Monitoring infection of tomato fruit by Tomato yellow leaf curl virus

Abstract

Fruit constitutes a strong sink organ and thus accumulates infecting viruses, but there is limited information about the infection process of viruses in fruit. Tomato yellow leaf curl virus (TYLCV, genus Begomovirus, family Geminiviridae) is one of the most important viruses affecting the production of tomato fruit. Using real-time quantitative PCR, TYLCV was shown to accumulate with increasing titres in early developing tomato fruit tissues from anthesis until 21 days post-anthesis. In situ hybridization demonstrated that TYLCV DNA and transcripts of the coat protein gene localized specifically to the phloem tissue of young fruit as well as sepals and petals. Embryos of developing seeds were also found to be infected. Expression of a host histone H4 gene was used as a marker for S-phase and the gene was also found to be expressed in phloem cells of young tomato fruit. The results indicate that TYLCV is transported to developing tomato fruit, where the virus titre gradually increases because of movement and probably also due to virus replication. In this study, the accumulation and localization of TYLCV in early developing tomato fruit are monitored for the first time.

No Evidence for Seed Transmission of Tomato Yellow Leaf Curl Sardinia Virus in Tomato

“…The same is true for virus-localization studies in seeds and embryos, often considered the proof for seed transmissibility. Indeed, TYLCV DNA has been detected in the embryos of infected tomato seeds using in situ hybridization [ 35 ], a technique that cannot selectively discriminate if whole molecules are present in the observed tissues.…”

Emerging evidence of seed transmission of begomoviruses: implications in global circulation and disease outbreak

“…Whitefly transmission of TYLCV was also observed from symptomatic and asymptomatic seedlings raised from infected seeds to healthy tomato plants, which strengthen the concept that offsprings from infected tomato plant can act as a source of inoculum for B. tabaci-mediated transmission. Just et al (2017) demonstrated the localization of TYLCV DNA and transcripts of the CP gene specifically to the phloem tissue of young fruit, sepals, petals, and embryo of developing tomato seed through in situ hybridization experiments. The accumulation of TYLCV with increasing titers was observed in early developing tomato fruit tissues from anthesis until 21 days post-anthesis through qPCR (Kil et al, 2017(Kil et al, , 2018.…”