Seasonal flower power
A crucial aspect of crop management is the timing of flowering because that’s often related to when the edible parts are produced, or seeds for planting next year. Flowering can be triggered by warm spells or cold snaps, and climate change may bring changes to weather patterns that could shift growing seasons or wreck planting calendars entirely.
It’s therefore crucial to understand the genetic and molecular basis of flowering. Professor Caroline Dean and colleagues at the John Innes Centre (JIC, an institute of BBSRC) are investigating the molecular control of flowering time, focusing specifically on the acceleration of flowering by a period of prolonged cold, a process known as vernalization.
Dean’s lab has found that UK varieties of Arabidopsis will flower after a four week cold snap, but varieties in Sweden require a 14-week cold period. “They are each adapted to the prevailing climate,” says Dean. “This involves changes to the plant’s memory system – the same mechanism that influences cell memory in our own bodies.”
Scientists use Arabidopsis widely in plant genetics. Image: iStock
The memory system in vernalization is epigenetic, which means that there are adjustments in plant gene activity due to factors other than changes in the underlying DNA as is usually the case. It involves changes to chromatin, a protein-DNA complex. Changes to these chromatin proteins, induced during the cold of winter, keeps the DNA in a form unable to be switched back on when plants are returned to the warm.
The FLC (Flowering Locus C) gene plays just such a critical role in delaying flowering over winter so that plants bloom when it is warmer. The UK is predicted to have warmer, wetter winters in the future, and so understanding the influence of changing temperature on the FLC gene on flowering is necessary now but will be even more important as climate change affects local weather patterns.
And even though the research is on plants, Dean says investigating epigenetic systems could reveal much about the molecular basis of development in other living systems. “This kind of epigenetic mechanism is important for specifying the fate of cells in our body because mis-regulation leads to diseases such as cancer,” she says. “Analysis of the plant vernalization system is likely to reveal fundamental mechanisms of general relevance in disease and development.”