PT  - JOURNAL ARTICLE
AU  - Kyoichi Kodama
AU  - Mélanie K. Rich
AU  - Akiyoshi Yoda
AU  - Shota Shimazaki
AU  - Xiaonan Xie
AU  - Kohki Akiyama
AU  - Yohei Mizuno
AU  - Aino Komatsu
AU  - Yi Luo
AU  - Hidemasa Suzuki
AU  - Hiromu Kameoka
AU  - Cyril Libourel
AU  - Jean Keller
AU  - Keiko Sakakibara
AU  - Tomoaki Nishiyama
AU  - Tomomi Nakagawa
AU  - Kiyoshi Mashiguchi
AU  - Kenichi Uchida
AU  - Kaori Yoneyama
AU  - Yoshikazu Tanaka
AU  - Shinjiro Yamaguchi
AU  - Masaki Shimamura
AU  - Pierre-Marc Delaux
AU  - Takahito Nomura
AU  - Junko Kyozuka
TI  - An Ancestral Function of Strigolactones as Symbiotic Rhizosphere Signals
AID  - 10.1101/2021.08.20.457034
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.08.20.457034
4099  - http://biorxiv.org/content/early/2021/08/20/2021.08.20.457034.1.short
4100  - http://biorxiv.org/content/early/2021/08/20/2021.08.20.457034.1.full
AB  - In flowering plants, carotenoid-derived strigolactones (SLs) have dual functions as hormones that regulate growth and development, and as rhizosphere signaling molecules that induce symbiosis with arbuscular mycorrhizal (AM) fungi. Here, we report the identification of bryosymbiol (BSB), a previously unidentified SL from the bryophyte Marchantia paleacea. BSB is also found in vascular plants, indicating that it is ancestral in land plants. BSB synthesis is enhanced at AM symbiosis permissive conditions and BSB deficient mutants are impaired in AM symbiosis. In contrast, the absence of BSB synthesis has little effect on the growth and gene expression. We show that the introduction of the SL receptor of Arabidopsis renders M. paleacea cells BSB-responsive. These results suggest that BSB is not perceived by M. paleacea cells due to the lack of cognate SL receptors. We propose that SLs originated as AM symbiosis-inducing rhizosphere signaling molecules and were later recruited as plant hormone.Competing Interest StatementThe authors have declared no competing interest.