Intron–hairpin RNA Derived from Replication Associated Protein C1 Gene Confers Immunity to Tomato Yellow Leaf Curl Virus Infection in Transgenic Tomato Plants

Abstract

The whitefly-transmitted Tomato Yellow Leaf Curl Virus (TYLCV) is the major pathogen of tomato crop in Cuba and one of the most outstanding viral diseases of plants worldwide. In this work, we have developed transgenic tomato plants, transformed with an intron-hairpin genetic construction to induce post- transcriptional gene silencing against the early TYLCV replication associated protein gene (C1). The intron-hairpin RNA produced involves 726 nts of the 3' end of the TYLCV C1 gene as the arms of the hairpin, and the castor bean catalase intron. Transgenic tomato plants belonging to line 126, which harbor a single transgene copy, showed immunity to TYLCV, even in extreme conditions of infection (4-leaf-stage plants and 300 to many hundreds viruliferous whiteflies per plant during 60 days). Dot blot hybridization of these plants showed no TYLCV DNA presence 60 days after inoculation. Small interfering RNA molecules were detected in both inoculated and non-inoculated plants from line 126. These transgenic tomato plants of the otherwise very TYLCV-susceptible Campbell-28 tomato cultivar, are the first report of resistance to a plant DNA virus obtained by the use of the intron-hairpin RNA approach.

Stability of Transgenic Resistance Against Plant Viruses

“…Taking into consideration these first studies several of the numerous succeeding reports (Fuentes et al, 2006;Germundsson & Valkonen, 2006;Praveen et al, 2010;Kawazu et al, 2009;Yang et al, 2004) of engineered transgenic resistance to plant viruses have examined the possible effect of heterologous virus infection in the resistance. However, not always an influence on resistance was observed.…”

RNA interference: concept to reality in crop improvement

“…There are many other transgenic plants with enhanced defence by RNAi-mediated gene silencing, such as Tomato Yellow Leaf Curl Virus (TYLC)-resistant tomato (Fuentes et al 2006), Rice Tungro Bacilliform Virus (RTBV)-resistant rice (Tyagi et al 2008) and Citrus Tristeza Virus (CTV)-resistant mexican lime (López et al 2010). Schwind et al (2009) have even shown that using hpRNA construct in Solanum lycopersicum (tomato) against Potato Spindle Tuber Viroid (PSTVd) produce PSTVd-resistant tomato plant varieties.…”

Banana bunchy top disease (BBTD) symptom expression in banana and strategies for transgenic resistance: A review

“…PTGS used in the development of resistance against the viruses ACMV (Vanitharani et al, 2003, Vanderschuren et al, 2007, mungbean yellow mosaic virus (MYMV) (Pooggin et al, 2003), Sri Lankan cassava mosaic virus (SLCMV), East African cassava mosaic virus (EACMV) , TYLCV (Abhary et al, 2006, Fuentes et al, 2006Zrachya et al, 2007), bean golden mosaic virus (BGMV) (Bonfim et al, 2007), and TLCV (Ramesh et al, 2007). Although only in its early stages, research utilizing this process to achieve virus resistance is very promising in that any viral coding or noncoding sequences can be targeted and no protein need be expressed.…”