title: Seed Embryo Development Is Regulated via anAN3-MINI3Gene Cascade.
abstract: In agriculture, seed mass is one of the most important components related to seed yield.MINISEED3(MINI3) which encodes the transcriptional activator WRKY10, is thought to be a pivotal regulator of seed mass. InArabidopsisSHORT HYPOCOTYL UNDER BLUE1 (SHB1) associates with the promoter ofMINI3, regulating embryo cell proliferation (both cell division and elongation), which, in turn, modulates seed mass. Furthermore, the recruitment of SHB1 via MINI3 to both its cognate promoter and that ofIKU2implies a two-step amplification for countering the low expression level ofIKU2, which is thought to function as a molecular switch for seed cavity enlargement. However, it is largely unknown how embryo cell proliferation, which encompasses both cell division and elongation, is regulated by SHB1 and MINI3 function. Here, we show that a loss of function mutation within the transcriptional coactivator ANGUSTIFOLIA3 (AN3), increases seed mass. Further, AN3 associates with theMINI3promoterin vivo. Genetic evidence indicates that the absence of MINI3 function suppresses the decrease of cell number observed inan3-4mutants by regulating cell division and in turn inhibits increased cell size of thean3-4line by controlling cell elongation. Thus, seed embryo development is modulated via anAN3-MINI3gene cascade. This regulatory model provides a deeper understanding of seed mass regulation, which may in turn lead to increased crop yields.
authors.affiliation: The Key Laboratory of Biotechnology for Medicinal Plant of Jiangsu Province, School of Life Science, Jiangsu Normal UniversityXuzhou, China; Centre for Transformational Biotechnology of Medicinal and Food Plants, Jiangsu Normal University - The University of EdinburghXuzhou, China.
authors.forename: Lai-Sheng
authors.initials: LS
authors.lastname: Meng
authors.affiliation: School of Bioengineering and Biotechnology, Tianshui Normal University Tianshui, China.
authors.forename: Yi-Bo
authors.initials: YB
authors.lastname: Wang
authors.affiliation: Centre for Transformational Biotechnology of Medicinal and Food Plants, Jiangsu Normal University - The University of EdinburghXuzhou, China; Institute of Molecular Plant Sciences, School of Biological Sciences, The University of EdinburghEdinburgh, UK.
authors.forename: Gary J
authors.initials: GJ
authors.lastname: Loake
authors.affiliation: The Key Laboratory of Biotechnology for Medicinal Plant of Jiangsu Province, School of Life Science, Jiangsu Normal UniversityXuzhou, China; Centre for Transformational Biotechnology of Medicinal and Food Plants, Jiangsu Normal University - The University of EdinburghXuzhou, China.
authors.forename: Ji-Hong
authors.initials: JH
authors.lastname: Jiang
keywords: ANGUSTIFOLIA3 (AN3); Arabidopsis; MINISEED3 (MINI3); embryo cell division; embryo cell elongation; seed mass