( In the long dark days of winter garde...)Genetic snooze button governs timing of spring flowers

Addressing scientists here today (Aug. 9) at a meeting of the American Society of Plant Biologists, University of Wisconsin-Madison researcher Richard Amasino described studies that have begun to peel back some of the mystery of how plants pace the seasons to bloom at the optimal time of year.

"Flowering at the right time is all about competition," says Amasino, Howard Hughes Medical Institute Professor and UW-Madison professor of biochemistry.

Amasino and his colleagues have studied, in particular, the behaviors of biennial plants, which require long periods of exposure to the cold to initiate flowering in the spring. What they have found reveals some of the complex interplay of genes and environment and provides hints that, one day, it may be possible to exert precise control over flowering, a process essential for plant reproduction and fruiting and that has enormous implications for agriculture.

Flowers are the reproductive organs of plants and are responsible for forming seeds and fruit. As their name implies, biennials complete their life cycles in two years, germinating, growing and overwintering the first year. The second year, the plants flower in the spring and die back in the fall.

That biennial strategy, Amasino explains, arose as flowering plants, which first evolved some 100 million years ago during the age of the dinosaurs, spread to fill the niches of nature. Spring blooming confers numerous advantages, not the least of which is leafing out and flowering before the competition.

But how do the plants know when to flower?

"If you carve out that niche, you need to get established in the fall, but you need to make darn sure you don't flower in the fall," Amasino says. In the case of biennials, "the plants can somehow measure how much cold t
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Source:University of Wisconsin-Madison