title: Identification and characterization of Dicer-like, Argonaute and RNA-dependent RNA polymerase gene families in maize.
abstract: Eukaryotic gene expression is regulated at least by two processes, RNA interference at the post-transcriptional level and chromatin modification at the transcriptional level. Distinct small RNAs (approximately 21-24 nucleotides; sRNAs) were demonstrated to play vital roles in facilitating gene silencing. In plants, the generation of these sRNAs mainly depends on some proteins encoded by respective Dicer-like (DCL), Argonaute (AGO) and RNA-dependent RNA polymerases (RDR) gene families. Here, we analyzed the DCL, AGO and RDR gene families in maize, including gene structure, phylogenetic relationships, protein conserved motifs and genomic localization among gene family members. A total of 5 Zmdcl, 18 Zmago and 5 Zmrdr genes were identified in maize. Phylogenetic analyses clustered each of these genes families into four subfamilies. In addition, gene chromosomal localization revealed that five pairs of Zmago genes resulted from tandem or segmental duplication, respectively. EST expression data mining revealed that these newly identified genes had temporal and spatial expression pattern. Furthermore, the transcripts of these genes were detected in the leaves by two different abiotic stress treatments using semi-quantitative RT-PCR. The data demonstrated that these genes exhibited different expression levels in stress treatments. The results of this study provided basic genomic information for these gene families and insights into the probable roles of these genes in plant growth and development. This will further provide a solid foundation for future functional genomics studies of Dicer-like, Argonaute and RDR gene families in maize.
authors.affiliation: Key Laboratory of Crop Biology, Anhui Agricultural University, Hefei, China. qianyexiong@yahoo.com.cn
authors.forename: Yexiong
authors.initials: Y
authors.lastname: Qian
authors.forename: Ying
authors.initials: Y
authors.lastname: Cheng
authors.forename: Xiao
authors.initials: X
authors.lastname: Cheng
authors.forename: Haiyang
authors.initials: H
authors.lastname: Jiang
authors.forename: Suwen
authors.initials: S
authors.lastname: Zhu
authors.forename: Beijiu
authors.initials: B
authors.lastname: Cheng
mesh_terms: D000595:Amino Acid Sequence; D032461:Chromosomes, Plant / Q000235:genetics; D017124:Conserved Sequence; D020224:Expressed Sequence Tags; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D008969:Molecular Sequence Data; D005810:Multigene Family; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D012324:RNA-Dependent RNA Polymerase / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment; D020539:Sequence Analysis, Protein; D003313:Zea mays / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D012324:RNA-Dependent RNA Polymerase