Expansion of the gamma-gliadin gene family in Aegilops and Triticum

BMC Evolutionary Biology

Research Article

Nadejda N Chikida¹  Elena Z Kochieva²  Luud JWJ Gilissen³  Ingrid M van der Meer³  Elma MJ Salentijn⁴  Marinus JM Smulders⁵  Svetlana V Goryunova⁶ 

[1] All-Russian Institute of Plant Industry, 190000, St. Petersburg, Russia;Bioengineering Center, 117312, Moscow, Russia;Plant Research International, Wageningen UR, P.O. Box 16, NL-6700 AA, Wageningen, The Netherlands;Allergy Consortium, Wageningen, The Netherlands;Wageningen UR Plant Breeding, Wageningen UR, P.O. Box 16, NL-6700 AA, Wageningen, The Netherlands;Plant Research International, Wageningen UR, P.O. Box 16, NL-6700 AA, Wageningen, The Netherlands;Wageningen UR Plant Breeding, Wageningen UR, P.O. Box 16, NL-6700 AA, Wageningen, The Netherlands;Plant Research International, Wageningen UR, P.O. Box 16, NL-6700 AA, Wageningen, The Netherlands;Allergy Consortium, Wageningen, The Netherlands;Wageningen UR Plant Breeding, Wageningen UR, P.O. Box 16, NL-6700 AA, Wageningen, The Netherlands;Vavilov Institute of General Genetics, Russian Academy of Sciences, 119991, Moscow, Russia;

关键词: Gamma-gliadin;    Wheat;    Triticum;    Aegilops;    Multigene family;    Evolution;   

DOI  :  10.1186/1471-2148-12-215

 received in 2012-04-28, accepted in 2012-10-31,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundThe gamma-gliadins are considered to be the oldest of the gliadin family of storage proteins in Aegilops/Triticum. However, the expansion of this multigene family has not been studied in an evolutionary perspective.ResultsWe have cloned 59 gamma-gliadin genes from Aegilops and Triticum species (Aegilops caudata L., Aegilops comosa Sm. in Sibth. & Sm., Aegilops mutica Boiss., Aegilops speltoides Tausch, Aegilops tauschii Coss., Aegilops umbellulata Zhuk., Aegilops uniaristata Vis., and Triticum monococcum L.) representing eight different genomes: Am, B/S, C, D, M, N, T and U. Overall, 15% of the sequences contained internal stop codons resulting in pseudogenes, but this percentage was variable among genomes, up to over 50% in Ae. umbellulata. The most common length of the deduced protein, including the signal peptide, was 302 amino acids, but the length varied from 215 to 362 amino acids, both obtained from Ae. speltoides. Most genes encoded proteins with eight cysteines. However, all Aegilops species had genes that encoded a gamma-gliadin protein of 302 amino acids with an additional cysteine. These conserved nine-cysteine gamma-gliadins may perform a specific function, possibly as chain terminators in gluten network formation in protein bodies during endosperm development. A phylogenetic analysis of gamma-gliadins derived from Aegilops and Triticum species and the related genera Lophopyrum, Crithopsis, and Dasypyrum showed six groups of genes. Most Aegilops species contained gamma-gliadin genes from several of these groups, which also included sequences from the genera Lophopyrum, Crithopsis, and Dasypyrum. Hordein and secalin sequences formed separate groups.ConclusionsWe present a model for the evolution of the gamma-gliadins from which we deduce that the most recent common ancestor (MRCA) of Aegilops/Triticum-Dasypyrum-Lophopyrum-Crithopsis already had four groups of gamma-gliadin sequences, presumably the result of two rounds of duplication of the locus.

【 授权许可】

Unknown   
© Goryunova et al.; licensee BioMed Central Ltd. 2012. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.