Blue light perception by both roots and rhizobia inhibits nodule formation in lotus japonicus

Aya Shimomura, Ayumi Naka, Nobuyuki Miyazaki, Sayaka Moriuchi, Susumu Arima, Shusei Sato, Hideki Hirakawa, Makoto Hayashi, Maskit Maymon, Ann M. Hirsch, Akihiro Suzuki

    Research output: Contribution to journalArticlepeer-review

    8 Citations (Scopus)


    In many legumes, roots that are exposed to light do not form nodules. Here, we report that blue light inhibits nodulation in Lotus japonicus roots inoculated with Mesorhizobium loti. Using RNA interference, we suppressed the expression of the phototropin and cryptochrome genes in L. japonicus hairy roots. Under blue light, plants transformed with an empty vector did not develop nodules, whereas plants exhibiting suppressed expression of cry1 and cry2 genes formed nodules. We also measured rhizobial growth to investigate whether the inhibition of nodulation could be caused by a reduced population of rhizobia in response to light. Although red light had no effect on rhizobial growth, blue light had a strong inhibitory effect. Rhizobial growth under blue light was partially restored in signature-Tagged mutagenesis (STM) strains in which LOV-HK/PAS-and photolyaserelated genes were disrupted. Moreover, when Ljcry1A and Ljcry2B-silenced plants were inoculated with the STM strains, nodulation was additively increased. Our data show that blue light receptors in both the host plant and the symbiont have a profound effect on nodule development. The exact mechanism by which these photomorphogenetic responses function in the symbiosis needs further study, but they are clearly involved in optimizing legume nodulation.

    Original languageEnglish
    Pages (from-to)786-796
    Number of pages11
    JournalMolecular Plant-Microbe Interactions
    Issue number10
    Publication statusPublished - 2016 Oct

    ASJC Scopus subject areas

    • Physiology
    • Agronomy and Crop Science


    Dive into the research topics of 'Blue light perception by both roots and rhizobia inhibits nodule formation in lotus japonicus'. Together they form a unique fingerprint.

    Cite this