An Ancestral Function of Strigolactones as Symbiotic Rhizosphere Signals

Kyoichi Kodama (1) , Mélanie Rich (2) , Akiyoshi Yoda (3, 4) , Shota Shimazaki (1) , Xiaonan Xie (3, 4) , Kohki Akiyama (5) , Yohei Mizuno (1) , Aino Komatsu (1) , Yi Luo (1) , Hidemasa Suzuki (1) , Hiromu Kameoka (1) , Cyril Libourel (2) , Jean Keller (2) , Keiko Sakakibara (6) , Tomoaki Nishiyama (7) , Tomomi Nakagawa (8) , Kiyoshi Mashiguchi (9) , Kenichi Uchida (10) , Kaori Yoneyama (11) , Yoshikazu Tanaka (1) , Shinjiro Yamaguchi (9) , Masaki Shimamura (12) , Pierre-Marc Delaux (13) , Takahito Nomura (3, 4) , Junko Kyozuka (1)

1 Tohoku University [Sendai]
2 LRSV - Laboratoire de Recherche en Sciences Végétales
3 TUAT - Tokyo University of Agriculture and Technology
4 Utsunomiya University [Utsunomiya]
5 Osaka Prefecture University
6 Rikkyo University [Tokyo]
7 KU - Kanazawa University
8 NIBB - National Institute for Basic Biology [Okazaki]
9 Kyoto University
10 Teikyo University
11 Ehime University [Matsuyama, Japon]
12 Hiroshima University
13 Evolution des Interactions Plantes-Microorganismes

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.

Mots clés: Arbuscular mycorrhiza; Plant evolution; Strigolactone

Domaines: Evolution [q-bio.PE]

Kyoichi Kodama, Mélanie Rich, Akiyoshi Yoda, Shota Shimazaki, Xiaonan Xie, et al.. An Ancestral Function of Strigolactones as Symbiotic Rhizosphere Signals. Nature Communications, 2022, 13, pp.3974. ⟨10.1101/2021.08.20.457034⟩. ⟨hal-03366956⟩