GARDENERS and farmers have always been at the mercy of the seasons when it
comes to the timing of flowering. But thanks to a gene called FRIGIDA,
they may soon be able to make plants flower whenever they want.
Keri Torney of the John Innes Centre in Norwich has been studying how cold
controls the flowering of Arabidopsis, the weed that takes the role of
lab rat in plant genetics. Torney wanted to know why Arabidopsis
growing in the temperate climate of Dijon in France flowers much earlier than
Arabidopsis growing in Stockholm, which has a much harsher winter.
Torney鈥檚 colleagues discovered FRIGIDA, the gene that ensures
Arabidopsis only flowers when cold conditions end. She found that the Dijon
variety has a mutated form of FRIGIDA, which means it does not need to
experience a cold phase to flower.
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鈥淭he plants have evolved to lose this gene because winter in Dijon is not
cold enough,鈥� Torney told the BA meeting. This is why different varieties of the
same plant can be found growing in varying climates.
Understanding how FRIGIDA functions may have great importance for
agriculture. Torney expects that crops such as wheat will have varying forms of
the gene, or one like it, depending on the climate in which they are grown.
鈥淒ifferent types of wheat are grown all over the world,鈥� says Torney, 鈥渂ut by
cross-breeding varieties with different forms of FRIGIDA you should be
able to get a crop that will grow in varying climates with increased
辫谤辞诲耻肠迟颈辞苍.鈥�
Peter Hedden of the Long Ashton Research Station of the Institute of Arable
Crops Research near Bristol agrees that understanding the mechanisms that
control flowering may benefit agriculture. However, he says that in some cases
factors such as day length may be more important than temperature for
controlling when cereal crops flower.
Hedden thinks FRIGIDA may be more useful if it can be persuaded to
stop plants flowering. 鈥淪ugar beet is a biannual crop that is planted in spring
and flowers after the following winter. If there is an unusually cold spring
when it is planted, then it flowers too early and the resulting crop cannot be
processed properly,鈥� says Hedden. 鈥淲here cold is a requirement and you fully
understand the mechanism, then I鈥檓 sure there is potential for turning it off.鈥�