi. It became clear.

　Understanding the mechanism of plant-microbial symbiosis leads to the development of plants with improved symbiotic ability with microorganisms. The findings obtained from the discovery of LAN can be expected to contribute to the cultivation of crops in oligotrophic lands and the realization of clean agriculture that does not rely on chemical fertilizers.

Paper information:[PLOS Genetics] LACK OF SYMBIONT ACCOMMODATION controls intracellular symbiont accommodation in root nodule and arbuscular mycorrhizal symbiosis in Lotus japonius