The P0 gene of Sugarcane yellow leaf virus encodes an RNA silencing suppressor with unique activities.

The Sugarcane yellow leaf virus (SCYLV) P0, a member of the highly heterologous proteins of poleroviruses, is a suppressor of posttranscriptional gene silencing (PTGS) and has additional activities not seen in other P0 proteins. The P0 protein in previously tested poleroviruses (Beet western yellows virus and Cucurbit aphid-borne yellows virus), suppresses local, but not systemic, PTGS induced by both sense GFP and inverted repeat GF using its F-box-like domain to mediate destabilization of the Argonaute1 protein. We now report that the SCYLV P0 protein not only suppressed local PTGS induced by sense GFP and inverted repeat GF in Nicotiana benthamiana, but also triggered a dosage dependent cell death phenotype in infiltrated leaves and suppressed systemic sense GFP-PTGS.

Maize streak virus-resistant transgenic maize: a first for Africa.

In this article, we report transgene-derived resistance in maize to the severe pathogen maize streak virus (MSV). The mutated MSV replication-associated protein gene that was used to transform maize showed stable expression to the fourth generation. Transgenic T2 and T3 plants displayed a significant delay in symptom development, a decrease in symptom severity and higher survival rates than non-transgenic plants after MSV challenge, as did a transgenic hybrid made by crossing T2 Hi-II with the widely grown, commercial, highly MSV-susceptible, white maize genotype WM3.

Inhibition of maize streak virus (MSV) replication by transient and transgenic expression of MSV replication-associated protein mutants.

Maize streak disease is a severe agricultural problem in Africa and the development of maize genotypes resistant to the causal agent, Maize streak virus (MSV), is a priority. A transgenic approach to engineering MSV-resistant maize was developed and tested in this study. A pathogen-derived resistance strategy was adopted by using targeted deletions and nucleotide-substitution mutants of the multifunctional MSV replication-associated protein gene (rep).