Research

To complete translation, replication and movement through cells, a virus relies mostly on the interactions of its genome and encoded-proteins with host factors.  Knockouts of specific factors or even subtle changes in their properties can trigger a lack of compatibility in plant-virus interactions and failure of the virus to infect its host.  Natural recessive resistance against plant viruses often involves mutations within the host translation initiation factors, which are not detrimental to the host.  To understand how these mutations act as resistance genes, it is imperative to know how RNA viruses are translated and what are the key regulatory elements in the viral RNAs.

The broad objective of my research program will be to delve into the mechanistic details of viral translation control, which will be integrated into the larger context of viral replication and plant virus resistance. Of particular interest is the Potyviridaefamily, which encompasses about 30% of the most damaging crop viruses. These RNA viruses pose a curious conundrum on how they are translated.  Unlike cellular mRNAs which utilize a 5’ m7(G)ppp(G) cap structure and a 3’ poly(A) tail, the Potyviridaerather contain an internal ribosome entry site (IRES) elements, which recruit the ribosomes at internal positions at close proximity of the initiation AUG rather than entering or scanning from the 5’ end.   However, to date, little is known on Potyviridae translational strategies. 

A key solution to the devastating effects of viral pathogens is to understand how they gain a foothold in the host cells and against other competing pathogens. The overarching goals of my research program are to:

  1. Explore how viruses interact with other common pathogens, undermining the ecological role of viruses as potential drivers of evolution of disease epidemics and severity by positively and/or negatively regulating fungal pathogenicity. 
  2. Elucidate how +ssRNA plant viruses parasitize the host translation apparatus to synthesize their proteins. Indeed viruses must co-opt host translation apparatus to synthesize their own proteins. Consequently, they have evolved unique strategies to outcompete host mRNAs for these limiting machineries. Many deviates from the canonical cap-dependent translation process by relying on various translation elements. The ability of viral RNA sequences to drive powerful protein expression opens opportunities for biotechnology in this era of plant pharmaceutical farming.
  3. Dissect how these viruses avoid or subvert host defenses; of specific interest are the various mechanisms of resistance against Potato Virus Y (PVY), which remains a major threat for potato production. The defense strategies include loss or mutation of essential host eukaryotic translation initiation factors eIF4E that can’t longer be physically recruited by PVY, and the strain-specific Nytbr gene, popular in commercial varieties of potatoes but only efficient against PVY O and not the necrotic strains that are dominating the crop fields.

Protocols

Please find our helpful protocols from the link blow. If you are looking for things beyond this, feel free to contact us.

Preparation and electroporation of oat protoplasts from cell suspension culture.

Curr Protoc Microbiol. 2007 Jun;Chapter 16:Unit 16D.3. doi: 10.1002/9780471729259.mc16d03s05.

http://www.ncbi.nlm.nih.gov/pubmed/18770615

Protein protocols from Lab member Robyn Robderts:

Recipes: