Scientists identify microbes that can increase plant growth

Washington, Jan 27 (ANI): Through work originally designed to remove contaminants from soil, scientists have identified plant-associated microbes that can improve plant growth on marginal land.

The findings by the team of scientists, from the U.S. Department of Energy's (DOE) Brookhaven National Laboratory and their Belgium colleagues, may help scientists design strategies for sustainable biofuel production that do not use food crops or agricultural land.

"Biofuels are receiving increased attention as one strategy for addressing the dwindling supplies, high costs, and environmental consequences of fossil fuels," said Brookhaven biologist and lead author Daniel (Niels) van der Lelie, who leads the Lab's biofuels research program.

"But competition with agricultural resources is an important socioeconomic concern," he added.

Van der Lelie's team has experience with plants growing on extremely marginal soil - soil contaminated with heavy metals and other industrial chemicals.

In prior research, his group has incorporated the molecular "machinery" used by bacteria that degrade such contaminants into microbes that normally colonize poplar trees, and used the trees to clean up the soil.

An added benefit, the scientists observed, was that the microbe-supplemented trees grew faster - even when no contaminants were present.Poplar plants at 1 (A) and 10 (B) weeks after being treated with endophytic bacteria (strain S. proteamaculans 568) compared with control plants.

The inoculated plants show increased root and shoot formation, particularly after 10 weeks.

According to co-author Safiyh Taghavi, "This work led to our current search for bacteria and the metabolic pathways within them that increase biomass and carbon sequestration in poplar trees growing on marginal soils, with the goal of further improving poplar for biofuel production on non-agricultural lands."

In the current study, the scientists isolated bacteria normally resident in poplar and willow roots, which are known as endophytic bacteria, and tested selected strains' abilities to increase poplar growth in a controlled greenhouse environment.

They also sequenced the genes from four selected bacterial species and screened them for the production of plant-growth promoting enzymes, hormones, and other metabolic factors that might help explain how the bacteria improve plant growth.

"Understanding such microbial-plant interactions may yield ways to further increase biomass," van der Lelie said. (ANI)