Clemson, South Carolina, USA
September 29, 2010

Plant geneticists can develop new plant varieties to flourish in harsh growing conditions, but there can be undesirable consequences: The newcomer can pass on unintended traits to other species and potentially impact environment and ecology systems.

The U.S. Department of Agriculture funds Clemson University molecular biologist Hong Luo's research on how to improve plants without turning them into environmental problems. The USDA recently awarded Luo $400,000 to continue his work. Haibo Liu, an expert in turfgrass physiology, is the co-principal investigator. It is the third time federal officials have funded Luo's project for nearly $1.2 million to date.

Luo's research focuses on plants that are economically important.

"Many people do not realize that turfgrass is part of the state’s green industry, the No. 2 agriculture sector in South Carolina," said Luo. "We are looking at how to help it grow in stressful environments, such as drought or where the water may have a high salinity level."

Other plants Luo and his colleagues study include switchgrass, which is used as a renewable biofuel; soybeans; and cotton. The research moves along two paths. The scientists look for genes in the plants that regulate traits to help them flourish. The researchers also look for ways to genetically engineer crops, mostly by improving the plants' ability to perform better under adverse environmental conditions.

“One plant I work with is creeping bentgrass, which is used on golf courses," said Luo. "We are looking for genes that would improve its salt tolerance, allowing growers to irrigate with brackish water. It would not only offer growers a benefit but also golf course managers. It could be a real plus for South Carolina and other coastal states."

But, Luo points out, bentgrass is a perennial and that poses a greater environmental risk.

"Many crops are annual plants, which are more sexually isolated and resistant to crossing with plants that do not share to a high degree the same genetic code. Modern varieties of corn, for example, would not necessarily reproduce with heirloom varieties. Many perennials, including bentgrass, are more likely to successfully reproduce with its kin and even with plant species that it shares less genetic information with."

Perennials with enhanced growing traits can grow faster and spread more robustly, which could impact other co-habiting species. The potential of crossing with other plants, passing on their improved traits to plants that weren't meant to have the benefits raises additional concerns about the environmental and ecological consequences.

To control invasiveness, Luo investigates molecular ways to sterilize trait-enhanced plants.

"We are looking at sterilizing the male part of the plant — pollen — or sterilizing the whole plant," he said. "We need to prevent transgene escape before a perennial can be approved for widespread use."

Luo and his collaborator, Liu, also are conducting field trial experiments to study the environmental and ecological impact of the genetically modified perennial species.

Their research and field trials provide data for USDA assessments of the risks of genetically engineered perennials. A number of annuals, including varieties of corn, soybeans and cotton, have been approved for commercialization.

Luo's work with grasses has implications for food, fiber and fuel crops. Plant geneticists Halina Knap and Brandon Moore collaborate with him. Knap's specialty is soybeans. Moore is working with cotton.

Photo: Clemson University