Transgenic cereals taught land reclamation for the first time

Denis Strigun, Naked Science

An international group of scientists has developed a method that allows you to grow cereals that purify territories from contamination by ammunition. The results of the study are presented in Plant Biotechnology Journal (Zhang et al., Expression in grasses of multiple transgenes for degradation of municipal compounds on live fire training ranges).

The long-term consequences of the use of ammunition include chemical contamination of territories. Now the basis of many explosives are toxic compounds, such as TNT (TNT) and RDX (RDX), which can accumulate in soil and plants even due to unexploded shells. At the same time, RDX does not bind well to the soil and can penetrate into groundwater, spreading over considerable distances. Existing methods of land reclamation (especially military landfills) are extremely expensive.

In a new paper, scientists from the University of Washington (USA) and York University (UK) proposed using transgenic cereals for such purification. Previous studies have shown that some bacteria, in particular the pathogens Rhodococcus rhodochrous and Enterobacter cloacae, can cleave RDX and TNT into neutral elements due to the genes xplA, xplB and nfsI encoding nitroreductase. However, bacteria also require other food sources, so in experiments their genes are included in the genome of weeds.

The authors applied the approach for the first time on two types of cereals: millet (Panicum virgatum) and shoot-forming vole (Agrostis stolonifera). To do this, a cassette of the xplA, xplB and nfsI genes was included in the genome of the lines of both plants. The results showed that the expression of the first two is significantly increased (in one line, the expression of xplB has doubled), while nfsI is still slightly expressed in comparison with them. Following the expression of genes in plants, the production of the corresponding enzymes also increased.

Then the scientists conducted tests on contaminated soil. The analysis confirmed that transgenic grass breaks down the RDX contained in it faster than wild grass. At the same time, the accumulation of toxins in the field was slower, in millet it did not occur at all. It is also noteworthy that by absorbing nitrogen extracted from the compounds, plants, in particular, the vole, increased biomass: the increase compared to wild was 1.5–2.5 times. The root of each transgenic plant was able to reclaim the earth within half a meter.

A snapshot from the University of Washington press release
New grasses neutralize toxic pollution from bombs, explosives and munitions – VM

According to the researchers, transgenic cereals are an affordable way to clean up dual-use land, since they can also be used in the food industry. At the same time, the new approach can reduce the risk of poisoning among the population: previous studies have shown that consumption of RDX in large doses (for example, with water) can cause hepatitis and damage to the central nervous system (CNS). The next step will be to test the technology in various conditions and assess its safety for wild plants.

Portal "Eternal youth" http://vechnayamolodost.ru  24.11.2016