Much of our understanding of evolution in the animal and plant kingdoms is based on the transfer of genetic information from parents to offspring. In a surprising discovery, researchers find globally cultivated crop plants such as wheat, maize, rice, and barley belonging to the grass family, can transfer genetic material from one plant to another across wide evolutionary distances.
This process of gene transfer, called lateral gene transfer (LGT) is a potent evolutionary force that could enable crops to grow faster, bigger or stronger and adapt quicker and better to new environments.
“Grasses are taking an evolutionary shortcut by borrowing genes from their neighbors. By using genetic detective work to trace the origin of each gene, we found over 100 examples where the gene had a significantly different history to the species it was found in,” says Luke Dunning, PhD, senior author of the research from the Department of Animal and Plant Sciences at the University of Sheffield.
The study, led by scientists at the University of Sheffield, U.K., is published in an article titled “Widespread lateral gene transfer among grasses” in the journal New Phytologist. These findings could inform investigations into developing crops that are more resistant to the effects of climate change and help tackle food security problems.
“Whilst only a relatively small proportion of genes are transferred between species, this process potentially allows grasses to cherry pick information from other species,” says Dunning.
These new results compel us to reconsider our view on genetically modified food crops because it is now evident that grasses use a very similar process. LGT can move genetic material across wide evolutionary distances which means it may have greater effects than hybridization through sexual reproduction and chromosomal recombination.
“We still don’t know how this is happening or what the full implications are but we know it is widespread in grasses, a family of plants that provide a majority of the food we eat,” says Samuel Hibdige, PhD, and first author on the study. “We detected foreign DNA in a wide range of grasses with all kinds of life history strategies indicating it is not restricted to those with a specific trait. However, we did detect a statistical increase in species which possess certain kinds of modified stems called rhizomes.” This is likely because growth through rhizomes that are underground stems that send out roots and shoots from nodes, boosts opportunities for transfer into the germline.
In future work the team plans to determine the biological mechanism behind LGT in grass species and to investigate whether this is an ongoing process that contributes to crop varieties.