Plants could clean up toxic soil
Turkish scientists have discovered a plant that can remove boron from soils. They say that it could provide a low-cost way of 'cleaning up' soil contaminated with this naturally occurring trace element that is toxic to most crops at high concentrations.
Scientists from Selçuk University in Konya, Turkey, have found that Gypsophila sphaerocephala — a plant that usually grows on dry slopes and limestone rocks — can survive in boron-contaminated soils and accumulates boron in its tissues. They also suggest that, once it has been harvested, the plant could be transported to sites with very low levels of boron, helping to add the trace element to the soil in regions where it is boron deficient.
The researchers suggest that either developing boron-tolerant crops, or using boron-accumulating plants such as Gypsophila sphaerocephala, may provide a more effective — and cheaper — solution.
Mohamed Hamoud, a plant molecular biotechnologist at Tanta University in Egypt, welcomes the research findings, saying that they could help increase the area in which cereals such as wheat could be successfully cultivated.
Natural hyperaccumulators, such as Gypsophila sphaerocephala, tend to grow slowly, he says. But genetic engineering could be used to create fast-growing plants that carry boron-tolerance genes to improve their ability to tolerate, and accumulate, boron. "It's an approach I call 'cleaning by genes'," he says
The technique could be particularly useful in developing countries, he adds, because the costs of growing plants are minimal compared to those of soil removal and replacement.