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5 December 2013 11:26 am ,
Vol. 342 ,
Researchers have been hot on the trail of the elusive Denisovans, a type of ancient human known only by their DNA and...
Thousands of scientists in the Russian Academy of Sciences (RAS) are about to lose their jobs as a result of the...
Dyslexia, a learning disability that hinders reading, hasn't been associated with deficits in vision, hearing, or...
Exotic, elusive, and dangerous, snakes have fascinated humankind for millennia. They can be hard to find, yet their...
Researchers have sequenced and analyzed the first two snake genomes, which represent two evolutionary extremes. The...
Snake venoms are remarkably complex mixtures that can stun or kill prey within minutes. But more and more researchers...
At age 30, Dutch biologist Freek Vonk has built up a respectable career as a snake scientist. But in his home country,...
Since arriving on the island of Guam in the 1940s, the brown tree snake ( Boiga irregularis ) has extirpated native...
- 5 December 2013 11:26 am , Vol. 342 , #6163
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ScienceShot: The Secret of the Black Dahlia
26 November 2012 3:30 pm
Gardeners can choose from more than 20,000 varieties of dahlias, including whites, yellows, deep reds, and magentas. But the rarer black dahlias are especially alluring. Now, a team of researchers in Austria has turned the eye of science on what makes a dahlia black. The team collected 14 varieties of black dahlia—with names such as "Black Barbara," "Arabian Night," "Karma Choc" (left), and "Tisa" (right)—and five varieties with tamer colors, then extensively analyzed their petals. They measured the activity of enzymes that make pigments, investigated gene expression, and measured the pigments themselves. Their conclusion: The black color comes from high levels of anthocyanins, the pigments that—at lower levels—also give orange and red dahlias their colors. The team reports in BMC Plant Biology that they think that most black dahlias raise their anthocyanin levels by blocking an enzyme in the pathway that makes flavones, another molecule that has the same precursor as anthocyanins. If scientists could figure out that trick, they might be able to engineer dahlias to make more black varieties.
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