Molecular characterization and phylogenetic analysis of novel Wx genes from Psathyrostachys juncea and Eremopyrum bonaepartis
Author:
Wu Lijuan1, Yang Zaijun2, Wang Junqiang3, He Jundong3, Jiang Jin4, Fang Fang4, Shen Shian3, Hu Xinkun3
Affiliation:
1. College of Agronomy, Sichuan Agricultural University, Chengdu, Sichuan, China 2. Key Laboratory of Southwest China Wildlife Resources Conservation of the Ministry of Education, China West Normal University, Nanchong, Sichuan, China 3. Key Laboratory of Southwest China Wildlife Resources Conservation of the Ministry of Education, China West Normal University, Nanchong, Sichuan, China + Institute of Ecology, China West Normal University, Nanchong, Sichuan, China 4. Nanchong Academy of Agricultural Sciences, Nanchong, Sichuan, China
Abstract
The ratio of amylose/amylopectin can greatly influence the end-use quality of
wheat products, and amylose synthesis only needs the granule-bound starch
synthase I that is encoded by the Waxy (Wx) gene. Hence, the Wx allele
variability is a vital determinant of amylose synthesis. In this study, four
novel Wx genes were isolated from two diploid Triticeae species. Their
sequence variations were analyzed, which showed that the polymorphism among
the Wx-F1 alleles was low; only seven single nucleotide polymorphisms (SNPs)
and one amino acid (AA) residue change (Arg541 ? Cys) were detected in the
exon regions, and this change in Wx-F1b was predicted to have deleterious
effects on protein function. The two Wx-Ns1 alleles in this study were
different from two published alleles obtained using three overlapping primer
sets. The polymorphism among the four Wx-Ns1 alleles was high, and 37 SNPs
and ten AA residue changes were found, while all of those substitutions were
neutral. However, one substitution (Leu237 ? Pro) between Wx-H1 and Wx-Ns1
was predicted that would probably affect the protein function. Divergence
time analysis showed that Wx-Ns1a diverged from Wx-Ns1b about 1.06 MYAs.
Phylogenetic analysis indicated that Wx-F1 were more closely related to
Wx-O1 from Henrardia persica, Wx-R1 from Secale cereale ssp. cereale, and
Wx-Xe1 from Eremopyrum triticeum, while Wx-Ns1 were more closely related to
Wx-H1 from Hordeum vulgare ssp. vulgare and Wx-Hch1 from Hordeum chilense.
These genes may be important candidates for wheat quality improvement.
Publisher
National Library of Serbia
Subject
Plant Science,Genetics
Reference47 articles.
1. AINSWORTH, C., J., CLARK, J., BALSDON (1993): Expression, organisation and structure of the genes encoding the waxy protein (granule-bound starch synthase) in wheat. Plant. Mol. Biol., 22:67-82. 2. BIRD, A.R., M.A., CONLON, C.T., CHRISTOPHERSEN, D.L., TOPPING (2010): Resistant starch, large bowel fermentation and a broader perspective of prebiotics and probiotics. Benef. Microbes, 1:423-431. 3. CABALLERO, L., E., BANCEL, C., DEBITON, G., BRANLARD (2008): Granule-bound starch synthase (GBSS) diversity of ancient wheat and related species. Plant Breeding, 127:548-553. 4. CHAO, S., P.J., SHARP, A.J., WORLAND, E.J., WARHAM, R.M.D., KOEBNER, M.D., GALE (1989): RFLP-based genetic maps of wheat homoeologous group 7 chromosomes. TAG, 78:495-504. 5. CHENNA, R., H., SUGAWARA, T., KOIKE, R., LOPEZ, T.J., GIBSON, D.G., HIGGINS, J.D., THOMPSON (2003): Multiple sequence alignment with the Clustal series of programs. Nucleic Acids Res., 31:3497-3500.
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