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A team of UW scientists has genetically modified poplar trees to soak up dangerous chemicals in the ground and air by absorbing them into their roots, stems and leaves.

 

The preliminary results of the researcher’s efforts were released in a paper found in this week’s edition of the Proceedings of the National Academy of Sciences, the abstract of which can be can be found here. Several science news outlets have also reported the study.

 

The trees break the pollutants down into harmless byproducts that don’t harm the environment in a process called phytoremediation.

 

By inserting a gene ordinarily found in rabbit livers into the trees’ genetic material, a group of researchers enhanced the poplars’ natural ability to breaks down carcinogens, or cancer-causing molecules.

 

This rabbit gene (cytochrome P450 2E1) helps the trees increase their production of an enzyme that serves as a catalyst for the elimination and removal of carcinogens like trichloroethylene (an industrial solvent), vinyl chloride, carbon tetrachloride, benzene and chloroform.

 

The genetically-modified poplars remove up to 91 percent of pollutants from a liquid solution, nearly 53 times faster than unmodified trees. The transgenic trees also removed 79 percent of trichloroethylene from the air of a sealed container after a seven-day experiment, a photo of which can be seen here.

 

While these “transgenic” poplars (Populus tremula x Populus alba) are only inches high and reside in test tubes, the scientists hope to eventually plant them near Superfund sites, locations identified by the government as being exceptionally polluted.

 

They would serve as an inexpensive way of reclaiming previously abandoned areas.

 

But there are some concerns about the idea of changing the poplars’ genetic code, with some researchers fearing that the trees may spread the rabbit gene to wild poplars or harm insects and animals.

 

Stuart Strand, one of the lead researchers on the phytoremediation project, is quick to acknowledge these concerns.

 

“Some fears are unfounded or sort of silly, such as ‘frankenplants’ with bunny heads in flowers or other cartoonish ideas… but we are concerned about the possibility of spread of the genes in the poplar population,” he said, calling the uncontrolled release of the gene “undesirable.”

 

More work remains to be done to ensure that temporary, immediate compounds created by the breakdown process don’t harm wildlife, he said.

 

Stuart pointed out that the poplars were chosen because they flower infrequently and in a controllable manner, and because the type of poplar they are working with does not grow from fallen branches.

 

Caution is key to genetic research, he said.

 

“The questions will always be: what is the purpose, the expected result? Is it useful or informative in someway? Is it safe?”