Trans-Dominant Interference by Synthetic Coat Protein of Tomato Yellow Leaf Curl Virus Expressed in Transgenic Tomato

Begomoviruses are the main biotic threat of tomatoes, resulting in substantial losses worldwide. The coat protein is the most conserved protein in begomoviruses and is essentially required by monopartite begomoviruses for infection in susceptible plants. Its expression in transgenic plants may interfere with the uncoating of the viral DNA upon infection. A study was conducted to investigate the effect of expressing viral coat protein in transgenic plants on the induction of resistance to Tomato yellow leaf curl virus Oman (TYLCV-OM). The synthetic codon-optimized coat protein (CP_syn) of TYLCV-OM was transformed into Tomato var. Pusa Ruby using Agrobacterium. CPsyn was expressed in transgenic tomato plants to avoid gene silencing of the transgene upon virus infection. T1 transgenic lines were challenged with TYLCV-OM for resistance evaluation. Plants of three transgenic lines out of seven showed resistance response and most plants did not develop disease symptoms. Real-time quantitative PCR showed that the CPsyn helped reduce virus particles by 150-fold. Transforming tomato plants with CPsyn resulted in the induction of resistance to TYLCV-OM. The transgenic plants are valuable resource to understand the function of the coat protein and to provide resistance against the main begomoviruses infecting tomatoes.