Marchantia polymorpha as a model for evolutionary biology

Kimitsune Ishizaki

Land plants evolved from an ancestral charophycean alga at least more than 470 million years ago. This was one of the major events for all life on planet earth. Among the extant taxa of land plants, bryophytes, which include liverworts, mosses, and hornworts, represent the earliest diversing group of terrestrial flora and are descendants of some of the very first non-vascular plants. Marchantia polymorpha is a common, easily cultivated dioecious thalloid liverwort species, and the haploid gametophytic generation dominates over the diploid sporophytic generation during its life cycle [1]. The whole genome of M. polymorpha has been sequenced, and revealed low genetic redundancy in most regulatory pathways, with this portion of its genome resembling that predicted for the ancestral land plant [2]. We have been focusing on the potential of M. polymorpha as a model plant for molecular genetics, and have been developing crucial experimental procedures and resources [3]. We have found growth condition rich in far-red light promotes transition to the reproductive phase, which has made crosses in laboratory possible. We have also developed an efficient transformation system for M. polymorpha using Agrobacterium tumefaciens [4,5]. Four kinds of selectable markers and various reporters including green fluorescent protein (GFP), β-glucuronidase (GUS), and luciferase (LUC), have been successfully used for M. polymorpha [6]. Therefore, it has become feasible to perform various transgenic experiments using M. polymorpha; for example, introduction of reporter constructs, overexpression, gene silencing and targeted gene modification. T-DNA tagging strategy, and physical mutagenesis have been established for M. polymorpha, which promote forward genetics in this basal land plant. In this talk, I would like to introduce and discuss about the experimental platform founded on M. polymorpha that will contribute to fundamental understanding of the evolution and diversity of various regulatory systems in land plants.

 

[1] Shimamura, M. (2016). Marchantia polymorpha: Taxonomy, phylogeny and morphology of a model system. Plant Cell Physiol. 57, 230-256.

[2] Bowman, J.L. Kohchi, T., Yamato, K.T., et al. (2017). Insight into land plant evolution garnered from the Marchantia polymorpha genome. Cell 171, 287-304.

[3] Ishizaki, K., Nishihama, R., Yamato, K.T., Kohchi, T. (2016). Molecular genetic tools and techniques for Marchantia polymorpha research. Plant Cell Physiology 57, 262-270.

[4] Ishizaki, K., Chiyoda, S., Yamato, K.T., Kohchi, T. (2008). Agrobacterium-mediated transformation of the haploid liverwort Marchantia polymorpha L. an emerging model for plant biology. Plant Cell Physiology 49, 1084-1091.

[5] Kubota, A., Ishizaki, K., Hosaka, M., Kohchi, T. (2013). Efficient Agrobacterium-mediated transformation of the liverwort Marchantia polymorpha using regenerating thalli. Biosci. Biotechnol. Biochem. 77, 167-172.

[6] Ishizaki, K., Nishihama, R., Ueda, M., Inoue, K., Ishida, S., Nishimura, Y., Shikanai, T., Kohchi, T. (2015). Development of Gateway binary vector series with four different selection markers for the liverwort Marchantia polymorpha. PLoS ONE. 10, e0138876.

 


Presenting Author:  Kimitsune Ishizaki

Author Affiliation: Graduate School of Science, Kobe University, Kobe 657-8501, Japan