This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: You may check your phone before deciding what to wear tomorrow. Plants do something similar: they carry an internal gadget called a "Season-Meter" that tracks temperatures over the preceding weeks or months to help determine when to flower.
By comparing two wild perennial plant species over two years, researchers from the University of Tsukuba found that each of the three genes in this Season-Meter operates over a different timescale, ranging from days to nearly five months, and that together they reliably forecast all four seasons of the year. The research is published in PLOS One. Many challenges plants face do not occur only once; they recur on a predictable, roughly annual cycle, such as winter cold preceding spring or shortening daylight before autumn.
Because these environmental signals are predictable, evolution has favored systems that allow plants to prepare in advance rather than react only to today's weather. Such preparation requires an internal memory. Since DNA itself cannot record a changing environment, plants instead preserve information about past temperatures through epigenetic changes in chromatin.
Rather than responding only to the temperature on a given day, plants appear to carry something like a built-in gadget that researchers have named the Season-Meter. It keeps a running tally of how temperatures have unfolded over the preceding weeks and months, allowing plants to forecast the season ahead and decide when to grow, flower or wait. A single warm day in midwinter fools this internal Season-Meter into blooming early, whereas a single cold snap in spring holds back flowering that is already on schedule.
Although scientists have long known that plants remember past temperatures, no standard method has existed for measuring how far back this epigenetic memory extends or whether it operates similarly across plants and genes. To address this gap, researchers studied two wild, long-lived species in the mustard family that grow naturally in Japan: wasabi, which grows in a mountain forest, and A. halleri, which grows along a mountain stream. They tracked the same three genes in both species over two full years.
By comparing each gene's activity with temperature records from the preceding weeks and months, the team estimated the span of past temperatures most strongly reflected in each gene's activity. They found that the Season-Meter comprises three genes that integrate past temperatures over distinct time scales. One gene looked back only a few days, another a few weeks and the third nearly five months, the longest interval measured in this system so far.
Extract — continue reading at the source.
