Molecular evolution of dimeric α-amylase inhibitor genes in wild emmer wheat and its ecological association

Abstract

Backgroundα-Amylase inhibitors are attractive candidates for the control of seed weevils, as these insects are highly dependent on starch as an energy source. In this study, we aimed to reveal the structure and diversity of dimeric α-amylase inhibitor genes in wild emmer wheat from Israel and to elucidate the relationship between the emmer wheat genes and ecological factors using single nucleotide polymorphism (SNP) markers. Another objective of this study was to find out whether there were any correlations between SNPs in functional protein-coding genes and the environment.ResultsThe influence of ecological factors on the genetic structure of dimeric α-amylase inhibitor genes was evaluated by specific SNP markers. A total of 244 dimeric α-amylase inhibitor genes were obtained from 13 accessions in 10 populations. Seventy-five polymorphic positions and 74 haplotypes were defined by sequence analysis. Sixteen out of the 75 SNP markers were designed to detect SNP variations in wild emmer wheat accessions from different populations in Israel. The proportion of polymorphic loci P (5%), the expected heterozygosity He, and Shannon's information index in the 16 populations were 0.887, 0.404, and 0.589, respectively. The populations of wild emmer wheat showed great diversity in gene loci both between and within populations. Based on the SNP marker data, the genetic distance of pair-wise comparisons of the 16 populations displayed a sharp genetic differentiation over long geographic distances. The values of P, He, and Shannon's information index were negatively correlated with three climatic moisture factors, whereas the same values were positively correlated by Spearman rank correlation coefficients' analysis with some of the other ecological factors.ConclusionThe populations of wild emmer wheat showed a wide range of diversity in dimeric α-amylase inhibitors, both between and within populations. We suggested that SNP markers are useful for the estimation of genetic diversity of functional genes in wild emmer wheat. These results show significant correlations between SNPs in the α-amylase inhibitor genes and ecological factors affecting diversity. Ecological factors, singly or in combination, explained a significant proportion of the variations in the SNPs, and the SNPs could be classified into several categories as ecogeographical predictors. It was suggested that the SNPs in the α-amylase inhibitor genes have been subjected to natural selection, and ecological factors had an important evolutionary influence on gene differentiation at specific loci.

Wild emmer: genetic resources, gene mapping and potential for wheat improvement

“…Natural populations of wild emmer have wide genotypic variations in agronomic traits (Nevo et al 2002, and references therein). These traits can be grouped as: (1) agronomic, including biomass, earliness, grain nitrogen content, and yield (Nevo 2001); (2) amino acid composition ; (3) protein quality and quantity including high grain protein, novel gliadins, and glutenins (Nevo et al 1986b;Nevo and Payne 1987;Pagnotta et al 1995;Xu et al 2004;Uauy et al 2006b;Qi et al 2006;Li et al 2007); (4) micronutrient contents (Cakmak et al 2000(Cakmak et al , 2004; (5) abiotic stress tolerances including salt, drought, and heat Khanna-Chopra and Viswanathan 1999;Peleg et al 2005Peleg et al , 2006; (6) herbicide resistances (Krugman et al 1995(Krugman et al , 1997Snape et al 1991); and (7) biotic stress tolerances including powdery mildew (Moseman et al 1984;Nevo et al 1985), Fusarium head blight (Buerstmayr et al 2003;Stack et al 2002;Oliver et al 2007), leaf rust, stem rust, stripe rust , Nevo et al 1986aAnikster et al 2005), wheat soil-borne mosaic virus (Hunger et al 1992), tan spot (Pyrenophora tritici-repentis) (Chu et al 2008;Singh et al 2006Singh et al , 2007, Stagonospora nodorum leaf blotch (Singh et al 2007;Chu et al 2008), and insects (alpha-amylase inhibitor) (Wang et al 2008).…”

“…Pm16, originally mapped on chromosome 4A by monosomic analysis (Reader and Miller 1991), was recently mapped on 5BS using SSR markers . Pm31, previously reported as derived from wild emmer (Xie et al 2003), was subsequently identiWed as Pm21 because of a pedigree error (Xie 2006;ZY Liu, personal communication). Recently, two novel powdery mildew resistance genes (temporarily designated PmG3M and PmG16) were mapped on chromosomes 6BL and 7AL, respectively, using SSR and resistance gene analog (RGA) markers (Table 1; Xie 2006).…”

“…Pm31, previously reported as derived from wild emmer (Xie et al 2003), was subsequently identiWed as Pm21 because of a pedigree error (Xie 2006;ZY Liu, personal communication). Recently, two novel powdery mildew resistance genes (temporarily designated PmG3M and PmG16) were mapped on chromosomes 6BL and 7AL, respectively, using SSR and resistance gene analog (RGA) markers (Table 1; Xie 2006). PmG3M from accession G-305-3M conferred resistance to 41 powdery mildew isolates collected from diVerent wheat species and from various locations in Israel.…”

Genome diversity in wild grasses under environmental stress

“…Several recent studies have assessed the relationship of environmental conditions to genetic diversity in wild plant populations (3)(4)(5)(6)(7). Diversity measured within neutral genetic markers (5,6) and functional loci (4,7) has shown significant association to climatic conditions.…”

<b>A non-linear mixed-effects model to describe the effect of acarbose intake on postprandial glycaemia in a single rat

“…The high cost of the disease demands that public and private health systems investigate new treatments, intervention programs (Ejtahed et al, 2012;König, Kookhan, Schaffner, Deibert, & Berg, 2014;Shen, Obin, & Zhao., 2013;Costa & Longo, 2014) and drugs capable to improve the patients' quality of life. In living beings, the α-amylases are enzymes that catalyze the hydrolysis of polysaccharides, such as starch and glycogen, to yield glucose and maltose (Wang et al, 2008). However, some organic compounds, among them acarbose, may inhibit the activity of these enzymes (Geng & Bai, 2008;Ritz et al, 2012) and thus prevent or attenuate hyperglycemic peaks (Coniff, Shapiro, Seaton, & Bray, 1995;Pereira et al, 2011;Scheen, Magalhaes, Salvatore, & Lefebvre, 1994;Sybuia, Guilhermetti, Mangolim, Bazotte, & Matioli, 2014-2015Wong & Jenkins, 2007).…”