tailieunhanh - báo cáo hóa học:" RNAi dependent epigenetic marks on a geminivirus promoter"

Tuyển tập các báo cáo nghiên cứu về hóa học được đăng trên tạp chí sinh học đề tài :RNAi dependent epigenetic marks on a geminivirus promoter | Virology Journal BioMed Central Short report Open Access RNAi dependent epigenetic marks on a geminivirus promoter Afzal Muhammad Dogar Address Swiss Institute for Experimental Cancer Research ISREC Ch. des Boveresses 155 CH-1066 Epalinges Switzerland Email Afzal Muhammad Dogar - Corresponding author Published 30 January 2006 Received 21 June 2005 Accepted 30 January 2006 Virology Journal 2006 3 5 doi I743-422X-3-5 This article is available from http content 3 1 5 2006 Dogar licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License http licenses by which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. Abstract Nicotiana benthamiana plants were stably transformed with an intron-spliced dsRNA producing construct cognate to bidirectional promoter of African cassava mosaic geminivirus ACMV DNA A. Transgenic lines expressed multiple siRNAs species upon ACMV infection. The de novo DNA methylation and an increased proportion of histone H3 Lysine-9 methylation H3K9 at intergenic region IGR of ACMV DNA A were observed. Introduction In plants RNA interference or post transcriptional gene silencing PTGS acts as a natural anti-viral defense system for neutralizing pathogenic nucleic acids either through a change in RNA stability in the cytoplasm or through mechanisms that use the RNA itself to induce methylation and silencing of homologous nuclear genes 1 . In addition there are more than one Dicer and Argonaute proteins in plants . Arabidopsis genome encodes four Dicers 2 and ten Argonate orthologs 3 . Geminiviruses are single-stranded circular DNA viruses that cause economically significant diseases in a wide range of crop plants worldwide 4 . They replicate in the plant cell nuclei through transcription and replication competent double stranded DNA .