Transcriptome phenology of Arabidopsis halleri

Seasonal change is the major source of environmental variation throughout the globe. For example, day length and temperature drastically change in annual cycle. Because most organisms have been evolved in natural seasonal environments, their molecular systems of environmental responses are expected to be shaped by adaptation for seasonal changes. Various phenological events in organisms were classically recognized and broadly taken as products of adaptations. In plants, seasonal controls are found in many aspects of their life history: germination, leaf expansion, flowering and leaf fall. In addition to these visible phenological events, physiological changes, e.g. photosynthetic activity and nutrient recycle, take place. To reveal details of molecular machinery for environmental responses, vast number of molecular studies has been performed under rather simple, controlled laboratory conditions. Although some earlier studies analyzed expression of selected key genes under natural environments, current our understanding on how the molecular machinery of plants as a whole work under seasonal environments remains limited. Examples include how plants manage simultaneous multiple-stresses and how plants process noisy environmental signals in their phenological responses. To address these questions, we employed field transcriptomics. It is an emerging approach characterized by statistical analysis of massive time-series transcriptome data collected under field environments and corresponding meteorological data.