P-259 - Susceptibility (S) genes for durable virus disease resistance in tomato

Tomato is one of the most produced vegetable crops in the world and is affected by global disease outbreaks caused by viruses, such as begomoviruses (DNA viruses) and tobamoviruses (RNA viruses). Viral genomes, like TYLCV, ToLCNDV and ToBRFV encode only a small number (5-10) of proteins. Therefore, viruses fully depend on host proteins encoded by susceptibility (S-)genes for their proliferation and disease development. We aim to identify tomato genotypes with durable resistance to viral diseases by using impaired plant susceptibility (S) genes. Thus far only a few S-genes have been identified. Pelota (ty-5), encodes a messenger RNA (mRNA) surveillance factor, and a mutation in Pelota causes tolerance to TYLCV disease. PRiL (DNA primase large subunit) was identified as an S-gene for ToLCNDV in melon and Tom1/3 and Tom2a are S-genes for ToBRFV. We have identified additional S-gene mutants by forward genetics for TYLCV, and by reverse genetics for TYLCV, ToLCNDV and ToBRFV. Since plant S-genes are shown to be conserved across plant species, the identified S-genes and their mechanistic knowledge can be transferred to other crops.