A Classification and Prediction Hybrid Model Construction with the IQPSO-SVM Algorithm for Atrial Fibrillation Arrhythmia.

Atrial fibrillation (AF) is the most common cardiovascular disease (CVD), and most existing algorithms are usually designed for the diagnosis (i.e., feature classification) or prediction of AF. Artificial intelligence (AI) algorithms integrate the diagnosis of AF electrocardiogram (ECG) and predict the possibility that AF will occur in the future. In this paper, we utilized the MIT-BIH AF Database (AFDB), which is composed of data from normal people and patients with AF and onset characteristics, and the AFPDB database (i.e., PAF Prediction Challenge Database), which consists of data from patients with Paroxysmal AF (PAF; the records contain the ECG preceding an episode of PAF), and subjects who do not have documented AF. We extracted the respective characteristics of the databases and used them in modeling diagnosis and prediction. In the aspect of model construction, we regarded diagnosis and prediction as two classification problems, adopted the traditional support vector machine (SVM) algorithm, and combined them. The improved quantum particle swarm optimization support vector machine (IQPSO-SVM) algorithm was used to speed the training time. During the verification process, the clinical FZU-FPH database created by Fuzhou University and Fujian Provincial Hospital was used for hybrid model testing. The data were obtained from the Holter monitor of the hospital and encrypted. We proposed an algorithm for transforming the PDF ECG waveform images of hospital examination reports into digital data. For the diagnosis model and prediction model trained using the training set of the AFDB and AFPDB databases, the sensitivity, specificity, and accuracy measures were 99.2% and 99.2%, 99.2% and 93.3%, and 91.7% and 92.5% for the test set of the AFDB and AFPDB databases, respectively. Moreover, the sensitivity, specificity, and accuracy were 94.2%, 79.7%, and 87.0%, respectively, when tested using the FZU-FPH database with 138 samples of the ECG composed of two labels. The composite classification and prediction model using a new water-fall ensemble method had a total accuracy of approximately 91% for the test set of the FZU-FPH database with 80 samples with 120 segments of ECG with three labels.

Mechanisms of wheat (Triticum aestivum) grain storage proteins in response to nitrogen application and its impacts on processing quality.

Basis for the effects of nitrogen (N) on wheat grain storage proteins (GSPs) and on the establishment of processing quality are far from clear. The response of GSPs and processing quality parameters to four N levels of four common wheat cultivars were investigated at two sites over two growing seasons. Except gluten index (GI), processing quality parameters as well as GSPs quantities were remarkably improved by increasing N level. N level explained 4.2~59.2% and 10.4~80.0% variability in GSPs fractions and processing quality parameters, respectively. The amount of N remobilized from vegetative organs except spike was significantly increased when enhancing N application. GSPs fractions and processing quality parameters except GI were only highly and positively correlated with the amount of N remobilized from stem with sheath. N reassimilation in grain was remarkably strengthened by the elevated activity and expression level of glutamine synthetase. Transcriptome analysis showed the molecular mechanism of seeds in response to N levels during 10~35 days post anthesis. Collectively, we provided comprehensive understanding of N-responding mechanisms with respect to wheat processing quality from N source to GSPs biosynthesis at the agronomic, physiological and molecular levels, and screened candidate genes for quality breeding.

Allelic variations of α-gliadin genes from species of Aegilops section Sitopsis and insights into evolution of α-gliadin multigene family among Triticum and Aegilops.

The α-gliadins account for 15-30 % of the total storage protein in wheat endosperm and play important roles in the dough extensibility and nutritional quality. On the other side, they act as a main source of toxic peptides triggering celiac disease. In this study, 37 α-gliadins were isolated from three species of Aegilops section Sitopsis. Sequence similarity and phylogenetic analyses revealed novel allelic variation at Gli-2 loci of species of Sitopsis and regular organization of motifs in their repetitive domain. Based on the comprehensive analyses of a large number of known sequences of bread wheat and its diploid genome progenitors, the distributions of four T cell epitopes and length variations of two polyglutamine domains are analyzed. Additionally, according to the organization of repeat motifs, we classified the α-gliadins of Triticum and Aegilops into eight types. Their most recent common ancestor and putative divergence patterns were further considered. This study provides new insights into the allelic variations of α-gliadins in Aegilops section Sitopsis, as well as evolution of α-gliadin multigene family among Triticum and Aegilops species.

Genetic map of Triticum turgidum based on a hexaploid wheat population without genetic recombination for D genome.

BACKGROUND: A synthetic doubled-haploid hexaploid wheat population, SynDH1, derived from the spontaneous chromosome doubling of triploid F1 hybrid plants obtained from the cross of hybrids Triticum turgidum ssp. durum line Langdon (LDN) and ssp. turgidum line AS313, with Aegilops tauschii ssp. tauschii accession AS60, was previously constructed. SynDH1 is a tetraploidization-hexaploid doubled haploid (DH) population because it contains recombinant A and B chromosomes from two different T. turgidum genotypes, while all the D chromosomes from Ae. tauschii are homogenous across the whole population. This paper reports the construction of a genetic map using this population. RESULTS: Of the 606 markers used to assemble the genetic map, 588 (97%) were assigned to linkage groups. These included 513 Diversity Arrays Technology (DArT) markers, 72 simple sequence repeat (SSR), one insertion site-based polymorphism (ISBP), and two high-molecular-weight glutenin subunit (HMW-GS) markers. These markers were assigned to the 14 chromosomes, covering 2048.79 cM, with a mean distance of 3.48 cM between adjacent markers. This map showed good coverage of the A and B genome chromosomes, apart from 3A, 5A, 6A, and 4B. Compared with previously reported maps, most shared markers showed highly consistent orders. This map was successfully used to identify five quantitative trait loci (QTL), including two for spikelet number on chromosomes 7A and 5B, two for spike length on 7A and 3B, and one for 1000-grain weight on 4B. However, differences in crossability QTL between the two T. turgidum parents may explain the segregation distortion regions on chromosomes 1A, 3B, and 6B. CONCLUSIONS: A genetic map of T. turgidum including 588 markers was constructed using a synthetic doubled haploid (SynDH) hexaploid wheat population. Five QTLs for three agronomic traits were identified from this population. However, more markers are needed to increase the density and resolution of this map in the future study.

The impact of single nucleotide polymorphism in monomeric alpha-amylase inhibitor genes from wild emmer wheat, primarily from Israel and Golan.

BACKGROUND: Various enzyme inhibitors act on key insect gut digestive hydrolases, including alpha-amylases and proteinases. Alpha-amylase inhibitors have been widely investigated for their possible use in strengthening a plant's defense against insects that are highly dependent on starch as an energy source. We attempted to unravel the diversity of monomeric alpha-amylase inhibitor genes of Israeli and Golan Heights' wild emmer wheat with different ecological factors (e.g., geography, water, and temperature). Population methods that analyze the nature and frequency of allele diversity within a species and the codon analysis method (comparing patterns of synonymous and non-synonymous changes in protein coding sequences) were used to detect natural selection. RESULTS: Three hundred and forty-eight sequences encoding monomeric alpha-amylase inhibitors (WMAI) were obtained from 14 populations of wild emmer wheat. The frequency of SNPs in WMAI genes was 1 out of 16.3 bases, where 28 SNPs were detected in the coding sequence. The results of purifying and the positive selection hypothesis (p < 0.05) showed that the sequences of WMAI were contributed by both natural selection and co-evolution, which ensured conservation of protein function and inhibition against diverse insect amylases. The majority of amino acid substitutions occurred at the C-terminal (positive selection domain), which ensured the stability of WMAI. SNPs in this gene could be classified into several categories associated with water, temperature, and geographic factors, respectively. CONCLUSIONS: Great diversity at the WMAI locus, both between and within populations, was detected in the populations of wild emmer wheat. It was revealed that WMAI were naturally selected for across populations by a ratio of dN/dS as expected. Ecological factors, singly or in combination, explained a significant proportion of the variations in the SNPs. A sharp genetic divergence over very short geographic distances compared to a small genetic divergence between large geographic distances also suggested that the SNPs were subjected to natural selection, and ecological factors had an important evolutionary role in polymorphisms at this locus. According to population and codon analysis, these results suggested that monomeric alpha-amylase inhibitors are adaptively selected under different environmental conditions.

Phylogenetic inferences in Avena based on analysis of FL intron2 sequences.

The development and application of molecular methods in oats has been relatively slow compared with other crops. Results from the previous analyses have left many questions concerning species evolutionary relationships unanswered, especially regarding the origins of the B and D genomes, which are only known to be present in polyploid oat species. To investigate the species and genome relationships in genus Avena, among 13 diploid (A and C genomes), we used the second intron of the nuclear gene FLORICAULA/LEAFY (FL int2) in seven tetraploid (AB and AC genomes), and five hexaploid (ACD genome) species. The Avena FL int2 is rather long, and high levels of variation in length and sequence composition were found. Evidence for more than one copy of the FL int2 sequence was obtained for both the A and C genome groups, and the degree of divergence of the A genome copies was greater than that observed within the C genome sequences. Phylogenetic analysis of the FL int2 sequences resulted in topologies that contained four major groups; these groups reemphasize the major genomic divergence between the A and C genomes, and the close relationship among the A, B, and D genomes. However, the D genome in hexaploids more likely originated from a C genome diploid rather than the generally believed A genome, and the C genome diploid A. clauda may have played an important role in the origination of both the C and D genome in polyploids.

Characterization and comparative analysis of HMW glutenin 1Ay alleles with differential expressions.

BACKGROUND: High-molecular-weight glutenin subunits (HMW-GSs) have been considered as most important seed storage proteins for wheat flour quality. 1Ay subunits are of great interest because they are always silent in common wheat. The presence of expressed 1Ay subunits in diploid and tetraploid wheat genotypes makes it possible to investigate molecular information of active 1Ay genes. RESULTS: We identified 1Ay subunits with different electrophoretic mobility from 141 accessions of diploid and tetraploid wheats, and obtained the complete ORFs and 5' flanking sequences of 1Ay genes including 6 active and 3 inactive ones. Furthermore, the 5' flanking sequences were characterized from 23 wild diploid species of Triticeae. All 6 active 1Ay possess a typical HMW-GS primary structure and some novel characteristics. The conserved cysteine residue within the repetitive domain of y-type subunits was replaced by phenylalanine residue in subunits of 1Ay (Tu-e1), 1Ay (Tu-e2), 1Ay (Ta-e2) and 1Ay (Td-e). Particularly, 1Ay (Ta-e3) has an unusual large molecular weight of 2202 bp and was one of the known largest y-type HMW-GSs. The translations of 1Ay (Tu-s), 1Ay (Ta-s) and 1Ay (Td-s) were disrupted by premature stop codons in their coding regions. The 5' flanking sequences of active and inactive 1Ay genes differ in a few base substitutions and insertions or deletions. The 85 bp deletions have been found in promoter regions of all 1Ay genes and the corresponding positions of 6 species from Aegilops and Hordeum. CONCLUSION: The possession of larger molecular weight and fewer conserved cysteine residues are unique structural features of 1Ay genes; it would be interested to express them in bread wheat and further to examine their impact to processing quality of wheat. The 1Ay genes from T. urartu are closer to the genes from T. turgidum dicoccon and T. aestivum, than those from T. monococcum aegilopoides. The 85 bp deletion and some variations in the 5'flanking region, have not interrupted expression of 1Ay genes, whereas the defects in the coding regions could be responsible to the silence of the 1Ay genes. Some mutational events in more distant distal promoter regions are also possible causes for the inactivation of 1Ay genes.

Molecular characterization of two silenced y-type genes for Glu-B1 in Triticum aestivum ssp. yunnanese and ssp. tibetanum.

The high molecular weight glutenin subunits (HMW-GSs) are a major class of common wheat storage proteins. The bread-making quality of common wheat flour is influenced by the composition of HMW-GSs. In the present study, two unexpressed 1By genes from Triticum aesitvum L.ssp.yunnanese AS332 and T. aesitvum ssp.tibetanum AS908 were respectively cloned and characterized. The results indicated that both of the silenced 1By genes in AS332 and AS908 were 1By9. In contrast to previously reported mechanisms for silenced genes 1Ax and 1Ay, which was due to the insertion of transposon elements or the presence of premature stop codon via base substitution of C-->T transition in trinucleotides CAA or CAG, the silence of 1By9 genes was caused by premature stop codons via the deletion of base A in trinucleotide CAA, which lead to frameshift mutation and indirectly produced several premature stop codons (TAG) downstream of the coding sequence.

[Isolation and characterization of a low molecular weight glutenin gene from Taenitherum Nevski].

More and more low-molecular-weight glutenin(LMW glutenin) genes were isolated and characterized from hexaploid wheat (Triticum aestivum L.). However, few homologous genes were obtained from its relative species, which limited our understanding of the relationships among them. Therefore, it is necessary to isolate LMW glutenin homologous genes from wheat wild relative species. Using a pair of specific oligonucleotide PCR primers for Taenitherum genomic DNA, a LMW glutenin gene sequence, with nucleotide sequence in 1 035 bp and deduced amino acid sequence with 343 amino acid residues, was obtained. This sequence was a typical LMW glutenin sequence and characterized by a signal peptide of 21 amino acid residues, a N-terminal conservative domain of 13 amino acid residues, a repetitive domain of short peptide, and a C-terminal conservative domain. Sequence alignment showed the main differences and the relationships between LMW glutenin genes from wheat and Taenitherum. The results presented here give a reference to isolate LMW glutenin gene from Taenitherum, as well as other wheat wild relatives.

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

BACKGROUND: alpha-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 alpha-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. RESULTS: The influence of ecological factors on the genetic structure of dimeric alpha-amylase inhibitor genes was evaluated by specific SNP markers. A total of 244 dimeric alpha-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. CONCLUSION: The populations of wild emmer wheat showed a wide range of diversity in dimeric alpha-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 alpha-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 alpha-amylase inhibitor genes have been subjected to natural selection, and ecological factors had an important evolutionary influence on gene differentiation at specific loci.

SNP and haplotype identification of the wheat monomeric alpha-amylase inhibitor genes.

Seventy-three gene sequences encoding monomeric alpha-amylase inhibitors were characterized from cultivated wheat "Chinese Spring", group 6 nullisomic-tetrasomic lines of "Chinese Spring" and diploid putative progenitors of common wheat. The monomeric alpha-amylase inhibitors from the different sources shared very high homology (99.54%). The different alpha-amylase inhibitors, which were determined by the 24 single nucleotide polymorphisms (SNPs) of their gene sequences, were investigated. A total of 15 haplotypes were defined by sequence alignment, among which 9 haplotypes were found with only one single sequence sample. Haplotype H02 was found to be the main haplotype occurring in 83 WMAI sequence samples, followed by haplotype H11. The median-joining network for the 15 haplotypes of monomeric alpha-amylase inhibitor gene sequences from hexaploid wheats was star like, and at least two subclusters emerged. Furthermore evidence of homologous recombination was found between the haplotypes. The relationship between nucleotide substitutions and the amino acid changes in WMAI of hexaploid wheats was summarized. It was clear that only five polymorphic sites in the nucleotide sequence of WMAI resulted in amino acid variations, and that should be the reason for different structure and function of inhibitors. However, little evidence could be found that there were WMAI genes in the A genome of hexaploid wheat, whereas it could conclude from our results that the A genome diploid wheat had WMAI genes. The overall information on the monomeric alpha-amylase inhibitors from wheat and Aegilops strongly support the view that these inhibitors have evolved from a common ancestral gene through duplication and mutation.

Sequence variations and haplotype identification of wheat dimeric alpha-amylase inhibitor genes in einkorn wheats.

This study characterizes 80 dimeric alpha-amylase inhibitor genes from 68 accessions of the einkorn wheats Triticum urartu, T. boeoticum, and T. monococcum. The mature protein coding sequences of WDAI genes were analyzed. Nucleotide sequence variations in these regions resulted from base substitution and/or indel mutations. Most of the WDAI gene sequences from T. boeoticum and all sequences from T. monococcum had one nucleotide insertion in the coding region, such that these alpha-amylase inhibitor sequences could not encode the correct mature proteins. We identified 21 distinct haplotypes from the diploid wheat WDAI gene sequences. A main haplotype was found in 15 gene samples from the A(u) genome and 35 gene samples from the A(m) genome. The T. monococcum and T. boeoticum accessions shared the same main haplotype, with 25 samples from T. monococcum and 10 from T. boeoticum. The WDAI gene sequences from the A(u) and A(m) genomes could be obviously clustered into two clades, but the sequences from the A(m) genome of T. boeoticum and T. monococcum could not be clearly distinguished. The phylogenetic analysis revealed that the WDAI gene sequences from the A(m) genome had accumulated fewer variations and evolved at a slower rate than the sequences from the A(u) genome. Although some accessions from only one or two areas had unique mutations at the same position, the diversity of WDAI gene sequences in diploid wheat showed little relationship to the origin of the accessions.

QTL mapping of domestication-related traits in soybean (Glycine max).

BACKGROUND AND AIMS: Understanding the genetic basis underlying domestication-related traits (DRTs) is important in order to use wild germplasm efficiently for improving yield, stress tolerance and quality of crops. This study was conducted to characterize the genetic basis of DRTs in soybean (Glycine max) using quantitative trait locus (QTL) mapping. METHODS: A population of 96 recombinant inbred lines derived from a cultivated (ssp. max) x wild (ssp. soja) cross was used for mapping and QTL analysis. Nine DRTs were examined in 2004 and 2005. A linkage map was constructed with 282 markers by the Kosambi function, and the QTL was detected by composite interval mapping. KEY RESULTS: The early flowering and determinate habit derived from the max parent were each controlled by one major QTL, corresponding to the major genes for maturity (e1) and determinate habit (dt1), respectively. There were only one or two significant QTLs for twinning habit, pod dehiscence, seed weight and hard seededness, which each accounted for approx. 20-50 % of the total variance. A comparison with the QTLs detected previously indicated that in pod dehiscence and hard seededness, at least one major QTL was common across different crosses, whereas no such consistent QTL existed for seed weight. CONCLUSIONS: Most of the DRTs in soybeans were conditioned by one or two major QTLs and a number of genotype-dependent minor QTLs. The common major QTLs identified in pod dehiscence and hard seededness may have been key loci in the domestication of soybean. The evolutionary changes toward larger seed may have occurred through the accumulation of minor changes at many QTLs. Since the major QTLs for DRTs were scattered across only six of the 20 linkage groups, and since the QTLs were not clustered, introgression of useful genes from wild to cultivated soybeans can be carried out without large obstacles.

EST-SSR DNA polymorphism in durum wheat (Triticum durum L.) collections.

SSRs derived from EST were molecular markers belonging to the transcribed region of the genome. Therefore, any polymorphism detected using EST-SSRs might reflect the better relationship among species or varieties. Using wheat EST-SSR markers, 60 durum wheat (Triticum durum L.) accessions from seven countries were investigated. Twenty-five primer pairs could amplify successfully in the 60 durum wheat accessions, of which tri-nucleotide repeats were the dominant type, and revealed 26 loci on all seven wheat homologous chromosome groups. A total of 87 eSSR alleles were detected, and the number of alleles detected by a single pair of primers ranged from 1 to 11, with an average of 3.3 alleles per locus. Higher numbers of alleles and PIC were identified on the B genome than those on the A genome.

Characterization of two HMW glutenin subunit genes from Taenitherum Nevski.

The compositions of high molecular weight (HMW) glutenin subunits from three species of Taenitherum Nevski (TaTa, 2n = 2x = 14), Ta. caput-medusae, Ta. crinitum and Ta. asperum, were investigated by SDS-PAGE analysis. The electrophoresis mobility of the x-type HMW glutenin subunits were slower or equal to that of wheat HMW glutenin subunit Dx2, and the electrophoresis mobility of the y-type subunits were faster than that of wheat HMW glutenin subunit Dy12. Two HMW glutenin genes, designated as Tax and Tay, were isolated from Ta. crinitum, and their complete nucleotide coding sequences were determined. Sequencing and multiple sequences alignment suggested that the HMW glutenin subunits derived from Ta. crinitum had the similar structures to the HMW glutenin subunits from wheat and related species with a signal peptide, and N- and C-conservative domains flanking by a repetitive domain consisted of the repeated short peptide motifs. However, the encoding sequences of Tax and Tay had some novel modification compared with the HMW glutenin genes reported so far: (1) A short peptide with the consensus sequences of KGGSFYP, which was observed in the N-terminal of all known HMW glutenin genes, was absent in Tax; (2) There is a specified short peptide tandem of tripeptide, hexapeptide and nonapeptide and three tandem of tripeptide in the repetitive domain of Tax; (3) The amino acid residues number is 105 (an extra Q presented) but not 104 in the N-terminal of Tay, which was similar to most of y-type HMW glutenin genes from Elytrigia elongata and Crithopsis delileana. Phylogenetic analysis indicated that Tax subunit was mostly related to Ax1, Cx, Ux and Dx5, and Tay was more related to Ay, Cy and Ry.

[Molecular cloning of a novel low-molecular-weight glutenin subunit gene from wheat variety "Chuanmai 42"].

Using PCR-amplification method, the coding sequences of a novel low-molecular-weight glutenin (LMW-GS) gene, LMWCM42-1, was isolated from the genomic DNA of wheat (Triticum aestivum L.) variety 'Chuanmai 42'. The full coding region of this gene consisted of 846 nucleotides, and encoded a protein with 281 amino acids. LMWCM42-1 is a typical low-molecular-weight glutenin subunit (LMW-GS) gene. In spite of high similarity with the known LMW-GSs, LMWCM42-1 was quite different from the known LMW-GS in the N-terminal, central repetitive domain and C-terminal domain. It was found that LMWCM42-1 was located within the Glu-D3 locus by phylogenetic analysis.

[Characterization of low-molecular-weighT i-type glutenin subunit genes from diploid wheat in relation to the gene family structure].

The low-molecular-weight (LMW) glutenin subunits are important for aspects of wheat quality and dough processing, and the LMW-i type glutenin is one of the typical glutenins. However, a detailed description of the DNA structure and encoded polypeptides of the LMW-i type glutenin subunit gene family is still lacking. In this study, two LMW-i type glutenin subunit genes, i.e., LMW-Eb from Triticum boeoticum and LMW-Em from T. monococcum, were obtained from genomic DNA, respectively. The LMW-Eb is a novel gene and the LMW-Em has the identical sequence with a known gene. To comprehensively understand the LMW-i type glutenin subunit gene family structure, all known LMW-i type glutenin subunit genes were comparatively analyzed. Detailed comparison of these genes revealed a high-level of single nucleotide polymorphisms (SNP). In these LMW glutenin subunits, the percentage of glutamine and proline were approximately 38.27 and 12.77%, respectively. They started directly from the repetitive domain with ISQQQ- after the signal sequence, which the N-terminal regions were absent. In addition, there are three consensus repeat motifs (i.e. PPFSQQQQ, PPISQQQQ and PPYSQQQQ) in the repetitive domains of these LMW glutenin subunits. The C-terminal I domain is the most conserved region, while the domains of C-terminal II and III are more variable. The eight cysteine residues are highly conserved. These genes could be clustered into two major groups, among which one group could be further divided into five subgroups. Furthermore, to date, all known LMW-i type glutenin subunit genes are located on chromosome 1A, whereas no LMW-i type glutenin subunit gene is obtained from the B and D genomes in wheat.

Molecular characterization of of alpha-gliadin genes from wild emmer wheat (Triticum dicoccoides).

According to the two distal and conserved regions of known alpha-gliadin genes, gene-specific primers for alpha-gliadin were designed, and the coding regions of four gliadin genes (i.e. GliTd-1, GliTd-2, GliTd-3 and GliTd-4) with the length of about 800 bp were isolated from the genomic DNA of wild emmer wheat (Triticum dicoccoides). No introns were observed. Sequence comparison indicated that these genes should be classified as alpha-gliadins. GliTd-3 (GenBank accession No.DQ140351) and GliTd-4 (DQ140352) were potentially functional, whereas GliTd-1 (DQ140349) and GliTd-2 (DQ140350) were both pseudogenes by the definition of in-frame stop codons and frameshifts. Six conserved cysteine residues were observed. Sequence analysis suggested that the motif units of repetitive domain for the four newly detected genes were different from the known genes, and the QQQP sequence before the position 60 was more toxic to coeliac patients. Codons for proline were strongly biased. Codons (CAG and CAA) for glutamine were clustered into the specific regions, and the high percentage of pseudogenes resulted from the mutation of CAG --> TAG.

[The effect of phKL gene on homoeologous pairing of wheat-alien hybrids is situated between gene mutants of Ph1 and Ph2].

In natural populations of common wheat landrace, there has a phKL gene promoting homoeologous pairing of wheat-alien hybrids. In this study, the effects were compared among phKL, ph1b, ph2a and ph2b on homoeologous pairing of wheat-alien hybrids. The effects were indicated as ph1b > phKL > ph2b > ph2a, i. e. phKL gene was situated between gene mutants of Ph1 and Ph2.