Nature Notebook – Bloomtime Master Gene

Our first spring wildflowers, those of the skunk cabbage, will be blooming soon. Snow drops and crocuses will make their appearances as well. Why do some flowers “choose” to ignore the snow and others wait until much later to bloom?

Hormones.

More precisely, the genes that control the hormones.

One gene, APETALA 1 (AP1), is particularly important. It is sensitive to weather, temperature and photoperiod (number of hours of daylight vs. darkness). When AP1 senses the proper conditions for its species, it sends an ALL STOP signal to the genes directing leaf growth. Then AP1 produces proteins that switch on the genes that actually produce flowers.

Some of these genes are also influenced by air temperature and, thus, have the final “say” as to whether or not a flower is produced. Warm temperatures activate the gene and a flower blooms. Cold temperatures inhibit it so no flowers.