March 22, 2012
It’s Official: Warm Weather Causes Flowers To Bloom
Scientists have completed research in attempts to explain what we see in our parks and gardens every year: with the onset of warmer weather comes blooming flowers and trees.
Funded by the Biotechnology and Biological Sciences Research Council (BBSRC), scientists from the John Innes Center have investigated the effects of warm weather and global climate changes on flowering plants and trees. Their findings on this research will be published soon in the journal Nature.
The research identified a control gene, called PIF4, whose job it is to activate a flowering pathway, causing the flowers to bloom. When the temperature gets below a certain point, the gene is unable to act.
“What is striking is that temperature alone is able to exert such specific and precise control on the activity of PIF4,” said Dr Phil Wigge, the lead scientist in the study.
This is not the first time scientists have looked at PIF4 in plants. Previously, the gene had been shown to control other plant responses to warmth, particularly growth. With this new research, the scientists have found this same gene is also responsible for activating flowering when the temperatures turn warm.
When plants flower, a special molecule called Florigen is activated. Florigen can be activated by many signals, like the longer days that accompany spring. While some plants rely more heavily on temperature to spark their flowering and leaf emergence, others depend on longer days to start their new life cycles.
The affects of daylight on Florigen has already been documented. This study is the first of its kind to understand how temperature instead of daylight acts as a Florigen activator.
Plants can still flower when the temperatures are cooler, albeit through other pathways. If PIF4 is activated too late, it will not bind to the flowering molecule Florigen and therefore will not accelerate flowering. When the temperatures rise, PIF4 will bind to Florigen and plants will flower more quickly via the PIF4 pathways.
“Our findings explain at the molecular level what we observe in our gardens as the warmer temperatures of spring arrive,” said Wigge.
“It also explains why plants are flowering earlier as a result of climate change.”
By unlocking these mysteries and understanding why plants flower and bloom when they do, Wigge and his colleagues hope to develop crops that will be resistant to climate changes and fluctuations. When crops react strongly to warmer temperatures, their yield is reduced. By understanding at the molecular level how these plants react to temperature and when they begin to bloom and mature, the team hopes they can breed a heartier and more resilient crop.
According to NOAA´s 2008 State of the Climate Report, Wigge´s research may be coming at just the right time. The report shows the Earth is warming at a rate of .29 degrees Fahrenheit per decade and average surface temperature has warmed about 1 degree Fahrenheit since 1970. In fact, the eight warmest years on record have occurred in the last 11 years, with the title of warmest year going to 2005.
“Knowing the key players in the temperature response pathways will be a valuable tool for safeguarding food security in an era of climate change,” said Wigge.