VOA慢速英语2012 Agriculture Report - Steps Toward Drought-Resistant Crops, 'Designer' Rice

Agriculture Report - Steps Toward Drought-Resistant Crops, 'Designer' Rice

This is the VOA Special English Agriculture Report.
A discovery in a laboratory could help lead to new generation of drought-resistant crops. Drought conditions cause plants to produce a stress hormone¹ called abscisic acid. This chemical activates³ a set of protein molecules⁴ called receptors. These receptors then activate² a series of changes to help the plant survive.
The natural reaction of the receptors is to close so-called guard cells on and inside the leaves. That closure decreases water loss and stops the plant from growing to save water during a drought.
Researchers say they have discovered a way to "supercharge," or increase, this reaction. Sean Cutler at the University of California, Riverside, led the team. The scientists engineered abscisic acid receptors that can be turned on at will and stay on. They tested hundreds of versions of engineered receptor genes⁵ until they found ones that worked right together.
The team worked with Arabidopsis, a plant often used in experiments. The results recently appeared in the Proceedings⁶ of the National Academy of Sciences.
Professor Cutler says testing the new receptors in the field may take several years. He also points out that drought is not the only cause of plant stress.
SEAN CUTLER: "If a plant grows in the deserts normally, like a cactus⁷, what would be stressful for a crop plant is not stressful for a cactus because it has evolved to live in that ecological⁸ niche⁹ where the water is very rare. So it would really mean, you know, any significant deviation¹⁰ from the normal or ideal growth conditions for an organism."
In another development, scientists have produced a new system for analyzing¹¹ genetic¹² markers in rice plants. A genetic marker is a DNA¹³ sequence with a known location. It can help scientists identify nearby genes linked to individual qualities, or traits.
Anna McClung and Georgia Eizenga are genetic scientists with the United States Department of Agriculture. Their new system will let researchers genetically¹⁴ "fingerprint¹⁵" rice varieties and gain a better understanding of the markers.
Until now, breeders have been limited to using perhaps two hundred markers. But modern technology lets scientists identify differences throughout the plant's genome, its genetic map. Ms. McClung says that means the ability to identify new genes that control biological pathways.
ANNA McCLUNG: "You know, biological pathways in the plant that may control yield, disease resistance, nutritional¹⁶ quality ... "
The finding could make it easier in the future for farmers to grow "designer rice," rice bred to meet their specific needs.
And that's the VOA Special English Agriculture Report, written by Jerilyn Watson. I'm Karen Leggett.

1 hormone   

n.荷尔蒙，激素，内分泌

参考例句：

• Hormone implants are used as growth boosters.激素植入物被用作生长辅助剂。
• This hormone interacts closely with other hormones in the body.这种荷尔蒙与体內其他荷尔蒙紧密地相互作用。

2 activate   

vt.使活动起来，使开始起作用

参考例句：

• We must activate the youth to study.我们要激励青年去学习。
• These push buttons can activate the elevator.这些按钮能启动电梯。

3 activates   

使活动，起动，触发( activate的第三人称单数 )

参考例句：

• Activates the window and displays it in its current size and position. 激活窗口，保持当前的大小及位置不变。
• Pulling out the alarm switch activates alarm and pushing it deactivates it. 闹钟的开和关是通过拔出和按入闹铃开关实现的。

4 molecules   

分子( molecule的名词复数 )

参考例句：

• The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
• Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里，大分子裂变为小分子。

5 genes   

n.基因( gene的名词复数 )

参考例句：

• You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因，所以能够活得很长。 来自《简明英汉词典》
• Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪

6 proceedings   

n.进程，过程，议程；诉讼(程序)；公报

参考例句：

• He was released on bail pending committal proceedings. 他交保获释正在候审。
• to initiate legal proceedings against sb 对某人提起诉讼

7 cactus   

n.仙人掌

参考例句：

• It was the first year that the cactus had produced flowers.这是这棵仙人掌第一年开花。
• The giant cactus is the vegetable skycraper.高大的仙人掌是植物界巨人。

8 ecological   

adj.生态的，生态学的

参考例句：

• The region has been declared an ecological disaster zone.这个地区已经宣布为生态灾难区。
• Each animal has its ecological niche.每种动物都有自己的生态位.

9 niche   

n.壁龛；合适的职务(环境、位置等)

参考例句：

• Madeleine placed it carefully in the rocky niche. 玛德琳小心翼翼地把它放在岩石壁龛里。
• The really talented among women would always make their own niche.妇女中真正有才能的人总是各得其所。

10 deviation   

n.背离，偏离；偏差，偏向；离题

参考例句：

• Deviation from this rule are very rare.很少有违反这条规则的。
• Any deviation from the party's faith is seen as betrayal.任何对党的信仰的偏离被视作背叛。

11 analyzing   

v.分析；分析( analyze的现在分词 )；分解；解释；对…进行心理分析n.分析

参考例句：

• Analyzing the date of some socialist countries presents even greater problem s. 分析某些社会主义国家的统计数据，暴露出的问题甚至更大。 来自辞典例句
• He undoubtedly was not far off the mark in analyzing its predictions. 当然，他对其预测所作的分析倒也八九不离十。 来自辞典例句

12 genetic   

adj.遗传的，遗传学的

参考例句：

• It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
• Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。

13 DNA   

(缩)deoxyribonucleic acid 脱氧核糖核酸

参考例句：

• DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
• Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。

14 genetically   

adv.遗传上

参考例句：

• 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

15 fingerprint   

n.指纹；vt.取...的指纹

参考例句：

• The fingerprint expert was asked to testify at the trial.指纹专家应邀出庭作证。
• The court heard evidence from a fingerprint expert.法院听取了指纹专家的证词。

16 nutritional   

adj.营养的，滋养的

参考例句：

• A diet lacking in nutritional value will not keep a person healthy.缺乏营养价值的饮食不能维持人的健康。
• The labels on food products give a lot of information about their nutritional content.食品上的标签提供很多关于营养成分的信息。