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LinkedInPosts Tagged: genome
New Diagnostic Tool Helps Solve Plant Problems
UC IPM has created a diagnostic tool to help easily diagnose pest problems in your garden or...
Nothing common about these beans
As you're ladling up country-style pinto beans for your weekend barbecue or fixing a cold three-bean salad from kidney, string and navy beans for a summer picnic, pause to remember what a long and storied history these “common bean” varieties share and the new scientific advances that promise to boost their productivity worldwide.
This week, a new genome sequencing is being reported for the common bean, which ranks as the world's 10th most widely grown food crop and includes the culinary favorites above, whose varieties together comprise a $1.2 billion crop in the United States.
“The availability of this new whole-genome sequence for beans is already paying off,” said Paul Gepts, professor in the Department of Plant Sciences at UC Davis and co-author of the new sequencing study.
Gepts, who leads the bean-breeding program at UC Davis, notes that the new sequence is being used to confirm many of the findings made earlier by his UC Davis research group, including identification of the common bean's two points of origin and domestication.
Sequencing and bean ancestry
The common bean is thought to have originated in Mexico more than 100,000 years ago, but -- as the Gepts group earlier discovered – was domesticated separately at two different geographic locations in Mesoamerica and the southern Andes.
“This finding makes the common bean an unusually interesting experimental system because the domestication process has been replicated in this crop,” Gepts said.
The sequencing team compared gene sequences from pooled populations of plants representing these two regions and found that only a small fraction of the genes are shared between common bean species from the two locations. This supports the earlier finding that the common bean was domesticated in two separate events -- one at each location -- but distinct genes were involved in each event.
The new whole-genome sequencing is also helping to identify genetic “markers” that can be used to speed up breeding of new and more productive bean varieties in the United States, East Africa and elsewhere, Gepts said.
The nitrogen connection
All of bean varieties that belong to the “common bean” group share with the closely related soybean the highly valued ability to form symbiotic relationships with “nitrogen-fixing” bacteria in the soil.
The plants and the bacteria work together to convert nitrogen in the atmosphere into ammonia – which includes nitrogen in a form that enriches the soil and feeds crops. Nitrogen-fixing crop plants can actually reduce or eliminate the need for farmers to apply expensive fertilizers.
One goal of the new sequencing project was to better understand the genetic basis for how such symbiotic relationships between nitrogen-fixing plants and bacteria are formed and sustained, with an eye toward increasing fuel- and food-crop productivity.
The research team successfully identified a handful of genes involved with moving nitrogen around, which could be helpful to farmers who intercrop beans with other crops that don't fix nitrogen.
Findings from this study are reported this week online in the journal Nature Genetics. The sequencing project was led by researchers at the University of Georgia, U.S. Department of Energy Joint Genome Institute, Hudson Alpha Institute for Biotechnology and North Dakota State University.
Foodborne illnesses and the 100K Genome Project
Bart Weimer, professor in the UC Davis School of Veterinary Medicine, serves as director of the 100K Genome Project and co-director of the recently established BGI@UC Davis facility, where the sequencing will be done. Other collaborators include the U.S. Centers for Disease Control and Prevention and the U.S. Department of Agriculture.
The new five-year microbial pathogen project focuses on making the food supply safer for consumers. The group will build a free, public database including sequence information for each pathogen's genome — the complete collection of its hereditary information. The database will contain the genomes of important foodborne pathogens including Salmonella, Listeria, and E. coli, as well as the most common foodborne and waterborne viruses that sicken people and animals.
The project will provide a roadmap for developing tests to identify pathogens and help trace their origins more quickly. The new genome database also will enable scientists to make discoveries that can be used to develop new methods for controlling disease-causing bacteria in the food chain.
"This landmark project will revolutionize our basic understanding of these disease-causing microorganisms," said Harris Lewin, vice chancellor for research at UC Davis.
The sequencing project is critically important for tackling the continuing outbreaks of often-deadly foodborne diseases around the world. In the United States alone, foodborne diseases annually sicken 48 million people and kill 3,000, according to the CDC.
"The lack of information about food-related bacterial genomes is hindering the research community's ability to improve the safety and security of the world food supply," Weimer said. "The data provided by the 100K Genome Project will make diagnostic tests quicker, more reliable, more accurate and more cost-effective."
"We see this project as a way to improve quality of life for a great many people, while minimizing a major business risk for food producers and distributors," said Mike McMullen, president of Agilent’s Chemical Analysis Group.
A consumer-focused article about the project is available on the FDA website.
(This article was condensed from a UC Davis news release. Read the full press release and watch a video of Bart Weimer giving an overview of the project.)
Honey Bees and Malaria
You don't usually see "honey bees" and "malaria" in the same sentence. That won't be the case,...
A honey bee heads toward a tower of jewels (Echium wildpretii). (Photo by Kathy Keatley Garvey)
The malaria mosquito, Anopheles gambiae. (Photo by Anthony Cornel, UC Davis)
First draft of genome of wheat stripe rust published in Public Library of Science
The stripe rust disease of wheat caused by the highly specialized fungal pathogen Puccinia striiformis f. sp. tritici has been responsible for recurrent episodes of large yield losses and economic hardship among grain-based agricultural societies for centuries. Current epidemics of new aggressive races of Puccinia striiformis that appear after the year 2000 pose significant threats to food security worldwide and, in particular, in developing countries in Africa and central Asia. In spite of its economic importance, the Puccinia striiformis genomic sequence is not currently available.
In order to get access to the genes of this pathogen, a team of researchers – including Professor Jorge Dubcovsky (also a Howard Hughes Medical Institute researcher) and Professor Richard Michelmore, director of the UC Davis Genome Center, Project Scientist Dario Cantu and Manjula Govindarajulu, a postdoctoral researcher in Michelmore’s lab - used cutting-edge technology to rapidly sequence a large portion of the genome of one of the Puccinia striiformis more virulent and aggressive races. They assembled long stretches of the Puccinia striiformis genome and established a preliminary automatic annotation of its genes, with a special focus on those likely to be involved in pathogenicity.
This information is available in the open-access article published by the Public Library of Science and made publically available through the National Center of Biotechnology information and a dedicated web page.
“This shotgun sequence assembly does not substitute for the need of a complete and annotated Puccinia striiformis genome, but it provides immediate access to a large proportion, more than about 88 percent, of the genes from this pathogen,” said Cantu. “This public information has the potential to accelerate a new wave of studies to determine the mechanisms used by this pathogen to infect wheat, and hopefully to reduce current yield loses caused by this pathogen.”
These researchers, in collaboration with others at the John Innes Institute in the UK, are currently sequencing new and old races of Puccinia striiformis to investigate their differences in virulence and aggressiveness.
This project was supported in part by funds provided through a grant from the Bill & Melinda Gates Foundation, and the National Research Initiative Competitive Grants from the USDA National Institute of Food and Agriculture.
