title: The C-terminal motif of SiAGO1b is required for the regulation of growth, development and stress responses in foxtail millet (Setaria italica (L.) P. Beauv).
abstract: Foxtail millet (Setaria italica (L.) P. Beauv), which belongs to the Panicoideae tribe of the Poaceae, is an important grain crop widely grown in Northern China and India. It is currently developing into a novel model species for functional genomics of the Panicoideae as a result of its fully available reference genome sequence, small diploid genome (2n=18, ~510Mb), short life cycle, small stature and prolific seed production. Argonaute 1 (AGO1), belonging to the argonaute (AGO) protein family, recruits small RNAs and regulates plant growth and development. Here, we characterized an AGO1 mutant (siago1b) in foxtail millet, which was induced by ethyl methanesulfonate treatment. The mutant exhibited pleiotropic developmental defects, including dwarfing stem, narrow and rolled leaves, smaller panicles and lower rates of seed setting. Map-based cloning analysis demonstrated that these phenotypic variations were attributed to a C-A transversion, and a 7-bp deletion in the C-terminus of the SiAGO1b gene in siago1b Yeast two-hybrid assays and BiFC experiments revealed that the mutated region was an essential functional motif for the interaction between SiAGO1b and SiHYL1. Furthermore, 1598 differentially expressed genes were detected via RNA-seq-based comparison of SiAGO1b and wild-type plants, which revealed that SiAGO1b mutation influenced multiple biological processes, including energy metabolism, cell growth, programmed death and abiotic stress responses in foxtail millet. This study may provide a better understanding of the mechanisms by which SiAGO1b regulates the growth and development of crops.
authors.affiliation: Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Xiaotong
authors.initials: X
authors.lastname: Liu
authors.affiliation: Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Sha
authors.initials: S
authors.lastname: Tang
authors.affiliation: Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Guanqing
authors.initials: G
authors.lastname: Jia
authors.affiliation: Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China. Agronomy & Horticulture, University of Nebraska-Lincoln, Beadle Center E207, Lincoln, NE 68583-0660, USA.
authors.forename: James C
authors.initials: JC
authors.lastname: Schnable
authors.affiliation: Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Haixia
authors.initials: H
authors.lastname: Su
authors.affiliation: Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Chanjuan
authors.initials: C
authors.lastname: Tang
authors.affiliation: Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China. zhihui@caas.cn diaoxianmin@caas.cn.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhi
authors.affiliation: Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China. zhihui@caas.cn diaoxianmin@caas.cn.
authors.forename: Xianmin
authors.initials: X
authors.lastname: Diao
mesh_terms: D000595:Amino Acid Sequence; D060565:Argonaute Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment; D032983:Setaria Plant / Q000235:genetics / Q000254:growth & development / Q000502:physiology*
chemical_list: D060565:Argonaute Proteins; D010940:Plant Proteins
keywords: AGO1; EMS mutant; HYL1; RNA-seq.; development; foxtail millet; growth; map-based cloning