Analysis of gluten proteins composition during grain filling in two durum wheat cultivars submitted to two water regimes

Durum wheat ( Triticum turgidum L. subsp . durum) is one of the major crops in the Mediterranean basin, where water stress often occurs during grain filling which represents a critical stage for the synthesis and accumulation of storage proteins (gliadins and glutenins). The aim of the study is to evaluate, by two-dimensional gel electrophoresis (2DE SDS-PAGE), the storage proteins composition of two durum wheat cultivars (Ciccio and Svevo) cultivated in a growth chamber under two different water regimes (control and water deficit). At milk stage and physiological maturity, gluten proteins have been extracted and separated by 2DE SDS-PAGE. The analysis of the gels was performed by the software ImageMaster 2D Platinum (Amersham). The results showed differences in protein expression within the different gel regions between water regimes and cultivars; under water deficit the rate of protein accumulation was faster for all the protein regions, either at milk and physiological stage. Protein accumulation within high molecular weight (H) region resulted faster in Ciccio than in Svevo mainly in the control treatment. In the low molecular weight region between 48 and 35 kDa (L 48-35), the cultivar Ciccio showed a higher protein expression than Svevo. Furthermore under water deficit a marked increase in H region volume and a decrease in the L 48-35 region was observed only for Svevo; instead in Ciccio no change was observed showing this cultivar a greater stability on changing water regime. Further studies by the use of mass spectrometry are necessary to identify specific peptides relative to drought stress during grain filling as well as to investigate the relationships with technological quality

Influence of Organic and Conventional Farming on Grain Yield and Protein Composition of Chickpea Genotypes

Chickpea is a key crop in sustainable cropping systems and for its nutritional value. Studies on agronomic and genetic influences on chickpea protein composition are missing. In order to obtain a deep insight into the genetic response of chickpeas to management in relation to agronomic and quality traits, a two-year field trial was carried out with eight chickpea genotypes under an organic and conventional cropping system. Protein composition was assessed by SDS-PAGE in relation to the main fractions (vicilin, convicilin, legumin, lectin, 2s-albumin). Crop response was highly influenced by year and presumably also by management, with a −50% decrease in grain yield under organic farming, mainly due to a reduction in seed number per m2. No effect of crop management was observed on protein content, despite significant differences in terms of protein composition. The ratio between the major globulins, 7s vicilin and 11s legumin, showed a negative relationship with grain yield and was found to be higher under organic farming. Among genotypes, black-seed Nero Senise was characterized by the highest productivity and water-holding capacity, associated with low lectin content. These findings highlight the importance of the choice of chickpea genotypes for cultivation under organic farming in relation to both agronomic performance and technological and health quality

Response of carotenoids and tocols of durum wheat in relation to water stress and sulfur fertilization

Lipophilic antioxidants are essential components of plant defense against stressful conditions. The response of carotenoids and tocols to water deficit and sulfur fertilization was investigated in durum wheat cultivars. The amounts of tocols and carotenoids were evaluated in both whole meal and semolina samples. Differences among cultivars were observed. Simeto cultivar showed a significant effect of water regime on whole meal and semolina carotenoids, with about 20% and 15% increase, respectively. Also tocols and tocotrienols of Simeto were positively affected by water stress (about 10% increase and 15% increase in whole meals and semolinas). Sulfur fertilization positively impacted mainly Ofanto whole-grain and semolina carotenoids, semolina tocols, and tocotrienols. In conclusion, water deficit occurring under a Mediterranean environment was responsible for an improvement of lipophilic antioxidant content in durum wheat; in contrast sulfur supplementation did not improve the response of the antioxidant pool under water deficit

Assessment of grain protein composition in old and modern Italian durum wheat genotypes

The effect of durum wheat breeding on technological quality was mainly investigated in relation to allelic polymorphism, in particular for glutenins, while fewer information are available on the changes in grain protein proportion. In the present investigation, an old and a modern group of durum wheat genotypes, grown in Mediterranean environment, were evaluated for grain protein composition, according to Osborne extraction procedure. In modern genotypes, a higher relative content of soluble glutenin was observed which might contribute to their better technological performance. Moreover, a slight decrease both in the amount of gliadin fraction, mainly responsible for gluten related disorders, and in the monomeric to polymeric protein ratio was observed in the modern durum wheat varieties. Among the genotypes investigated, Svevo and Saragolla, showed the lowest gliadin and the highest glutenin content, while the old genotypes Cappelli showed an opposite behaviour

Analysis of gluten proteins composition during grain filling in two durum wheat cultivars submitted to two water regimes

Durum wheat (Triticum turgidum L. subsp. durum) is one of the major crops in the Mediterranean basin, where water stress often occurs during grain filling which represents a critical stage for the synthesis and accumulation of storage proteins (gliadins and glutenins). The aim of the study is to evaluate, by two-dimensional gel electrophoresis (2DE SDS-PAGE), the storage proteins composition of two durum wheat cultivars (Ciccio and Svevo) cultivated in a growth chamber under two different water regimes (control and water deficit). At milk stage and physiological maturity, gluten proteins have been extracted and separated by 2DE SDS-PAGE. The analysis of the gels was performed by the software ImageMaster 2D Platinum (Amersham). The results showed differences in protein expression within the different gel regions between water regimes and cultivars; under water deficit the rate of protein accumulation was faster for all the protein regions, either at milk and physiological stage. Protein accumulation within high molecular weight (H) region resulted faster in Ciccio than in Svevo mainly in the control treatment. In the low molecular weight region between 48 and 35 kDa (L 48-35), the cultivar Ciccio showed a higher protein expression than Svevo. Furthermore under water deficit a marked increase in H region volume and a decrease in the L 48-35 region was observed only for Svevo; instead in Ciccio no change was observed showing this cultivar a greater stability on changing water regime. Further studies by the use of mass spectrometry are necessary to identify specific peptides relative to drought stress during grain filling as well as to investigate the relationships with technological quality

Effect of Sulphur Fertilization on Grain Quality and Protein Composition of Durum Wheat (Triticum durum Desf.)

The reduction of atmosphere emission of SO2 and the massive use of fertilizers high in nitrogen and phosphorus resulted in a decrease of the sulphur content in the soil. In durum wheat cultivation, sulphur supply plays a key role not only for plant growth, but also for grain quality. Sulphur is an essential macronutrient primarily used to synthesize methionine and cysteine and it is also involved in establishing protein structures by disulphide bonds. The aim of this study was to evaluate the effect of sulphur nutrition on grain quality and protein composition of durum wheat cultivars grown under water deficit conditions, typical of Mediterranean areas. To this purpose, in the 2003-2004 and 2004-2005 crop seasons a field trial was carried out by comparing two water regimes (irrigated and rainfed), two sulphur fertilizer levels and two durum wheat cultivars. Under our experimental conditions, an increase in protein and gluten content in the rainfed treatment and a positive effect of sulphur fertilization on quality parameters were observed. Few changes were observed in protein composition in response to sulphur fertilization

Agronomic Response to Irrigation and Biofertilizer of Peanut (<i>Arachis hypogea</i> L.) Grown under Mediterranean Environment

Peanut is a staple crop suitable for mechanized harvest and a source of plant proteins and fatty acids. It is widespread in Asia and North America, while there is limited cultivation in Europe despite potentially favorable climatic conditions. To test the adaptability of peanut in the Mediterranean area, a two-year field trial was carried out with one Spanish-type and one Virginia-type genotype cultivated under two water regimes (full irrigation and half irrigation supply). In order to test the response to fertilization management, three treatments were carried out, including an unfertilized control, a N-fertilized treatment, and a N-fertilized treatment inoculated with a commercial mixture of plant-growth promoting microorganisms, including two Bacillus species, Trichoderma and arbuscular mycorrhizal fungi (AMF). Microbiological soil analysis assessed the robustness of bacilli and their viability in soil. The Virginia-type genotype showed a better adaptability, with a positive response to irrigation and biofertilization. In particular, the inoculated treatment led to the highest agricultural crop water productivity, with important implications for sustainability. The impact of agronomic strategies was evaluated also in relation to storage proteins. The expression of 7s vicilin fraction showed a variability associated with water supply