[Cloning and sequence analysis of AGO1 gene in Panax ginseng]

Argonaute 1 (AGO1) is a core component of the RNA-induced silencing complex (RISC) which plays a crucial role in small RNA-mediated gene silencing. AGO1 gene has been characterized in various plants, such as Arabidopsis and rice. However, there is no information about AGO1 in the medicinal plant species, Panax ginseng. Using the rapid amplification of cDNA ends technology (RACE), we cloned full-length PgAGO1 cDNA from Panax ginseng. It is 3 776 bp in length, including 204 bp of 5' UTR, 254 bp of 3' UTR, and 3 318 bp of ORF encoding 1106 amino acids. The molecular weight (MW) and theroretical isoelectric point (pI) of the deduced PgAGO1 protein is 122.22 kDa and 9.71, respectively. PgAGO1 shares 91.72% similarity with Arabidopsis AtAGO1 and contains three consered domains, including DUF1785, PAZ and Piwi, suggesting it is an authentic AGO. PgAGO1 was expressed in all of the tissues analyzed with the highest level in flowers and the lowest level in roots. The results provide useful information for further elucidating the function of AGO1 in Panax ginseng.