Assessing surface wax chemical diversity as a tool to defend against abiotic and biotic stress in canola
Researcher: Mark Smith, Agriculture and Agri-Food Canada, Saskatoon SK
Project Code: CARP CCC 2018.18
Final Report: April 2020
Summary: The outer surfaces of land plants are covered by a complex water-repelling material referred to as cuticular wax. This layer plays a fundamental role in prevention of water loss from the plant and in defense against attack by insect pests and fungal pathogens. For canola, little is known about the chemical composition of cuticular wax, its synthesis, biological function, and if there is chemical diversity within Canadian varieties. A 2-year study was conducted by Agriculture and Agri-Food Canada researchers to determine the chemical composition of wax in B. napus and to investigate the distribution of these chemicals on different plant parts and between different canola varieties. To aid in potential breeding efforts for new wax traits, researchers also identified genes encoding enzymes involved in wax biosynthesis and genes that regulate wax production. Results showed that B. napus wax is a complex mixture of aliphatic (chain like) hydrocarbons, with five main components and many minor ones. The chemical composition of wax in B. napus appears relatively uniform over the plant, with significant differences in composition only seen in petals. Low chemical diversity of wax was observed between B. napus varieties. Although this could limit the usefulness of natural diversity in breeding for new wax related traits, searching for induced diversity such as diversity in mutagenized populations may be a way to identify the germplasm needed to manipulate wax profiles if required. This work has considerably enhanced our understanding of wax chemistry and biosynthesis in B. napus and identified gaps where further knowledge is required. For example, knowing the chemistry of wax will help in determining how different components function in plant defense.
Click the links below to download a short version of the report, the full detailed long version of the report, or the related Canola Digest PDF.