1Division of Plant pathology, Indian Agricultural Research Institute, New Delhi-110012
2Division of Biochemistry, Indian Agricultural Research Institute, New Delhi-110012, India.
Abstracts of the papers presented at the International Conference of Indian Virological Society on “Emerging and Re-emerging viral Diseases of the Tropics and Subtropics” at Indian Agricultural Research Institute, New Delhi, India, December 11–14, 2007.
In eukaryotes, RNA silencing is an evolutionary conserved surveillance system triggered by small non-coding RNAs regulating various processes including development, maintenance of genome integrity and antiviral responses. A number of silencing suppressor proteins of viral origin have been identified so for, however, molecular basis of silencing suppression is poorly understood. Here we show that HcPro of Papaya ring spot virus (PRSV) inhibit RNA silencing by targeting the dsRNAs. Expression of the suppressor protein of PRSV in plants interfered with miRNA controlled developmental pathways that share components with antiviral RNA silencing pathway. In addition, HcPro enhanced the RNA accumulation of a heterologous virus (CMV). Symptomatology and replication of PRSV was studied at different temperature profile suggesting an optimum temperature requirement to establish the virus infection and multiplication. It will be interesting to correlate the temperature and small RNA binding ability of HcPro with antiviral response via RNAi.
