Featured Research

from universities, journals, and other organizations

Scientists Identify Gene For Resistance To Parasitic 'Witchweed'

Date:
August 31, 2009
Source:
University of Virginia
Summary:
Scientists have identified a gene in cowpea (black-eyed pea) that confers resistance to attack from witchweed, a parasitic plant. This discovery will help researchers better understand how some plants can resist Striga, while others, such as corn and sorghum, are susceptible.

Black-eyed pea.
Credit: iStockphoto

The parasitic flowering plant Striga, or "witchweed," attacks the roots of host plants, draining needed water and nutrients and leaving them unable to grow and produce any grains. Witchweed is endemic throughout sub-Saharan Africa, causing crop losses that surpass hundreds of millions of dollars annually and exacerbating food shortages in the region.

Among the crops heavily parasitized by witchweed is black-eyed pea, known in Africa as "cowpea" or "niebe" in Francophone countries.

About 80 percent of the world's cowpea crop is grown in sub-Saharan Africa, mostly by subsistence farmers who lack the resources to purchase expensive herbicides and fertilizers. In this region, cowpea is the primary protein source for millions of people, who consume the entire plant – the pea for soups, stews and breads, the leaves as fresh greens, the stems as hay and fodder for cattle.

As the use of cowpea expanded over time, so did the prevalence of Striga gesnerioides, the type of witchweed adapted to parasitize it. Today, witchweed is so virulent that farmers in this semi-arid region must relocate their cowpea crop to new soil every few years.

Now, scientists at the University of Virginia have identified a gene in cowpea that confers resistance to witchweed attack. This discovery will help researchers better understand how some plants can resist Striga, while others, such as corn and sorghum, are susceptible.

The findings are presented in the Aug. 28 issue of the journal Science.

"Discovery of this resistance gene is not only important for improving cowpea, but may help us develop strategies for improving resistance to Striga in other affected crops," said Michael P.Timko, the U.Va. biology professor who led the study.

Currently there are no natural sources of Striga resistance in corn or sorghum, both of which are major cereal grains in the African diet.

"Making plants durably resistant to Striga could have a significant impact on food security for Africa," Timko said.

In recent years, he and other scientists have sequenced the cowpea genome and are using this information to develop cowpea plants with multiple improved agronomic traits.

"It is now possible for us to identify all possible genes for Striga resistance in cowpeas, as well as resistance to other cowpea pathogens," Timko said. "We may even eventually breed a more drought-resistant plant and varieties that have higher levels and a better balance of nutrients. We've reached a point where we can manipulate this plant for the good of millions of people."

Timko's approach is to improve the performance of plants by identifying genes that control key characteristics, and then using selective breeding to emphasize those traits.

While he is finding success breeding parasite-resistant hybrids, there are at least seven different races of Striga, each capable of adapting to changing varieties of cowpeas.

"We are trying to create a plant that is resistant across the board," he said. "Striga is hyper-virulent. This is warfare between the cowpea plant and its parasite, and we keep trying to stay ahead of the enemy."


Story Source:

The above story is based on materials provided by University of Virginia. Note: Materials may be edited for content and length.


Cite This Page:

University of Virginia. "Scientists Identify Gene For Resistance To Parasitic 'Witchweed'." ScienceDaily. ScienceDaily, 31 August 2009. <www.sciencedaily.com/releases/2009/08/090827141351.htm>.
University of Virginia. (2009, August 31). Scientists Identify Gene For Resistance To Parasitic 'Witchweed'. ScienceDaily. Retrieved July 29, 2014 from www.sciencedaily.com/releases/2009/08/090827141351.htm
University of Virginia. "Scientists Identify Gene For Resistance To Parasitic 'Witchweed'." ScienceDaily. www.sciencedaily.com/releases/2009/08/090827141351.htm (accessed July 29, 2014).

Share This




More Plants & Animals News

Tuesday, July 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deadly Ebola Virus Threatens West Africa

Deadly Ebola Virus Threatens West Africa

AP (July 28, 2014) West African nations and international health organizations are working to contain the largest Ebola outbreak in history. It's one of the deadliest diseases known to man, but the CDC says it's unlikely to spread in the U.S. (July 28) Video provided by AP
Powered by NewsLook.com
Traditional African Dishes Teach Healthy Eating

Traditional African Dishes Teach Healthy Eating

AP (July 28, 2014) Classes are being offered nationwide to encourage African Americans to learn about cooking fresh foods based on traditional African cuisine. The program is trying to combat obesity, heart disease and other ailments often linked to diet. (July 28) Video provided by AP
Powered by NewsLook.com
Asteroid's Timing Was 'Colossal Bad Luck' For The Dinosaurs

Asteroid's Timing Was 'Colossal Bad Luck' For The Dinosaurs

Newsy (July 28, 2014) The asteroid that killed the dinosaurs struck at the worst time for them. A new study says that if it hit earlier or later, they might've survived. Video provided by Newsy
Powered by NewsLook.com
Raw: Sea Turtle Hatchlings Emerge from Nest

Raw: Sea Turtle Hatchlings Emerge from Nest

AP (July 27, 2014) A live-streaming webcam catches loggerhead sea turtle hatchlings emerging from a nest in the Florida Keys. (July 27) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins