A novel zinc-finger protein with a proline-rich domain mediates ABA-regulated seed dormancy in Arabidopsis.
Seed dormancy is an important developmental process that prevents pre-harvest sprouting in many grains and other seeds. Abscisic acid (ABA), a plant hormone, plays a crucial role in regulating dormancy but the underlying molecular regulatory mechanisms are not fully understood. An Arabidopsis zinc-finger gene, MEDIATOR OF ABA-REGULATED DORMANCY 1 ( MARD1 ) was identified and functionally analyzed. MARD1 expression is up-regulated by ABA. A T-DNA insertion in the promoter region downstream of two ABA-responsive elements (ABREs) renders MARD1 unable to respond to ABA. The mard1 seeds are less dormant and germinate in total darkness; their germination is resistant to external ABA at the stage of radicle protrusion. These results suggest that this novel zinc-finger protein with a proline-rich N-terminus is an important downstream component of the ABA signaling pathway that mediates ABA-regulated seed dormancy in Arabidopsis.
He
Yuehui
Y
Plant Physiology/Biochemistry/Molecular Biology Program, University of Kentucky, Lexington, KY 40546-0236, USA.
Gan
Susheng
S
D000040:Abscisic Acid / Q000494:pharmacology*; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics*; D001665:Binding Sites / Q000235:genetics; D002352:Carrier Proteins / Q000235:genetics*; D003624:Darkness; D004351:Drug Resistance; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005816:Genetic Complementation Test; D018525:Germination / Q000187:drug effects / Q000235:genetics / Q000528:radiation effects; D005966:Glucuronidase / Q000235:genetics / Q000378:metabolism; D008027:Light; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D010937:Plant Growth Regulators / Q000494:pharmacology; D030821:Plants, Genetically Modified; D011392:Proline / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012639:Seeds / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development; D017386:Sequence Homology, Amino Acid; D016335:Zinc Fingers / Q000235:genetics*
D029681:Arabidopsis Proteins; D002352:Carrier Proteins; C491109:MARD1 protein, Arabidopsis; D010937:Plant Growth Regulators; D011993:Recombinant Fusion Proteins; D000040:Abscisic Acid; D011392:Proline; D005966:Glucuronidase