Roots aren't glamorous, but they are essential for pulling life from the soil. Answering pivotal questions surrounding roots (and the countless processes in which they are involved) represents part of a new research cluster aimed at understanding plant growth and development.
Other than the marshmallow-smothered sweet potatoes served up at Thanksgiving every year, roots don't get much public adoration. They do their jobs with little fanfare, huddled out of sight, while leaves and flowers get the glory. So in the interest of root respect, a few facts:
- The deepest root ever documented (on a wild fig tree in Africa) burrowed 400 feet into the ground.
- Prairie grass has more bulk underground in the roots than above ground in the leaves.
- More than half the surface area of a root is practically invisible, made up of tiny hairs.
"We lack basic information on many aspects of root biology, which is crucial for developing crop varieties with more efficient root systems." — Elison Blancaflor, Ph.D.
As they snake down into the soil, roots anchor the plant and largely through those root hairs soak up water and nutrients to send upward. But much about roots remains a mystery: Scientists don't know, for example, exactly why some roots can weather a drought, or survive for months buried in frozen ground, or even manage the hydraulics of channeling, sometimes thousands of gallons of water each day, against the force of gravity. For that matter, scientists still can't fully explain why roots grow down and not up. "There are still many unanswered questions," said Elison Blancaflor, Ph.D., of the Plant Biology Division at the Noble Research Institute.
That's why Blancaflor is heading up the Plant Growth and Development Research Cluster, which aims to dig deeper into root science. Formed in 2014, the cluster is one of five research clusters that unite the scientific muscle of the Noble Research Institute behind a single purpose. (The other research clusters are Low-Input Agriculture, Plant-Microbe Interactions, Breeder's Toolbox and Plant-Animal Interactions.) In addition to Blancaflor, Xuefeng Ma, Ph.D., of the Forage Improvement Division's small grains breeding laboratory, helps steer the cluster. But members of all three operating divisions are involved, including James Rogers, Ph.D., an agronomist in the Agricultural Division's Center for Advanced Agricultural Systems and Technology.
While each division has pursued its own projects throughout the decades, the clusters create research teams that are greater than the sum of their parts. All of the groups are tackling the most formidable agricultural problems facing farmers and ranchers of the Southern Great Plains and beyond.
"Hopefully we can find some useful genes that would lead to development of better root architecture - deeper roots, better root mass." — Xuefeng Ma, Ph.D.
The Plant Growth and Development Research Cluster identified roots as one early focus because so much knowledge is still lacking. The growth of roots in soils, the shape of the individual root cells, the powers of resilience all these properties involve thousands of intricate, overlapping biological processes that must be tightly regulated throughout the life of the plant, Blancaflor said. Yet, he added, "We lack basic information on many aspects of root biology, which is crucial for developing crop varieties with more efficient root systems."
The project will study root development in vital forage crops, such as tall fescue, alfalfa and winter wheat.
"Hopefully we can find some useful genes that would lead to development of better root architecture deeper roots, better root mass," Ma said. By finding key genes, scientists can then turn to breeding crops that are more resilient.
The job of taking the research findings outside the laboratory will fall to Rogers, who specializes in pasture and range management. In addition to surviving harsh conditions, plants with stronger roots may be better able to withstand grazing pressure. Animals can shear too much off the top of a plant, which weakens its ability to revive.
Better knowledge of roots may also be useful in the effort to enable farmers to move away from tilling their fields, Rogers said. Mechanical plowing exposes the soil, leaving it vulnerable to erosion, especially on the wind-whipped plains. Plowing can also create a compact layer of soil below the surface. To break this up, farmers use subsoiler plows to rip through that hard layer. Certain plants can provide the same purpose without leaving a field exposed.
"Roots themselves can till the soil," Rogers said.
"... I'm interested in what goes on above the ground, like the levels of moisture, fertilizer and how animals respond to forage quality. But sometimes to understand what's going on above the ground, you need to know what's happening below." — James Rogers, Ph.D.
One plant, the Nitro radish, produces a large taproot that punches deep holes into the ground.
"It's like a natural subsoiler," Rogers said.
As research uncovers more secrets about roots, farmers and ranchers may eventually have more choices for plants that act as natural tillers.
For his part, Rogers welcomes the attention to root biology and concedes that he, too, would not have thought as much about roots were it not for the new research cluster.
"I do applied research, so I'm interested in what goes on above the ground, like the levels of moisture, fertilizer and how animals respond to forage quality," he said. "But sometimes to understand what's going on above the ground, you need to know what's happening below."
Even though the cluster is less than two years old, Blancaflor and his team have discovered a handful of genes and proteins that play pivotal roles in root architecture, such as the length and shape of the root hair, and zone of growth.
He says one big challenge will be translating those findings to tangible benefits: "Can increasing the length, density or longevity of root hairs by changing the expression of specific genes really lead to more efficient roots for water and nutrient acquisition? What root types are better for the Southern Great Plains shallow ones so they can better scavenge for immobile nutrients like phosphorus or deeper ones so they can access limited water better? These are some of the questions we are going to answer."