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1.
Plant Cell ; 36(9): 3809-3823, 2024 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-39056474

RESUMO

The domestication of crops, coupled with agroecosystem development, is associated with major environmental changes and provides an ideal model of phenotypic plasticity. Here, we examined 32 genotypes of three tetraploid wheat (Triticum turgidum L.) subspecies, wild emmer, emmer, and durum wheat, which are representative of the key stages in the domestication of tetraploid wheat. We developed a pipeline that integrates RNA-Seq data and population genomics to assess gene expression plasticity and identify selection signatures under diverse nitrogen availability conditions. Our analysis revealed differing gene expression responses to nitrogen availability across primary (wild emmer to emmer) and secondary (emmer to durum wheat) domestication. Notably, nitrogen triggered the expression of twice as many genes in durum wheat compared to that in emmer and wild emmer. Unique selection signatures were identified at each stage: primary domestication mainly influenced genes related to biotic interactions, whereas secondary domestication affected genes related to amino acid metabolism, in particular lysine. Selection signatures were found in differentially expressed genes (DEGs), notably those associated with nitrogen metabolism, such as the gene encoding glutamate dehydrogenase (GDH). Overall, our study highlights the pivotal role of nitrogen availability in the domestication and adaptive responses of a major food crop, with varying effects across different traits and growth conditions.


Assuntos
Domesticação , Regulação da Expressão Gênica de Plantas , Nitrogênio , Tetraploidia , Transcriptoma , Triticum , Triticum/genética , Triticum/metabolismo , Nitrogênio/metabolismo , Transcriptoma/genética , Genótipo
2.
Theor Appl Genet ; 137(9): 210, 2024 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-39198268

RESUMO

KEY MESSAGE: Two allelic variants of Pp-A3 and Pp-B1 were identified in purple durum wheat. Molecular markers at both loci were developed and validated on an independent panel, offering a breakthrough for wheat improvement. Purple wheats are a class of cereals with pigmented kernels of particular interest for their antioxidant and anti-inflammatory properties. Although two complementary loci (Pp-B1 and Pp-A3), responsible for purple pericarp have been pinpointed in bread wheat (Triticum aestivum L.), in durum wheat (Triticum durum Desf.) the causative genes along with functional and non-functional alleles are still unknown. Here, using a quantitative trait loci (QTL) mapping approach on a RIL population derived from purple and non-purple durum wheat genotypes, we identified three major regions on chromosomes 2A, 3A, and 7B explaining the highest phenotypic variation (> 50%). Taking advantage of the Svevo genome, a MYB was reannotated on chromosome 7B and reported as a candidate for Pp-B1. An insertion of ~ 1.6 kb within the first exon led to a non-functional allele (TdPpm1b), whereas the functional allele (TdPpm1a) was characterized and released for the first time in durum wheat. Pp-A3 was instead identified as a duplicated gene, of which only one was functional. The promoter sequencing of the functional allele (TdPpb1a) revealed six 261-bp tandem repeats in purple durum wheat, whereas one unit (TdPpb1b) was found in the yellow once. Functional molecular markers at both loci were developed to precisely discriminate purple and not purple genotypes, representing a valuable resource for selecting superior purple durum lines at early growth stages. Overall, our results expand the understanding of the function of MYB and bHLH activators in durum wheat, paving new ways to explore cis-regulatory elements at the promoter level.


Assuntos
Alelos , Mapeamento Cromossômico , Genótipo , Fenótipo , Locos de Características Quantitativas , Triticum , Triticum/genética , Triticum/crescimento & desenvolvimento , Mapeamento Cromossômico/métodos , Marcadores Genéticos , Genes de Plantas , Pigmentação/genética , Cromossomos de Plantas/genética
3.
Theor Appl Genet ; 136(12): 242, 2023 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-37947927

RESUMO

KEY MESSAGE: Simultaneous improvement for GY and GPC by using GWAS and GBLUP suggested a significant application in durum wheat breeding. Despite the importance of grain protein concentration (GPC) in determining wheat quality, its negative correlation with grain yield (GY) is still one of the major challenges for breeders. Here, a durum wheat panel of 200 genotypes was evaluated for GY, GPC, and their derived indices (GPD and GYD), under eight different agronomic conditions. The plant material was genotyped with the Illumina 25 k iSelect array, and a genome-wide association study was performed. Two statistical models revealed dozens of marker-trait associations (MTAs), each explaining up to 30%. phenotypic variance. Two markers on chromosomes 2A and 6B were consistently identified by both models and were found to be significantly associated with GY and GPC. MTAs identified for phenological traits co-mapped to well-known genes (i.e., Ppd-1, Vrn-1). The significance values (p-values) that measure the strength of the association of each single nucleotide polymorphism marker with the target traits were used to perform genomic prediction by using a weighted genomic best linear unbiased prediction model. The trained models were ultimately used to predict the agronomic performances of an independent durum wheat panel, confirming the utility of genomic prediction, although environmental conditions and genetic backgrounds may still be a challenge to overcome. The results generated through our study confirmed the utility of GPD and GYD to mitigate the inverse GY and GPC relationship in wheat, provided novel markers for marker-assisted selection and opened new ways to develop cultivars through genomic prediction approaches.


Assuntos
Proteínas de Grãos , Triticum , Triticum/genética , Triticum/metabolismo , Estudo de Associação Genômica Ampla , Proteínas de Grãos/metabolismo , Locos de Características Quantitativas , Melhoramento Vegetal , Grão Comestível/genética
4.
J Sci Food Agric ; 103(11): 5521-5528, 2023 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-37058574

RESUMO

BACKGROUND: Pasta is a worldwide popular Italian food made exclusively of durum wheat. The choice of variety to be used to produce pasta is at the discretion of the producer based on the peculiar characteristics of each cultivar. The availability of analytical approaches for the tracking of specific varieties along the productive chain is becoming increasingly important to authenticate the pasta products and distinguish between fraudulent activities and cross-contaminations during the production process. Among the different methods, molecular approaches based on DNA markers are the most used for these purposes because of their ease of use and high reproducibility. RESULTS: In the present study, we used an easy simple sequence repeats-based method to identify the durum wheat varieties used to produce 25 samples of semolina and commercial pasta comparing their molecular profile with those of the four varieties declared by the producer and other 10 durum wheat cultivars commonly used in pasta production. All of the samples showed the expected molecular profile; however, most of them present also a foreign allele indicating a possible cross-contamination. Moreover, we evaluated the accuracy of the proposed approach through the analysis of 27 hand-made mixtures with increasing amounts of a specific contaminant variety, allowing the estimation of the limit of detection of 5% (w/w). CONCLUSION: We demonstrated the feasibility of the proposed method and its effectiveness in the detection of not declared varieties when these are present in a percentage equal to or higher than 5%. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.


Assuntos
Farinha , Triticum , Triticum/genética , Triticum/química , Reprodutibilidade dos Testes , Farinha/análise , Grão Comestível , Itália
5.
BMC Plant Biol ; 22(1): 519, 2022 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-36344939

RESUMO

BACKGROUND: Rapid reductions in emissions from fossil fuel burning are needed to curb global climate change. Biofuel production from crop residues can contribute to reducing the energy crisis and environmental deterioration. Wheat is a renewable source for biofuels owing to the low cost and high availability of its residues. Thus, identifying candidate genes controlling these traits is pivotal for efficient biofuel production. Here, six multi-locus genome-wide association (ML-GWAS) models were applied using 185 tetraploid wheat accessions to detect quantitative trait nucleotides (QTNs) for fifteen traits associated with biomass composition. RESULTS: Among the 470 QTNs, only 72 identified by at least two models were considered as reliable. Among these latter, 16 also showed a significant effect on the corresponding trait (p.value < 0.05). Candidate genes survey carried out within 4 Mb flanking the QTNs, revealed putative biological functions associated with lipid transfer and metabolism, cell wall modifications, cell cycle, and photosynthesis. Four genes encoded as Cellulose Synthase (CeSa), Anaphase promoting complex (APC/C), Glucoronoxylan 4-O Methyltransferase (GXM) and HYPONASTIC LEAVES1 (HYL1) might be responsible for an increase in cellulose, and natural and acid detergent fiber (NDF and ADF) content in tetraploid wheat. In addition, the SNP marker RFL_Contig3228_2154 associated with the variation in stem solidness (Q.Scsb-3B) was validated through two molecular methods (High resolution melting; HRM and RNase H2-dependent PCR; rhAMP). CONCLUSIONS: The study provides new insights into the genetic basis of biomass composition traits on tetraploid wheat. The application of six ML-GWAS models on a panel of diverse wheat genotypes represents an efficient approach to dissect complex traits with low heritability such as wheat straw composition. The discovery of genes/genomic regions associated with biomass production and straw quality parameters is expected to accelerate the development of high-yielding wheat varieties useful for biofuel production.


Assuntos
Estudo de Associação Genômica Ampla , Triticum , Triticum/metabolismo , Biocombustíveis , Tetraploidia , Fenótipo
6.
Genomics ; 113(5): 2989-3001, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34182080

RESUMO

Studying and understanding the genetic basis of polyphenol oxidases (PPO)-related traits plays a crucial role in genetic improvement of crops. A tetraploid wheat collection (T. turgidum ssp., TWC) was analyzed using the 90K wheat SNP iSelect assay and phenotyped for PPO activity. A total of 21,347 polymorphic SNPs were used to perform genome-wide association analysis (GWA) in TWC and durum wheat sub-groups, detecting 23 and 85 marker-trait associations (MTA). In addition, candidate genes responsible for PPO activity were predicted. Based on the 23 MTAs detected in TWC, two haplotypes associated with low and high PPO activity were identified. Four SNPs were developed and validated providing one reliable marker (IWB75732) for marker assisted selection. The 23 MTAs were used to evaluate the genetic divergence (FST > 0.25) between the T. turgidum subspecies, providing new information important for understanding the domestication process of Triticum turgidum ssp. and in particular of ssp. carthlicum.


Assuntos
Catecol Oxidase , Tetraploidia , Triticum , Catecol Oxidase/genética , Domesticação , Evolução Molecular , Estudo de Associação Genômica Ampla , Haplótipos , Polimorfismo de Nucleotídeo Único , Triticum/enzimologia , Triticum/genética
7.
Theor Appl Genet ; 134(12): 4013-4024, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34477900

RESUMO

KEY MESSAGE: The suppression of the HYD-1 gene by a TILLING approach increases the amount of ß-carotene in durum wheat kernel. Vitamin A deficiency is a major public health problem that affects numerous countries in the world. As humans are not able to synthesize vitamin A, it must be daily assimilated along with other micro- and macronutrients through the diet. Durum wheat is an important crop for Mediterranean countries and provides a discrete amount of nutrients, such as carbohydrates and proteins, but it is deficient in some essential micronutrients, including provitamin A. In the present work, a targeting induced local lesions in genomes strategy has been undertaken to obtain durum wheat genotypes biofortified in provitamin A. In detail, we focused on the suppression of the ß-carotene hydroxylase 1 (HYD1) genes, encoding enzymes involved in the redirection of ß-carotene toward the synthesis of the downstream xanthophylls (neoxanthin, violaxanthin and zeaxanthin). Expression analysis of genes involved in carotenoid biosynthesis revealed a reduction of the abundance of HYD1 transcripts greater than 50% in mutant grain compared to the control. The biochemical profiling of carotenoid in the wheat mutant genotypes highlighted a significant increase of more than 70% of ß-carotene compared to the wild-type sibling lines, with no change in lutein, α-carotene and zeaxanthin content. This study sheds new light on the molecular mechanism governing carotenoid biosynthesis in durum wheat and provides new genotypes that represent a good genetic resource for future breeding programs focused on the provitamin A biofortification through non-transgenic approaches.


Assuntos
Engenharia Metabólica , Oxigenases de Função Mista/genética , Provitaminas/biossíntese , Sementes/química , Triticum/genética , Vitamina A/biossíntese , Carotenoides , Grão Comestível/química , Grão Comestível/genética , Alimentos Fortificados , Técnicas de Inativação de Genes , Genótipo , Filogenia , Melhoramento Vegetal , Triticum/química , Xantofilas , Zeaxantinas/biossíntese
8.
Int J Mol Sci ; 22(9)2021 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-33946478

RESUMO

Mounting evidence indicates the key role of nitrogen (N) on diverse processes in plant, including development and defense. Using a combined transcriptomics and metabolomics approach, we studied the response of seedlings to N starvation of two different tetraploid wheat genotypes from the two main domesticated subspecies: emmer and durum wheat. We found that durum wheat exhibits broader and stronger response in comparison to emmer as seen from the expression pattern of both genes and metabolites and gene enrichment analysis. They showed major differences in the responses to N starvation for transcription factor families, emmer showed differential reduction in the levels of primary metabolites while durum wheat exhibited increased levels of most of them to N starvation. The correlation-based networks, including the differentially expressed genes and metabolites, revealed tighter regulation of metabolism in durum wheat in comparison to emmer. We also found that glutamate and γ-aminobutyric acid (GABA) had highest values of centrality in the metabolic correlation network, suggesting their critical role in the genotype-specific response to N starvation of emmer and durum wheat, respectively. Moreover, this finding indicates that there might be contrasting strategies associated to GABA and glutamate signaling modulating shoot vs. root growth in the two different wheat subspecies.


Assuntos
Regulação da Expressão Gênica de Plantas , Nitrogênio/metabolismo , Plântula/genética , Triticum/genética , Metaboloma , Plântula/metabolismo , Tetraploidia , Transcriptoma , Triticum/metabolismo
9.
Molecules ; 26(9)2021 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-33946829

RESUMO

Wheat represents one of the most important cereals for mankind. However, since wheat proteins are also the causative agent of several adverse reactions, during the last decades, consumers have shown an increasing interest in the old wheat genotypes, which are generally perceived as more "natural" and healthier than the modern ones. Comparison of nutritional value for modern and old wheat genotypes is still controversial, and to evaluate the real impact of these foods on human health comparative experiments involving old and modern genotypes are desirable. The nutritional quality of grain is correlated with its proteomic composition that depends on the interplay between the genetic characteristics of the plant and external factors related to the environment. We report here the label-free shotgun quantitative comparison of the metabolic protein fractions of two old Sicilian landraces (Russello and Timilia) and the modern variety Simeto, from the 2010-2011 and 2011-2012 growing seasons. The overall results show that Timilia presents the major differences with respect to the other two genotypes investigated. These differences may be related to different defense mechanisms and some other peculiar properties of these genotypes. On the other hand, our results confirm previous results leading to the conclusion that with respect to a nutritional value evaluation, there is a substantial equivalence between old and modern wheat genotypes. Data are available via ProteomeXchange with identifier .


Assuntos
Genótipo , Proteínas de Plantas/genética , Triticum/genética , Metabolismo Energético , Itália , Espectrometria de Massas , Proteínas de Plantas/metabolismo , Proteômica/métodos , Triticum/metabolismo
10.
Int J Mol Sci ; 21(2)2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31936286

RESUMO

By selecting for prostrate growth habit of the juvenile phase of the cycle, durum wheat cultivars could be developed with improved competitive ability against weeds, and better soil coverage to reduce the soil water lost by evaporation. A panel of 184 durum wheat (Triticum turgidum subsp. durum) genotypes, previously genotyped with DArT-seq markers, was used to perform association mapping analysis of prostrate/erect growth habit trait and to identify candidate genes. Phenotypic data of plant growth habit were recorded during three consecutive growing seasons (2014-2016), two different growth conditions (field trial and greenhouse) and two sowing periods (autumn and spring). Genome-wide association study revealed significant marker-trait associations, twelve of which were specific for a single environment/year, 4 consistent in two environments, and two MTAs for the LSmeans were identified across all environments, on chromosomes 2B and 5A. The co-localization of some MTAs identified in this study with known vernalization and photoperiod genes demonstrated that the sensitivity to vernalization and photoperiod response are actually not only key components of spring/winter growth habit, but they play also an important role in defining the magnitude of the tiller angle during the tillering stage. Many zinc-finger transcription factors, such as C2H2 or CCCH-domain zinc finger proteins, known to be involved in plant growth habit and in leaf angle regulation were found as among the most likely candidate genes. The highest numbers of candidate genes putatively related to the trait were found on chromosomes 3A, 4B, 5A and 6A. Moreover, a bioinformatic approach has been considered to search for functional ortholog genes in wheat by using the sequence of rice and barley tiller angle-related genes. The information generated could be used to improve the understanding of the mechanisms that regulate the prostrate/erect growth habit in wheat and the adaptive potential of durum wheat under resource-limited environmental conditions.


Assuntos
Genoma de Planta/genética , Estudo de Associação Genômica Ampla , Locos de Características Quantitativas/genética , Triticum/genética , Mapeamento Cromossômico , Cromossomos de Plantas/genética , Genótipo , Humanos , Fenótipo , Polimorfismo de Nucleotídeo Único/genética , Estações do Ano , Triticum/crescimento & desenvolvimento
12.
Int J Mol Sci ; 20(22)2019 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-31739436

RESUMO

Macro- and micronutrients, essential for the maintenance of human metabolism, are assimilated daily through the diet. Wheat and other major cereals are a good source of nutrients, such as carbohydrates and proteins, but cannot supply a sufficient amount of essential micronutrients, including provitamin A. As vitamin A deficiency (VAD) leads to several serious diseases throughout the world, the biofortification of a major staple crop, such as wheat, represents an effective way to preserve human health in developing countries. In the present work, a key enzyme involved in the branch of carotenoids pathway producing ß-carotene, lycopene epsilon cyclase, has been targeted by a Targeting Induced Local Lesions in Genomes (TILLING) approach in a "block strategy" perspective. The null mutant genotype showed a strong reduction in the expression of the lcyE gene and also interesting pleiotropic effects on an enzyme (ß-ring hydroxylase) acting downstream in the pathway. Biochemical profiling of carotenoids in the wheat mutant lines showed an increase of roughly 75% in ß-carotene in the grains of the complete mutant line compared with the control. In conclusion, we describe here the production and characterization of a new wheat line biofortified with provitamin A obtained through a nontransgenic approach, which also sheds new light on the molecular mechanism governing carotenoid biosynthesis in durum wheat.


Assuntos
Biofortificação , Engenharia Genética , Triticum/genética , Triticum/metabolismo , Vitamina A/metabolismo , Alelos , Sequência de Bases , Carotenoides/metabolismo , Regulação da Expressão Gênica de Plantas , Marcação de Genes , Engenharia Genética/métodos , Genômica/métodos , Humanos , Liases Intramoleculares/genética , Liases Intramoleculares/metabolismo , Mutação , Filogenia , Plantas Geneticamente Modificadas
14.
Int J Mol Sci ; 19(12)2018 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-30563213

RESUMO

Stem rust, caused by Puccinia graminis f. sp. tritici (Pgt), is a major biotic constraint to wheat production worldwide. Disease resistant cultivars are a sustainable means for the efficient control of this disease. To identify quantitative trait loci (QTLs) conferring resistance to stem rust at the seedling stage, an association mapping panel consisting of 230 tetraploid wheat accessions were evaluated for reaction to five Pgt races under greenhouse conditions. A high level of phenotypic variation was observed in the panel in response to all of the races, allowing for genome-wide association mapping of resistance QTLs in wild, landrace, and cultivated tetraploid wheats. Twenty-two resistance QTLs were identified, which were characterized by at least two marker-trait associations. Most of the identified resistance loci were coincident with previously identified rust resistance genes/QTLs; however, six regions detected on chromosomes 1B, 5A, 5B, 6B, and 7B may be novel. Availability of the reference genome sequence of wild emmer wheat accession Zavitan facilitated the search for candidate resistance genes in the regions where QTLs were identified, and many of them were annotated as NOD (nucleotide binding oligomerization domain)-like receptor (NLR) genes or genes related to broad spectrum resistance.


Assuntos
Mapeamento Cromossômico/métodos , Resistência à Doença , Locos de Características Quantitativas , Triticum/genética , Basidiomycota/patogenicidade , Cromossomos de Plantas/genética , Loci Gênicos , Estudo de Associação Genômica Ampla , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Tetraploidia , Triticum/microbiologia
15.
J Food Sci Technol ; 55(11): 4458-4467, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30333642

RESUMO

The aim of this study was to develop fortified breads of durum wheat semolina (DW) partially substituted at 10%, 15%, 20% and 30% with white sorghum or yellow pea wholemeal flours (WS, YP, respectively) or using wholemeal flour from a natural mixture of rye and durum wheat (RDW). The physico-chemical composition of the raw materials, rheological properties of dough, the bread quality characteristics, glycaemic index and sensory quality of bread were examined. Compared to 100% DW, 100% YP had twice the protein levels, RDW had almost three times the dietary fibre, while the colorimetric indices for WS and YP flour addition showed increased redness (for RDW) and similar yellowness (for YP). With respect to the control dough (100% DW), RDW and addition of WS or YP produced showed negative impact on water absorption (RDW, WS), stability (RDW, YP), dough strength (RDW, WS, YP), tenacity and extensibility ratio (RDW, YP), loaf volume (RDW, WS, YP), yellowness (RDW, WS) and sensory acceptance of bread (RDW, WS). However, these changes were counterbalanced by higher dietary fibre and lower glycaemic index of the breads, especially for RDW and at high additions of WS and YP (20-30%). Moreover, breads fortified with YP were better in terms of colour and overall acceptability scores.

16.
BMC Genomics ; 18(1): 122, 2017 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-28143400

RESUMO

BACKGROUND: In plants carotenoids play an important role in the photosynthetic process and photo-oxidative protection, and are the substrate for the synthesis of abscisic acid and strigolactones. In addition to their protective role as antioxidants and precursors of vitamin A, in wheat carotenoids are important as they influence the colour (whiteness vs. yellowness) of the grain. Understanding the genetic basis of grain yellow pigments, and identifying associated markers provide the basis for improving wheat quality by molecular breeding. RESULTS: Twenty-four candidate genes involved in the biosynthesis and catabolism of carotenoid compounds have been identified in wheat by comparative genomics. Single nucleotide polymorphisms (SNPs) found in the coding sequences of 19 candidate genes allowed their chromosomal location and accurate map position on two reference consensus maps to be determined. The genome-wide association study based on genotyping a tetraploid wheat collection with 81,587 gene-associated SNPs validated quantitative trait loci (QTLs) previously detected in biparental populations and discovered new QTLs for grain colour-related traits. Ten carotenoid genes mapped in chromosome regions underlying pigment content QTLs indicating possible functional relationships between candidate genes and the trait. CONCLUSIONS: The availability of linked, candidate gene-based markers can facilitate breeding wheat cultivars with desirable levels of carotenoids. Identifying QTLs linked to carotenoid pigmentation can contribute to understanding genes underlying carotenoid accumulation in the wheat kernels. Together these outputs can be combined to exploit the genetic variability of colour-related traits for the nutritional and commercial improvement of wheat products.


Assuntos
Carotenoides/metabolismo , Pigmentação/genética , Pigmentos Biológicos/metabolismo , Triticum/genética , Triticum/metabolismo , Carotenoides/biossíntese , Mapeamento Cromossômico , Estudos de Associação Genética , Estudo de Associação Genômica Ampla , Redes e Vias Metabólicas , Fenótipo , Filogenia , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Triticum/classificação
17.
Mol Biol Evol ; 33(7): 1740-53, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27189559

RESUMO

Domestication and breeding have influenced the genetic structure of plant populations due to selection for adaptation from natural habitats to agro-ecosystems. Here, we investigate the effects of selection on the contents of 51 primary kernel metabolites and their relationships in three Triticum turgidum L. subspecies (i.e., wild emmer, emmer, durum wheat) that represent the major steps of tetraploid wheat domestication. We present a methodological pipeline to identify the signature of selection for molecular phenotypic traits (e.g., metabolites and transcripts). Following the approach, we show that a reduction in unsaturated fatty acids was associated with selection during domestication of emmer (primary domestication). We also show that changes in the amino acid content due to selection mark the domestication of durum wheat (secondary domestication). These effects were found to be partially independent of the associations that unsaturated fatty acids and amino acids have with other domestication-related kernel traits. Changes in contents of metabolites were also highlighted by alterations in the metabolic correlation networks, indicating wide metabolic restructuring due to domestication. Finally, evidence is provided that wild and exotic germplasm can have a relevant role for improvement of wheat quality and nutritional traits.


Assuntos
Metabolômica/métodos , Triticum/genética , Triticum/metabolismo , Evolução Biológica , Mapeamento Cromossômico/métodos , Cromossomos de Plantas , Produtos Agrícolas/genética , Produtos Agrícolas/metabolismo , Domesticação , Evolução Molecular , Fenótipo , Melhoramento Vegetal , Locos de Características Quantitativas , Sementes/genética , Sementes/metabolismo , Tetraploidia
18.
Theor Appl Genet ; 130(10): 2005-2024, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28656363

RESUMO

KEY MESSAGE: A major locus for resistance to different Fusarium diseases was mapped to the most distal end of Th. elongatum 7EL and pyramided with Th. ponticum beneficial genes onto wheat 7DL. Perennial Triticeae species of the Thinopyrum genus are among the richest sources of valuable genes/QTL for wheat improvement. One notable and yet unexploited attribute is the exceptionally effective resistance to a major wheat disease worldwide, Fusarium head blight, associated with the long arm of Thinopyrum elongatum chromosome 7E (7EL). We targeted the transfer of the temporarily designated Fhb-7EL locus into bread wheat, pyramiding it with a Th. ponticum 7el1L segment stably inserted into the 7DL arm of wheat line T4. Desirable genes/QTL mapped along the T4 7el1L segment determine resistance to wheat rusts (Lr19, Sr25) and enhancement of yield-related traits. Mapping of the Fhb-7EL QTL, prerequisite for successful pyramiding, was established here on the basis of a bioassay with Fusarium graminearum of different 7EL-7el1L bread wheat recombinant lines. These were obtained without resorting to any genetic pairing promotion, but relying on the close 7EL-7el1L homoeology, resulting in 20% pairing frequency between the two arms. Fhb-7EL resided in the telomeric portion and resistant recombinants could be isolated with useful combinations of more proximally located 7el1L genes/QTL. The transferred Fhb-7EL locus was shown to reduce disease severity and fungal biomass in grains of infected recombinants by over 95%. The same Fhb-7EL was, for the first time, proved to be effective also against F. culmorum and F. pseudograminearum, predominant agents of crown rot. Prebreeding lines possessing a suitable 7EL-7el1L gene/QTL assembly showed very promising yield performance in preliminary field tests.


Assuntos
Resistência à Doença/genética , Doenças das Plantas/genética , Poaceae/genética , Triticum/genética , Mapeamento Cromossômico , Cromossomos de Plantas , Cruzamentos Genéticos , Fusarium , Marcadores Genéticos , Pigmentação , Melhoramento Vegetal , Doenças das Plantas/microbiologia , Locos de Características Quantitativas , Triticum/microbiologia
19.
Eur J Agron ; 87: 19-29, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28769550

RESUMO

The impact of breeding on grain yields of wheat varieties released during the 20th century has been extensively studied, whereas less information is available on the changes in gluten quality associated with effects on the amount and composition of glutenins and gliadins. In order to explore the effects of breeding during the 20th century on gluten quality of durum wheat for processing and health we have compared a set of old and modern Italian genotypes grown under Mediterranean conditions. The better technological performance observed for the modern varieties was found to be due not only to the introgression of superior alleles of high (HMW-GS) and low molecular weight (LMW-GS) glutenin subunits encoded at Glu-B1 and Glu-B3 loci, but also to differential expression of specific storage proteins. In particular, the higher gluten index observed in modern genotypes was correlated with an increased glutenin/gliadin ratio and the expression of B-type LMW-GS which was, on average, two times higher in the modern than in the old group of durum wheat genotypes. By contrast, no significant differences were found between old and modern durum wheat genotypes in relation to the expression of α-type and γ-type gliadins which are major fractions that trigger coeliac disease (CD) in susceptible individuals. Furthermore, a drastic decrease was observed in the expression of ω-type gliadins in the modern genotypes, mainly ω-5 gliadin (also known as Tri a 19) which is a major allergen in wheat dependent exercise induced anaphylaxis (WDEIA). Immunological and 2DE SDS-PAGE analyses indicated that these differences could be related either to a general down-regulation or to differences in numbers of isoforms. Lower rainfall during grain filling period was related to overall higher expression of HMW-GS and ω-gliadins. In conclusion, breeding activity carried out in Italy during the 20th century appears to have improved durum wheat gluten quality, both in relation to technological performance and allergenic potential.

20.
J Food Sci Technol ; 53(2): 1319-27, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27162413

RESUMO

In this work the effect of bran addition (5 %, 10 %, 15 %, 20 %, 25 %, 30 %) on sensory, nutritional and mechanical properties of bread made from a durum wheat semolina enriched with selenium (cultivar PR22D89) was addressed; traditional and whole-meal bread from the same cultivar PR22D89, without any further bran addition, were also investigated for comparative purpose. In order to improve the durum wheat functional bread, different structuring agents (agar agar, gellan gum, guar seed flour, hydroxy-propyl-cellulose, modified food starch-CAPSUL® and tapioca starch) were firstly screened and then optimized. Sensory, textural and nutritional properties of bread were studied in each step. Results showed that bread from PR22D89 cultivar with addition of bran up to 30 % was completely accepted from the textural, nutritional and sensory points of view with proper utilization of guar seed flour or modified food-starch (2 %).

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