title: LABA1, a Domestication Gene Associated with Long, Barbed Awns in Wild Rice.
abstract: Common wild rice (Oryza rufipogon), the wild relative of Asian cultivated rice (Oryza sativa), flaunts long, barbed awns, which are necessary for efficient propagation and dissemination of seeds. By contrast, O. sativa cultivars have been selected to be awnless or to harbor short, barbless awns, which facilitate seed processing and storage. The transition from long, barbed awns to short, barbless awns was a crucial event in rice domestication. Here, we show that the presence of long, barbed awns in wild rice is controlled by a major gene on chromosome 4, LONG AND BARBED AWN1 (LABA1), which encodes a cytokinin-activating enzyme. A frame-shift deletion in LABA1 of cultivated rice reduces the cytokinin concentration in awn primordia, disrupting barb formation and awn elongation. Sequencing analysis demonstrated low nucleotide diversity and a selective sweep encompassing an ∼800-kb region around the derived laba1 allele in cultivated rice. Haplotype analysis revealed that the laba1 allele originated in the japonica subspecies and moved into the indica gene pool via introgression, suggesting that humans selected for this locus in early rice domestication. Identification of LABA1 provides new insights into rice domestication and also sheds light on the molecular mechanism underlying awn development.
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, National Center for Evaluation of Agricultural Wild Plants (Rice), Beijing Key Laboratory of Crop Genetic Improvement, Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, China.
authors.forename: Lei
authors.identifier: http://orcid.org/0000-0002-9117-7391
authors.initials: L
authors.lastname: Hua
authors.affiliation: Department of Plant Breeding and Genetics, Cornell University, Ithaca, New York 14953-1901.
authors.forename: Diane R
authors.initials: DR
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, National Center for Evaluation of Agricultural Wild Plants (Rice), Beijing Key Laboratory of Crop Genetic Improvement, Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, China.
authors.forename: Lubin
authors.initials: L
authors.lastname: Tan
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, National Center for Evaluation of Agricultural Wild Plants (Rice), Beijing Key Laboratory of Crop Genetic Improvement, Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, China.
authors.forename: Yongcai
authors.initials: Y
authors.lastname: Fu
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, National Center for Evaluation of Agricultural Wild Plants (Rice), Beijing Key Laboratory of Crop Genetic Improvement, Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, China.
authors.forename: Fengxia
authors.initials: F
authors.lastname: Liu
authors.affiliation: Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Agricultural University, Changsha 410128, China.
authors.forename: Langtao
authors.initials: L
authors.lastname: Xiao
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, National Center for Evaluation of Agricultural Wild Plants (Rice), Beijing Key Laboratory of Crop Genetic Improvement, Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, China.
authors.forename: Zuofeng
authors.initials: Z
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, National Center for Evaluation of Agricultural Wild Plants (Rice), Beijing Key Laboratory of Crop Genetic Improvement, Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Fu
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, National Center for Evaluation of Agricultural Wild Plants (Rice), Beijing Key Laboratory of Crop Genetic Improvement, Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, China.
authors.forename: Xianyou
authors.initials: X
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, National Center for Evaluation of Agricultural Wild Plants (Rice), Beijing Key Laboratory of Crop Genetic Improvement, Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Gu
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, National Center for Evaluation of Agricultural Wild Plants (Rice), Beijing Key Laboratory of Crop Genetic Improvement, Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, China.
authors.forename: Hongwei
authors.identifier: http://orcid.org/0000-0003-4082-6627
authors.initials: H
authors.lastname: Cai
authors.affiliation: Department of Plant Breeding and Genetics, Cornell University, Ithaca, New York 14953-1901.
authors.forename: Susan R
authors.identifier: http://orcid.org/0000-0001-9246-3106
authors.initials: SR
authors.lastname: McCouch
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, National Center for Evaluation of Agricultural Wild Plants (Rice), Beijing Key Laboratory of Crop Genetic Improvement, Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, China suncq@cau.edu.cn.
authors.forename: Chuanqing
authors.identifier: http://orcid.org/0000-0002-3589-9058
authors.initials: C
authors.lastname: Sun
mesh_terms: D000483:Alleles; D032461:Chromosomes, Plant / Q000235:genetics; D003001:Cloning, Molecular; D018556:Crops, Agricultural / Q000235:genetics* / Q000254:growth & development; D003583:Cytokinins / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D014644:Genetic Variation; D006239:Haplotypes / Q000235:genetics; D009711:Nucleotides / Q000235:genetics; D012275:Oryza / Q000033:anatomy & histology* / Q000235:genetics* / Q000254:growth & development / Q000648:ultrastructure; D010641:Phenotype; D020161:Physical Chromosome Mapping; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D012641:Selection, Genetic; D014158:Transcription, Genetic
chemical_list: D003583:Cytokinins; D009711:Nucleotides; D010940:Plant Proteins