title: Natural variation of C-repeat-binding factor (CBFs) genes is a major cause of divergence in freezing tolerance among a group of Arabidopsis thaliana populations along the Yangtze River in China.
abstract: We used a monophyletic group of four natural populations of Arabidopsis thaliana expanded from a single ancestor along the Yangtze River c. 90,000 yr ago to study the molecular mechanism of the divergence in their freezing tolerance, in order to gain an insight into the genetic basis of their local adaption to low temperatures. Freezing tolerance assays, measurements of metabolites in the raffinose biosynthesis pathway and transactivation-activity assays of variation in forms of cold-responsive transcription factors were conducted on the four populations. Quantitative trait locus mapping was adopted with F₂ populations of the most- and least freezing-tolerant populations. The degree of freezing tolerance among the four populations was negatively correlated with the lowest monthly average temperature of January in their native habitats, and positively correlated to the expression level of some cold-regulated genes. We identified a major locus harboring three cold-responsive transcription factor genes CBF1-3, and found a nucleotide insertion in CBF2 in all populations except SXcgx, which generated a dysfunctional CBF2 protein. The CBF2 in SXcgx experienced a stronger natural selection in the cooler environment after CBF3 lost its response to low temperature, which possibly reflects a local adaptation of these populations during the expansion from a common ancestor.
authors.affiliation: State Key Laboratory for Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing, 100871, China.
authors.forename: Juqing
authors.initials: J
authors.lastname: Kang
authors.affiliation: State Key Laboratory for Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing, 100871, China.
authors.forename: Huiting
authors.initials: H
authors.lastname: Zhang
authors.affiliation: State Key Laboratory for Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing, 100871, China.
authors.forename: Tianshu
authors.initials: T
authors.lastname: Sun
authors.affiliation: State Key Laboratory for Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing, 100871, China.
authors.forename: Yihao
authors.initials: Y
authors.lastname: Shi
authors.affiliation: State Key Laboratory for Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing, 100871, China.
authors.forename: Jianqiao
authors.initials: J
authors.lastname: Wang
authors.affiliation: The Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
authors.forename: Baocai
authors.initials: B
authors.lastname: Zhang
authors.affiliation: College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China.|Center for Macroecology, Evolution and Climate, Department of Biology, University of Copenhagen, Universitetsparken 15, DK-2100, Copenhagen, Denmark.
authors.forename: Zhiheng
authors.initials: Z
authors.lastname: Wang
authors.affiliation: The Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
authors.forename: Yihua
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: State Key Laboratory for Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing, 100871, China.|The National Plant Gene Research Center (Beijing), Beijing, 100101, China.
authors.forename: Hongya
authors.initials: H
authors.lastname: Gu
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D053898:Biosynthetic Pathways / Q000235:genetics; D002681:China; D002874:Chromosome Mapping; D004187:Disaccharides / Q000378:metabolism; D017753:Ecosystem; D005615:Freezing; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics*; D014644:Genetic Variation; D008969:Molecular Sequence Data; D016366:Open Reading Frames / Q000235:genetics; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic / Q000235:genetics; D040641:Quantitative Trait Loci; D011887:Raffinose / Q000378:metabolism; D045483:Rivers; D013997:Time Factors; D015533:Transcriptional Activation / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; D004187:Disaccharides; C013536:6 beta-galactinol; D011887:Raffinose
keywords: Arabidopsis thaliana; C-repeat-binding factor (CBF); Yangtze River; freezing tolerance; local adaptation; natural variation