title: Repression of callus initiation by the miRNA-directed interaction of auxin-cytokinin in Arabidopsis thaliana.
abstract: In tissue culture systems plant cells can be induced to regenerate to whole plants. A particularly striking example of cellular reprogramming is seen in this regeneration process, which typically begins with the induction of an intermediate cell mass referred to as callus. The identity of the key genetic cues associated with callus formation is still largely unknown. Here a microRNA-directed phytohormonal interaction is described which represses callus initiation and formation in Arabidopsis thaliana. miR160 and ARF10 (At2g28350), a gene encoding an auxin response factor, were shown to exhibit a contrasting pattern of transcription during callus initiation from pericycle-like cells. The callus initiation is faster and more prolific in a miR160-resistant form of ARF10 (mARF10), but slower and less prolific in the transgenic line over-expressing miR160c (At5g46845), arf10 and arf10 arf16 mutants than that in the wild type. ARF10 repressed the expression of Arabidopsis Response Regulator15 (ARR15, At1g74890) via its direct binding to the gene's promoter. The loss of function of ARR15 enhanced callus initiation and partly rescued the phenotype induced by the transgene Pro35S:miR160c. Overexpression of ARR15 partly rescues the callus initiation defect of mARF10 plants. Our findings define miR160 as a key repressor of callus formation and reveal that the initiation of callus is repressed by miR160-directed interaction between auxin and cytokinin.
authors.affiliation: The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, School of Life Sciences, Shandong University, Jinan, Shandong, China.
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Liu
authors.affiliation: The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, School of Life Sciences, Shandong University, Jinan, Shandong, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Li
authors.affiliation: The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, School of Life Sciences, Shandong University, Jinan, Shandong, China.
authors.forename: Long
authors.initials: L
authors.lastname: Wang
authors.affiliation: The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, School of Life Sciences, Shandong University, Jinan, Shandong, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
authors.affiliation: The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, School of Life Sciences, Shandong University, Jinan, Shandong, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Lu
authors.affiliation: The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, School of Life Sciences, Shandong University, Jinan, Shandong, China.
authors.forename: Yanchong
authors.initials: Y
authors.lastname: Yu
authors.affiliation: The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, School of Life Sciences, Shandong University, Jinan, Shandong, China.
authors.forename: Shuo
authors.initials: S
authors.lastname: Li
authors.affiliation: The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, School of Life Sciences, Shandong University, Jinan, Shandong, China.
authors.forename: Ming-Yi
authors.initials: MY
authors.lastname: Bai
authors.affiliation: Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China.
authors.forename: Yuxin
authors.initials: Y
authors.lastname: Hu
authors.affiliation: The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, School of Life Sciences, Shandong University, Jinan, Shandong, China. xfn0990@sdu.edu.cn.
authors.forename: Fengning
authors.initials: F
authors.lastname: Xiang
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D003583:Cytokinins / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D010937:Plant Growth Regulators / Q000378:metabolism*; D012038:Regeneration; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: C505216:ARF10 protein, Arabidopsis; D029681:Arabidopsis Proteins; D003583:Cytokinins; D007210:Indoleacetic Acids; D035683:MicroRNAs; D010937:Plant Growth Regulators; D014157:Transcription Factors; C000613513:microRNA162, Arabidopsis
keywords: ARF10; Arabidopsis thaliana; auxin; auxin-cytokinin interaction; callus; cytokinin; miR160