Development of Tolcv-resistance Transgenic Tomato Plants by Amirnas

Diseases caused by geminiviruses which are transmitted by whiteflies, leafhoppers or treehoppers greatly affect the yield of infected crops leading to enormous economic loss. The diseases have been so serious to their host crops that novel combating methods need to be developed in order to contain them. The discovery of RNAi, especially the microRNA (miR) mechanism, has opened a new era for plant virus combat since amiRs have been implicated as useful candidates to silence genes of agricultural interests. And transgenic plants harboring artificial miRs (amiRs) have shown brilliant promises of virus resistance. As the pre-coat (AV2) protein is also a candidate RNAi suppressor encoded by a geminivirus, Tomato leaf curl virus (ToLCV) and overlaps with the coat protein gene AV1, in the present study, we sought to investigate whether the AV2-amiR strategy could be extended further in a similar manner to achieve broad spectrum resistance against ToLCVs. We designed and applied amiRs for targeting the AV1 and AV2 genes of ToLCV and generated tomato transgenic lines which would over express the amiRs. These lines were then used for testing ToLCV resistance under glass-house conditions.