Investigation of activity of Tobamovirus in pepper plants containing L4 resistance gene

Abstract

Pepper mild mottle virus (PMMoV) is a plant virus belonging to the Virgaviridae family; it significantly reduces pepper yield production worldwide. The PMMoV is spread by contaminated seeds and there is no chemical treatment available. Therefore, resistant pepper varieties containing the L4 gene are recommended for the management of PMMoV. A considerable amount of evidence suggests that the L4 gene confers resistance to PMMoV in pepper. The aim of the project is to confirm the status of the L4 gene for resistance to PMMoV in pepper varieties, several inoculations were performed on pepper plants containing L3, L4 resistant genes and susceptible pepper plants without the resistance genes. The L4 resistant plants produced mottling, mosaic, leaf curl, stem necrosis symptoms in the tested pepper plants but there was no amplicon observed with specific primers of PMMoV in RT-PCR analyses. To determine if the L3 and L4 genes are controlling resistance to PMMoV, RT-PCR analyzes were conducted using PMMoV and Tomato brown rugose fruit virus (ToBRFV) where both viruses belong to the same family. The molecular studies revealed that the L4 gene controls resistance mechanisms to PMMoV but it is not able to govern Tobamovirus, ToBRFV. We showed that pepper plants harboring the L3 and L4 gene have the ability to precisely control the mechanism of resistance to PMMoV compared to pepper plants carrying only the L3 gene. A complete genome sequence of PMMoV was obtained and submitted to Genbank with MW523006 accessıon number in the NCBI system.