|Dr. Richard Kormelink
|"Plant viruses: a biological-mechanistic and evolutionary perspective on their default status"
But what is the default status of a virus? Most plant viruses are known from acute infections leading to disease. During food crop production these diseases are most effectively combatted by introgression breeding of dominant resistance (R) genes, encoding intracellular sensors of innate immunity with structural similarity to toll-like receptors from vertebrate systems, and/or avoiding the infestation of crops by insects that transmit the virus. In the absence of R genes, plants defend themselves against viral infections by antiviral RNAi or other non-host resistance mechanisms.
In contrast to plant viral diseases, more and more cases of plant viral latency/persistency are observed in which disease is not the outcome. In some of these, instead, even beneficial effects to the plant host are observed, e.g. drought resistance, larger seeds, increased pollination. Nowadays, the discovery of viruses that do not immediately cause disease is boosted by metagenomics and high throughput sequencing (HTS) efforts that help to decipher the virome of many different plant, animal and insect species. Large genome sequencing projects additionally have revealed the presence of (copy) DNA sequences in the genome of many different plant species, from DNA and even RNA viruses. Whether these are actively transcribed and play a role in development and/or homeostasis is hardly studied.
So could it be that the natural default status of plant viruses is latency/persistency, and (how) do copy DNA sequences from (partial) viral genome sequences, endogenized in the genome of many different plant species, or other mechanisms play a role in the establishment/maintenance of latency/persistency? Several cases will be discussed.
|グローバルイノベーション研究院 食料分野 福原チーム
|グローバルイノベーション研究院・農学研究院 福原 敏行
e-mail: fuku( ここに @ を入れてください）cc.tuat.ac.jp