Relationship between the D genome of hexaploid wheats (AABBDD) and Ae. squarrosa as deduced by seed storage proteins and molecular marker analyses

The electrophoretical analyses of seed storage protein components from the gliadin and glutenin fractions in T. aeslivum ssp. vulgare, compaction, sphaerococcum, macha, vavilovii, and spelta have revealed limited variation at the tightly linked coding loci Gli-D1/Glu-D3, and Glu-D1, located respectively on the short and long arm of chromosome ID, and at the GH-D2 locus, positioned on the short arm of chromosome 6D. Much higher variation was observed, for the same protein components, in the wild diploid Ae. squarrosa, the D genome donor of the aestivum group. Genetic variation in the same wheat subspecies and in Ae. squarrosa has also been evaluated by Southern hybridization of genomic DNAs, which were digested with several restriction enzymes, and hybridized with cloned sequences of genes coding for seed storage proteins. The much higher degree of variation observed for the seed storage protein genes of Ae. squarrosa, in comparison with the variation exhibited by the proteins encoded by the D genome chromosomes of hexaploid wheats, supports the hypothesis that a limited number of crosses gave rise to hexaploid wheats of the aestivum group

The silencing of TdIPK1 genes enhances micronutrient concentration in durum wheat grain

Phytic acid (PA) is the main storage form of phosphorus in kernel and is considered an anti-nutritional compound because of its ability to bind to essential minerals such as iron (Fe), zinc (Zn), potassium (K), calcium (Ca) and magnesium (Mg), thus limiting their availability, especially for populations whose diet is largely based on staple crops. This study reports a promising nutrient biofortification approach of durum wheat. The approach was based on the silencing of the gene encoding the inositol pentakisphosphate 2- kinase 1 (IPK1), involved in the last step of the PA biosynthetic pathway, through a Targeting Induced Local Lesions IN Genomes (TILLING) approach. Single knockout mutants for the IPK1 homeoalleles were identified and crossed to pyramid the two mutations. Although an elevated number of plants (F2 and F3 progenies) were analysed, no genotypes lacking both the homeoalleles were recovered, suggesting that the expression of IPK1 is crucial for seed formation in the spike and/or for plant germination and development. The characterization of the single null genotypes highlighted that the partial TdIPK1-B1- mutants showed a lower accumulation of PA in the kernel along with a higher content of essential microelements (Fe, Mn, Zn) compared to the control wild-type. The pattern of mineral accumulation was different for the TdIPK1-A1- mutants which only presented a greater accumulation of K

Absolute and relative quantitation of amylase/trypsin-inhibitors by LC-MS/MS from wheat lines obtained by CRISPR-Cas9 and RNAi

Quantitation of wheat proteins is still a challenge, especially regarding amylase/trypsin-inhibitors (ATIs). A selection of ATIs was silenced in the common wheat cultivar Bobwhite and durum wheat cultivar Svevo by RNAi and gene editing, respectively, in order to reduce the amounts of ATIs. The controls and silenced lines were analyzed after digestion to peptides by LC-MS/MS with different approaches to evaluate changes in composition of ATIs. First, a targeted method with stable isotope dilution assay (SIDA) using labeled peptides as internal standards was applied. Additionally, four different approaches for relative quantitation were conducted, in detail, iTRAQ labeled and label free quantitation (LFQ) combined with data dependent acquisition (DDA) and data independent acquisition (DIA). Quantitation was performed manually (Skyline and MASCOT) and with different proteomics software tools (PLGS, MaxQuant, and PEAKS X Pro). To characterize the wheat proteins on protein level, complementary techniques as high-performance liquid chromatography (HPLC) and gel electrophoresis were performed. The targeted approach with SIDA was able to quantitate all ATIs, even at low levels, but an optimized extraction is necessary. The labeled iTRAQ approach revealed an indistinct performance. LFQ with low resolution equipment (IonTrap) showed similar results for major ATIs, but low abundance ATIs as CM1, were not detectable. DDA measurements with an Orbitrap system and evaluation using MaxQuant showed that the relative quantitation was dependent on the wheat species. The combination of manual curation of the MaxQuant search with Skyline revealed a very good performance. The DIA approach with analytical flow found similar results compared to absolute quantitation except for some minor ATIs, which were not detected. Comparison of applied methods revealed that peptide selection is a crucial step for protein quantitation. Wheat proteomics faces challenges due to the high genetic complexity, the close relationship to other cereals and the incomplete, redundant protein database requiring sensitive, precise and accurate LC-MS/MS methods

Chemical investigation and screening of anti-proliferative activity on human cell lines of pure and nano-formulated lavandin essential oil

Lavandin essential oil (LEO), a natural sterile hybrid obtained by crossbreeding L. angustifolia × L. latifolia, is mainly composed by active components belonging to the family of terpenes endowed with relevant anti-proliferative activity, which can be enhanced by proper application of nanotechnology. In particular, this study reports the chemical characterization and the screening of the anti-proliferative activity on different human cell lines of pure and nano-formulated lavandin essential oil (EO). LEO and its formulation (NanoLEO) were analyzed by HS/GC-MS (Headspace/Gas Chromatography-Mass Spectrometry) to describe and compare their chemical volatile composition. The most abundant compounds were linalool and 1,8-cineole (LEO: 28.6%; 27.4%) (NanoLEO: 60.4%; 12.6%) followed by α-pinene (LEO: 9.6%; NanoLEO: 4.5%), camphor (LEO: 6.5%; NanoLEO: 7.0%) and linalyl acetate (LEO: 6.5%; NanoLEO: 3.6%). The cytotoxic effects of LEO and NanoLEO were investigated on human neuroblastoma cells (SHSY5Y), human breast adenocarcinoma cells (MCF-7), human lymphoblastic leukemia cells (CCRF CEM), human colorectal adenocarcinoma cells (Caco-2) and one normal breast epithelial cell (MCF10A) by the MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide)-assay. Caco-2, MCF7 and MCF10A normal cells resulted more resistant to the treatment with LEO, while CCRF-CEM and SHSY5Y cells were more sensitive. The antiproliferative effect of LEO resulted amplified when the essential oil was supplied as nanoformulation, mainly in Caco-2 cells. Scanning and transmission electron microscopy investigations were carried out on Caco-2 cells to outline at ultrastructural level possible affections induced by LEO and NanoLEO treatments

Increasing the amylose content of durum wheat through silencing of the SBEIIa genes

<p>Abstract</p> <p>Background</p> <p>High amylose starch has attracted particular interest because of its correlation with the amount of Resistant Starch (RS) in food. RS plays a role similar to fibre with beneficial effects for human health, providing protection from several diseases such as colon cancer, diabetes, obesity, osteoporosis and cardiovascular diseases. Amylose content can be modified by a targeted manipulation of the starch biosynthetic pathway. In particular, the inactivation of the enzymes involved in amylopectin synthesis can lead to the increase of amylose content. In this work, genes encoding starch branching enzymes of class II (SBEIIa) were silenced using the RNA interference (RNAi) technique in two cultivars of durum wheat, using two different methods of transformation (biolistic and Agrobacterium). Expression of RNAi transcripts was targeted to the seed endosperm using a tissue-specific promoter.</p> <p>Results</p> <p>Amylose content was markedly increased in the durum wheat transgenic lines exhibiting <it>SBEIIa </it>gene silencing. Moreover the starch granules in these lines were deformed, possessing an irregular and deflated shape and being smaller than those present in the untransformed controls. Two novel granule bound proteins, identified by SDS-PAGE in SBEIIa RNAi lines, were investigated by mass spectrometry and shown to have strong homologies to the waxy proteins. RVA analysis showed new pasting properties associated with high amylose lines in comparison with untransformed controls. Finally, pleiotropic effects on other starch genes were found by semi-quantitative and Real-Time reverse transcription-polymerase chain reaction (RT-PCR).</p> <p>Conclusion</p> <p>We have found that the silencing of <it>SBEIIa </it>genes in durum wheat causes obvious alterations in granule morphology and starch composition, leading to high amylose wheat. Results obtained with two different methods of transformation and in two durum wheat cultivars were comparable.</p

Production and characterization of wheat lines silenced in alpha amylase/trypsin inhibitor genes involved in adverse reactions to wheat

Although wheat is the most consumed crop worldwide, it is also the main factor triggering different adverse reactions, among which celiac disease, true allergies and Non Celiac Wheat Sensitivity (NCWS). Among allergies, the so called \u201cbaker\u2019s asthma\u201d, is the most common professional asthma in Europe and is caused mainly by proteins present in the soluble fraction, especially alpha-amylase/trypsin inhibitors (ATI). Recent findings indicate in this class of proteins also the main factor triggering NCWS, that at present affects people with a frequency around 1:80, higher than celiac disease (1:100), but this is still a matter of debate. On this basis, we have produced RNAi wheat plants (both durum and bread wheat) in which different ATI genes have been silenced, to be used as a proof of concept, in order to test if they have a minor impact on adverse reactions, by using in vitro tests. We have silenced CM3, CM16 and 0.28 genes and have now available several lines in T4 generation. ELISA tests and immunoblotting analysis, by using a monoclonal antibody against ATI proteins, have shown that RNAi silenced wheat kernels present a lower amount of ATI proteins. Moreover, we are characterizing these lines in relation to respiratory allergies. Protein extracts from silenced plants are being tested by using human sera of allergic patients in order to verify if a lower amount of immunogenic polypeptides is recognized in comparison to wild type untransformed plants. If this is the case, the realization of new wheat genotypes expressing a lower amount of ATI proteins can be a realistic target to be reached by classical breeding procedures

Characterization of Triticum turgidum sspp. durum, turanicum, and polonicum grown in Central Italy in relation to technological and nutritional aspects

IntroductionWheat is a staple food, with the two most common species being Triticum aestivum and Triticum turgidum ssp. durum. Moreover, the latter, T. turgidum, includes other tetraploid subspecies, among which the sspp. turanicum (Khorasan wheat) and polonicum (Polish wheat), whose importance has increased in the last decades, representing alternative crops for marginal areas, in addition to being a source of genetic diversity.MethodsIn this work, different accessions of these three subspecies of T. turgidum have been grown in 2 years in the same environment and have been characterized for technological properties and factors affecting nutritional quality, such as fiber amount and the content of micro- and macro-nutrients in grains, and for root morphological traits.ResultsThese analyses allowed the identification, in particular, of a Polish wheat accession showing better technological performances, a higher amount of positive micro- and macro-elements, and a lower amount of toxic cadmium. The modern variety Svevo and the Polish Pol2 showed the lowest and the highest shoot:root ratio, respectively. The high shoot:root ratio in Pol2 was mainly attributable to the decrease in root growth. Although Pol2 had a lower root biomass, its particular root morphology made it more efficient for nutrient uptake, as evident from the greater accumulation of micro- and macro-nutrients.DiscussionThese results underline that it is not possible to draw general conclusions about the difference between primitive and modern wheats, but rather a case-by-case approach should be chosen

Silencing of ATI genes involved in adverse reactions to wheat by RNAi and CRISPR-Cas9 technologies

Although wheat is consumed worldwide as a staple food, it can give rise to different adverse reactions, some of which have not been deeply characterized. They are caused mainly by wheat proteins, both gluten and non-gluten proteins. Structural and metabolic proteins, like \u3b1amylase/trypsin inhibitors (ATI) are involved in the onset of wheat allergies (bakers\u2019 asthma) and probably non-coeliac wheat sensitivity (NCWS). The ATI are encoded by a multigene family dispersed over several. Notably, WTAI-CM3 and WTAI-CM16 subunits are involved in the onset of bakers\u2019 asthma and are likely to contribute to NCWS. In this study we report the RNAi silencing of WTAI-CM3, WTAI-CM16 and WMAI-0.28 genes in the bread wheat cultivar Bobwhite and the CRISPR/Cas9 mediated gene knockout of WTAI-CM3 and WTAI-CM16 in the durum wheat cultivar Svevo. We have obtained different RNAi transgenic lines showing an effective decrease in the expression in the targeted genes. These lines do not show differences in terms of yield, but have unintended effects on the accumulation of the high molecular weight glutenin subunits which play a crucial role in the technological performances of wheat flour. Furthermore, the editing of WTAI-CM3 and WTAI-CM16 genes was obtained through a CRISPR-Cas9 multiplexing strategy in the Italian durum wheat cultivar Svevo with a marker-free approach. The regeneration of plants without selection agents allowed T0 homozygous mutant plants to be obtained without the integration in the wheat genome of CRISPR/Cas9 vectors, demonstrating the capability of CRISPR technology to produce wheat lines in a reduced time compared to conventional breeding approaches. The possibility to develop new wheat genotypes accumulating a lower amount of proteins effectively involved in such pathologies, not only offers the possibility to use them as a basis for the creation of wheat varieties with a lower impact on adverse reactions, but also to test if these proteins are actually implicated in those pathologies for which the triggering factor has yet to be established

Enhancing grain size in durum wheat using RNAi to knockdown GW2 genes

Sestili F., Pagliarello R., Zega A., Saletti R., Pucci A., Botticella E., Masci S., Tundo S., Moscetti I., Foti S., Lafiandra D. 2019 Enhancing grain size in durum wheat using RNAi to knock-down GW2 genes. Theoretical and Applied Genetics, 132(2): 419-429 https://doi.org/10.1007/s00122-018-3229-9. Abstract Key message Knocking down GW2 enhances grain size by regulating genes encoding the synthesis of cytokinin, gibberellin, starch and cell wall. Abstract Raising crop yield is a priority task in the light of the continuing growth of the world’s population and the inexorable loss of arable land to urbanization. Here, the RNAi approach was taken to reduce the abundance of Grain Weight 2 (GW2) transcript in the durum wheat cultivar Svevo. The effect of the knockdown was to increase the grains’ starch content by 10–40%, their width by 4–13% and their surface area by 3–5%. Transcriptomic profiling, based on a quantitative real-time PCR platform, revealed that the transcript abundance of genes encoding both cytokinin dehydrogenase 1 and the large subunit of ADP-glucose pyrophosphorylase was markedly increased in the transgenic lines, whereas that of the genes encoding cytokinin dehydrogenase 2 and gibberellin 3-oxidase was reduced. A proteomic analysis of the non-storage fraction extracted from mature grains detected that eleven proteins were differentially represented in the transgenic compared to wild-type grain: some of these were involved, or at least potentially involved, in cell wall development, suggesting a role of GW2 in the regulation of cell division in the wheat grain

Wheat ati cm3, cm16 and 0.28 allergens produced in pichia pastoris display a different eliciting potential in food allergy to wheat

International audienceAlthough wheat is a staple food for most of the human population, some of its components trigger adverse reactions. Among wheat components, the alpha-amylase/trypsin inhibitors (ATI) are important triggers of several allergies and activators of innate immunity. ATI are a group of exogenous protease inhibitors and include several polypeptides. The three ATI polypeptides named CM3, CM16 and 0.28 are considered major allergens, and might also play a role in other common wheat-related pathologies, such as Non Celiac Wheat Sensitivity and even Celiac Disease. On this basis, we pointed to obtain high amounts of them in purity and to evaluate their allergenicity potential. We thus isolated the mRNA corresponding to the three ATI genes CM3, CM16 and 0.28 from 28 days post-anthesis wheat kernels and the corresponding cDNAs were used for heterologous expression in Pichia pastoris. The three purified proteins were tested in degranulation assay against human sera of patients with food allergy to wheat. A large range of degranulation values was observed for each protein according to the sera tested. All of the three purified proteins CM3, CM16 and 0.28 were active as allergens because they were able to induce basophils degranulation on wheat allergic patients' sera, with the highest values of beta-hexosaminidase release observed for CM3 protein