title: Molecular characterization and evolutionary origins of farinin genes in Brachypodium distachyon L.
abstract: Farinins are one of the oldest members of the gluten family in wheat and Aegilops species, and they influence dough properties. Here, we performed the first detailed molecular genetic study on farinin genes in Brachypodium distachyon L., the model species for Triticum aestivum. A total of 51 b-type farinin genes were cloned and characterized, including 27 functional and 24 non-functional pseudogenes from 14 different B. distachyon accessions. All genes were highly similar to those previously reported from wheat and Aegilops species. The identification of deduced amino acid sequences showed that b-type farinins across Triticeae genomes could be classified as b1-, b2-, b3-, and b4-type farinins; however, B. distachyon had only b3- and b4-type farinins. Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) revealed that farinin genes are transcribed into mRNA in B. distachyon at much lower levels than in Triticeae, despite the presence of cis-acting elements in promoter regions. Phylogenetic analysis suggested that Brachypodium farinins may have closer relationships with common wheat and further confirmed four different types of b-type farinins in Triticeae and Brachypodium genomes, corresponding to b1, b2, b3 (group 1), and b4 (group 2). A putative evolutionary origin model of farinin genes in Brachypodium, Triticum, and the related species suggests that all b-type farinins diverged from their common ancestor ~3.2 million years ago (MYA). The b3 and b4 types could be considered older in the farinin family. The results explain the loss of b1- and b2-type farinin alleles in Brachypodium.
authors.affiliation: College of Life Science, Capital Normal University, Beijing, 100048, China.
authors.forename: Saminathan
authors.initials: S
authors.lastname: Subburaj
authors.affiliation: College of Life Science, Capital Normal University, Beijing, 100048, China.
authors.forename: Nana
authors.initials: N
authors.lastname: Luo
authors.affiliation: College of Life Science, Capital Normal University, Beijing, 100048, China.
authors.forename: Xiaobing
authors.initials: X
authors.lastname: Lu
authors.affiliation: College of Life Science, Capital Normal University, Beijing, 100048, China.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Li
authors.affiliation: College of Life Science, Capital Normal University, Beijing, 100048, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Cao
authors.affiliation: College of Life Science, Capital Normal University, Beijing, 100048, China. yingkaohu@sohu.com.
authors.forename: Yingkao
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Department of Plant Pathology, Kansas State University, Manhattan, KS, 66506, USA.
authors.forename: Jiarui
authors.initials: J
authors.lastname: Li
authors.affiliation: College of Life Science, Capital Normal University, Beijing, 100048, China. yanym@cnu.edu.cn.|Hubei Collaborative Innovation Center for Grain Industry (HCICGI), 434025, Jingzhou, China. yanym@cnu.edu.cn.
authors.forename: Yueming
authors.initials: Y
authors.lastname: Yan
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D058431:Brachypodium / Q000235:genetics*; D018744:DNA, Plant / Q000235:genetics; D019143:Evolution, Molecular; D017343:Genes, Plant; D005983:Glutens / Q000235:genetics*; D054643:INDEL Mutation; D005810:Multigene Family; D010802:Phylogeny; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic; D011544:Pseudogenes; D017422:Sequence Analysis, DNA; D014908:Triticum / Q000235:genetics
chemical_list: D018744:DNA, Plant; D005983:Glutens
keywords: Brachypodium distachyon L.; Evolution; Farinins; Molecular cloning; qRT-PCR