Hypergravity response in the moss Physcomitrella patens
Bryophytes have been suggested to be among the oldest land plants to expand their habitats from aquatic to land environments. Bryophytes may have been subjected to remarkable changes in many environments including buoyancy, light, and temperature, and so on. Among these environmental changes, the effects of gravity on land should have induced alterations in the anatomy, physiology and growth of bryophytes. Few studies, however, have reported the gravitational responses in bryophytes; Physiological and anatomical analyses have yet to be done on the gravitational responses in bryophytes. To understand how gravity affects the anatomy and physiology of bryophytes, we grew the moss, Physcomitrella patens under a hypergravity environment such as 10 xg and found that growth and plant numbers were significantly increased at 10 xg. Chloroplast sizes were also increased and consistently, the photosynthesis rate of P. patens was also enhanced at 10 xg (Takemura et al. 2017). Then next, to understand how the hypergravity may affect global gene expression and consequently affect the anatomical and physiological changes, we performed RNA-seq analysis with the moss grown under a hypergravity condition.