Phytotoxicity of Silver Nanoparticles with Different Surface Properties on Monocots and Dicots Model Plants

The aim of the research was to evaluate the effect of three types of silver nanoparticles (AgNPs) with different physicochemical properties and silver ions delivered in the form of silver nitrate (AgNO3) at the concentration of 50 mg L−1 on germination and initial growth of monocots (common wheat, sorghum) and dicots (garden cress, white mustard). The AgNPs were prepared using trisodium citrate (TCSB-AgNPs), tannic acid (TA-AgNPs), and cysteamine hydrochloride (CHSB-AgNPs). They exhibited comparable shape, size distribution, and an average size equal to 15 ± 3 nm which was confirmed with the use of transmission electron microscopy. The electrokinetic characteristics revealed that CHSB-AgNPs have positive, whereas TCSB-AgNPs and TA-AgNPs negative surface charge. First, toxicity of the silver compounds was assessed using the Phytotestkit test. Next, after transferring seedlings to pots, shoot length, leaf surface, shoot dry mass, electrolyte leakage measurement, and photosystem II (PSII) efficiency were determined. AgNPs and silver ions delivered in the form of AgNO3 reduced root and shoots length of common wheat, sorghum, and garden cress; leaves surface of garden cress and white mustard; and shoots dry mass of white mustard. The positively charged CHSB-AgNPs and silver ions delivered in the form of AgNO3 showed the greatest inhibition effect. Moreover, silver ions and positively charged CHSB-AgNPs were more toxic to PSII of model plants than negatively charged TCSB-AgNPs and TA-AgNPs. AgNPs impact differed in the case of monocots and dicots, but the size of the changes was not significant, so it concerned individual parameters. The results revealed the interaction strength, which was generally similar in all tested plants, i.e., increasing negative effect in sequence TCSB-AgNPs < TA-AgNPs < silver ions delivered in the form of AgNO3 < CHSB-AgNPs.

Allelopathic activiti of eastern galega seeds with oil crops

Relevanсe. The novelty of our research lies in the fact that for the first time the allelopathic interaction of eastern galega seeds with a wide range of oilseeds is being studied. The aim of this work is to study the allelopathic effect in the initial stages of plant ontogenesis. The objectives of the study were to identify cultures with a positive and negative impact on the growth and development of sprouts of eastern galega. The objects of research were eastern galega Magister, false saffron Alexandrite, saperda mustard Lux, spring rape Tavrion, hemp Nadezhda, spring cress Iskra, white mustard Lucia, abyssinian colewort Polet, ethiopian niger seed Medea, oil radish Fiolina, damascene fennelflower Yalita, hybrid sunflower P63 LE 10 (XF 3020), winter camelina Baron, spring camelina Velez, oilseed flax Istok. The experiments were carried out in two layouts in 2019–2020 on the basis of a separate division of the Federal research center for fiber crops in the Penza region.Methods. The evaluation of allelopathic activity was carried out using a method that involves the germination of plant seeds, followed by the calculation of the percentage of germination. The number of seeds and seedlings at different stages of ontogenesis was determined along with measuring the length of the root, stem and leaf.Results. At the initial stages of ontogenesis, a weak negative allelopathic effect on the eastern galega is exerted by the abyssinian colewort Polet — the number of fullfledged seedlings was -6,1% to the control. A positive effect on the germination and development of galega seedlings is exerted by damascene fennelflower Yalita (+8,3% to control), ethiopian niger seed Medea (+8,1 to control), oilseed flax Istok (+6,4% to control). In general, the length of the galega seedling was at the level of control with damascene fennelflower and ethiopian niger seed is 3,27 and 3,24 cm (-0,40 and 0,43 cm respectively). A significant decrease is observed in the variants with oilseed flax, spring camelina, winter camelina, spring rape, false saffron, sunflower, saperda mustard, white mustard, hemp, abyssinian colewort and spring cress — from 2,81 to 1,66 cm (-0,86–2,01 cm to control).

Phytotoxic Effects of Selected Herbal Extracts on the Germination, Growth and Metabolism of Mustard and Oilseed Rape

The use of plants that have high allelopathic potential as natural herbicides in the form of aqueous extracts is gaining popularity in environmentally friendly agriculture. Usually, their effect on the germination and growth of weeds is investigated. However, less attention is paid to the effect of the allelopathic compounds from extracts on cultivated plants. Therefore, the aim of this study was to evaluate the impact of herbal extracts that have allelopathic properties on selected physiological and biochemical processes of two plants of great economic importance—white mustard (Sinapis alba L.) and oilseed rape (Brassica napus L. var. oleifera). The extracts were prepared from mountain arnica (Arnica montana L.), ribwort (Plantago lanceolata L.), hypericum (Hypericum perforatum L.), common milfoil (Achillea millefolium L.), sunflower (Helianthus annuus L.) and sage (Salvia officinalis L.). The germination of white mustard and oilseed rape was most inhibited by the extracts that were prepared from sage and sunflower. Additionally, in the germinating plants, the sunflower extracts increased the membrane permeability, which indicates membrane injuries. The metabolic changes in the plants were monitored using isothermal calorimetry and FT-Raman spectroscopy. The total heat production, which provided information about the metabolic activity of the white mustard and oilseed rape, was decreased the most by the sage extract but generally all of the tested extracts disturbed the shape of the heat emission curves compared to the water control. The impact of the allelopathic compounds that are present in the herbal extracts on the metabolism of the seedlings was clearly visible on the FT-Raman spectra—in the fatty acids and flavonoids range, confirmed using a cluster analysis. In conclusion, the herbal extracts from medicinal plants that have herbicidal activity could be used as a natural herbicide for weed control, but since they may also have negative impacts on cultivated plants, preliminary tests are advisable to find the extract from the species that has the least negative effect on a protected crop.

Phytoremediation Potential of Flowering Plants in Relation to Copper

Heavy metals such as cadmium, chromium, nickel, mercury, lead, copper, zinc and others are among the priority environmental pollutants. Determination of their content in its main subsystems is an obligatory component in environmental monitoring and certification of agricultural products. On the other hand, all metals are natural components of soil-forming rocks, and some metals are classified as biogenic microelements, and their absence provokes functional disorders in living organisms. This article describes the results of studying the phytoremediation potential of flowering plants in relation to copper ions under laboratory conditions. The following flowering plants were selected as test crops: tansy phacelia, white mustard, small-flowered marigolds and a mixture of cereal grasses consisting of red fescue, perennial ryegrass and bluegrass in a ratio of 40%, 50%, 10%, respectively. Within the experiment, copper ions in concentrations of 2 and 10 maximum permissible concentration (MPC) were introduced into the soil sampled from the territory of agricultural lands (leached medium-thick heavy loamy chernozem with a high level of humus, mobile phosphorus and exchangeable potassium and a low level of nitrate nitrogen, copper in gross and mobile forms). It was found that all plants selected as test crops are capable of accumulating copper ions from the soil to varying degrees, which makes it possible to use them in phytoremediation of agricultural lands planned for organic farming. The ability to accumulate copper ions increases in the following order: white mustard < small-flowered marigolds < tansy phacelia < mixture of cereal grasses. The maximum effect of soil phytoremediation was revealed in the variant with a mixture of cereal grasses. When they are grown, the content of copper ions in the soil with the introduction of 2 MPC decreases by 38.8%, with the introduction of 10 MPC the concentration decreases by 47.8%.

Divergent Effects of Antibiotics on Plants and Microbiota in Soils with Contrasting Humus Content

Despite the large number of scientific studies on the effects of antibiotics on soil microorganisms, little is known about the role played by soil organic matter (humus) in the interaction of antibiotics with microorganisms and plants, including the impacts on respiration and growth rate and the implications for nitrogen metabolism, which is an important factor in soil fertility The aim of this study was to analyze the effects of two widely used antibiotics, tetracycline and streptomycin, on microbiotic activity and plant growth in two soils with dissimilar organic carbon content, at the extremes of the fertility spectrum based on humus content. The study used humus-rich (Corg 5.4%) and humus-poor soils (Corg 1.5%) and measured basal respiration, substrate-induced respiration, nitric oxide emission, germination, and growth of white mustard 3 and 60 days after three progressively increasing doses of antibiotics were applied. Tetracycline was found to impair the ecological function of humus-rich soil by reducing denitrification and compromising soil microbial activity, while the effect of streptomycin on humus-poor soil was to reduce nitrification and soil fertility due to nitrogen escape. Both streptomycin and tetracycline increased the microbial biomass and suppressed the growth of white mustard seeds, which indicates an increase in the allelopathic activity of microorganisms in the soil conditions under the influence of antibiotics and their metabolites. Due to the low sorption of streptomycin in humus-poor soils, it poses a great danger to agricultural production, especially in areas of low fertility. In humus-rich soils, high concentrations of tetracycline caused numerous problems, including death of the crop plants. Thus, the effect of antibiotics as well as the more traditional soil pollutants, such as heavy metals, to a large extent, depends on the humus content of soils.

In Vitro Evidence on Bioaccessibility of Flavonols and Cinnamoyl Derivatives of Cruciferous Sprouts

Cruciferous sprouts are rising in popularity as a hallmark of healthy diets, partially because of their phytochemical composition, characterized by the presence of flavonols and cinnamates. However, to shed light on their biological activity, the ability to assimilate (poly)phenols from sprouts (bioaccessible fraction) during gastrointestinal digestion needs to be studied. In this frame, the present work studies the effect of the physicochemical and enzymatic characteristics of gastrointestinal digestion on flavonols and cinnamoyl derivatives, by a simulated static in vitro model, on different cruciferous (red radish, red cabbage, broccoli, and white mustard) sprouts. The results indicate that, although the initial concentrations of phenolic acids in red radish (64.25 mg/g fresh weight (fw)) are lower than in the other sprouts studied, their bioaccessibility after digestion is higher (90.40 mg/g fw), followed by red cabbage (72.52 mg/g fw), white mustard (58.72 mg/g fw), and broccoli (35.59 mg/g fw). These results indicate that the bioaccessibility of (poly)phenols is not exclusively associated with the initial concentration in the raw material, but that the physico-chemical properties of the food matrix, the presence of other additional molecules, and the specific characteristics of digestion are relevant factors in their assimilation.

Effect of Sinapis alba L. as an Insectary Plant on the Occurrence of Aphis fabae Scop., Coccinellidae and Syrphidae in Broad Bean

Introducing insectary plants along with principal crops is an effective way to increase the biological diversity of beneficial insects and improve the stability of ecological equilibrium in agrocenoses and could be an alternative to chemical plant protection, particularly in organic farming. The goal of this study was to determine the effect of white mustard as a companion plant in broad bean cultivation on the occurrence of Aphis fabae Scop., Syrphidae, and Coccinellidae. The study also aimed at finding the optimum row separation of broad bean plants. It also evaluated the effectiveness of the thinning of mustard in a specific time to eliminate excessive competition with the main crop. The results showed that white mustard contributed to visible suppression of A. fabae abundance on broad bean (to the level similar as with the use of chemical protection). S. alba contributed to an increased abundance of hoverflies and lady beetles on broad bean despite the relatively low abundance of their prey, i.e., aphids. Mustard thinning positively affected abundance of larvae and adults of lady beetles as well as improved predator-prey ratio for hoverfly larvae and adult lady beetles. The most appropriate distance between broad bean rows when white mustard was introduced was 65 cm, with the concomitant conduct of mustard thinning when the broad bean plants reached flower bud formation. White mustard can be recommended as an element increasing the role of natural enemies of aphids in mixed crops, however, its strong growth should be taken into account and the plant density should be properly adjusted to avoid excessive competition with main plant.

Influence of the sowing time and mineral fertilizers on the productivity of annual grass mixtures

The productivity of annual feed grass mixtures (vetch + oats, Sudan grass + white mustard, Sudan grass + oilseed radish), sown after the winter rye harvesting during the “shooting” phase (the 1st time of sowing), during the “heading” phase (the 2nd time of sowing), and during the phase of complete ripeness (the 3d time of sowing), was studied in the conditions of forest-steppe soils of the Volga Region (the Republic of Mordovia). The experiment was carried out in 2018-2020 on heavy loamy soils against the background of three doses of mineral fertilizers use (without fertilizers, N16P16K16 + N30, N16P16K16 + N60). It has been established that the duration of vegetation of feed mixtures according to the time of sowing when harvesting for green mass was: at the first the time of sowing - 63-85 days, at the second - 63-76 days, at the third - 56-62 days. The highest height of the plant was at the first time of sowing with the use of fertilizers at a dose of N16P16K16 + N60, the lowest - at the third time of sowing. The highest growth was achieved by Sudan grass (48-116 cm), the lowest - by the mixture of vetch and oats (18-67 cm). The highest yield of green mass (14.0 t/ha) was observed when cultivating Sudan grass mixed with oilseed radish on the background of N16P16K16 + N60 at the first time of sowing. For mixture of Sudan grass with white mustard, the yield was 2-7 % lower, and for vetch + oats mixture - 32-45 % lower. The same was observed according to the yield of dry matter and feed units. As to the protein content, mixtures of Sudan grass with cruciferous crops exceeded the vetch + oats mixture by 7-26 %. The fiber content in the grass mixtures was decreasing from the first time of sowing to the last. The greatest amount of fiber (28.11-28.72 %) was observed during the second time of sowing. The economic assessment showed that the cultivation of annual grass mixtures after winter rye without mineral fertilizers was the most cost-effective (29-208 %). The highest efficiency (202-208 %) was provided by the mixture of Sudan grass with oilseed radish and white mustard.

Microcystin-LR, a Cyanobacterial Toxin, Induces DNA Strand Breaks Correlated with Changes in Specific Nuclease and Protease Activities in White Mustard (Sinapis alba) Seedlings

There is increasing evidence for the induction of programmed cell death (PCD) in vascular plants by the cyanobacterial toxin microcystin-LR (MC-LR). Our aim was to detect the occurrence of PCD-related DNA strand breaks and their possible connections to specific nuclease and protease activities. DNA breaks were studied by the deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) method in the photoperiodically grown dicot model of white mustard (Sinapis alba). In-gel nuclease and protease activity assays showed changes in the activities of specific isoenzymes during treatments with MC-LR. Strand breaks occurred both in the developing root epidermis and cortex. Several isoenzyme activities were related to these breaks, for example: an increase in the activity of neutral 80–75 kDa, acidic high MW (100–120 kDa) and, most importantly, an increase in the activity of neutral 26–20 kDa nucleases, all of them having single-stranded DNA cleaving (SSP nuclease) activities. Increases in the activities of alkaline proteases in the 61–41 kDa range were also detected and proved to be in relation with MC-LR-induced PCD. This is one of the first pieces of evidence on the correlation of PCD-related DNA strand breaks with specific hydrolase activities in a model dicot treated with a cyanobacterial toxin known to have environmental importance.

A Brief Look at Current Usda Work on Pests and Diseases

If a farmer has nematode problems or has too many weeds or fungal attacks a simple solution is to spread some mustard on them. Agricultural Research Service and university scientists are experimenting with mustards as an alternative to fighting crop pests chemically. The system biofumigates pests with stands of white mustard, brown mustard, and rapeseed.. Biofumigation refers to natural substances plants release while decomposing that make surrounding soils toxic to some weeds, nematodes, and fungi. The experiments, in Washington State, dovetail with increasing grower interest in mustard crops for pest control and as "green manure" meaning it can be disked into soil to improve tilth, organic matter, aeration, and water filtration. Despite such benefits, there is still much to learn about how mustards control pests and under what conditions they work best.