title: A KNOTTED1-LIKE HOMEOBOX protein regulates abscission in tomato by modulating the auxin pathway.
abstract: A gene encoding a KNOTTED1-LIKE HOMEOBOX PROTEIN1 (KD1) is highly expressed in both leaf and flower abscission zones. Reducing the abundance of transcripts of this gene in tomato (Solanum lycopersicum) by both virus-induced gene silencing and stable transformation with a silencing construct driven by an abscission-specific promoter resulted in a striking retardation of pedicel and petiole abscission. In contrast, Petroselinum, a semidominant KD1 mutant, showed accelerated pedicel and petiole abscission. Complementary DNA microarray and quantitative reverse transcription-polymerase chain reaction analysis indicated that regulation of abscission by KD1 was associated with changed abundance of genes related to auxin transporters and signaling components. Measurement of auxin content and activity of a DR5::β-glucuronidase auxin reporter assay showed that changes in KD1 expression modulated the auxin concentration and response gradient in the abscission zone.
authors.affiliation: Department of Plant Sciences, University of California, Davis, California 95616 (C.M., M.S.R.);Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani Center, Bet-Dagan 50250, Israel (S.M.);Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Agricultural University, Changsha 410128, China (L.X., J.T., Q.L.); andCrops Pathology and Genetic Research Unit, United States Department of Agriculture-Agricultural Research Service, Davis, California 95616 (C.-Z.J.).
authors.forename: Chao
authors.initials: C
authors.lastname: Ma
authors.affiliation: Department of Plant Sciences, University of California, Davis, California 95616 (C.M., M.S.R.);Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani Center, Bet-Dagan 50250, Israel (S.M.);Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Agricultural University, Changsha 410128, China (L.X., J.T., Q.L.); andCrops Pathology and Genetic Research Unit, United States Department of Agriculture-Agricultural Research Service, Davis, California 95616 (C.-Z.J.).
authors.forename: Shimon
authors.initials: S
authors.lastname: Meir
authors.affiliation: Department of Plant Sciences, University of California, Davis, California 95616 (C.M., M.S.R.);Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani Center, Bet-Dagan 50250, Israel (S.M.);Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Agricultural University, Changsha 410128, China (L.X., J.T., Q.L.); andCrops Pathology and Genetic Research Unit, United States Department of Agriculture-Agricultural Research Service, Davis, California 95616 (C.-Z.J.).
authors.forename: Langtao
authors.initials: L
authors.lastname: Xiao
authors.affiliation: Department of Plant Sciences, University of California, Davis, California 95616 (C.M., M.S.R.);Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani Center, Bet-Dagan 50250, Israel (S.M.);Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Agricultural University, Changsha 410128, China (L.X., J.T., Q.L.); andCrops Pathology and Genetic Research Unit, United States Department of Agriculture-Agricultural Research Service, Davis, California 95616 (C.-Z.J.).
authors.forename: Jianhua
authors.initials: J
authors.lastname: Tong
authors.affiliation: Department of Plant Sciences, University of California, Davis, California 95616 (C.M., M.S.R.);Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani Center, Bet-Dagan 50250, Israel (S.M.);Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Agricultural University, Changsha 410128, China (L.X., J.T., Q.L.); andCrops Pathology and Genetic Research Unit, United States Department of Agriculture-Agricultural Research Service, Davis, California 95616 (C.-Z.J.).
authors.forename: Qing
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Department of Plant Sciences, University of California, Davis, California 95616 (C.M., M.S.R.);Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani Center, Bet-Dagan 50250, Israel (S.M.);Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Agricultural University, Changsha 410128, China (L.X., J.T., Q.L.); andCrops Pathology and Genetic Research Unit, United States Department of Agriculture-Agricultural Research Service, Davis, California 95616 (C.-Z.J.) msreid@ucdavis.edu cjiang@ucdavis.edu.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Reid
authors.affiliation: Department of Plant Sciences, University of California, Davis, California 95616 (C.M., M.S.R.);Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani Center, Bet-Dagan 50250, Israel (S.M.);Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Agricultural University, Changsha 410128, China (L.X., J.T., Q.L.); andCrops Pathology and Genetic Research Unit, United States Department of Agriculture-Agricultural Research Service, Davis, California 95616 (C.-Z.J.) msreid@ucdavis.edu cjiang@ucdavis.edu.
authors.forename: Cai-Zhong
authors.initials: CZ
authors.lastname: Jiang
mesh_terms: D005638:Fruit / Q000187:drug effects / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D020868:Gene Silencing / Q000187:drug effects; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D007210:Indoleacetic Acids / Q000378:metabolism*; D007700:Kinetics; D018551:Solanum lycopersicum / Q000235:genetics / Q000502:physiology*; D009154:Mutation / Q000235:genetics; D010797:Phthalimides / Q000494:pharmacology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D018398:Homeodomain Proteins; D007210:Indoleacetic Acids; D010797:Phthalimides; D010940:Plant Proteins; D012333:RNA, Messenger; C002687:alpha-naphthylphthalamic acid