Recent climate change has shifted the flowering time of many plant species. During the International Year of Biodiversity in 2010, this flowering time shift has been highlighted because coordination between pollinating animals and plants could be at risk
Professor Dr. Kentaro Shimizu, a plant biologist at the University of Zurich, and Japanese colleagues have shown that a gene for plant flowering works as a memory of temperature during the past six weeks, and would be useful for accurate projection (prediction) of the plant response to temperature changes.
Many plants flower in spring by detecting prolonged cold temperature (called vernalization). In natural conditions, temperature shows day/night, day-by-day, and weekly fluctuations that are often inconsistent with seasonal trends. Without memory of past temperatures, it would be difficult for plants to detect seasons in natural, noisy environments. A major obstacle to projecting (predicting) flowering response has been the lack of visible change during the cold duration. An evolutionary biologist at the University of Zurich, Kentaro Shimizu, and a PhD student, Masaki Kobayashi, in collaboration with Japanese researchers led by Dr. Hiroshi Kudoh, measured the internal state of plants by quantifying the expression level of a key flowering-time gene called FLC. Such molecular measurements, undertaken over two years, showed that the regulatory network of the FLC gene stores the information of temperatures over the past six weeks.
Time series analysis revealed that as much as 83% of the variation in FLC expression is explained solely by the temperature for the previous six weeks, but not by the temperatures over shorter or longer periods. The projection (prediction) from the model based on this time series analysis fits the gene expression pattern under contrasting temperature regimes in artificial transplant experiments. This indicates that such modeling incorporating the molecular basis of flowering-time regulation will contribute to projecting plant responses to future climate changes.