Climate change is threatening many of the world's crops, according to a new report in the journal Diversity, which suggested that many of those agriculturally significant plants are an urgent priority for conservation. But gene-editing tools might help us engineer new varieties of the crops we now grow so they can withstand some of the changes that are likely coming to our climate. Barley, for example, might sprout from a seed, or germinate, too soon if rainfall occurs at an unusual time of year, because water can trigger germination. Thus, agricultural scientists have been trying to solve that premature sprouting problem, in which barley can turn into a seedling too soon.
CRISPR/Cas9 technology can be used to edit the genomes of virtually any species, including barley. Scientists knew from previous research that two barley genes called qsd1, and qsd2 are involved in grain and seed dormancy. Reporting in the Plant Biotechnology Journal, researchers targeted both genes to create individual mutant strains of ‘Golden Promise’ barley as well as double mutants. Germination tests were then done on all of the edited barley as well as non-edited controls.
The researchers found that germination had been effectively delayed in all of the mutant strains. When the mutants were exposed to colder temperatures, or if they were treated with a solution of 3 percent hydrogen peroxide, germination was encouraged. This suggested that the mutants were not producing dying grains, they had simply been dormant longer. A accumulation of abscisic acid was seen in all of the mutants as well, and though this buildup does not maintain grain dormancy, it is consistent with a delay in germination. In single qsd2 mutants, germination could happen in dark but not light conditions.
“We could successfully produce mutant barley that was resistant to pre-harvest sprouting, using the CRISPR/Cas9 technology. Also, our study has not only clarified the roles of qsd1 and qsd2 in grain germination or dormancy, but has also established that qsd2 plays a more significant role,” noted first study author Dr. Hiroshi Hisano, an Associate Professor at Okayama University.
This work could improve crop yield, and since barley is a crucial ingredient in many brews, it may help secure the future supply of the world's beer.
