Field release with GM barley

“We are interested in soil life.”

Genetically modified (GM) barley is being grown in the open in Germany for the first time, on a site belonging to the University of Giessen. The aim is to investigate the effect that two GM barley lines developed in the US have on beneficial fungi and, as a result, on soil quality. One of the two barley lines has a genetically engineered resistance to fungal diseases. - GMO Safety spoke to Karl-Heinz Kogel of the University of Giessen about the trial.

Dr. Karl-Heinz Kogel , Professor of plant diseases and plant protection at the University of Giessen.The research project dealing with genetically modified barley is funded by the Federal Ministry of Education and Research (BMBF) as part of the biological safety research programme.The release experiment with GM barley was authorised by the Federal Office of Consumer Protection and Food Safety (BVL).

GMO Safety: You are investigating two genetically modified barley lines that were developed in the US. Over there they have been trying since the mid-90s to optimise barley with the help of genetic engineering, i.e. to improve its brewing qualities and to make it more utilisable as a feedstuff. What interests you about these barley lines?

Karl-Heinz Kogel: We are interested in whether there are undesirable traits as well as the improved feed quality and increased resistance. We are particularly interested in soil life, in harmful effects on beneficial fungi like mycorrhizas, which colonise the rhizosphere of crops and wild plants. These fungi are known to have extremely beneficial effects on plant growth and plant health. These effects are also used in biological crop protection. At our institute we study these relationships intensively, which is why we are so interested in the question of whether these beneficial soil fungi may be affected by genetically modified barley.

What we are doing with the genetically modified barley is biological safety research. The research is integrated in the new international Masters programme in agro-biotechnology, which we have set up at the University of Giessen. It is very important to us that our students consider the safety of transgenic plants.

GMO Safety: One of the two transgenic barley lines that you are investigating has a resistance to fungal diseases. In principle there is a problem that it could damage beneficial fungi as well.

Karl-Heinz Kogel: This type of barley has an additional gene for endochitinase. This enzyme breaks down chitin, but only in the cell walls of fungi, not the chitin that is found in insects. It therefore makes sense to investigate to what extent beneficial soil fungi are affected by the endochitinase in the barley. It may be that this enzyme affects the soil fungi. This is why we are also looking at plant residues left in the soil.

However, it has now been shown in laboratory experiments that this endochitinase is highly specific. The enzyme that is produced in the transgenic barley increases the resistance to a specific disease, a root rot that is widespread in the US and also occurs in Europe. The enzyme is extremely effective against this pathogen (Rhizoctonia). We already know from laboratory experiments that it has no, or very little, effect on other fungi. Now we want to test this in the field.

GMO Safety: But you are also working with a second genetically modified barley line which produces a bacterial glucanase.

Karl-Heinz Kogel: This gene is expressed exclusively in the grains of the GM barley and the glucanase is present only in the corn. This barley line was developed to improve the quality of barley as chicken feed and for malting during beer production. Certain glucans are known to occur in the cell walls of almost all fungi. For this reason we want to investigate what impact the glucanase in this transgenic barley line has on soil fungi. Because of the tissue-specific expression of the glucanase gene, however, effects on soil organisms can occur only when GM barley grains decompose.

I would also like to mention the second focus of our research project, which is being handled by Prof. Uwe Sonnewald at the University of Erlangen. There the two new barley lines are being tested to see whether there are differences in the gene expression or in the plant substances between these and conventional barley varieties. We are interested in whether there is substantial equivalence between the transgenic and the conventional line, i.e. whether they are the same apart from the introduced new traits.

GMO Safety: People keep voicing concerns that your release experiment with genetically modified barley could lead to outcrossings.

Karl-Heinz Kogel: In this respect, barley is a ‘safe’ plant, since it is 99 per cent self-pollinating, i.e. the barley pollen fertilises the stigma of the same flower. This occurs – at least with our plants – when the flowers are closed, so that there is hardly any contact with insects or any pollen drift. In very rare cases pollen may be carried by the wind, but barley pollen is very sensitive to the sun’s rays and to drought. In the unlikely case of pollination occurring with wild barley or wild grasses, the hybrids will not produce progeny. All hybrids are sterile. This has been demonstrated in long research series. I therefore believe it is extremely unlikely that the barley in our experiment would spread.

In addition, we have to comply with very stringent safety requirements laid down by the authorising authority. We will sow 9.6 square metres with transgenic barley. Around it we will sow a cordon of conventional barley to act as a pollen trap. Then comes a five-metre strip of bare fallow ground

and finally 25 metres of white clover. This is planted so that any wild grasses can immediately be spotted and destroyed.

GMO Safety: How widespread are fungal diseases in barley and how do farmers deal with the problem at the moment?

Karl-Heinz Kogel: Barley is naturally more resistant than wheat to fungal disease. Nevertheless, there are often problems with barley, like the disease caused by Fusarium. These are fungi that occur on the ears and produce mycotoxins – toxic substances which can end up in food. This is one of the biggest problems in crop growing worldwide. It is important to develop new biotechnical approaches to tackle this disease, especially because there is hardly any effective chemical crop protection for this problem.

GMO Safety: Genetic engineering methods can open up new options for tackling fungal diseases. How realistic is it that barley with genetically conferred fungal resistance will actually be cultivated in ten or twenty years’ time?

Karl-Heinz Kogel: We are hopeful that in the medium to long term, it will be possible to significantly reduce the amount of pesticides applied by cultivating these kinds of barley. Whether the two barley lines in our trial will actually be cultivated it is impossible to tell. But new generations of genetically modified plants open up opportunities for more ecological and economical farming.

I am certain that future fungal-resistant crops could compete on the market. In particular, I am convinced that in the coming years biotechnology will focus on cereals. From a biosafety perspective in particular, cereals are extremely suitable candidates for genetically engineered grain improvements.