title: The alternative splicing of EAM8 contributes to early flowering and short-season adaptation in a landrace barley from the Qinghai-Tibetan Plateau.
abstract: The early flowering of Lalu was determined to be due to a novel spontaneous eam8 mutation, which resulted in intron retention and the formation of a putative truncated protein. Barley is a staple crop grown over an extensive area in the Qinghai-Tibetan Plateau. Understanding the genetic mechanism for its success in a high altitude is important for crop improvement in marginal environments. Early flowering is a critical adaptive trait that strongly influences reproductive fitness in a short growing season. Loss-of-function mutations at the circadian clock gene EARLY MATURITY 8 (EAM8) promote rapid flowering. In this study, we identified a novel, spontaneous recessive eam8 mutant with an early flowering phenotype in a Tibetan barley landrace Lalu, which is natively grown at a high altitude of approximately 4000 m asl. The co-segregation analysis in a F2population derived from the cross Lalu (early flowering) × Diqing 1 (late flowering) confirmed that early flowering of Lalu was determined to be due to an allele at EAM8. The eam8 allele from Lalu carries an A/G alternative splicing mutation at position 3257 in intron 3, designated eam8.l; this alternative splicing event leads to intron retention and a putative truncated protein. Of the 134 sequenced barley accessions, which are primarily native to the Qinghai-Tibet Plateau, three accessions carried this mutation. The eam8.l mutation was likely to have originated in wild barley due to the presence of the Lalu haplotype in H. spontaneum from Tibet. Overall, alternative splicing has contributed to the evolution of the barley circadian clock and in the short-season adaptation of local barley germplasm. The study has also identified a novel donor of early-flowering barley which will be useful for barley improvement.
authors.affiliation: Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, No. 23, Xinning Road, Xining, 810008, Qinghai, People's Republic of China.|University of Chinese Academy of Sciences, No. 19 (Jia), Shijingshan District, Beijing, 100049, People's Republic of China.
authors.forename: Tengfei
authors.initials: T
authors.lastname: Xia
authors.affiliation: Triticeae Research Institute, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, People's Republic of China.
authors.forename: Lianquan
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, No. 23, Xinning Road, Xining, 810008, Qinghai, People's Republic of China.|University of Chinese Academy of Sciences, No. 19 (Jia), Shijingshan District, Beijing, 100049, People's Republic of China.
authors.forename: Jinqing
authors.initials: J
authors.lastname: Xu
authors.affiliation: Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, No. 23, Xinning Road, Xining, 810008, Qinghai, People's Republic of China.
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.affiliation: Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, No. 23, Xinning Road, Xining, 810008, Qinghai, People's Republic of China.
authors.forename: Baolong
authors.initials: B
authors.lastname: Liu
authors.affiliation: Triticeae Research Institute, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, People's Republic of China.
authors.forename: Ming
authors.initials: M
authors.lastname: Hao
authors.affiliation: Tibet Agriculture and Animal Husbandry College, Linzhi, 860000, Tibet, People's Republic of China.
authors.forename: Xi
authors.initials: X
authors.lastname: Chang
authors.affiliation: Tibet Academy of Agricultural and Animal Husbandry Sciences, Lhasa, 850002, Tibet, People's Republic of China.
authors.forename: Tangwei
authors.initials: T
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, No. 23, Xinning Road, Xining, 810008, Qinghai, People's Republic of China.
authors.forename: Shiming
authors.initials: S
authors.lastname: Li
authors.affiliation: Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, No. 23, Xinning Road, Xining, 810008, Qinghai, People's Republic of China.
authors.forename: Huaigang
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, No. 23, Xinning Road, Xining, 810008, Qinghai, People's Republic of China. dcliu7@yahoo.com.|Triticeae Research Institute, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, People's Republic of China. dcliu7@yahoo.com.
authors.forename: Dengcai
authors.identifier: http://orcid.org/0000-0001-5508-1125
authors.initials: D
authors.lastname: Liu
authors.affiliation: Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, No. 23, Xinning Road, Xining, 810008, Qinghai, People's Republic of China. shenyuhu@nwipb.cas.cn.|Key Laboratory of Crop Molecular Breeding of Qinghai Province, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, No. 23, Xinning Road, Xining, 810008, Qinghai, People's Republic of China. shenyuhu@nwipb.cas.cn.
authors.forename: Yuhu
authors.identifier: http://orcid.org/0000-0002-2720-2724
authors.initials: Y
authors.lastname: Shen
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics; D000483:Alleles; D017398:Alternative Splicing; D000531:Altitude; D056926:CLOCK Proteins / Q000235:genetics* / Q000502:physiology; D002681:China; D002874:Chromosome Mapping; D018744:DNA, Plant / Q000235:genetics; D035264:Flowers / Q000502:physiology*; D017343:Genes, Plant; D006239:Haplotypes; D001467:Hordeum / Q000235:genetics* / Q000502:physiology; D009154:Mutation; D010641:Phenotype; D010940:Plant Proteins / Q000235:genetics* / Q000502:physiology; D012621:Seasons; D017422:Sequence Analysis, DNA
chemical_list: D018744:DNA, Plant; D010940:Plant Proteins; D056926:CLOCK Proteins