Identification of a pluripotency-inducing small compound, PLU, that induces callus formation via Heat Shock Protein 90-mediated activation of auxin signaling

Yuki Nakashima; Yuka Kobayashi; Mizuki Murao; Rika Kato; Hitoshi Endo; Asuka Higo; Rie Iwasaki; Mikiko Kojima; Yumiko Takebayashi; Ayato Sato; Mika Nomoto; Hitoshi Sakakibara; Yasuomi Tada; Kenichiro Itami; Seisuke Kimura; Shinya Hagihara; Keiko U Torii; Naoyuki Uchida

doi:10.3389/fpls.2023.1099587

Identification of a pluripotency-inducing small compound, PLU, that induces callus formation via Heat Shock Protein 90-mediated activation of auxin signaling

Front Plant Sci. 2023 Mar 8:14:1099587. doi: 10.3389/fpls.2023.1099587. eCollection 2023.

Authors

Yuki Nakashima^{1

2}, Yuka Kobayashi^{1

3}, Mizuki Murao^{1

2}, Rika Kato^{2

4}, Hitoshi Endo⁵, Asuka Higo^{1

6}, Rie Iwasaki⁵, Mikiko Kojima⁷, Yumiko Takebayashi⁷, Ayato Sato⁵, Mika Nomoto^{1

2}, Hitoshi Sakakibara^{7

8}, Yasuomi Tada^{1

2}, Kenichiro Itami^{2

5}, Seisuke Kimura^{9

10}, Shinya Hagihara⁴, Keiko U Torii^{5

11}, Naoyuki Uchida^{1

2

5}

Affiliations

¹ Center for Gene Research, Nagoya University, Nagoya, Japan.
² Graduate School of Science, Nagoya University, Nagoya, Japan.
³ School of Science, Nagoya University, Nagoya, Japan.
⁴ Center for Sustainable Resource Science, RIKEN, Saitama, Japan.
⁵ Institute of Transformative Bio-Molecules, Nagoya University, Nagoya, Japan.
⁶ Institute for Advanced Research, Nagoya University, Nagoya, Japan.
⁷ Center for Sustainable Resource Science, RIKEN, Yokohama, Japan.
⁸ Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan.
⁹ Department of Industrial Life Sciences, Faculty of Life Science, Kyoto Sangyo University, Kyoto, Japan.
¹⁰ Center for Plant Sciences, Kyoto Sangyo University, Kyoto, Japan.
¹¹ Howard Hughes Medical Institute and Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, United States.

Abstract

Plants retain the ability to generate a pluripotent tissue called callus by dedifferentiating somatic cells. A pluripotent callus can also be artificially induced by culturing explants with hormone mixtures of auxin and cytokinin, and an entire body can then be regenerated from the callus. Here we identified a pluripotency-inducing small compound, PLU, that induces the formation of callus with tissue regeneration potency without the external application of either auxin or cytokinin. The PLU-induced callus expressed several marker genes related to pluripotency acquisition via lateral root initiation processes. PLU-induced callus formation required activation of the auxin signaling pathway though the amount of active auxin was reduced by PLU treatment. RNA-seq analysis and subsequent experiments revealed that Heat Shock Protein 90 (HSP90) mediates a significant part of the PLU-initiated early events. We also showed that HSP90-dependent induction of TRANSPORT INHIBITOR RESPONSE 1, an auxin receptor gene, is required for the callus formation by PLU. Collectively, this study provides a new tool for manipulating and investigating the induction of plant pluripotency from a different angle from the conventional method with the external application of hormone mixtures.

Keywords: Arabidopsis thaliana; HSP90; auxin; callus; pluripotency; small compound.

Grants and funding

This work was supported by MEXT/JSPS KAKENHI (Grant numbers JP17H06476, JP20K21422, JP21H02513, JP20H04883, JP20H05409, JP20H05905, JP20H05912, JP21H02503 and JP22K15140), the Mitsubishi Foundation, and the Asahi Glass Foundation. This work is also partially supported by Nagoya University Research Fund.