Establishment of efficient Trichosanthes mottle mosaic virus-derived gene silencing in cucurbit plants.

The Cucurbitaceae family includes a wide range of economically important fruits and vegetables; however, the laborious and highly inefficient genetic transformation efficacy of cucurbits has hindered the exploration of their gene functions. Virus-induced gene silencing (VIGS) technology, employed from the antiviral RNA silencing defense, has emerged as a viable alternative for high-throughput study of plant gene function. In this study, we successfully established a VIGS system utilizing Trichosanthes mottle mosaic virus (TrMMV), a new member of the genus Tobamovirus. We demonstrated the high efficacy and durability of gene silencing mediated by the TrMMV-VIGS vector in Nicotiana benthamiana, as well as in several cucurbit species, including Cucurbita pepo, Cucumis sativus, C. lanatus, and C. melo. The insertion of 90-400 bp fragments into the vector led to effective silencing of the target gene in both C. sativus and C. melo, with a notably higher silencing efficiency observed in C. melo. Furthermore, the TrMMV-VIGS vector induced a pronounced photobleaching phenotype in the flowers of C. melo, underscoring its potential application in functional genomic research concerning floral traits in this particular species. Taken together, the TrMMV-VIGS system developed herein will facilitate rapid and high-throughput identification of gene functions in cucurbit crops.