|MONGEON, JULIE - Towson University|
|SAVIC, JELENA - University Of Belgrade|
Submitted to: Journal of Sugar Beet Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/28/2017
Publication Date: 11/28/2017
Citation: Smigocki, A.C., Mongeon, J., Savic, J. 2017. Sugar beet proteinase inhibitor (BvSTI) gene promoter is regulated by insects and wounding in transgenic Nicotiana. Journal of Sugar Beet Research. 55:1-28.
Interpretive Summary: Gene regulatory switches that up-regulate the production of beneficial gene products at a time when and where they are most needed during plant growth and development are considered most desirable for devising effective molecular strategies for crop improvement. We isolated a sugar beet gene switch from a gene known to be associated with enhanced tolerance to a major pest of sugar beet, the sugar beet root maggot. We determined that the sugar beet gene switch can function in other plants and that it can be turned on when leaves and roots are mechanically damaged or attacked by predatory insects. We conclude that this gene switch can be used to drive the production of other disease resistance genes at sites of pest and pathogen invasion to enhance the capacity of the plant to defend itself and reduce damage to the plant. Scientists and breeders will use this information to develop improved crops with disease resistance that will increase yields, reduce usage of harmful pesticide and provide safer produce for the consumer.
Technical Abstract: A regulatory sequence from a serine proteinase inhibitor gene (BvSTIpro) shown to be up-regulated in resistant interactions with a root pest of sugar beet, the sugar beet root maggot, was fused to the ß-glucuronidase (GUS) reporter gene to characterize its expression patterns in transgenic Nicotiana benthamiana plants. GUS gene activity was detected in leaves and roots of several independently derived BvSTIpro-GUS transformants. In 2- and 6-week old plants, GUS expression was observed throughout leaves and roots, comparable to GUS staining detected in plants transformed with the positive control 35S-GUS gene construct. At 10-14 weeks, GUS expression in the leaves and roots was reduced as compared to the younger plants and the 35S-GUS control but was up-regulated by abiotic and biotic stress. At 6 to 24 hours after mechanical wounding, GUS expression increased throughout the wounded leaves and roots of 14-week old plants to constitutive levels observed with the 35S-GUS gene. Fall armyworm (Spodoptera frugiperda) feeding on BvSTIpro-GUS leaves and roots similarly induced GUS gene activity like those observed with the 35S-GUS control. We demonstrate that the BvSTI promoter induced gene expression in response to abiotic and biotic stress. Fusion of the BvSTI promoter to resistance genes should provide expression at sites of pest and pathogen invasion to augment the capacity of the plant to defend itself.