Tech Tuesday

Genome Work Continues, and a Different Kind of Breakthrough

Scientists sequence genes of two pathogens and a plant that helps with evolutionary understanding, and the American Society of Agronomy has a first.

This week the in-box has news of two major advances in genome work by researchers. The work of sequencing the genes of different kinds of plants unlocks a lot of secrets researchers can use going forward to do everything from control a pathogen, to have a better understanding of the inner workings of different plant types.

First up is news today that USDA's Agricultural Research Service, along with an international team of researchers, has sequenced the genomes of two fungal pathogens - one threatening global wheat supplies and the other that limits production of a tree crop that could be a top source of biofuel.

The two pathogens - wheat stem rust and poplar leaf rust - were sequenced in a collaborative effort that included USDA-ARS, the U.S. Department of Energy Joint Genome Institute, the National Science Foundation, the Broad Institute of Harvard and the Massachusetts Institute of technology, the University of Minnesota and the French National Institute for Agricultural Research. The results of the six-year project were published in the Proceedings of the National Academy of Sciences.

Wheat stem rust causes major epidemics in barley and wheat worldwide. A strain known as Ug99 has spread across Africa and into Central Asia, and has been able to overcome most of the stem-rust resistant wheat varieties developed over the past 50 years.

Poplar stem rust can cause significant losses to poplar tree plantations. This is an important crop for the wood industry and is increasingly important as a biofuel source because of its rapid and significant production capacity.

This study is the first genome-wide characterization of any rust fungus, which includes more than 6,000 species. Rust fungi depend on living tissue of their hosts to survive. The pathogens secrete proteins that enable them to block the host plant's defenses and steal nutrients. The research uncovered evidence that both pathogens have large numbers of such "effector" proteins, an indication that they likely co-evolved with their host plants, according to researchers.

Because they need a plant host to survive, lab work has been a challenge. But genetic sequencing opens a window into new ways to control both pathogens.

A New Kind of Genome

Purdue Researchers have published the first sequence for a non-seed vascular plant - Selaginella moellendorffii (spikemoss) - which should give scientists a much better understanding of how all kinds of plants evolved over the past 500 million years. A team of 100 scientists from 11 countries worked to sequence the spikemoss genome, which is a lycophyte. This is the oldest living vascular plant type, which sheds spores to reproduce (not seeds) and have a singular vascular vein through their leaves.

The spikemoss has been on earth for at least 200 million years and understanding its inner workings will help expand knowledge scientists have about all types of plants. For example, the spikemoss is missing genes known in other plants to control flowering, phase changes from juvenile plants to adults and other functions. That means the plant performs those functions in unknown ways.

The new genome will help scientists understand how its genes give the plant some of its characteristics. And the genome will show how this class of plants is evolutionarily connect to other plants. This expanded understanding will help plant breeders and other scientists in a number of ways. For example, they will learn which genes present only in flowering plants that may function for development of fruits and seeds, which are important to agriculture.

A New Sheriff in Town

The American Society of Agronomy has a new president elect and Plant Science Professor Sharon Clay is breaking plenty of new ground in the role. She is the first women ever chose as president-elect for the organization. Her term begins in January 2012 and she will serve as president in 2013.

The South Dakota State University professor was elected by society members for the position in balloting earlier this year. Clay is also the first SDSU professor elected to the post. Clay has long been active in ASA serving on a range of committees. And she was selected as a Fellow of the American Society of Agronomy in 2009, the highest professional recognition given by the society. Congrats Dr. Clay.

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