title: Biphasic regulation of the transcription factor ABORTED MICROSPORES (AMS) is essential for tapetum and pollen development in Arabidopsis.
abstract: Viable pollen is essential for plant reproduction and crop yield. Its production requires coordinated expression at specific stages during anther development, involving early meiosis-associated events and late pollen wall formation. The ABORTED MICROSPORES (AMS) transcription factor is a master regulator of sporopollenin biosynthesis, secretion and pollen wall formation in Arabidopsis. Here we show that it has complex regulation and additional essential roles earlier in pollen formation. An inducible-AMS reporter was created for functional rescue, protein expression pattern analysis, and to distinguish between direct and indirect targets. Mathematical modelling was used to create regulatory networks based on wild-type RNA and protein expression. Dual activity of AMS was defined by biphasic protein expression in anther tapetal cells, with an initial peak around pollen meiosis and then later during pollen wall development. Direct AMS-regulated targets exhibit temporal regulation, indicating that additional factors are associated with their regulation. We demonstrate that AMS biphasic expression is essential for pollen development, and defines distinct functional activities during early and late pollen development. Mathematical modelling suggests that AMS may competitively form a protein complex with other tapetum-expressed transcription factors, and that biphasic regulation is due to repression of upstream regulators and promotion of AMS protein degradation.
authors: Division of Plant & Crop Sciences, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, Leicestershire, LE12 5RD, UK.
authors: Alison C
authors: AC
authors: Ferguson
authors: Faculty of Biology, University of Manchester, Michael Smith Building, Oxford Road, Manchester, M13 9PL, UK.|School of Mathematics, University of Manchester, Alan Turing Building, Oxford Road, Manchester, M13 9PL, UK.
authors: Simon
authors: S
authors: Pearce
authors: Division of Plant & Crop Sciences, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, Leicestershire, LE12 5RD, UK.|Centre for Plant Integrative Biology, University of Nottingham, Sutton Bonington Campus, Loughborough, Leicestershire, LE12 5RD, UK.|School of Mathematical Sciences, University of Nottingham, Nottingham, NG7 2RD, UK.
authors: Leah R
authors: LR
authors: Band
authors: Division of Plant & Crop Sciences, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, Leicestershire, LE12 5RD, UK.
authors: Caiyun
authors: C
authors: Yang
authors: Division of Plant & Crop Sciences, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, Leicestershire, LE12 5RD, UK.
authors: Ivana
authors: I
authors: Ferjentsikova
authors: Centre for Plant Integrative Biology, University of Nottingham, Sutton Bonington Campus, Loughborough, Leicestershire, LE12 5RD, UK.|School of Mathematical Sciences, University of Nottingham, Nottingham, NG7 2RD, UK.
authors: John
authors: J
authors: King
authors: Joint International Research Laboratory of Metabolic & Developmental Sciences, Shanghai Jiao Tong University-University of Adelaide Joint Centre for Agriculture and Health, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
authors: Zheng
authors: Z
authors: Yuan
authors: Joint International Research Laboratory of Metabolic & Developmental Sciences, Shanghai Jiao Tong University-University of Adelaide Joint Centre for Agriculture and Health, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
authors: Dabing
authors: D
authors: Zhang
authors: Division of Plant & Crop Sciences, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, Leicestershire, LE12 5RD, UK.|Centre for Plant Integrative Biology, University of Nottingham, Sutton Bonington Campus, Loughborough, Leicestershire, LE12 5RD, UK.
authors: Zoe A
authors: ZA
authors: Wilson
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism*; D003907:Dexamethasone / Q000494:pharmacology; D005298:Fertility / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D011058:Pollen / Q000187:drug effects / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D011485:Protein Binding / Q000187:drug effects; D059748:Proteolysis / Q000187:drug effects; D011993:Recombinant Fusion Proteins / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D051792:Basic Helix-Loop-Helix Proteins; D003907:Dexamethasone; D011993:Recombinant Fusion Proteins; C480845:AMS protein, Arabidopsis
keywords: 
  Arabidopsis thaliana
  ; aborted microspores (AMS); anther development; pollen development; regulatory network modelling; tapetum