title: Map-Based Cloning of Seed Dormancy1-2 Identified a Gibberellin Synthesis Gene Regulating the Development of Endosperm-Imposed Dormancy in Rice.
abstract: Natural variation in seed dormancy is controlled by multiple genes mapped as quantitative trait loci in major crop or model plants. This research aimed to clone and characterize the Seed Dormancy1-2 (qSD1-2) locus associated with endosperm-imposed dormancy and plant height in rice (Oryza sativa). qSD1-2 was delimited to a 20-kb region, which contains OsGA20ox2 and had an additive effect on germination. Naturally occurring or induced loss-of-function mutations of the gibberellin (GA) synthesis gene enhanced seed dormancy and also reduced plant height. Expression of this gene in seeds (including endospermic cells) during early development increased GA accumulation to promote tissue morphogenesis and maturation programs. The mutant allele prevalent in semidwarf cultivars reduced the seed GA content by up to 2-fold at the early stage, which decelerated tissue morphogenesis including endosperm cell differentiation, delayed abscisic acid accumulation by a shift in the temporal distribution pattern, and postponed dehydration, physiological maturity, and germinability development. As the endosperm of developing seeds dominates the moisture equilibrium and desiccation status of the embryo in cereal crops, qSD1-2 is proposed to control primary dormancy by a GA-regulated dehydration mechanism. Allelic distribution of OsGA20ox2, the rice Green Revolution gene, was associated with the indica and japonica subspeciation. However, this research provided no evidence that the primitive indica- and common japonica-specific alleles at the presumably domestication-related locus functionally differentiate in plant height and seed dormancy. Thus, the evolutionary mechanism of this agriculturally important gene remains open for discussion.
authors.affiliation: Plant Science Department, South Dakota State University, Brookings, South Dakota 57007 (H.Y., J.F., L.Z., J.Z., M.S.M., X.-Y.G.);Agricultural College, Yangzhou University, Yangzhou 225009, China (Z.C., J.Y.); andDepartment of Agriculture, Southeast Missouri State University, Malden, Missouri 63863 (D.H.B.).
authors.forename: Heng
authors.initials: H
authors.lastname: Ye
authors.affiliation: Plant Science Department, South Dakota State University, Brookings, South Dakota 57007 (H.Y., J.F., L.Z., J.Z., M.S.M., X.-Y.G.);Agricultural College, Yangzhou University, Yangzhou 225009, China (Z.C., J.Y.); andDepartment of Agriculture, Southeast Missouri State University, Malden, Missouri 63863 (D.H.B.).
authors.forename: Jiuhuan
authors.identifier: http://orcid.org/0000-0002-8153-8691
authors.initials: J
authors.lastname: Feng
authors.affiliation: Plant Science Department, South Dakota State University, Brookings, South Dakota 57007 (H.Y., J.F., L.Z., J.Z., M.S.M., X.-Y.G.);Agricultural College, Yangzhou University, Yangzhou 225009, China (Z.C., J.Y.); andDepartment of Agriculture, Southeast Missouri State University, Malden, Missouri 63863 (D.H.B.).
authors.forename: Lihua
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Plant Science Department, South Dakota State University, Brookings, South Dakota 57007 (H.Y., J.F., L.Z., J.Z., M.S.M., X.-Y.G.);Agricultural College, Yangzhou University, Yangzhou 225009, China (Z.C., J.Y.); andDepartment of Agriculture, Southeast Missouri State University, Malden, Missouri 63863 (D.H.B.).
authors.forename: Jinfeng
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Plant Science Department, South Dakota State University, Brookings, South Dakota 57007 (H.Y., J.F., L.Z., J.Z., M.S.M., X.-Y.G.);Agricultural College, Yangzhou University, Yangzhou 225009, China (Z.C., J.Y.); andDepartment of Agriculture, Southeast Missouri State University, Malden, Missouri 63863 (D.H.B.).
authors.forename: Muhamad S
authors.initials: MS
authors.lastname: Mispan
authors.affiliation: Plant Science Department, South Dakota State University, Brookings, South Dakota 57007 (H.Y., J.F., L.Z., J.Z., M.S.M., X.-Y.G.);Agricultural College, Yangzhou University, Yangzhou 225009, China (Z.C., J.Y.); andDepartment of Agriculture, Southeast Missouri State University, Malden, Missouri 63863 (D.H.B.).
authors.forename: Zhuanqin
authors.initials: Z
authors.lastname: Cao
authors.affiliation: Plant Science Department, South Dakota State University, Brookings, South Dakota 57007 (H.Y., J.F., L.Z., J.Z., M.S.M., X.-Y.G.);Agricultural College, Yangzhou University, Yangzhou 225009, China (Z.C., J.Y.); andDepartment of Agriculture, Southeast Missouri State University, Malden, Missouri 63863 (D.H.B.).
authors.forename: Donn H
authors.initials: DH
authors.lastname: Beighley
authors.affiliation: Plant Science Department, South Dakota State University, Brookings, South Dakota 57007 (H.Y., J.F., L.Z., J.Z., M.S.M., X.-Y.G.);Agricultural College, Yangzhou University, Yangzhou 225009, China (Z.C., J.Y.); andDepartment of Agriculture, Southeast Missouri State University, Malden, Missouri 63863 (D.H.B.).
authors.forename: Jianchang
authors.initials: J
authors.lastname: Yang
authors.affiliation: Plant Science Department, South Dakota State University, Brookings, South Dakota 57007 (H.Y., J.F., L.Z., J.Z., M.S.M., X.-Y.G.);Agricultural College, Yangzhou University, Yangzhou 225009, China (Z.C., J.Y.); andDepartment of Agriculture, Southeast Missouri State University, Malden, Missouri 63863 (D.H.B.) xingyou.gu@sdstate.edu.
authors.forename: Xing-You
authors.identifier: http://orcid.org/0000-0002-1879-9602
authors.initials: XY
authors.lastname: Gu
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D000483:Alleles; D018556:Crops, Agricultural; D056625:Endosperm / Q000235:genetics / Q000502:physiology; D005838:Genotype; D018525:Germination / Q000235:genetics; D005875:Gibberellins / Q000378:metabolism; D012275:Oryza / Q000235:genetics / Q000502:physiology*; D057445:Plant Dormancy / Q000235:genetics*; D010937:Plant Growth Regulators / Q000378:metabolism*; D040641:Quantitative Trait Loci / Q000235:genetics*; D012639:Seeds / Q000235:genetics / Q000502:physiology
chemical_list: D005875:Gibberellins; D010937:Plant Growth Regulators; D000040:Abscisic Acid