Plant Virology Lab (PVL) has studied on how to solve various problems caused by plant viruses with a translational biological perspective. We have continued to carry out researches by bringing problems from the field to our lab and applying the technology developed in our lab back to the site. Among the plant viruses, geminiviruses and nanoviruses, which have single-stranded DNA as genomes, have been mainly focused on in our studies. We are investigating the outbreak status of those viruses in Asia and many other countries, including Korea, and developing diagnostic systems that can accurately carry out, and conducting researches on virus resistance in host plants and disease symptom development mechanisms of those viruses.

Due to climate change and the creating of new income sources, tropical and subtropical crops that were not cultivated in Korea continue to be introduced and cultivated. In the process of introducing these new crops mainly from Southeast Asia, ssDNA viruses infecting introducing plants have been continuously inflowed together. EuLCV and PaLCGdV, which flowed into Korea in the process of introducing papaya and passion fruit, are typical examples. New outbreaks of these ssDNA viruses have been constantly identified, and pathological characteristics of these viruses have been studied (host range, transmission, etc.). In addition, in order to proactively respond to viruses that have not yet been introduced into the country but are highly likely to be introduced, research is being carried out continuously on characterization of viruses that occur mainly in the region through joint research with researchers from Asian and European countries (Myanmar, Bangladesh, Pakistan, Indonesia, Thailand, Taiwan, Vietnam and Italy).

Many plant viruses are transmitted by insects, and sap and seeds of infected plants can also act as inoculation sources. It is known that only a few plant viruses can be transmitted through infected seeds. Seed transmissions have been newly identified and reported for ssDNA viruses (TYLCV, ToLCNDV, SPLCV and PepYLCIV) that have not been reported to date. My research is being conducted on what plant factors are involved in the process of seed transmission. In addition, insect vector-mediated transmission of some viruses can only be occurred by certain insect species or biotype (quasispecies), and transmission pattern varies depending on the distribution of certain microorganism populations in insects. Research on analyzing the mechanism by focusing on the interaction of the ssDNA virus with the vector insect is also being carried out continuously.

For accurate virus control, it is important to understand not only the virus, but also the insect vectors that transmit the virus and the host plants that are infected. In particular, since weeds and other crops that are not major host crops can act as intermediate hosts to help spread the virus, research on it is also very important to identify and analyze host weeds. Various weeds that grow naturally in Korea have been analyzed how they can act as virus infection sources by linking them to their life cycle. Even though the same virus species are infected, they can show different aspects in symptom development with a few differences in the genome sequence. The interaction analysis between ssDNA virus and host plant is conducted, including research on the mechanism of symptom development by using natural mutants and artificially point-mutated viruses. In addition, studies are underway on what key elements in virus-tolerant plants are limiting viral replication.

Almost all of the ssDNA viruses are transmitted by viruliferous insect vectors such as whitefly, and are known not to be transmitted by mechanical sap inoculation. For the study on viruses, smooth viral infections to plants must come first, and it is very difficult to obtain and maintain insect vectors for all viruses in order to infect a virus that is not mechanically transmitted. In this case, infectious clones, which can be produced by cloning the ssDNA virus genome to the binary vector and then transforming it into an agrobacterium, can be used as an easily available source of infection. Modifying some of viral genes in this source makes it easier to study various functions. By producing and securing infectious clones of ssDNA viruses occurring at home and abroad, it is laying the foundation for use in various researches.

For virus diagnosis, methods based on nucleic acid amplification and antigen-antibody reaction are mainly used. The nucleic acid amplification-based diagnostic methods are used for many diagnoses due to their high accuracy, but it is known as a technology more suitable for diagnosing in the laboratory than in the field. Using isothermal amplification technologies such as loop-mediated amplification (LAMP) and recombinase polymerase amplification (RPA), developing system that can diagnose viruses quickly and accurately in the field is carried out continuously. In addition, it is being conducted to develop an on-site diagnostic kit with recombinant scFv antibody protein, which can be uniquely bound to a specific virus protein, produced by expressing in E. coli after selecting using the phage display technology. In addition, virome analysis, which analyzes virus populations in symptomatic plants based on next generation sequencing technology, is also conducted from plants and insect vectors.