Research in my lab seeks to understand the physiological and molecular mechanisms underlining interactions between plants, insect herbivores, and pathogenic microbes. The two key questions of my research program are: (1) what mechanisms do plants employ to respond to a variety of biotic stressors? and (2) what components of these mechanisms can be genetically altered to facilitate development of innovative strategies to enhance host plant resistance? My approach to these questions relies on combining field observations and laboratory experiments including genomic, transcriptomic and metabolomic tools as well as concepts and methods from various biological disciplines to attain a comprehensive understanding of the wide spectrum of interactions involved.
#1 PLANT-APHID INTERACTIONS
Aphids are amongst the most damaging pests of plants that use their stylets to penetrate the plant tissue to consume large amounts of phloem sap and thus deprive the plant of photoassimilates. In addition, some aphids vector important viral diseases of plants. In the lab, there are currently several projects that study various aspects of plant-aphid interactions.
a. Phloem transport of amino acids: a novel target to disrupt bacterial symbiosis in soybean aphids
b. Evaluation of PAD4 over-expressing transgenics to soybean aphids
c. Impact of feeding location on aphid behavior and fecundity
d. Diurnal feeding in aphids as a potential mechanism of osmoregulation
e. Targeted translatome profiling to determine plant response to aphid feeding
f. Mechanisms of host plant resistance in soybean aphid-resistant germplasm
#2 ALTERNATIVE SPLICING IN PLANT DEFENSE
The functional impact of alternative splicing on plant proteins is understudied but recent examples highlight its importance in regulating a wide range of physiological and developmental processes including biotic stress response. Functional characterization of AS events will provide significant new insights into regulation of plant processes. This project is aimed at determining the role of a splice variant of an important plant defense modulator.
#3 POTATO NECROTIC VIRUSES
Potato viruses are the most important seed potato pathogens and are a significant burden on commercial potato production. They cause costly yield and quality reduction and reduce profit margins for producers. Three vector-borne tuber-necrotic viruses are currently economically important threats for the potato industry. These viruses include the aphid-transmitted potato virus Y (PVY), the plasmodiphora-transmitted potato mop-top virus (PMTV) and the nematode-transmitted tobacco rattle virus (TRV). This project utilizes two advanced molecular techniques for screening advanced breeding potato clones for these necrotic viruses, which will accelerate Colorado potato breeding program.
#4 MECHANISMS OF TOLERANCE IN WHEAT TO WHEAT CURL MITE AND THE WHEAT STREAK MOSAIC VIRUS
Tolerance is a category of host plant resistance defined as the ability of a plant to withstand or recover from damage caused by pest/pathogen populations equal to those on susceptible cultivars. Plant tolerance does not impose the same levels of selection pressure as resistance genes; therefore, virulent populations are less likely to evolve. The objective for this project is to identify the molecular mechanisms associated with tolerance to Wheat Curl Mite and the Wheat Streak Mosaic Virus.
#5 DEVELOPMENT OF BCTV RESISTANCE IN SUGAR BEET
Sugar beet production in the Western United States is under threat from a major viral disease, Beet curly top virus (BCTV) and Rhizomania caused by Beet necrotic yellow vein virus (BNYVV). BCTV vectored by the beet leafhopper, is mainly controlled using insecticides including neonicotinoid seed treatments and cultural practices aimed at either avoiding beet leafhoppers (by early planting) and/or controlling weeds to reduce the presence of alternate hosts for the vector. Although, host/genetic resistance against the virus exists, the resistance is low to intermediate, and there are reports of breakdown of resistance due to the emergence of resistance breaking BCTV isolates. This project is focused on identifying and validating viral genes to be used with the CRISPR/Cas9 system for the development of virus resistance in sugar beets.