March 21: Symphony of soil signals protects wheat health

By Seth Truscott, College of Agricultural, Human & Natural Resource Sciences

PULLMAN, Wash. – High-tech equipment that will help scientists improve wheat health will be introduced to the public at 9 a.m. Tuesday, March 21, at the Biotechnology-Life Sciences Building (BLS) room 402 at Washington State University.

Senior scientist Robert Bonsall, right, and research leader David Weller use the new Synapt G2-Si HD mass spectrometer to understand the intricate web of chemical signals that drive the health and development of wheat (Photo by Seth Truscott, WSU CAHNRS)

The Plant Metabolomics Celebration will include short talks, lunchtime discussions and a lab tour. To attend, please RSVP to David Weller at or 509-335-6210. View a complete agenda at

The advanced mass spectrometry system in the Wheat Health Genetics and Quality Research Unit detects and identifies molecules based on their mass. This will allow WSU’s team of university and federal scientists for the first time to study the millions of tiny compounds involved in the relationship between wheat roots, soil and microbes.

Their discoveries could help farmers raise crops that are resistant to devastating root diseases and environmental stresses.

Getting to the root of natural antibiotics

“In wheat, most of the action goes on below ground, out of sight,” said David Weller, plant pathologist and head of the U.S. Department of Agriculture-Agricultural Research Service’s Pullman wheat research team. “This new mass spectrometer helps us understand the chemical symphony going on in the roots.”

His team sees promise in the natural antibiotics found in the symbiotic zone of roots, soil and microbes, known as the rhizosphere.

“In the soil, organisms use chemical signals to communicate,” said Robert Bonsall, a senior scientist at WSU who has studied the rhizosphere for nearly 25 years. “When a plant is attacked by a disease, it sends out an SOS. Bacteria that produce antibiotics come to the plant’s rescue.”

To understand this exchange, Bonsall and Weller look for chemical clues called biomarkers.

“All of these compounds – some from the plant, some produced by microorganisms – dramatically affect the health of the roots and the productivity of the plant,” said Weller. “It’s a beautifully coordinated symphony of chemical signals protecting the plant and helping its growth. Hundreds of thousands of organisms contribute to it.”

Decades of partnership with industry

The $700,000 liquid chromatography-mass spectrometry (LC-MS) system, built by Waters Corp. of Milford, Mass., replaces the WSU wheat research unit’s aging instrument. The Synapt G2-Si HD Mass Spectrometer and ACQUITY Ultra Performance Liquid Chromatography system was purchased in the fall following a successful test that assessed natural antibiotic levels in soils and on wheat roots from Lind, Wash.

The WSU Pullman unit’s work with Waters engineers and experts goes back decades and has been critical to Bonsall’s and Weller’s studies, they said.

“This is the first time that ion mobility – a feature of the Synapt system that distinguishes molecules based on their size, shape and ionic charge – has been applied to this area of biomarker research,” said Ken Rosnack, principal business development manager at Waters Corp. “We’re very excited that WSU will use this technology to probe the soil metabolome and advance our understanding of rhizosphere microbiology and plant pathology.”


News media contacts:
David Weller, USDA-ARS, 509-335-6210, cell 509-595-1498,
Robert Bonsall, WSU plant pathology, 509-335-6496,