Exploration of essential oils as alternatives to conventional fungicides in lupin cultivation

Lupin (Lupinus L.) has the potential to become a true alternative for soybean as protein source, especially in the more temperate regions in the world. However, diseases such as anthracnose (Colletotrichum lupini), gray mold (Botrytis cinerea), and root rot or brown spot (Pleiochaeta setosa) are important threats for lupin production, leading to yield and quality losses. Although conventional fungicides offer a solution to these problems, there is a growing interest in the use of alternative (biological) treatments. In this research, the applicability of four pure plant essential oils (clove oil, juniper oil, tea tree oil, and thyme essential oil) and timbor® (a Thymus vulgaris-derived plant extract) as alternatives for synthetic fungicides towards the lupin pathogens—C. lupini, B. cinerea, and P. setosa—was investigated. The anti-fungal effect of juniper oil was limited, whereas the other oils and timbor® clearly suppressed the growth and spore germination of all fungi. The in vitro experiments revealed that thyme essential oil and timbor® were most effective to inhibit conidial germination and mycelium growth. Furthermore, the results of the pot experiments demonstrated that these Thymus-derived compounds were able to suppress P. setosa brown spot and root rot symptoms. Additional trials are necessary to evaluate the effect of these compounds under field conditions. However, based on these in vitro and pot experiments, it can be concluded that pure essential oils and Thymus-derived plant extracts are promising anti-fungal agents, having the potential to become true alternatives for conventional fungicides in lupin cultivation. To the best of our knowledge, this is the first study demonstrating the potential of plant-derived compounds to treat the main diseases affecting lupin production

Effect of adjuvants on the efficiency of benthiavalicarb plus mancozeb (Valbon 1.6 kg/ha) on the control of late blight in potato

Industrial adjuvants were tested in combination with benthiavalicarb plus mancozeb (Valbon 1.6 kg/ha) in the field to investigate their efficacy on foliar late blight caused by Phytophthora infestans. The tested adjuvant-fungicide treatments for late blight control were applied 6 times at 7-day intervals. The effect of the adjuvant-fungicide treatments on epidemic development, tuber blight and tuber yields were determined. Because of the favourable weather conditions a high disease pressure could be observed. The incidence of foliage blight was scored and at the end of the growing season the disease level was lower in plots sprayed with the Valbon-adjuvant combinations than in plots treated with only Valbon. The addition of an adjuvant had a clearly positive effect on the tuber yield although the differences were not significant. In the plots treated with Valbon 6.9 % infected tubers were observed. The mean tuber infection of plots sprayed with the Valbon-adjuvant combinations fluctuated between 2.3 and 15.6 %

Plant development, yielding properties and kernel composition of winter wheat in relation to soil type and irrigation treatment under an organically elevated temperature

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Impact of crop husbandry practices and environmental conditions on wheat composition and quality : a review

The increasing interest in the production of bread wheat (Triticum aestivum L.) with specific quality traits requires a shift from the current breeding goal, being yield, to improved compositional and, consequently, functional traits. Since wheat is a key food crop, this must be attained while maintaining or even further increasing yield. Furthermore, as compositional requirements for specific applications are not well-defined, both protein and gluten content as well as the enzymatic activity remain most important. Given that these traits are majorly impacted by both genotype and environment, it is very complex to predict and ultimately control them. Different strategies, such as applying optimized agronomic practices, can temper these uncontrollable determinants which are equally important to steer wheat quality. As current research on their contribution to specific traits is highly fragmented, this report provides a comprehensive review of the influence of crop husbandry and environmental conditions on wheat yield and composition

Organic field trials of winter and summer crop mixtures of grain legumes and cereals in Belgium

Summer- and wintersown crop mixtures of faba beans or fodder peas together with wheat/barley/triticale were tested in field trials in the growing seasons 2013-2014 and 2014-2015. Different regionally available varieties and European plant material of faba bean and fodder pea were harvested together with cereals as dry grain. Special attention was paid to weed suppression capability and crop reliability

Chemoenzymatic approach toward the synthesis of 3-O-(α/β)-glucosylated 3-hydroxy-β-lactams

Glycosylation significantly alters the biological and physicochemical properties of small molecules. beta-Lactam alcohols comprise eligible substrates for such a transformation based on their distinct relevance in the chemical and medicinal community. In this framework, the unprecedented enzymatic glycosylation of the rigid and highly strained four-membered beta-lactam azaheterocycle was studied. For this purpose, cis-3-hydroxy-beta-lactams were efficiently prepared in three steps by means of a classical organic synthesis approach, while a biocatalytic step was implemented for the selective formation of the corresponding 3-O-alpha- and -beta-glucosides, hence overcoming the complexities typically encountered in synthetic glycochemistry and contributing to the increasing demand for sustainable processes in the framework of green chemistry. Two carbohydrate-active enzymes were selected based on their broad acceptor specificity and subsequently applied for the alpha- or beta-selective formation of beta-lactam-sugar adducts, using sucrose as a glucosyl donor

Particle-mediated intravenous delivery of antigen mRNA results in strong antigen-specific T-cell responses despite the induction of type I interferon

Cancer vaccines based on mRNA are extensively studied. The fragile nature of mRNA has instigated research into carriers that can protect it from ribonucleases and as such enable its systemic use. However, carrier-mediated delivery of mRNA has been linked to production of type I interferon (IFN) that was reported to compromise the effectiveness of mRNA vaccines. In this study, we evaluated a cationic lipid for encapsulation of mRNA. The nanometer-sized, negatively charged lipid mRNA particles (LMPs) efficiently transfected dendritic cells and macrophages in vitro. Furthermore, i.v. delivery of LMPs resulted in rapid expression of the mRNA-encoded protein in spleen and liver, predominantly in CD11c+ cells and to a minor extent in CD11b+ cells. Intravenous immunization of mice with LMPs containing ovalbumin, human papilloma virus E7, and tyrosinase related protein-2 mRNA, either combined or separately, elicited strong antigen-specific T-cell responses. We further showed the production of type I IFNs upon i.v. LMP delivery. Although this decreased the expression of the mRNA-encoded protein, it supported the induction of antigen-specific T-cell responses. These data question the current notion that type I IFNs hamper particle-mediated mRNA vaccines

Soil texture can predominantly control organic matter mineralization in temperate climates by regulating soil moisture rather than through direct stabilization

Soil organic carbon (OC) levels generally increase with increasing clay and silt content under a similar climatic zone because of increased association of OC to clay minerals and stronger occlusion inside aggregates. Surprisingly though, in Western Europe many silt loam soils actually bear low topsoil OC levels compared to lighter textured soils. Soil texture obviously also strongly controls moisture availability with consequent indirect impact on heterotrophic activity. We hypothesized that with increasingly frequent summer drought: 1) soil microbial activity in sandy soils is more likely impeded due to their limited water holding capacity retention during droughts, while soil OC mineralization in silty soils remain be less drought-limited; 2) capillary rise from sufficiently shallow groundwater would, on the other hand, alleviate the water stress in lighter textures. To test these hypotheses, we established a one-year field trial with manipulation of soil texture, monitoring of soil moisture and maize-C decomposition via 13/12C-CO2 emissions. The upper 0.5 m soil layer was replaced by sand, sandy loam and silt loam soil with low soil OC. Another sandy soil treatment with a gravel layer was also included beneath the sand layer to exclude capillary rise. Soil texture did not affect maize-C mineralization (Cmaize-min) until April 2019 and thereafter Cmaize-min rates were higher in the silt loam than in the sandy soils (P=0.01). θv correlated positively with the Cmaize-min rate for the sand-textured soils only but not for the finer textures. These results clearly highlight that soil texture controlled Cmaize-min indirectly through regulating moisture under the field conditions starting from about May, when soils faced a period of drought. By the end of the experiment, more added Cmaize was mineralized in the silt loam soil (81%) (P<0.05) than in the sandy soil (56%). Capillary rise did not result in a significant increase in cumulative Cmaize-min in the sandy soil, seemingly because the capillary fringe did not reach the sandy topsoil layer. These results imply that, under future climate scenarios the frequency of drought is expected to increase, the largely unimpeded microbial activity in silty soils might lead to a further stronger difference in soil OC with coarser textured soils under similar management

Sonoprinting of nanoparticle-loaded microbubbles : unraveling the multi-timescale mechanism

Ultrasound-triggered microbubble-assisted drug delivery is a promising tool for localized therapy. Several studies have shown the potential of nanoparticle-loaded microbubbles to effectively enhance the delivery of therapeutic agents to target tissue. We recently discovered that nanoparticle-carrying microbubbles can deposit the nanoparticles in patches onto cell membranes, a process which we termed 'sonoprinting'. However, the biophysical mechanisms behind sonoprinting are not entirely clear. In addition, the question remains how the ultrasound parameters, such as acoustic pressure and pulse duration, influence sonoprinting. Aiming for a better understanding of sonoprinting, this report investigates the behavior of nanoparticle-loaded microbubbles under ultrasound exposure, making use of three advanced optical imaging techniques with frame rates ranging from 5 frames per second to 10 million frames per second, to capture the biophysical cell-bubble interactions that occur on a multitude of timescales. We observed that non-spherically oscillating microbubbles release their nano particle payload in the first few cycles of ultrasound insonation. At low acoustic pressures, the released nano particles are transported away from the cells by microstreaming, which does not favor uptake of the nano particles by the cells. However, higher acoustic pressures ( > 300 kPa) and longer ultrasound pulses ( > 100 cycles) lead to rapid translation of the microbubbles, due to acoustic radiation forces. As a result, the released nanoparticles are transported along in the wake of the microbubbles, which eventually leads to the deposition of nanoparticles in elongated patches on the cell membrane, i.e. sonoprinting. We conclude that a sufficiently high acoustic pressure and long pulses are needed for sonoprinting of nanoparticles on cells

Quantifying the average number of nucleic acid therapeutics per nanocarrier by single particle tracking microscopy

Nucleic acid biopharmaceuticals are being investigated as potential therapeutics. They need to be incorporated into a biocompatible carrier so as to overcome several biological barriers. Rational development of suitable nanocarriers requires high-quality characterization techniques. While size, concentration, and stability can be very well measured these days, even in complex biological fluids, a method to accurately quantify the number of nucleic acid therapeutics encapsulated in nanocarriers is still missing. Here we present a method, based on concentration measurements with single particle tracking microscopy, with which it is possible to directly measure the number of plasmid DNA molecules per nanoparticle, referred to as the plasmid/NP ratio. Using DOTAP/DOPE liposomes as a model carrier, we demonstrate the usefulness of the method by investigating the influence of various experimental factors on the plasmid/NP ratio. We find that the plasmid/NP ratio is inversely proportional with the size of the pDNA and that the plasmid/NP decreases when lipoplexes are prepared at lower concentrations of pDNA and nanocarrier, with values ranging from 6.5 to 3 plasmid/NP. Furthermore, the effect of pre- and post-PEGylation of lipoplexes was examined, finding that pre-PEGylation results in a decreased plasmid/NP ratio, while post-PEGylation did not alter the plasmid/NP ratio. These proof-of-concept experiments show that single particle tracking offers an extension of the nanoparticle characterization toolbox and is expected to aid in the efficient development of nanoformulations for nucleic acid-based therapies