Research Early evolution of the land plant circadian clock Anna-Malin Linde1,2*, D. Magnus Eklund1,2*, Akane Kubota3*, Eric R. A. Pederson1,2, Karl Holm1,2, Niclas Gyllenstrand1,2, Ryuichi Nishihama3, Nils Cronberg4, Tomoaki Muranaka5, Tokitaka Oyama5, Takayuki Kohchi3 and Ulf Lagercrantz1,2 1Department of Plant Ecology and Evolution, Evolutionary Biology Centre, Uppsala University, Norbyv€agen 18D, SE-75236 Uppsala, Sweden; 2The Linnean Centre for Plant Biology in Uppsala, Uppsala, Sweden; 3Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan; 4Department of Biology, Lund University, Ecology Building, SE-22362 Lund, Sweden; 5Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan Summary Author for correspondence: While angiosperm clocks can be described as an intricate network of interlocked transcrip- Ulf Lagercrantz tional feedback loops, clocks of green algae have been modelled as a loop of only two genes. Tel: +46(0)18 471 6418 To investigate the transition from a simple clock in algae to a complex one in angiosperms, we Email:
[email protected] performed an inventory of circadian clock genes in bryophytes and charophytes. Additionally, Received: 14 December 2016 we performed functional characterization of putative core clock genes in the liverwort Accepted: 18 January 2017 Marchantia polymorpha and the hornwort Anthoceros agrestis. Phylogenetic construction was combined with studies of spatiotemporal expression patterns New Phytologist (2017) 216: 576–590 and analysis of M. polymorpha clock gene mutants. doi: 10.1111/nph.14487 Homologues to core clock genes identified in Arabidopsis were found not only in bryophytes but also in charophytes, albeit in fewer copies. Circadian rhythms were detected Key words: bryophyte, circadian clock, for most identified genes in M.