As nighttime temperatures rise faster than daytime temperatures, agricultural production faces a new challenge being explored by NC State University’s Dr. Colleen Doherty. Doherty, an assistant professor of Molecular and Structural Biochemistry, studies how plants perceive and respond to changing temperatures and other stressors that keep them from attaining optimal yields.
Doherty discussed her research with others from industry and academia during the 28th Annual Plant Molecular Biology Consortium at Wrightsville Beach Sept. 12-14, 2014. Students, postdoctoral researchers and faculty members from NC State, the University of North Carolina at Chapel Hill, Duke University and Wake Forest University joined staff from local agricultural biotechnology companies BASF, Bayer CropScience, Monsanto and Syngenta in the annual exchange of scientific information and research tips. Topics ranged from basic research on plant systems to application of research results to improve agriculture.
With the world population expected to exceed 9 billion people by 2050, Doherty’s presentation, “Time Management and Stress: Intersecting Regulatory Networks in Rice,” was timely. She discussed the effect of plant developmental stage and time of day (circadian rhythm) on gene regulation in response to stress.
Doherty started with a humorous analogy of time of day and its effect on stress – in this case the stress of taking an important biochemistry exam. Whereas you might manage exam stress well and get a good grade on that exam if you take it at 10 a.m., if you were awakened at 3 a.m. for the exam, it’s likely you wouldn’t do as well, because 3 a.m. is at the wrong part of your circadian clock.
Similarly, in plants, time of day affects response to stress. Using sudden osmotic shock, or high salt, in rice as a model system, Doherty researched the gene expression response to salt and how it varies based on time of day.
How does this relate to agriculture, since sudden osmotic shock in the middle of the night is an unlikely scenario?
Doherty said that increased variation in weather patterns is causing daytime temperatures to rise, but nighttime temperatures are increasing even more. As a result, the daily temperature range – the difference between day and night temperatures – is shrinking. Heat stress reduces crop yield, and nighttime heat stress means that plants are getting stressed at times when they aren’t prepared for it.
Because agricultural output must increase, not decrease, to feed a growing population, this alteration in the timing of when a stress occurs represents a new challenge to production agriculture, she said. Her research has implications for combatting reduced crop yield that is expected to result from climate change.
––Deborah M. Thompson
Director of Partnership Development