Title: Dynamics of transport and replication of the most important potato Y virus strains in primary and secondary infested potato plants
Contract number: UMO-2016/21 / B / NZ9 / 03573
Project manager: dr Krzysztof Treder
Start date: March 6, 2017
Completion date: March 5, 2020
Financing amount: PLN 1 155 432.0
Purpose of research
Viruses that replicate more effectively in a plant and / or cause systemic infection in a shorter period of time have a greater chance of evolutionary success. Both processes can be significantly affected by plant resistance and the ability of virus strains to break it. Therefore, the goal of the project is to determine whether potato Y virus strains (PVYNTN, PVYN-Wi and PVYO) differ in the speed of movement and propagation efficiency in infected plants, as well as whether and how the resistance of potato varieties affects both of these phenomena. In addition, the multiplication process of the virus strains will be studied at the molecular level. The multiplication of the virus is conditioned by the transcription of viral RNA and the translation of the viral protein. Both of these processes will be studied separately in cellular and extracellular model systems. A thorough understanding of the mechanisms of movement and replication of PVY strains in plants with different levels of resistance may answer the question about the reasons for the replacement of “old” PVY strains by new ones. Knowledge about the speed of movement, distribution and concentration of viruses during plant development can also have an important practical dimension.
Basic research planned to be implemented in the project
The initial stage of the research will involve the purification of preparations of PVY strains from infected plants by organic extraction, differential centrifugation and sucrose gradient centrifugation. Genomes of purified strains will be sequenced and compared to PVY genomes deposited in an online gene bank by researchers from around the world. This will allow strict genetic definition of the tested PVY isolates. The rest of the research work will be divided into three stages. First, the rate of movement of PVY strains will be assessed, as well as the efficiency of their replication in primary infected potato plants, differing in their degree of resistance to PVY. In the second stage, the same processes will be studied in secondary infested plants where the source of infection will be sick minibulbs. The aim of the third stage will be to analyze the replication efficiency of PVY strains at the molecular level using a cellular system – suspension culture and extracellular protein translation system in vitro.
Reasons for undertaking research on translocation and replication in PVY strains
The biological reasons for the rapid spread of new PVY strains are unknown. New strains can break down plant resistance and displace old variants by genetic changes resulting in increased virus replication rates and its faster and more efficient movement in the infected plant. Hence, examining the dynamics of these phenomena during primary and secondary infection caused by the most important strains of PVY in varieties with differentiated resistance may bring important knowledge about the biology of these important pathogens. Knowledge of the concentration and distribution of the virus at all developmental stages will allow to assess from which floors to take samples from plants of different ages and to which stage their testing makes diagnostic sense. In addition, the implementation of the project will allow to gain detailed knowledge about the molecular mechanisms of transport and replication of PVY strains, which may be important in the future for growing new, more resistant varieties.