SSS 2012-06-28
时间：2018-12-24 作者：英语课 分类：Scientific American(六)月
英语课
For many people summer equals tomatoes. That’s when folks can get their hands on gorgeous heirloom and traditional varieties, full of tomatoey flavor. Such tomatoes provide a stark 1 contrast to year-round supermarket ones, famous for tasting like, well, nothing. They’ve been bred for uniform color and ripening—not for taste.
Now scientists have determined 2 just what’s genetically 3 missing in store-bought tomatoes.
The researchers honed in on two transcription factors. Transcription factors are proteins that control the expression of genes 4—in this case they’re necessary for the production of chloroplasts, which allow sunlight to generate sugars and other compounds.
Darker green tomato fruit expresses genes that make possible increased photosynthesis—and so the fruits are able to produce more sugars for a tastier end product. But typical supermarket tomatoes, which had been bred to all turn light green at the same time, were also accidentally bred with reduced chloroplasts—and thus reduced sugar content. The research was published in the journal Science.
The scientists say understanding the genes involved in better flavor could enable growers to offer tastier supermarket varieties. So that when you say tomato, I can say to-ma-to or to-mah-to instead of bleech.
Thanks for the minute for Scientific American 60 second Science, I am Cynthia Graber.
1 stark
adj.荒凉的；严酷的；完全的；adv.完全地
- The young man is faced with a stark choice.这位年轻人面临严峻的抉择。
- He gave a stark denial to the rumor.他对谣言加以完全的否认。
2 determined
adj.坚定的；有决心的
- I have determined on going to Tibet after graduation.我已决定毕业后去西藏。
- He determined to view the rooms behind the office.他决定查看一下办公室后面的房间。
3 genetically
adv.遗传上
- All the bees in the colony are genetically related. 同一群体的蜜蜂都有亲缘关系。
- Genetically modified foods have already arrived on American dinner tables. 经基因改造加工过的食物已端上了美国人的餐桌。 来自英汉非文学 - 生命科学 - 基因与食物