Discriminant analysis of selected yield components and fatty acid composition of chosen Triticum monococcum, Triticum dicoccum and Triticum spelta accessions

This study analyses the variability of key yield components, the content of protein and crude fat in grain and the fatty acid composition of 50 spring accessions of Triticum monococcum, Triticum dicoccum and Triticum spelta of various origins. The average protein content of the grain of T. monococcum was 20.8%, of T. dicoccum 19.7%, and of spelt 17.0%. The crude fat content of T. monococcum grain (2.7%) was significantly higher compared with T. spelta (2.4%) and T. dicoccum (2.3%). In crude fat, fatty acids C18:2, C18:1 and C16 predominated. T. spelta was characterised by the highest concentrations of C18:2 and C16 (55.89% and 18.77% respectively), while T. monococcum had the highest content of C18:1 (26.35%). The structure of analysed fatty acids proved to be highly desirable in this species. A discriminant analysis performed separately for five variables: protein and fat content and three biometrical characters and separately for fatty acid composition enabled three Triticum species to be distinguished. These species also differed significantly with respect to the C18:1/C16 ratio which was equal to 1.78, 1.06, 1.47 and 0.99 in T. monococcum, T. dicoccum, T. spelta and Triticum aestivum respectively.     

Phloem sugars and amino acids as potential regulators of hordein expression in field grown malting barley (Hordeum vulgare L.)

The commercial quality of malting barley is dependent on the content and composition of grain proteins which are subjected to nitrogen (N) and sulfur (S) control. In nutrient deficient soils, grain protein content is mainly a consequence of the remobilization efficiency. In order to evaluate the effect of N and S soil availability on phloem amino acid and sugar export rates and B- and C-hordein gene expression during grain filling, a factorial combination of N and S fertilization assay was carried out under field conditions. Besides, several carbon (C) and N metabolites were analyzed in leaves and spikes. We observed that, even under soil N and S availabilities that do not limit yield, N and S fertilization induced significant changes in N and C metabolism. N phloem remobilization was promoted by S fertilization independently of N fertilization and C remobilization was also promoted by S fertilization but only in N fertilized plants. The B- and C-hordein gene expression correlated positively with sugar and amino acid exudation rate, respectively. Our results suggest an important role of the export rate of sugars and amino acids in the regulation of grain prolamine expression.     

Ocean Warming and CO2-Induced Acidification Impact the Lipid Content of a Marine Predatory Gastropod

Ocean warming and acidification are current global environmental challenges impacting aquatic organisms. A shift in conditions outside the optimal environmental range for marine species is likely to generate stress that could impact metabolic activity, with consequences for the biosynthesis of marine lipids. The aim of this study was to investigate differences in the lipid content of Dicathais orbita exposed to current and predicted future climate change scenarios. The whelks were exposed to a combination of temperature and CO₂-induced acidification treatments in controlled flowthrough seawater mesocosms for 35 days. Under current conditions, D. orbita foot tissue has an average of 6 mg lipid/g tissue, but at predicted future ocean temperatures, the total lipid content dropped significantly, to almost half. The fatty acid composition is dominated by polyunsaturated fatty acids (PUFA 52%) with an n-3:6 fatty acid ratio of almost 2, which remains unchanged under future ocean conditions. However, we detected an interactive effect of temperature and pCO₂ on the % PUFAs and n-3 and n-6 fatty acids were significantly reduced by elevated water temperature, while both the saturated and monounsaturated fatty acids were significantly reduced under increased pCO₂ acidifying conditions. The present study indicates the potential for relatively small predicted changes in ocean conditions to reduce lipid reserves and alter the fatty acid composition of a predatory marine mollusc. This has potential implications for the growth and survivorship of whelks under future conditions, but only minimal implications for human consumption of D. orbita as nutritional seafood are predicted.     

Optimization of Medium Using Response Surface Methodology for Lipid Production by Scenedesmus sp.

Lipid production is an important indicator for assessing microalgal species for biodiesel production. In this work, the effects of medium composition on lipid production by Scenedesmus sp. were investigated using the response surface methodology. The results of a Plackett–Burman design experiment revealed that NaHCO₃, NaH₂PO₄·2H₂O and NaNO₃ were three factors significantly influencing lipid production, which were further optimized by a Box–Behnken design. The optimal medium was found to contain 3.07 g L⁻¹ NaHCO₃, 15.49 mg L⁻¹ NaH₂PO₄·2H₂O and 803.21 mg L⁻¹ NaNO₃. Using the optimal conditions previously determined, the lipid production (304.02 mg·L⁻¹) increased 54.64% more than that using the initial medium, which agreed well with the predicted value 309.50 mg L⁻¹. Additionally, lipid analysis found that palmitic acid (C16:0) and oleic acid (C18:1) dominantly constituted the algal fatty acids (about 60% of the total fatty acids) and a much higher content of neutral lipid accounted for 82.32% of total lipids, which strongly proved that Scenedesmus sp. is a very promising feedstock for biodiesel production.     

Profiling of Polar Lipids in Marine Oleaginous Diatom Fistulifera solaris JPCC DA0580: Prediction of the Potential Mechanism for Eicosapentaenoic Acid-Incorporation into Triacylglycerol

The marine oleaginous diatom Fistulifera solaris JPCC DA0580 is a candidate for biodiesel production because of its high lipid productivity. However, the substantial eicosapentaenoic acid (EPA) content in this strain would affect the biodiesel quality. On the other hand, EPA is also known as the essential health supplement for humans. EPAs are mainly incorporated into glycerolipids in the microalgal cell instead of the presence as free fatty acids. Therefore, the understanding of the EPA biosynthesis including the incorporation of the EPA into glycerolipids especially triacylglycerol (TAG) is fundamental for regulating EPA content for different purposes. In this study, in order to identify the biosynthesis pathway for the EPA-containing TAG species, a lipidomic characterization of the EPA-enriched polar lipids was performed by using direct infusion electrospray ionization (ESI)-Q-TRAP-MS and MS/MS analyses. The determination of the fatty acid positional distribution showed that the sn-2 position of all the chloroplast lipids and part of phosphatidylcholine (PC) species was occupied by C16 fatty acids. This result suggested the critical role of the chloroplast on the lipid synthesis in F. solaris. Furthermore, the exclusive presence of C18 fatty acids in PC highly indicated the biosynthesis of EPA on PC. Finally, the PC-based acyl-editing and head group exchange processes were proposed to be essential for the incorporation of EPA into TAG and chloroplast lipids.     

Predicting Jatropha curcas seed-oil content, oil composition and protein content using near-infrared spectroscopy—A quick and non-destructive method

The potential of near-infrared reflectance spectroscopy (NIRS) to estimate the oil content, fatty acid composition, and protein content of Jatropha curcas seeds was studied. Seventy-four intact kernels from various sources were scanned by NIRS. All samples were analyzed for oil content (hexane extractions), fatty acid composition (gas chromatography), and protein content (Kjeldahl). Calibration equations were developed for oil content, individual fatty acids (oleic C18:1, linoleic C18:2, stearic C18:0 and palmitic C16:0), and protein content. The performance of the calibration equations was evaluated through external and cross-validation. The results showed that NIRS was a reliable, accurate and nondestructive technique to estimate oil and protein contents, as well as oleic and linoleic fatty acid concentrations in J. curcas kernels; NIRS provides a rapid, simple, and cost-effective alternative method for screening intact J. curcas kernels.     

Hormonal changes in grains of cv. Triumph and its mutant TL43 as affected by nitrogen fertilizer at heading time

A pot experiment was conducted to study the hormonal changes during the grain filling stage in barley lines of Triumph and its mutant TL43 with or without nitrogen fertilizer at heading time. The ABA, ZR and IAA contents in grains were higher under nitrogen treatment (HN) for both genotypes at 30 days post anthesis (DPA). No genotypic differences were observed in GA₃, ABA and IAA content over the grain filling stage and ZR content on 10 DPA exhibited the major difference, which might be associated with the decrease of A-type starch granules in endosperm of TL43. Triumph also showed significantly higher grain weight, lower hordein and glutelin contents than TL43. The changes of these characters might be correlated with the ZR deficiency of TL43 at early grain filling stage.     

Fatty acids profile,sterols, tocopherol and squalene content in Fagopyrum tataricum seed milling fractions

There is no data on the lipid profile of Fagopyrum tataricum grain and its milling products. Therefore, we aimed to assess the phytosterol and tocopherol content and fatty acid profile of the samples of F. tataricum. Grain was milled, then the milling product separated to hull, bran, and two flour fractions, differing in particle size. The highest level of lipids (total fatty acids – 83%, with dominant oleic acid – 40%) was observed in the bran fraction (380 μm > GA > 180 μm). All samples contained some natural cis fatty acids, such as vaccenic acid (C18:1 n-7; ~2.8%) and tocopherol (α-, β-, δ- and γ-tocopherol). The highest content of total tocopherol was also detected in the bran fraction (0.1% of lipids). The content of lipid soluble bioactive substances was different and depended on the size of obtained fraction, therefore properly designed grain processing technology can be used to produce food with high nutritional value.     

Intercepted solar radiation affects oil fatty acid composition in crop species

Solar radiation intercepted during grain filling affects growth of grain crops. Its effects on oil fatty acid composition have not been investigated. The objective of this work was to investigate the effect of intercepted solar radiation per plant on oil fatty acid composition in four crops. An experiment including a cultivar of soybean, maize and sunflower was sown at Balcarce, Argentina, during two growing seasons (2001–02 and 2004–05) and two experiments with a rape cultivar were conducted during in 2004 and 2005. The amount of intercepted solar radiation during grain filling was modified by shading (50–80%) and thinning plants (50%). In addition, the same cultivars of soybean and maize were sown in the field at Paraná, Argentina, during the 2004–05 growing season and in growth chambers under different day/night temperatures during grain filling. Regardless of the species, oleic acid percentage increased as intercepted solar radiation (ISR) per plant increased. The highest difference (13%) was observed in sunflower (shading vs. thinning) and the increase in oleic acid was associated with a reduction in both linoleic and linolenic acids. Saturated fatty acid percentage was not affected by intercepted solar radiation per plant. Differences among radiation treatments were observed not only at physiological maturity but also at earlier stages of the grain filling period. In soybean and maize, increasing daily mean temperature increased oleic acid percentage (r² ≥ 0.52). Changes in fatty acid composition in radiation experiments and treatments were not accounted for by variations in temperature (differences among treatments were ≤1 °C). In sunflower and maize, the source (ISR)–sink (grain number) ratio during the grain filling period better explained changes in oleic acid percentage than per plant ISR alone. Changes in fatty acid composition due to radiation treatments were as large as variations produced by changes in temperature in soybean and maize, but not in sunflower. Based on these results, management practices that increase intercepted radiation by the plant during grain filling could contribute to obtain oils with higher oleic acid percentage.     

The effect of Cd2+ on lipid components of sunflower (Helianthus annuus L.) seeds

The effect of seven levels of Cd²⁺ viz. 0, 10, 20, 30, 40, 60 and 80 ppm (µg/g soil) supplied as cadmium chloride, on lipid components of sunflower seeds was studied in a pot experiment. The total and neutral lipids decreased while polar lipids (phospho and glycolipids) increased with the increasing levels of Cd²⁺. Oleic acid and linoleic acids were the major fatty acids in the total, polar and neutral lipid fractions. Oleic acid generally increased while linoleic acid decreased in all the lipid fractions with Cd²⁺ levels. The neutral lipid fraction had higher levels of palmitic, palmitoleic, stearic and oleic acid as compared to the total and polar lipid fractions. The plant dry weight and seed yield decreased whereas cadmium concentration in seeds increased consistently with increasing Cd²⁺ levels.     

Variation in oil content and fatty acid profile of Calophyllum inophyllum L. with fruit maturity and its implications on resultant biodiesel quality

Variation in oil content and fatty acid profile (FAP) of Calophyllum inophyllum; a potential biodiesel feedstock species were studied at different maturity stages and biodiesel quality parameters were estimated based on the FAP. A steady increase in oil content was observed with maturity. Variation in palmitic (16:0) and linoleic (18:2) acids followed exactly opposite trends where palmitic acid content has decreased and linoleic acid content has increased 77 days after anthesis. Oleic acid (18:1) content has shown a steady increase. Stearic acid (18:0) content remained steady up to 68 days after anthesis and then felt slightly in 77 days after anthesis. Linoleic and eicosanoic acids were found to exist in low concentrations demonstrated very little compositional variation with fruit maturity. Estimated biodiesel parameters of all maturity stages were found to comply with industrial standards. Even though 48 days after anthesis had the most ideal FAP for biodiesel production, ∼77 days after anthesis is preferred point to harvest due to higher oil content.     

A Novel Lipid Extraction Method from Wet Microalga Picochlorum sp. at Room Temperature

A novel method using ethanol was proposed for extracting lipids from wet microalga Picochlorum sp. at room temperature and pressure. In this study, Central Composite design (CCD) was applied to investigate the optimum conditions of lipid extraction. The results revealed that the solvent to biomass ratio had the largest effect on lipid extraction efficiency, followed by extraction time and temperature. A high lipid extraction yield (33.04% of the dry weight) was obtained under the following extraction conditions: 5 mL solvents per gram of wet biomass for 37 min with gentle stirring at room temperature. The extraction yield was comparable to that obtained by the widely used Bligh-Dyer method. Furthermore, no significant differences in the distribution of lipid classes and fatty acid composition were observed according to different extraction methods. In conclusion, these results indicated that the proposed procedure using ethanol could extract lipids from wet biomass efficiently and had giant potential for lipid extraction at large scale.     

Predicting pre-harvest sprouting susceptibility in barley: Looking for “sensitivity windows” to temperature throughout grain filling in various commercial cultivars

Pre-harvest sprouting (PHS) is common in cereals that lack grain dormancy if maturing grain is exposed to rain. This phenomenon leads to immediate loss of seed viability, and since the malting process requires germination, its occurrence is highly undesirable in malting barley crops. Dormancy release rate is genetically and environmentally controlled. We evaluated the effect of temperature during grain filling on the dormancy release pattern (and then on the PHS susceptibility) of grains from five malting barley (Hordeum vulgare L.) cultivars widely sown in Argentina, with the aim of predicting PHS susceptibility of a barley crop from easy-to-gather data. Barley cultivars (Quilmes Ayelén, Q. Palomar, Q. Painé, B1215 and Scarlett) were sown on different dates over a 3-year period for generating variability in the thermal environment during grain filling. The period from pollination to physiological maturity (PM) was adjusted to a thermal time (TT) scale, which was then arbitrarily divided into 50 °C d intervals. Mean air temperature within each interval and for the whole filling period was calculated for the different sowing dates. Dormancy release pattern was followed by determining a weighed germination index (GI) throughout grain filling and maturation. We sought a linear relationship between temperature during grain filling and GI at some moment after PM. For all barley cultivars, except B1215, a significant (p < 0.001) and positive correlation was found between the GI of grains with 10–20% moisture content (fresh basis) and mean temperature within TT intervals located at the last stages of seed development. Then, simply temperature-based models for predicting crop PHS susceptibility were generated for each barley cultivar. Moreover, we intended a single, universal prediction model constructed with data from all cultivars. Two general forms were proposed, but the relationships were slightly less tight when each barley cultivar model was used. A preliminary validation for each cultivar model was done for three genotypes with independent data from four sites of the major barley production area in Argentina. When comparing experimental and field data regressions we did not find significant differences in slope for any cultivar (p > 0.25). However, most of the observed GIs were higher than predicted. This upwards displacement of GI–temperature relationship suggests the role of other environmental factors (i.e. water and soil N availability, day length), differing among tested locations. We are currently evaluating and quantifying the effect of these factors with the aim of improving PHS susceptibility prediction in malting barley crops.     

A 13CO2 Enrichment Experiment to Study the Synthesis Pathways of Polyunsaturated Fatty Acids of the Haptophyte Tisochrysis lutea

The production of polyunsaturated fatty acids (PUFA) in Tisochrysis lutea was studied using the gradual incorporation of a ¹³C-enriched isotopic marker, ¹³CO₂, for 24 h during the exponential growth of the algae. The ¹³C enrichment of eleven fatty acids was followed to understand the synthetic pathways the most likely to form the essential polyunsaturated fatty acids 20:5n-3 (EPA) and 22:6n-3 (DHA) in T. lutea. The fatty acids 16:0, 18:1n-9 + 18:3n-3, 18:2n-6, and 22:5n-6 were the most enriched in ¹³C. On the contrary, 18:4n-3 and 18:5n-3 were the least enriched in ¹³C after long chain polyunsaturated fatty acids such as 20:5n-3 or 22:5n-3. The algae appeared to use different routes in parallel to form its polyunsaturated fatty acids. The use of the PKS pathway was hypothesized for polyunsaturated fatty acids with n-6 configuration (such as 22:5n-6) but might also exist for n-3 PUFA (especially 20:5n-3). With regard to the conventional n-3 PUFA pathway, Δ6 desaturation of 18:3n-3 appeared to be the most limiting step for T. lutea, “stopping” at the synthesis of 18:4n-3 and 18:5n-3. These two fatty acids were hypothesized to not undergo any further reaction of elongation and desaturation after being formed and were therefore considered “end-products”. To circumvent this limiting synthetic route, Tisochrysis lutea seemed to have developed an alternative route via Δ8 desaturation to produce longer chain fatty acids such as 20:5n-3 and 22:5n-3. 22:6n-3 presented a lower enrichment and appeared to be produced by a combination of different pathways: the conventional n-3 PUFA pathway by desaturation of 22:5n-3, the alternative route of ω-3 desaturase using 22:5n-6 as precursor, and possibly the PKS pathway. In this study, PKS synthesis looked particularly effective for producing long chain polyunsaturated fatty acids. The rate of enrichment of these compounds hypothetically synthesized by PKS is remarkably fast, making undetectable the ¹³C incorporation into their precursors. Finally, we identified a protein cluster gathering PKS sequences of proteins that are hypothesized allowing n-3 PUFA synthesis.     

播种期和氮肥用量对春大麦灌浆期籽粒蛋白质和游离氨基酸含量的影响

为提供更合理的氮肥运筹和适宜播期以促进大麦的优质高产,以蒙啤1号、蒙啤3号、甘啤4号、垦啤7号4个春大麦品种为试材,研究了不同施氮水平和播期处理下内蒙古东部灌区春大麦灌浆期间籽粒蛋白质含量和游离氨基酸含量及其与成熟期籽粒蛋白质含量的相关性。结果表明,随着播期的推迟,相同灌浆期4个品种的籽粒游离氨基酸含量和蛋白质含量均呈升高的趋势;随着施氮量的增加,相同灌浆期4个品种的籽粒游离氨基酸含量和蛋白质含量均呈先升高后降低的趋势。成熟期籽粒蛋白质含量与花后7d、28d和35d籽粒蛋白质含量呈显著或极显著正相关。逐步回归分析结果表明,影响成熟期籽粒蛋白质含量最大的是花后28d籽粒蛋白质含量,而通径分析结果显示,对成熟期籽粒蛋白质含量影响最大的是花后14d的籽粒蛋白质含量。成熟期籽粒蛋白质含量与灌浆期籽粒游离氨基酸含量的相关性均达到极显著水平,对成熟期籽粒蛋白质含量影响最大的是花后7d的游离氨基酸含量,其次是花后21d的游离氨基酸含量。     

大豆原生质膜及混合细胞器膜脂脂肪酸对干旱胁迫的反应

本文分析了大豆复叶、真叶、子叶和发育子叶原生质膜及混合细胞器膜脂脂肪酸的组成、配比以及脂肪酸不饱和指数对干旱胁迫的反应。研究结果表明:大豆原生质膜及混合细胞器膜脂中主要有六种脂肪酸:豆蔻酸、棕榈酸、硬脂酸、油酸、亚油酸、亚麻酸,还有少量的月桂酸和花生酸和一种未标记的脂肪酸。干旱胁迫不改变大豆不同叶类组织原生质膜和混合细胞器膜脂脂肪酸的组成,但配比和组分含量却发生了很大变化。脂肪酸组分中变化最显著的是亚麻酸,其次是亚油酸和棕榈酸。亚麻酸与脂肪酸不饱和指数呈极显著的正相关。耐旱型品种(庆选101)膜脂对干旱的反应,为脂肪酸的饱和化作用较慢,不饱和脂肪酸含量高于不耐旱品种(黑农11)。同一品种不同叶类对干旱的抗性表现的顺序为:复叶>真叶>发育子叶>子叶。     

Effects of free air carbon dioxide enrichment and nitrogen supply on growth and yield of winter barley cultivated in a crop rotation

The increase in atmospheric CO₂ concentration [CO₂] has been demonstrated to stimulate growth of C₃ crops. Although barley is one of the important cereals of the world, little information exists about the effect of elevated [CO₂] on grain yield of this crop, and realistic data from field experiments are lacking. Therefore, winter barley was grown within a crop rotation over two rotation cycles (2000 and 2003) at present and elevated [CO₂](375 ppm and 550 ppm) and at two levels of nitrogen supply (adequate (N2): 262 kg ha⁻¹ in 1st year and 179 kg ha⁻¹ in 2nd year) and 50% of adequate (N1)). The experiments were carried out in a free air CO₂ enrichment (FACE) system in Braunschweig, Germany. The reduction in nitrogen supply decreased seasonal radiation absorption of the green canopy under ambient [CO₂] by 23%, while CO₂ enrichment had a positive effect under low nitrogen (+8%). Radiation use efficiency was increased by CO₂ elevation under both N levels (+12%). The CO₂ effect on final above ground biomass was similar for both nitrogen treatments (N1: +16%; N2: +13%). CO₂ enrichment did not affect leaf biomass, but increased ear and stem biomass. In addition, final stem dry weight was higher under low (+27%) than under high nitrogen (+13%). Similar findings were obtained for the amount of stem reserves available during grain filling. Relative CO₂ response of grain yield was independent of nitrogen supply (N1: +13%; N2: +12%). The positive CO₂ effect on grain yield was primarily due to a higher grain number, while changes of individual grain weight were small. This corresponds to the findings that under low nitrogen grain growth was unaffected by CO₂ and that under adequate nitrogen the positive effect on grain filling rate was counterbalanced by shortening of grain filling duration.     

Combined Effects of Nitrogen Concentration and Seasonal Changes on the Production of Lipids in Nannochloropsis oculata

Instead of sole nutrient starvation to boost algal lipid production, we addressed nutrient limitation at two different seasons (autumn and spring) during outdoor cultivation in flat panel photobioreactors. Lipid accumulation, biomass and lipid productivity and changes in fatty acid composition of Nannochloropsis oculata were investigated under nitrogen (N) limitation (nitrate:phosphate N:P 5, N:P 2.5 molar ratio). N. oculata was able to maintain a high biomass productivity under N-limitation compared to N-sufficiency (N:P 20) at both seasons, which in spring resulted in nearly double lipid productivity under N-limited conditions (0.21 g L⁻¹ day⁻¹) compared to N-sufficiency (0.11 g L⁻¹ day⁻¹). Saturated and monounsaturated fatty acids increased from 76% to nearly 90% of total fatty acids in N-limited cultures. Higher biomass and lipid productivity in spring could, partly, be explained by higher irradiance, partly by greater harvesting rate (~30%). Our results indicate the potential for the production of algal high value products (i.e., polyunsaturated fatty acids) during both N-sufficiency and N-limitation. To meet the sustainability challenges of algal biomass production, we propose a dual-system process: Closed photobioreactors producing biomass for high value products and inoculum for larger raceway ponds recycling waste/exhaust streams to produce bulk chemicals for fuel, feed and industrial material.     

Lipid composition of potatoes as affected by storage and potassium fertilization

The effects of storage treatments and potassium fertilization on the phospholipid, triglyceride and free fatty acid content of Russet Burbank potatoes were determined. Thin-layer chromatography of the lipids indicated at least 18 types of lipids were present. Eight were phospholipids which were the predominant lipid class in the potatoes. Phosphatidylcholine, phosphatidylinositol, phosphatidylethanolamine and phosphatidic acid comprise the major phospholipids. A large increase in phosphatidic acid and a decrease in phosphatidylcholine were observed in potatoes stored at 5.6 C (42 F). Potatoes fertilized with 240 lbs of potassium (calculated as K₂O) had a higher content of triglycerides compared to potatoes with no fertilization. Potatoes stored at 5.6 C (42 F) exhibited a decrease in triglyceride and phospholipid content but the free fatty acids were increased. The various lipid contents of reconditioned potatoes were similar to those of freshly harvested potatoes.