Cloning and molecular characterization of TaAGO1, a member of argonaute gene family in wheat (Triticum aestivum L.)

摘要

Argonaute (AGO) proteins play important roles in RNA silencing processes through formation of complexes with the mature microRNAs. In this study, a wheat AGO gene referred to?TaAGO1, which shares high similarities to?AtAGO1?in Arabidopsis and?OsAGO1?in rice, was characterized. As a cDNA full length of 3747 bp,TaAGO1?encodes a 1099-aa polypeptide with a molecular weight of 122 kD and an isoelectric point (pI) of 9.52. Subcellular prediction analysis suggests that?TaAGO1is to target onto the cytoplasm after?endoplasmic reticulum?(ER) sorted. Similar to AtAGO1 and OsAGO1,?TaAGO1?contains PIWI and DDH, two conserved domains in AGOs. Phylogenetic analysis indicated that?TaAGO1?was possibly derived from different progenitors with its homologous across diverse plant species. The transcripts of?TaAGO1?were significantly regulated by the stresses of phosphorus deprivation and dehydration, and exogenous treatment of abscisic acid (ABA), suggesting that this wheat AGO member also exerts roles on mediating above signaling transductions. Southern blotting analysis revealed that genome AA, SS, and DD, three diploids composing of the hexaploid wheat, all harbored two copies of?TaAGO1. Down-regulation of?TaAGO1?in?wheat led to conspicuously phenotypic alterations of the young plantlets, with a variety of abnormal growth features. Taking the results in this study together, it?was?implicated that?TaAGO1?exists as a subset of copies in wheat and plays critical roles on silencing of?appropriate?target genes via regulation of?TaAGO1-MiRNAs complex formation.