Barley gene mystery solved
Published on 14 October 2022
The latest research led by Sarah McKim and her team solved a mystery that has puzzled barley scientists for over 50 years. This work is just published in Nature Communications.
Plants develop many adaptations on their surfaces to survive harsh environments on land. One of these is the cuticle- a waxy, water-proofing seal covering all above ground parts of the plant. Plants interrupt their cuticle with adjustable air pores, called stomata, which they can open and close to control exchange of gases, like carbon dioxide, which plants need to grow. In almost all plants, stomata are spaced away from each other so that the pores can open and close without interfering with each other. Despite the importance of the cuticle and stomata for plant survival, and in crop performance, we know little about how plants develop these features.
Over 50 years ago, scientists described a barley plant where differences in a single gene caused clustered, misarranged stomata, as well as a defective cuticle. This was exciting since this gene represents a single point of control over both the cuticle and stomata, but for decades the identity of this gene remained unknown. Research led by Sarah McKim and her team at the University of Dundee solved this mystery.
Dr Sarah McKim, a Principal Investigator in the Division of Plant Sciences based at the James Hutton Institute explained, “We showed that this gene encodes a type of signaling protein which controls cascades of events in developing tissues. We also discovered the identity of another gene which has a similar role. Together these two genes interact early in plant growth to control not only cuticle and stomata but also other features important for plant defenses in the terrestrial environment. Both genes appear to have evolved millions of years ago when plants moved from being strictly aquatic to living on land.”
The research involved important contributions from collaborators from the Universities of Bristol and Copenhagen, as well as the barley research group James Hutton Institute. Dr McKim is part of the International Barley Hub, a major investment in barley research at the James Hutton Institute.
Taken together, this research answered a long-standing question about the genes used by plants to develop surfaces to survive on land, and the role of these genes in barley. Barley is a key global cereal and the most important crop in Scotland. This new knowledge could provide vital information about how these genes could be altered to improve plant performance and survival under stressful conditions.