Gene Developed Through Conventional Breeding To Improve Cowpea Aphid Resistance

The cowpea or black-eyed pea, as it is more commonly known, is a New Year’s tradition for good luck. But disease and particularly aphids, which can wreck a crop within a few a days, are especially bad luck for the cowpea, according to scientists. (Credit: Texas AgriLife Research photo by Blair Fannin)


The cowpea or black-eyed pea, as it is more commonly known, is a New Year's tradition for good luck. But disease and particularly aphids, which can wreck a crop within a few a days, are especially bad luck for the cowpea, according to scientists. Several new lines of cowpeas with genes that are aphid-resistant and less susceptible to disease are currently being tested by researchers with Texas AgriLife and other Texas A&M System entities.

"The cowpea has been an important and popular food crop throughout the southern U.S.," said Dr. B.B. Singh, a visiting professor in the soil and crop sciences department at Texas A&M. "It's commonly known as the southern pea, field pea, crowder pea, black-eyed pea, purple-hull pea and pinkeye pea widely grown in the southern states."

The researchers' discoveries could yield big rewards. An international food crop, the cowpea was most popular in the southern U.S. from the 1930s through '70s, and East Texas remains a large U.S. cowpea-producing region.

And during times of drought, the cowpea can be a viable alternative forage crop for livestock producers, due to its ability to fix nitrogen, tolerate drought and provide high-quality fodder, Singh said. It is a high-quality forage for cattle producers, with a protein content as high as 28 percent in seeds and 17 percent to 20 percent in the fodder after harvesting the seeds.

However, the aphid is currently the biggest threat to cowpea producers, Singh said.

"(Aphids) like dry weather," explained Singh, who has spent his entire career studying the cowpea. "Immediately after infestation, they start sucking the juice (sap) from cowpea leaves, stem, flowers and pods of the plants reducing their growth and development and causing severe reduction in yield. They also spread viruses. Aphids can ruin a crop within a few days."

Singh, came to the department as a visiting professor following his retirement two years ago from the International Institute of Tropical Agriculture, considered the epicenter of cowpea research.

At Texas A&M, Singh is working with colleagues Dr. J. Creighton Miller, D.C. Sheuring and Dr. Bill Payne using field trials in College Station to find a solution to the aphid problem.

Singh has brought more than 35 lines of cowpeas with drought and aphid tolerance, as well as resistance to other diseases and higher yield potential, to College Station. His work there has involved using conventional breeding methods to cross those lines with six Texas and California varieties in greenhouse and field settings.

"Many of the IITA lines are resistant to aphid, bacterial blight, powdery mildew and drought, whereas most of the U.S. lines are susceptible," Singh said. "A number of crosses were made to transfer the resistance to aphids and drought from the IITA lines to the U.S. lines."

In mid July, an aphid infestation hit the College Station trials, putting the new varieties to the test.

"It's been fairly severe, permitting selection of resistant plants from the F2 and F3 populations," he said. "Due to drought and aphids this crop season, all of the susceptible cowpea varieties and segregating plants have been completely damaged, showing 80 percent to 100 percent yield loss, while the aphid resistant varieties and segregating plants are completely healthy with normal yield. The resistance is simply inherited, very effective and highly stable across environments."

From the segregating populations, the resistant plants with diverse maturity dates, plant type, growth habits and seed types have been selected to meet the need for grain type, fodder-type and pasture-type cowpea varieties, he said.

"These are being advanced to achieve uniformity and multi-location testing for stability of resistance and yield potential," Singh added. The new aphid-resistant, high-yielding varieties could be available to farmers as early as 2011, Singh said.

"The cowpea has worldwide importance as a crop for both human and animal nutrition," said Payne of Texas AgriLife Research, assistant director for research at the Norman Borlaug Institute for International Agriculture. "Introducing improved disease- and drought-resistant and higher-yield varieties could not only have tremendous potential for Texas and U.S. agriculture, it could help provide poor and developing countries with an important alternative source of nutrition."

According to the International Institute of Tropical Agriculture in Africa, the cowpea is an important food crop in many African, Asian and South American countries, especially as an alternative source of protein where people cannot afford meat and fish. The crop typically is grown by subsistence farmers with limited agricultural resources, who use it to feed livestock or sell for additional income.

The international Food and Agriculture Organization estimates more than 7.5 million tons of cowpeas are produced annually worldwide, with sub-Saharan Africa responsible for about 70 percent of that amount.

"We are already involved in international research projects in Africa relating to cowpeas," Payne noted. "It's exciting to think where these new activities in College Station and the research already under way in Africa may lead."

-------------------------------------------------------------------------------------------------
Texas A&M AgriLife (2009, October 26). Gene Developed Through Conventional Breeding To Improve Cowpea Aphid Resistance.

Loss Of Tumor-suppressor And DNA-maintenance Proteins Causes Tissue Demise

Hair follicle regeneration by undamaged cells (red, left panel) is delayed by the presence of damaged cells (arrows, right panel). Damaged cells are maintained because of the absence of p53 (right panel). (Credit: Yaroslava Ruzankina, PhD; David Schoppy; Eric Brown, PhD, University of Pennsylvania School of Medicine)


A study published in the October issue of Nature Genetics demonstrates that loss of the tumor-suppressor protein p53, coupled with elimination of the DNA-maintenance protein ATR, severely disrupts tissue maintenance in mice. As a result, tissues deteriorate rapidly, which is generally fatal in these animals. In addition, the study provides supportive evidence for the use of inhibitors of ATR in cancer therapy.

Essentially, says senior author Eric Brown, PhD, Assistant Professor of Cancer Biology at the University of Pennsylvania School of Medicine, the findings highlight the fact that day-to-day maintenance required to keep proliferative tissues like skin and intestines functional is about more than just regeneration, a stem cell-based process that forms the basis of tissue renewal. It's also about housekeeping, the clearing away of damaged cells.

Whereas loss of ATR causes DNA damage, the job of p53 is to monitor cells for such damage and either stimulate the early demise of such cells or prevent their replication, the housekeeping part of the equation. The findings indicate that as messy as things can become in the absence of a DNA maintenance protein like ATR, failing to remove resulting damaged cells by also deleting p53, is worse. "Because the persistence of damaged cells in the absence of p53 prevents appropriate tissue renewal, these and other studies have underscored the importance not only of maintaining competent stem cells, but also of eliminating what gets in the way of regeneration," explains Brown.

"An analogy to our findings is what happens to trees during the changing seasons," says Brown. "In springtime, leaves are new and undamaged. But as the summer wears on, the effects of various influences - insects, drought, and disease - cause them to lose the pristine qualities they once had. However, the subsequent fall of these leaves presents a unique opportunity for regeneration later on, a chance to rejuvenate from anew without pre-existing obstacles. Similarly, by suppressing the accumulation of damaged cells in tissues, p53 permits more efficient tissue renewal when ATR is deleted."

Cells without ATR that remain uncleared may be block tissue regeneration either by effectively refusing to relinquish space to undamaged cells, or by secreting signals that halt regeneration until they have been removed.

These results came as something of a surprise, says Brown. Previous studies pairing DNA-repair mutations with p53 mutations always led to a partial rescue of the DNA repair mutation "We think this happens because p53 loss helps cells with just a little DNA damage to continue to contribute to the tissue" says Brown. So at a minimum, the team expected nothing to happen.

"But we got the opposite result: Absence of p53 did not rescue the tissue degeneration caused by ATR loss, it made it much worse. This result suggested that allowing mutant cells without ATR to persist is more harmful to tissues than eliminating them in the first place." Brown speculates that could be because the ATR mutation produces much more damage than most other DNA-repair defects.

According to Brown, their findings and those of other laboratories also reinforce the potential of a new therapeutic for cancer. That's because, among their other discoveries, the team noticed that cells missing both ATR and p53 have more DNA damage than those missing either gene alone. As a large fraction of human cancers have p53 mutations, he says, "p53-deficient tumors might be especially susceptible to ATR inhibition." Indeed, clinical trials already are underway involving an ATR partner protein called Chk1. "Our study provides supportive evidence for the potential use of ATR/Chk1 inhibitors in cancer therapy," says Brown

The report was supported by the National Institute on Aging and the Abramson Family Cancer Research Institute.

Laboratory members Yaroslava Ruzankina, PhD and MD/PhD student David Schoppy are lead authors of this study. Amma Asare, Carolyn Clark, and Robert Vonderheide, all from Penn, are co-authors.

-----------------------------------------------------------------------------------------------

DNA-maintenance Proteins Causes Tissue Demise." ScienceDaily 21 October 2009. 27 October 2009 /releases/2009/10/091015171453.htm>.

Definition of Biotechnology

What is biotechnology?

Biotechnology are defined as the controlled and deliberate manipulation of biological systems, whether it is the whole living cells or part of the cell components, for the efficient manufacture or processing of useful products. The fact that living organisms’ biological capabilities to evolve in such a vast scale means that we are able to obtain a broad mixture of substances by selecting the suitable organisms. Many of the substances are useful to people as food, fuel and medicines. Over the past three decades, biologists have gradually applied the methods of physics, chemistry and mathematics in order to gain precise knowledge, at the molecular level. Biologists are able to identified and learn how living cells make these substances. By combining this newly-gained knowledge with the methods of engineering and science, what has emerged is the concept of biotechnology which embraces all of the above-mentioned disciplines. One of the examples of biotechnology is the process of fermentation. Fermentation is a process using microbes to produce wine, cheese, beer, bread and yogurt.


How do Biotechnology Influencing the Industry

In actual fact, biotechnology has existed long before the term “biotechnology” came into use. It has changed the traditional industries such as food processing and fermentation. Biotechnology plays a major part in the development of new technology for industrial production of hormones, antibiotics and others chemicals, food and energy sources and processing of waste materials. Thus, it is important that this industry is staffed by trained bio technologists who are equipped with comprehensive biological knowledge and thorough practical training in engineering methods. Some of the major industries involved in biotechnology are agriculture, crop production and pharmaceutical products.