Variations in yield and gluten proteins in durum wheat varieties under late-season foliar versus soil application of nitrogen fertilizer in a northern Mediterranean environment

BACKGROUND: With the increasing demand for high-quality foodstuffs and concern for environmental sustainability, late-season nitrogen (N) foliar fertilization of common wheat is now an important and widespread practice. This study investigated the effects of late-season foliar versus soil N fertilization on yield and protein content of four varieties of durum wheat, Aureo, Ariosto, Biensur and Liberdur, in a three-year field trial in northern Italy. RESULTS: Variations in low-molecular-weight glutenins (LMW-GS), high-molecular-weight glutenins (HMW-GS) and gliadins were assessed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). It was found that N applied to the canopy did not improve protein rate compared with N application to the soil (general mean 138mg g 121), but moderately increased productivity in the high-yielding varieties Liberdur and Biensur (three-year means 7.23 vs 7.13 and 7.53 vs 7.09 t ha 121 respectively). Technological quality was mainly related to variety choice, Aureo and Ariosto having higher protein rates and glutenin/gliadin ratios. Also found was a strong \u2018variety 7 N application method\u2019 interaction in the proportions of protein subunits within each class, particularly LMW-GS and gliadins. A promising result was the higher N uptake efficiency, although as apparent balance, combined with higher HMW/LMW-GS ratio in var. Biensur. CONCLUSION: Late-season foliar N fertilization allows N fertilizer saving, potentially providing environmental benefits in the rainy climate of the northern Mediterranean area, and also leads to variety-dependent up-regulation of essential LMW-GS and gliadins. Variety choice is a key factor in obtaining high technological quality, although it is currently associated with modest grain yield. This study provides evidence of high quality in the specific high-yielding variety Biensur, suggesting its potential as a mono-varietal semolina for pasta production

Structural and Functional Features of Chars From Different Biomasses as Potential Plant Amendments

Biochars result from the pyrolysis of biomass waste of plant and animal origin. The interest in these materials stems from their potential for improving soil quality due to increased microporosity, carbon pool, water retention, and their active capacity for metal adsorption from soil and irrigation water. Applications in agriculture have been studied under different conditions, but the overall results are still unclear. Char structure, which varies widely according to the pyrolysis process and the nature of feedstock, is thought to be a major factor in the interaction of chars with soil and their metal ion adsorption/chelation properties. Furthermore, biochar nutrients and their elemental content can modify soil fertility. Therefore, the use of biochars in agricultural settings should be examined carefully by conducting experimental trials. Three key problems encountered in the use of biochar involve (i) optimizing pyrolysis for biomass conversion into energy and biochar, (ii) physicochemically characterizing biochar, and (iii) identifying the best possible conditions for biochar use in soil improvement. To investigate these issues, two types of wood pellets, plus digestate and poultry litter, were separately converted into biochar using different technologies: pyrolysis/pyrogasification or catalytic (thermo)reforming. The following physicochemical features for the different biochar batches were measured: pH, conductivity, bulk density, humidity and ash content, particle size, total organic substances, and trace element concentrations. Fine porous structure analysis and total elemental analysis were performed using environmental scanning electron microscopy along with energy-dispersive X-ray spectrometry (EDX). Phytotoxicity tests were performed for each biochar. Finally, we were able to (i) differentiate the biochars according to their physicochemical properties, microstructure, elemental contents, and original raw biomass; (ii) correlate the whole biochar features with their respective optimal concentrations when used as plant fertilizers or soil improvers; and (iii) show that biochars from animal origin were phytotoxic at lower concentrations than those from plant feedstock

Structural and Functional Features of Chars From Different Biomasses as Potential Plant Amendments

Biochars result from the pyrolysis of biomass waste of plant and animal origin. The interest in these materials stems from their potential for soil quality improvement due to increased micro-porosity, carbon pool, water retention, and their active capacity for metals adsorption from soil and irrigation water. Applications in agriculture have been studied under different conditions, but the overall results are still unclear. Char structure, which varies widely according to pyrolysis process and feedstock nature, is thought to be a major factor in the interaction of chars with soil and their metal ion adsorption/chelation properties. Furthermore, biochar nutrients and elemental content can modify soil fertility. Therefore, use of biochars in agricultural settings should be examined carefully by experimental trials. Three key issues in exploitation of biochar are: (i) optimization of pyrolysis for biomass conversion into energy and biochar, (ii) biochar physico-chemical characterization, and (iii) identification of the best possible conditions for its use in soil improvement. Two types of wood pellets, plus digestate and poultry litter, were separately converted into biochar using different technologies: pyrolysis/pyrogasification or catalytic (thermo)reforming. Physico-chemical features for the different biochar batches were measured: pH, conductivity, bulk density, humidity and ash content, particle size, total organic substances, and trace element concentrations. Fine porous structure and total elemental analysis were performed using Environmental Scanning Microscopy (ESEM) coupled with Energy-Dispersive X-ray Spectrometry (EDX). Phytotoxicity tests were performed for each biochar. In conclusion we were able to: i) differentiate the biochars according to their physico-chemical properties, microstructure, elemental contents, and the raw original biomass; ii) correlate the whole biochar features with their respective optimal concentrations when used as plant fertilizers or soil improvers; iii) show that biochars from animal origin were phytotoxic at lower concentrations than those from plant feedstock

Variations in yield and gluten proteins in durum wheat varieties under late-season foliar vs. soil application of nitrogen fertilizer in a northern Mediterranean environment

BACKGROUND: With the increasing demand for high-quality foodstuffs and concern for environmental sustainability, late-season nitrogen foliar fertilization of common wheat is now an important and widespread practice. RESULTS: We investigated the effects of late-season foliar vs. soil N fertilization on yield and protein content of four varieties of durum wheat, Aureo, Ariosto, Biensur and Liberdur, in a three-year field trial in northern Italy. Variations in LMW-GS, HMW-GS and gliadins were assessed by SDS-PAGE. We found that N applied to the canopy did not improve protein rate compared with N application to the soil (general mean: 138 mg g-1), but moderately increased productivity in the high-yielding varieties Liberdur and Biensur (three-year means: 7.23 vs. 7.13 t ha-1 and 7.53 vs. 7.09 t ha-1, in two varieties respectively). Technological quality was mainly related to variety choice, Aureo and Ariosto having higher protein rates and glutenin/gliadin ratios. We also found a strong ‘variety  N application method’ interaction in the proportions of protein sub-units within each class, particularly LMW-GS and gliadins. A promising result was the higher N uptake efficiency, although as apparent balance, combined with higher HMW/LMW-GS ratio in var. Biensur. CONCLUSION: Late-season foliar N fertilization allows N fertilizer saving, potentially providing environmental benefits in the rainy climate of the northern Mediterranean area, and also leads to variety-dependent up-regulation of essential LMW-GS and gliadins. Variety choice is a key factor in obtaining high technological quality, although it is currently associated with modest grain yield. We provide evidence of high quality in the specific high-yielding variety Biensur, suggesting its potential as a mono-varietal semolina for pasta production

Proteomics of durum wheat grain during transition to conservation agriculture

Nitrogen management in combination with sustainable agronomic techniques can have a great impact on the wheat grain proteome influencing its technological quality. In this study, proteomic analyses were used to document changes in the proportion of prolamins in mature grains of the newly released Italian durum wheat cv Achille. Such an approach was applied to wheat fertilized with urea (UREA) and calcium nitrate (NITRATE), during the transition to no-till Conservation Agriculture (CA) practice in a Mediterranean environment. Results obtained in a two-years field experiment study suggest low molecular weight glutenins (LMW-GS) as the fraction particularly inducible regardless of the N-form. Quantitative analyses of LMW-GS by 2D-GE followed by protein identification by LC-ESI-MS/MS showed that the stable increase was principally due to C-type LMW-GS. The highest accumulation resulted from a physiologically healthier state of plants treated with UREA and NITRATE. Proteomic analysis on the total protein fraction during the active phase of grain filling was also performed. For both N treatments, but at different extent, an up-regulation of different classes of proteins was observed: i) enzymes involved in glycolysis and citric acid cycles which contribute to an enhanced source of energy and carbohydrates, ii) stress proteins like heat shock proteins (HSPs) and antioxidant enzymes, such as peroxidases and superoxide dismutase which protect the grain from abiotic stress during starch and storage protein synthesis. In conclusion N inputs, which combined rate with N form gave high yield and improved quality traits in the selected durum wheat cultivar. The specific up-regulation of some HSPs, antioxidant enzymes and defense proteins in the early stages of grain development and physiological indicators related to fitness traits, could be useful bio-indicators, for wheat genotype screening under more sustainable agronomic conditions, like transition phase to no-till CA in Mediterranean environments

Comparison of effect of CdS QD and ZnS QD and their corresponding salts on growth, chlorophyll content and antioxidative capacity of tomato

When applied in the same concentration to tomato plants, cadmium sulfate (CdSO4) and zinc sulfate (ZnSO4) were transported from soil to roots and from roots to shoots more readily than their nano counterparts: cadmium sulfide quantum dots (CdS QD) and zinc sulfide quantum dots (ZnS QD). Compared to the CdS QD, he higher rate of transport of CdSO4 resulted in a greater negative effect on growth, chlorophyll content, antioxidant properties, lipid peroxidation and activation of antioxidant defence systems. Although ZnSO4 was transported more rapidly than ZnS QD, the overall effect of Zn addition was positive (increase in total plant mass, stem length, antioxidant content and decrease in lipid peroxidation). However, these effects were more pronounced in the case of ZnS QD, suggesting that the mechanisms underpinning the activity of ZnS QD and ZnSO4 were different. Thus, the risk of phytotoxicity and food chain transfer of the two elements depended on their form (salt or nanoform), and consequently their effects on plants’ growth and physiology were different

Gliadin and glutenin contents in in durum wheat mature grains under CONTROL and UREA and NITRATE fertilisation treatments.

<p>Gliadins (mg g^-1 flour; grey chart) and glutenin (GS) fractions (mg g^-1 flour; horizontallines: LMW-GS fraction; diagonal cross: HMW-GS fraction) in durum wheat grains fertilized with urea (UREA) and calcium nitrate (NITRATE) at the rate of 150 kg N ha^-1 plus unfertilized CONTROL in 2011 (a) and 2012 (b). Data are averages ± standard errors, for n = 3 independent replicates. Different letters indicate significant differences at p<0.05 (Fisher’s LSD test).</p

Quantitative densitometry analysis of LMW-GS from Group 1 and Group 2 extracted from wheat grains deriving from plants exposed to control conditions (unfertilized CONTROL) and to two fertilization treatments with Urea (UREA) and Calcium Nitrate (NITRATE) at the rate of 150 kg N ha^-1.

<p>Quantitative densitometry analysis of LMW-GS from Group 1 and Group 2 extracted from wheat grains deriving from plants exposed to control conditions (unfertilized CONTROL) and to two fertilization treatments with Urea (UREA) and Calcium Nitrate (NITRATE) at the rate of 150 kg N ha^-1.</p

Canopy reflectance of durum wheat plants (averaged over DC65, DC71, DC75 and DC77 phenological stages).

<p>Durum wheat plants were exposed to control conditions (unfertilized CONTROL, black triangle) and to N fertilization treatments with urea (UREA, white rhombus) and calcium nitrate (NITRATE, white circle) at the rate of 150 kg N ha^-1, in 2012.</p

ESI-LC-MS/MS identification and differential abundance of proteins from durum wheat immature grains.

<p>(a) Venn diagram showing the number of unique proteins in the 15 and 13 DPA (in 2011 and 2012, respectively) phase of grain filling, which were up-regulated in the different treatments, (b) Venn diagram showing the number of unique proteins in the 15 DPA and 13 DPA (in 2011 and 2012, respectively) phase of grain filling, which were down-regulated in the different treatments, (c) Heat map showing protein abundance by UREA (U) and NITRATE (N) fertilization treatments compared with unfertilized CONTROL (C). Data on single protein sequence and function obtained by LC-ESI-MS/MS analyses are listed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0156007#pone.0156007.s004" target="_blank">S3 Table</a>. Fold variation between data was normalised as follows: up-regulation 2, 3- fold bright red, > 3 fold dull red, down-regulation 2, 3-fold bright green, >3 fold dull green.</p