title: Germostatin resistance locus 1 encodes a PHD finger protein involved in auxin-mediated seed dormancy and germination.
abstract: Seed dormancy and germination are important physiological processes during the life cycle of a seed plant. Recently, auxin has been characterized as a positive regulator that functions during seed dormancy and as a negative regulator during germination. Through chemical genetic screenings, we have identified a small molecule, germostatin (GS), which effectively inhibits seed germination in Arabidopsis. GSR1 (germostatin resistance locus 1) encodes a tandem plant homeodomain (PHD) finger protein, identified by screening GS-resistant mutants. Certain PHD fingers of GSR1 are capable of binding unmethylated H3K4, which has been reported as an epigenetic mark of gene transcriptional repression. Biochemical studies show that GSR1 physically interacts with the transcriptional repressor ARF16 and attenuates the intensity of interaction of IAA17/ARF16 by directly interacting with IAA17 to release ARF16. Further results show that axr3-1, arf10 arf16 are hyposensitive to GS, and gsr1 not only resists auxin-mediated inhibition of seed germination but also displays decreased dormancy. We therefore propose that GSR1 may form a co-repressor with ARF16 to regulate seed germination. Besides promoting auxin biosynthesis via upregulating expression of YUCCA1, GS also enhances auxin responses by inducing degradation of DΙΙ-VENUS and upregulating expression of DR5-GFP. In summary, we identified GSR1 as a member of the auxin-mediated seed germination genetic network, and GS, a small non-auxin molecule that specifically acts on auxin-mediated seed germination.
authors.affiliation: Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, 200032, Shanghai, China.
authors.forename: Yajin
authors.initials: Y
authors.lastname: Ye
authors.affiliation: Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, 200032, Shanghai, China.
authors.forename: Ziying
authors.initials: Z
authors.lastname: Gong
authors.affiliation: Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, 200032, Shanghai, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Lu
authors.affiliation: Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, 200032, Shanghai, China.
authors.forename: Deyan
authors.initials: D
authors.lastname: Miao
authors.affiliation: Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, 200032, Shanghai, China.
authors.forename: Jianmin
authors.initials: J
authors.lastname: Shi
authors.affiliation: Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, 200032, Shanghai, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Lu
authors.affiliation: Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, 200032, Shanghai, China.|Faculty of Life Science and Technology, Kunming University of Science and Technology, 68 Wenchang Road, 650000, Yunnan, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D056970:Co-Repressor Proteins / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D053263:Gene Regulatory Networks; D017930:Genes, Reporter; D018525:Germination; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D007210:Indoleacetic Acids / Q000378:metabolism*; D009154:Mutation; D057445:Plant Dormancy; D010937:Plant Growth Regulators / Q000378:metabolism*; D012639:Seeds / Q000235:genetics / Q000502:physiology; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics; D014158:Transcription, Genetic
chemical_list: D029681:Arabidopsis Proteins; D056970:Co-Repressor Proteins; C000616711:GSR1 protein, Arabidopsis; D018398:Homeodomain Proteins; D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; D014157:Transcription Factors
keywords: Arabidopsis thaliana; PHD finger; auxin; chemical genetics; seed germination and dormancy; small molecule