title: SHORT HYPOCOTYL UNDER BLUE1 or HAIKU2 mixepression alters canola and Arabidopsis seed development.
abstract: Canola (Brassica napus) is a widely cultivated species and provides important resources of edible vegetable oil, biodiesel production and animal feed. Seed development in Arabidopsis and canola shares a similar path: an early proliferation of endosperm to form a large seed cavity, followed by a second phase in which the embryo grows to replace the endosperm. In Arabidopsis, the seed reaches almost its final volume before the enlargement of the embryo. SHORT HYPOCOTYL UNDER BLUE1 (SHB1) is a key regulatory gene of seed development with a broad expression beyond endosperm development. By contrast, its two target genes, MINISEED3 (MINI3) and HAIKU2 (IKU2), are narrowly expressed in early developing endosperm and early embryo. We overexpressed SHB1 in canola to explore the possibility of altering seed development. As an alternative strategy, we expressed the canola IKU2 ortholog in Arabidopsis endosperm under the control of a stronger MINI3 promoter. SHB1 targeted canola orthologs of Arabidopsis MINI3 and IKU2 and caused a significantly increased seed mass. Overaccumulation of IKU2 in the early stage of Arabidopsis seed development also significantly increased the final seed mass. Our studies provide a strong case for increasing the final seed mass by manipulating endosperm proliferation at a rather early developmental stage in crops.
authors.affiliation: Department of Plant Biology, University of Minnesota at Twin Cities, St Paul, MN, 55108, USA.
authors.forename: Yu-Guo
authors.initials: YG
authors.lastname: Xiao
authors.affiliation: State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong, 271018, China.
authors.forename: Qing-Bin
authors.initials: QB
authors.lastname: Sun
authors.affiliation: Department of Plant Biology, University of Minnesota at Twin Cities, St Paul, MN, 55108, USA.
authors.forename: Xiao-Jun
authors.initials: XJ
authors.lastname: Kang
authors.affiliation: Department of Horticultural Sciences, University of Minnesota at Twin Cities, St Paul, MN, 55108, USA.
authors.forename: Chang-Bin
authors.initials: CB
authors.lastname: Chen
authors.affiliation: Department of Plant Biology, University of Minnesota at Twin Cities, St Paul, MN, 55108, USA.
authors.forename: Min
authors.initials: M
authors.lastname: Ni
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D029688:Brassica napus / Q000235:genetics* / Q000254:growth & development; D018506:Gene Expression Regulation, Plant; D009154:Mutation; D010641:Phenotype; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics; D011401:Promoter Regions, Genetic; D011494:Protein Kinases / Q000235:genetics* / Q000378:metabolism; D012639:Seeds / Q000737:chemistry / Q000235:genetics / Q000254:growth & development*; D014157:Transcription Factors / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; C510290:MINISEED3 protein, Arabidopsis; D010940:Plant Proteins; C511745:SHB1 protein, Arabidopsis; D014157:Transcription Factors; D011494:Protein Kinases; C510291:HAIKU2 protein, Arabidopsis
keywords: HAIKU2 (IKU2); MINISEED3 (MINI3); SHORT HYPOCOTYL UNDER BLUE1 (SHB1); canola (Brassica napus); endosperm; seed development; seed mass