From southern Africa's pineapple lily to Western Australia's swamp bottlebrush, flowering plants are everywhere. Also called angiosperms, they make up 90 percent of all land-based, plant life.
New research published this week in the Proceedings of the National Academy of Sciences provides new insights into their genetic origin, an evolutionary innovation that quickly gave rise to many diverse flowering plants more than 130 million years ago. Moreover, a flower with genetic programming similar to a water lily may have started it all.
"Water lilies and avocado flowers are essentially 'genetic fossils' still carrying genetic instructions that would have allowed the transformation of gymnosperm cones into flowers," said biologist Doug Soltis, co-lead researcher at the University of Florida in Gainesville.
Gymnosperms are a group of seed-bearing plants that include conifers and cycads that produce "cones" as reproductive structures, one example being the well-known pine cone. "We show how the first flowering plants evolved from pre-existing genetic programs found in gymnosperm cones and then developed into the diversity of flowering plants we see today," he said. "A genetic program in the gymnosperm cone was modified to make the first flower."
But, herein is the riddle. How can flowers that contain both male and female parts develop from plants that produce cones when individual cones are either male or female? The solution, say researchers, is that a male gymnosperm cone has almost everything a flower has in terms of its genetic wiring.
Somehow a genetic change took place allowing a male cone to produce female organs as well--and, perhaps more importantly, allowed it to produce showy petal-like organs that enticed new interactions with pollination agents such as bees.
Analyzing genetic information encoded in a diverse array of evolutionarily distant flowers--water lily, avocado, California poppy and a
|Contact: Bobbie Mixon|
National Science Foundation