|| 要旨トップ | 目次 |||日本生態学会第61回全国大会 (2014年3月、広島) 講演要旨
一般講演（口頭発表） G0-01 (Oral presentation)
Plants grow and flower at appropriate times in a year by detecting seasons from environmental signals. For proper detection of seasons, plants should remember long-term tendency of the environment such as temperature for past certain period. We aim to reveal the molecular mechanism of this “memory” of temperature in a natural environment.
Chemical modifications of histones (histone modifications) function as “memory” mechanism in plants. In annual Arabidopsis thaliana, long-term cold exposure (vernalization) silences a flowering repressor gene, FLOWERING LOCUS C (FLC), associated with deposition of repressive histone modifications allowing the maintenance of the silencing. Through this “epigenetic memory of winter” mechanism, plants can flower after the temperature returns to warm.
We conducted our study in a natural population of perennial Arabidopsis halleri and analyzed seasonal change in FLC RNA expression and histone modifications at FLC. Statistical analysis revealed that RNA expression showed the best correlation with past temperature for 6 weeks whereas repressive histone modifications for much longer periods, i.e., 10 weeks. This indicates that change in RNA expression precedes those of repressive histone modifications, forming long-term memory of the environments.