DELAWARE, Ohio – Sideways-growing lateral roots make up the vast majority of a plant’s root system, but how those roots choose and maintain their precise pathways remains a mystery, says Ohio Wesleyan University’s Chris Wolverton.
“[Roots] sense things like moisture gradients, solid objects like rocks and pebbles, and can tell up from down, using these cues in ways that remain largely unknown to guide their growth,” explains Wolverton, Ph.D., associate professor of botany/microbiology.
And primary roots quickly correct their vertical up-and-down course if they begin to grow sideways, Wolverton notes, “[b]ut when the course was not-quite-vertical, how do they know where to go? Are they using the same cellular tools as the primary root to detect gravity? Are the same circuits that activate curvature in the primary root activated in lateral roots? Given their role in nutrient uptake, do lateral roots change their course when nutrient conditions change? In our most recent paper, we set out to address some of these questions about lateral root growth.”
In the paper, Wolverton and a group of Ohio Wesleyan students examine how soil phosphate levels impact the growth of lateral roots. Their study, “Low Phosphate Alters Lateral Root Setpoint Angle and Gravitropism,” appears in the January edition of the American Journal of Botany.
Wolverton conducted the project in collaboration with Ohio Wesleyan student-researchers and article co-authors Evan Bai, Bhavna Murali, and Kevin Barber.
Bai, a 2011 Ohio Wesleyan graduate and biochemistry major, currently is pursuing his doctorate in biological and biomedical sciences at Yale University. He also is among the authors on a study published last week in the peer-reviewed journal Science. Murali, a 2012 OWU graduate and genetics major, is pursuing her doctorate in molecular cell biology at Washington University in St. Louis, and Barber, a 2012 OWU alumnus and genetics major, is pursuing his Doctor of Veterinary Medicine degree at Western University of Health Sciences in Pomona, Calif.
Wolverton earned his doctorate at The Ohio State University and joined the Ohio Wesleyan faculty in 2002.
For the newly published research, he and his student co-authors studied the impact of low levels of orthophosphate (phosphate fertilizer) on the root systems of a small flowering plant called Arabidopsis thaliana. They determined that low levels of the phosphate impacted the orientation of the lateral roots, which Wolverton will continue to study to determine how such knowledge can help farmers and others to grow plants more effectively.
To read more about the new Ohio Wesleyan study, visit http://www.amjbot.org/content/100/1/175.abstract. To learn more about Ohio Wesleyan’s botany/microbiology courses, visit https://www.owu.edu/academics/departments-programs/department-of-botany-microbiology/. To read Wolverton’s blog about the research, visit http://www.gravitropic.net.
The American Journal of Botany is an internationally recognized journal accepting peer-reviewed research papers on all aspects of plant biology. The St. Louis-based journal has been published monthly since 1914 and is considered the flagship journal of the Botanical Society of America.
Founded in 1842, Ohio Wesleyan University is one of the nation’s premier small, private universities. Ohio Wesleyan offers more than 90 undergraduate majors, sequences, and courses of study, and 23 NCAA Division III varsity sports. OWU combines an internationally focused curriculum with off-campus learning and leadership opportunities that connect classroom theory with real-world practice. Located in Delaware, Ohio, OWU’s 1,850 students represent 41 states and 45 countries. The university is featured in the book “Colleges That Change Lives,” listed on the 2012 President’s Higher Education Community Service Honor Roll with distinction, and included on the “best colleges” lists of U.S. News & World Report and The Princeton Review. Learn more at www.owu.edu.