|MONGEON, JULIE - University Of Maryland|
Submitted to: Annual Beet Sugar Development Foundation Research Report
Publication Type: Research Technical Update
Publication Acceptance Date: 4/3/2017
Publication Date: 4/20/2017
Citation: Smigocki, A.C., Mongeon, J., Li, H. 2017. Sugar beet cell wall protein confers fungal and pest resistance in genetically engineered plants. Annual Beet Sugar Development Foundation Research Report. https://www.bsdf-assbt.org/bsdf-home/.
Interpretive Summary: Plant diseases and insect predators reduce the production of sugar from sugar beet roots. Disease and pest control measures rely on harmful chemical fungicides and insecticides, therefore, more environmentally sound measures for control need to be developed. Biotechnological approaches offer an alternate approach. We identified and characterized a repertoire of sugar beet traits (genes) that are involved in protecting the plant root from diseases and insect predators. One such trait (polygalacturonase-inhibiting protein gene, PGIP) provides protection against fungal attack. We isolated sugar beet PGIP genes and transferred them into tobacco plants to test PGIP function in fungal and insect resistance. We determined that sugar beet PGIP proteins protected tobacco plants against three highly virulent fungal strains and an insect pest that attacks hundreds of vegetable crops. We propose that sugar beet PGIPs may provide fungal disease and insect control in plants. Scientists and breeders will use this information to develop disease and insect resistant crops that will increase yields, reduce usage of harmful pesticide and provide safer produce for the consumer.
Technical Abstract: Sugar beet biomass and sugar yield are reduced by diseases caused by microbial pathogens and insect pest infestations. Since disease and pest control measures continue to rely on harmful chemical fungicides and insecticides, biotechnological approaches offer an alternate approach for disease and pest control in plants. Identification and characterization of the repertoire of sugar beet genes that are involved in defense responses is key for developing effective, environmentally safe, biotechnologically based strategies aimed at improving insect and disease resistance. Our search for resistance genes has been focused on defense responses in the sugar beet root, specifically to its most devastating insect pest, the sugar beet root maggot (SBRM). Using this approach as a model system for studying the mutual interaction of SBRM with a resistant and susceptible host, we identified a number of potential resistance genes, among them a gene encoding a polygalacturonase inhibitor protein (PGIP). When the sugar beet polygalacturonase inhibitor protein gene (BvPGIP) was introduced into Nicotiana benthamiana plants, the BvPGIP plants exhibited increased tolerance to several fungal pathogens that included Rhizoctonia solani, Fusarium solani and Botrytis cinerea. In addition, these BvPGIP plants were more resistant to fall armyworm larval feeding. Larvae weighed less and had higher mortality rates as compared to the controls. These results suggest that the sugar beet BvPGIP genes play an important role in plant defense and could provide an approach for controlling fungal and insect pest diseases in sugar beet and other crops.