Ozone: Invisible Enemy of Agriculture

A&LEverything has its place. Take water for example. In the sink, good. Under the sink, bad. The same goes for ozone (O3). Fifteen miles up in the stratosphere, more than just good: Essential for protecting life from DNA-damaging ultraviolet radiation. But down here in the troposphere, not so good. Ozone pollution may not be as charismatic as a plague of locusts or a hailstorm, but it’s responsible for nearly a billion dollars in reduced US corn productivity annually, not to mention respiratory distress for the residents of Houston and Mexico City.

And ozone is one diabolically tricky pollutant.  Not only is its threat invisible and wildly episodic -- dangerously high one day to non-existent the next, depending on wind and weather -- but its targets within susceptible plants are diverse and complex.  The challenge of genetically preparing corn to tolerate this elusive threat will be addressed by a five-year, $5.7 million NSF-sponsored project led by Plant Biology faculty Lisa Ainsworth and Andrew Leakey, entitled “Genetic and Genomic Approaches to Understand and Improve Maize Responses to Ozone”.

Lisa and Andrew’s approach will be to document with unprecedented breadth and precision the anatomical, physiological and molecular targets of ozone in the corn plant, surveying existing corn genetic resources for variation in response.  Once such targets are identified, genetically structured corn populations will be exposed to ozone and quantitatively assessed in order to map the gene loci responsible for tolerance and susceptibility.  These results will provide corn (and ultimately other crop) breeders with specific tools needed to develop lines whose ozone defenses incur as little cost to productivity as possible.

CornO3StudyBut how can anyone possibly study the effects of a pollutant as fickle as ozone?  Even Mexico City has its clear days.  The answer lies not thousands, but just a couple miles south of the U of I campus: SoyFACE.  At this open-field facility, soybean, maize and other plant species have been grown and studied under controlled, elevated ozone and/or carbon dioxide levels for over a decade.  Lisa and Andrew have been deeply involved in experiments at SoyFACE since its inception, and the new NSF project is an exciting, timely extension of that ongoing work.

The grant is one of NSF’s “Mid-Career Investigator Awards in Plant Genome Research”, intended to expand and enhance the research toolkits of recipients like Lisa and Andrew.  Accordingly, the project complements their proven expertise in plant physiology with state-of-the-art genetics, genomics and bioinformatics contributed by co-principal investigators Pat Brown (Ilinois Crop Science) and Lauren McIntyre (U of Florida), maize geneticist and statistical geneticist, respectively.

The beneficiaries of the research will be as diverse as ozone’s cellular targets.  Not only will the project serve farmers, but also budding young biologists as well.  Andrew was the charter faculty advisor for Plant Biology graduate students’ acclaimed PlantsiView outreach program at Urbana Middle School.  He will continue in that role under the auspices of NSF in the new corn-ozone project.  In addition, Andrew and Lisa plan to host forty local middle and high school girls each summer, to focus their eyes and attention on pollen, a tissue both especially susceptible to ozone and microscopically accessible to observation by curious young eyes.  Studies suggest that middle school is a critical make-or-break time for students’ experience with science, the best time "to show them science in a world-class research university ... to show the real-world value of doing this kind of work," says Andy.

Thanks to the News-Gazette and Daily Illini for images