The role of insect feeding and plant defense responses in Aster Yellows disease epidemiology
- To quantify the feeding behavior of aster leafhoppers on different host plants and examine the relationship between feeding time and AYp titer using the Electrical Penetration Graph technology followed by molecular quantification of phytoplasma titer via, LAMP, qPCR and ddPCR of plant tissue to quantify AYp titer
- To establish feeding and reproductive preferences of aster leafhoppers using Arabidopsis thaliana lines in which their defense mechanisms are activated or silenced
Both Aster Yellow (AY) disease and leafhoppers can result in significant crop and yield loss, including field failure in extreme cases. Previous research indicates that aster leafhoppers do not reproduce on canola, yet this crop is severely affected by AY disease. One possible explanation is in the time required to transmit Aster Yellow phytoplasmas (AYp), which is unknown for most plant species. Short periods of time could be enough for leafhoppers to transmit AYp to suboptimal plants such as canola and members of the Asteraceae family, while requiring a longer period for other plant species.
Quantification of the times required to acquire or transmit AYp can be directly converted into management recommendations. That is, it will allow the researchers to evaluate how much time between detection of insects may elapse before they will infect plants. Furthermore, if some trait such as activation or downregulation of a plant signaling pathway is found to be correlated with reduced insect oviposition, reduced feeding, impairment of insect development, and/or lower AY titer/milder symptoms, such knowledge could be incorporated into breeding programs to develop new crop varieties or enhance defense mechanisms in existing ones. This project will generate important information for the development of improved pest management practices for aster leafhoppers and AY disease, leading to reduced crop loss.