Biochemical and economical effect of application biostimulants containing seaweed extracts and amino acids as an element of agroecological management of bean cultivation

Biostimulants Enhance the Nutritional Quality of Soilless Greenhouse Tomatoes

The application of biostimulants in vegetable cultivation has emerged as a promising approach to enhance the nutritional quality of crops, particularly in controlled environment agriculture and soilless culture systems. In this study, we employed a rigorous methodology, applying various biostimulants amino acids, Plant Growth-Promoting Rhizobacteria (PGPR), fulvic acid, chitosan, and vermicompost along with mineral fertilizers, both foliar and via the roots, to soilless greenhouse tomatoes during spring cultivation. The experiment, conducted in a coir pith medium using the 'Samyeli F1' tomato cultivar, demonstrated that plants treated with biostimulants performed better than control plants. Notable variations in nutritional components were observed across treatments. PGPR had the best effects on the physical properties of the tomato fruit, showing the highest fruit weight, fruit length, equatorial diameter, fruit volume, fruit skin elasticity, and fruit flesh hardness while maintaining high color parameters L, a, and b. PGPR and fulvic acid demonstrated significant enhancements in total phenolics and flavonoids, suggesting potential boosts in antioxidant properties. Amioacid and vermicompost notably elevated total soluble solids, indicating potential fruit sweetness and overall taste improvements. On the other hand, vermicompost stood out for its ability to elevate total phenolics and flavonoids while enhancing vitamin C content, indicating a comprehensive enhancement of nutritional quality. In addition, vermicompost had the most significant impact on plant growth parameters and total yield, achieving a 43% increase over the control with a total yield of 10.39 kg/m2. These findings underline the specific nutritional benefits of different biostimulants, offering valuable insights for optimizing tomato cultivation practices to yield produce with enhanced health-promoting properties.

Potential of Plant-Based Extracts to Alleviate Sorbitol-Induced Osmotic Stress in Cabbage Seedlings

In light of expected climate change, it is important to seek nature-based solutions that can contribute to the protection of our planet as well as to help overcome the emerging adverse changes. In an agricultural context, increasing plant resistance to abiotic stress seems to be crucial. Therefore, the scope of the presented research was focused on the application of botanical extracts that exerted positive effects on model plants growing under controlled laboratory conditions, as well as plants subjected to sorbitol-induced osmotic stress. Foliar spraying increased the length and fresh mass of the shoots (e.g., extracts from Taraxacum officinale, Trifolium pratense, and Pisum sativum) and the roots (e.g., Solidago gigantea, Hypericum perforatum, and Pisum sativum) of cabbage seedlings grown under stressful conditions, as well as their content of photosynthetic pigments (Pisum sativum, Lens culinaris, and Hypericum perforatum) along with total phenolic compounds (Hypericum perforatum, Taraxacum officinale, and Urtica dioica). The antioxidant activity of the shoots measured with the use of DDPH (Pisum sativum, Taraxacum officinale, Urtica dioica, and Hypericum perforatum), ABTS (Trifolium pratense, Symphytum officinale, Valeriana officinalis, Pisum sativum, and Lens culinaris), and FRAP (Symphytum officinale, Valeriana officinalis, Urtica dioica, Hypericum perforatum, and Taraxacum officinale) assays was also enhanced in plants exposed to osmotic stress. Based on these findings, the most promising formulation based on Symphytum officinale was selected and subjected to transcriptomic analysis. The modification of the expression of the following genes was noted: Bol029651 (glutathione S-transferase), Bol027348 (chlorophyll A-B binding protein), Bol015841 (S-adenosylmethionine-dependent methyltransferases), Bol009860 (chlorophyll A-B binding protein), Bol022819 (GDSL lipase/esterase), Bol036512 (heat shock protein 70 family), Bol005916 (DnaJ Chaperone), Bol028754 (pre-mRNA splicing Prp18-interacting factor), Bol009568 (heat shock protein Hsp90 family), Bol039362 (gibberellin regulated protein), Bol007693 (B-box-type zinc finger), Bol034610 (RmlC-like cupin domain superfamily), Bol019811 (myb_SHAQKYF: myb-like DNA-binding domain, SHAQKYF class), Bol028965 (DA1-like Protein). Gene Ontology functional analysis indicated that the application of the extract led to a decrease in the expression of many genes related to the response to stress and photosynthetic systems, which may confirm a reduction in the level of oxidative stress in plants treated with biostimulants. The conducted studies showed that the use of innovative plant-based products exerted positive effects on crops and can be used to supplement current cultivation practices.

Plant Biostimulant as an Environmentally Friendly Alternative to Modern Agriculture

Ensuring the safety of crop production presents a significant challenge to humanity. Pesticides and fertilizers are commonly used to eliminate external interference and provide nutrients, enabling crops to sustain growth and defense. However, the addition of chemical substances does not meet the environmental standards required for agricultural production. Recently, natural sources such as biostimulants have been found to help plants with growth and defense. The development of biostimulants provides new solutions for agricultural product safety and has become a widely utilized tool in agricultural. The review summarizes the classification of biostimulants, including humic-based biostimulant, protein-based biostimulant, oligosaccharide-based biostimulant, metabolites-based biostimulants, inorganic substance, and microbial inoculant. This review attempts to summarize suitable alternative technology that can address the problems and analyze the current state of biostimulants, summarizes the research mechanisms, and anticipates future technological developments and market trends, which provides comprehensive information for researchers to develop biostimulants.

Knowledge gaps on how to adapt crop production under changing saline circumstances in the Netherlands

Salinization, the increase and accumulation of salts in water and soil, impacts productivity of arable crops and is exacerbated by climate change. The Netherlands, like several other deltas and semi-arid regions, faces increasing salinization that negatively impacts agriculture and freshwater availability. Although a lot of salinity expertise exist in the Netherlands, several knowledge gaps on the impact of salinization in the Netherlands, as well as steps to facilitate closing this knowledge gaps to improve saline agriculture in the Netherlands, still exist. This review/opinion article moves beyond existing papers on salinization in bringing together various adaptation measures by thoroughly reviewing the measures through a triple P (People, Planet, Profit) lens. Five main salinity adaptation measures of the crop-soil-water continuum are 1) breeding and selection of salt tolerant varieties, 2) increased cultivation of halophytes, 3) soil management interventions, 4) use of biostimulants, and 5) irrigation techniques. These adaptation measures are described, discussed and analysed for their compliance to the sustainable development elements People, Planet and Profit. All five adaptation measures have potential positive impact on livelihood, contribute to food security and generate revenue but on the other hand, these measures may contribute to unwarranted changes of the ecosystem. The paper ends with a concluding chapter in which the bottlenecks and knowledge gaps that need resolving are identified based on the critical, including triple P, assessment of the discussed adaptation measures. Three key knowledge gaps on breeding, agronomy, environmental sciences and socioeconomics are identified with several approaches that lead to insights elucidated. Thereby informing on future research and action plans to optimize implementation of salinity adaptation measures in the Netherlands.

Biostimulants and environmental stress mitigation in crops: A novel and emerging approach for agricultural sustainability under climate change

Pesticide and fertilizer usage is at the center of agricultural production to meet the demands of an ever-increasing global population. However, rising levels of chemicals impose a serious threat to the health of humans, animals, plants, and even the entire biosphere because of their toxic effects. Biostimulants offer the opportunity to reduce the agricultural chemical footprint owing their multilevel, beneficial properties helping to make agriculture more sustainable and resilient. When applied to plants or to the soil an increased absorption and distribution of nutrients, tolerance to environmental stress, and improved quality of plant products explain the mechanisms by which these probiotics are useful. In recent years, the use of plant biostimulants has received widespread attention across the globe as an ecologically acceptable alternative to sustainable agricultural production. As a result, their worldwide market continues to grow, and further research will be conducted to broaden the range of the products now available. Through this review, we present a current understanding of biostimulants, their mode of action and their involvement in modulating abiotic stress responses, including omics research, which may provide a comprehensive assessment of the crop's response by correlating molecular changes to physiological pathways activated under stress conditions aggravated by climate change.

Biostimulant Properties of Protein Hydrolysates: Recent Advances and Future Challenges

Over the past decade, plant biostimulants have been increasingly used in agriculture as environment-friendly tools that improve the sustainability and resilience of crop production systems under environmental stresses. Protein hydrolysates (PHs) are a main category of biostimulants produced by chemical or enzymatic hydrolysis of proteins from animal or plant sources. Mostly composed of amino acids and peptides, PHs have a beneficial effect on multiple physiological processes, including photosynthetic activity, nutrient assimilation and translocation, and also quality parameters. They also seem to have hormone-like activities. Moreover, PHs enhance tolerance to abiotic stresses, notably through the stimulation of protective processes such as cell antioxidant activity and osmotic adjustment. Knowledge on their mode of action, however, is still piecemeal. The aims of this review are as follows: (i) Giving a comprehensive overview of current findings about the hypothetical mechanisms of action of PHs; (ii) Emphasizing the knowledge gaps that deserve to be urgently addressed with a view to efficiently improve the benefits of biostimulants for different plant crops in the context of climate change.

Characterization of novel proteases identified by metagenomic analysis from dairy stabilization ponds

Cheese whey is the main by-product of dairy industries. It is used as a raw material for other value-added products, like whey protein concentrate. By using enzymes, this product can be further treated to obtain new higher value products, like whey protein hydrolysates. Proteases (EC: 3.4) represent a large segment of industrial enzymes, since they are used in several industries, including food. In this work, we describe three novel enzymes identified using a metagenomic approach. Metagenomic DNA from dairy industry stabilization ponds were sequenced, and the predicted genes were compared against the MEROPS database, focusing on families commercially used to produce whey protein hydrolysates. From a total of 849 candidates, 10 were selected for cloning and expression and three showed activities with both the chromogenic substrate, azocasein, and whey proteins. Particularly, Pr05, an enzyme from the yet uncultured phylum Patescibacteria, showed activity that is comparable to a commercial protease. All these novel enzymes could represent an alternative for dairy industries to produce value-added products from industrial by-products. KEY POINTS: • Over 19,000 proteases were predicted in a sequence-based metagenomic analysis. • Three proteases were successfully expressed and showed activity with whey proteins. • The enzyme Pr05 showed hydrolysis profiles of interest for food industry.

Willow (Salix babylonica) Extracts Can Act as Biostimulants for Enhancing Salinity Tolerance of Maize Grown in Soilless Culture

Salinity negatively affects agricultural production by reducing crop growth and yield. Botanical biostimulants can be used as innovative and sustainable tools to cope with abiotic stress. In this study, salicylic acid (SA) (25 µM) and willow leaf (WL) (0.1 and 0.2%) and bark (WB) (0.1 and 0.2%) extracts were applied as plant-based biostimulants to hydroponically grown maize in the absence and presence of salinity stress (60 mM NaCl). The hormone-like activity and mineral composition of willow extracts were analyzed, and the effects of willow extracts on growth parameters, chlorophyll content, antioxidative enzyme activities, protein levels and mineral nutrient concentrations of maize plants were measured. Within the tested biostimulant applications, 0.2% WB, 0.1% WL and 0.2% WL gave the most promising results, considering the stress alleviating effects. The shoot biomass was increased up to 50% with 0.1% WL treatment and Na⁺ uptake was reduced with biostimulant applications under saline conditions. Under stress, the protein concentrations of maize leaves were enhanced by 50% and 80% with high doses of WB and WL applications, respectively. Results indicate that willow tree prunings can be valuable bio-economy resources, and aqueous extracts prepared from their leaves and barks can be used as effective and eco-friendly biostimulants.

Application of Biostimulants in Tomato Plants (Solanum lycopersicum) to Enhance Plant Growth and Salt Stress Tolerance

Under the era of climate change, plants are forced to survive under increasingly adverse conditions. Application of biostimulants in plants is shown to mitigate the deleterious effects of abiotic stresses including salinity, enhancing plant tolerance and performance. The present study focuses on the effects of five biostimulants based on biocompost and biofertilizer compounds that have been applied to tomato plants grown in the presence (salt-stressed plants) or absence of salt stress (control plants). To study the beneficial effects of the biostimulants in tomato plants, a series of analyses were performed, including phenotypic and agronomic observations, physiological, biochemical and enzymatic activity measurements, as well as gene expression analysis (RT-qPCR) including genes involved in antioxidant defense (SlCu/ZnSOD, SlFeSOD, SlCAT1, SlcAPX), nitrogen (SlNR, SlNiR, SlGTS1) and proline metabolism (p5CS), potassium transporters (HKT1.1, HKT1.2), and stress-inducible TFs (SlWRKY8, SlWRKY31). Among all the biostimulant solutions applied to the plants, the composition of 70% biofertilizer and 30% biocompost (Bf70/Bc30) as well as 70% biocompost and 30% biofertilizer (Bc70/Bf30) formulations garnered interest, since the former showed growth promoting features while the latter displayed better defense responses at the time of harvesting compared with the other treatments and controls. Taken together, current findings provide new insight into the beneficial effects of biostimulants, encouraging future field studies to further evaluate the biostimulant effects in plants under a real environment which is compromised by a combination of abiotic and biotic stresses.

Computational Metabolomics Tools Reveal Metabolic Reconfigurations Underlying the Effects of Biostimulant Seaweed Extracts on Maize Plants under Drought Stress Conditions

Drought is one of the major abiotic stresses causing severe damage and losses in economically important crops worldwide. Drought decreases the plant water status, leading to a disruptive metabolic reprogramming that negatively affects plant growth and yield. Seaweed extract-based biostimulants show potential as a sustainable strategy for improved crop health and stress resilience. However, cellular, biochemical, and molecular mechanisms governing the agronomically observed benefits of the seaweed extracts on plants are still poorly understood. In this study, a liquid chromatography–mass spectrometry-based untargeted metabolomics approach combined with computational metabolomics strategies was applied to unravel the molecular ‘stamps’ that define the effects of seaweed extracts on greenhouse-grown maize (Zea mays) under drought conditions. We applied mass spectral networking, substructure discovery, chemometrics, and metabolic pathway analyses to mine and interpret the generated mass spectral data. The results showed that the application of seaweed extracts induced alterations in the different pathways of primary and secondary metabolism, such as phenylpropanoid, flavonoid biosynthesis, fatty acid metabolism, and amino acids pathways. These metabolic changes involved increasing levels of phenylalanine, tryptophan, coumaroylquinic acid, and linolenic acid metabolites. These metabolic alterations are known to define some of the various biochemical and physiological events that lead to enhanced drought resistance traits. The latter include root growth, alleviation of oxidative stress, improved water, and nutrient uptake. Moreover, this study demonstrates the use of molecular networking in annotating maize metabolome. Furthermore, the results reveal that seaweed extract-based biostimulants induced a remodeling of maize metabolism, subsequently readjusting the plant towards stress alleviation, for example, by increasing the plant height and diameter through foliar application. Such insights add to ongoing efforts in elucidating the modes of action of biostimulants, such as seaweed extracts. Altogether, our study contributes to the fundamental scientific knowledge that is necessary for the development of a biostimulants industry aiming for a sustainable food security.

Harnessing Synergistic Biostimulatory Processes: A Plausible Approach for Enhanced Crop Growth and Resilience in Organic Farming

Simple Summary

Demand for organically grown crops has risen globally due to its healthier and safer food products. From a sustainability perspective, organic farming offers an eco-friendly cultivation system that minimizes agrochemicals and producing food with little or no environmental footprint. However, organic agriculture’s biggest drawback is the generally lower and variable yield in contrast to conventional farming. Compatible with organic farming, the selective use of biostimulants can close the apparent yield gap between organic and conventional cultivation systems. A biostimulant is defined as natural microorganisms (bacteria, fungi) or biologically active substances that are able to improve plant growth and yield through several processes. Biostimulants are derived from a range of natural resources including organic materials (composts, seaweeds), manures (earthworms, fish, insects) and extracts derived from microbes, plant, insect or animal origin. The current trend is indicative that a mixture of biostimulants is generally delivering better growth, yield and quality rather than applying biostimulant individually. When used correctly, biostimulants are known to help plants cope with stressful situations like drought, salinity, extreme temperatures and even certain diseases. More research is needed to understand the different biostimulants, key components, and also to adjust the formulations to improve their reliability in the field.

Abstract

Demand for organically grown food crops is rising substantially annually owing to their contributions to human health. However, organic farm production is still generally lower compared to conventional farming. Nutrient availability, content consistency, uptake, assimilation, and crop responses to various stresses were reported as critical yield-limiting factors in many organic farming systems. In recent years, plant biostimulants (BSs) have gained much interest from researchers and growers, and with the objective of integrating these products to enhance nutrient use efficiency (NUE), crop performance, and delivering better stress resilience in organic-related farming. This review gave an overview of direct and indirect mechanisms of microbial and non-microbial BSs in enhancing plant nutrient uptake, physiological status, productivity, resilience to various stressors, and soil-microbe-plant interactions. BSs offer a promising, innovative and sustainable strategy to supplement and replace agrochemicals in the near future. With greater mechanistic clarity, designing purposeful combinations of microbial and non-microbial BSs that would interact synergistically and deliver desired outcomes in terms of acceptable yield and high-quality products sustainably will be pivotal. Understanding these mechanisms will improve the next generation of novel and well-characterized BSs, combining microbial and non-microbial BSs strategically with specific desired synergistic bio-stimulatory action, to deliver enhanced plant growth, yield, quality, and resilience consistently in organic-related cultivation.

Plant Material as a Novel Tool in Designing and Formulating Modern Biostimulants-Analysis of Botanical Extract from Linum usitatissimum L

Nowadays, researchers are looking into next-generation biostimulants that can be designed as a dedicated agronomic tool based on plant materials. The aim of the present study was to develop a novel biostimulating product, based on plant material in the form of linseed aqueous extracts. The scope of the research included the physicochemical characterization of the product and identification of its biostimulating potential. The study has confirmed that the plant biostimulant derived from L. usitatissimum can be used as a viable agronomic tool for growing soybean. The designed and produced biostimulant is rich in bioactive compounds, including amino acids, free fatty acids, carbohydrates, and micro- and macroelements. The tested biostimulant showed significantly lower values of surface tension in relation to water and a commercial biostimulant. The soybean crops responded to the application of the preparation by improvements in agronomic and morphological levels. The linseed macerates were effective in terms of soybean yields and profitability. Our findings serve as preliminary evidence for the viability of designing and developing novel biostimulants derived from plant materials. This comprehensive approach to designing and formulating novel bioproducts necessitates more extensive and targeted research to fully explain the mechanisms behind the improvements observed in the soybean cultivation.

Soybean Germination Response to Algae Extract and a Static Magnetic Field Treatment

The present study examines the separate and synergistic effects of macroalgal extract and static magnetic field (SMF) on the germination of soybean seeds (Glycine max (L.) Merrill), cv. Abelina, seedling growth, chlorophyll, and carotenoids content in leaves. Algal extract was produced from freshwater green macroalga (Cladophora glomerata) using ultrasound-assisted extraction. The germination tests were conducted in two stages. Firstly, different concentrations of extracts, 20%, 40%, 60%, 80%, and 100%, were applied to a paper substrate. The best results (taking into account germination percentage, seedlings length and weight, and pigments content in leaves) were observed for 20% and 80% extracts. At the same stage, germination of seeds exposed to SMF (exposure times for 3 and 12 min and magnetic inductions of 250 and 500 mT) was studied. The best developed seedlings were determined for the group treated at 3 min with a magnetic induction of 250 mT. In the final step, the simultaneous effects of 20% and 80% algal extracts and treatment with 3 min at 250 mT SMF were tested. Taking into account all the parameters, the simultaneous use of 20% extract and 3 min of 250 mT magnetic induction is recommended.

Uncovering the multi-level response of Glycine max L. to the application of allelopathic biostimulant from Levisticum officinale Koch

The interest expressed by the agriculture in the category of innovative biostimulants is due to the intensive search for natural preparations. Our study is the first ever to report a complex approach to the use of allelopathic extracts from Levisticum officinale Koch. roots in soybean cultivation, includes analyses of morphological observations, and analyses of biochemical indicators. Hot method of aqueous extraction was applied. The extracts were administered via foliar application and soil treatment. Lovage extracts had high contents of polyphenolic compounds and rich micro- and macroelemental composition. The infusions did not contain gibberellic acid and indole-3-acetic acid but the abscisic acid and saccharose, glucose, and fructose were found. The extracts modified soybean plant physiology, as manifested by changes in biometric traits. Plants responded positively by increased yield. Seeds from the treated plants had higher contents of micro- and macroelements, as well as total concentrations of lipids (with a slight decrease in protein content). In addition, they featured changes in their amino acid profile and fatty acid composition. The application of allelopathic biostimulant caused increased concentrations of isoflavones and saponins. The natural biostimulants from Levisticum officinale may become a valuable tool in the sustainable agriculture.

Recent Advances in the Molecular Effects of Biostimulants in Plants: An Overview

As the world develops and population increases, so too does the demand for higher agricultural output with lower resources. Plant biostimulants appear to be one of the more prominent sustainable solutions, given their natural origin and their potential to substitute conventional methods in agriculture. Classified based on their source rather than constitution, biostimulants such as humic substances (HS), protein hydrolysates (PHs), seaweed extracts (SWE) and microorganisms have a proven potential in improving plant growth, increasing crop production and quality, as well as ameliorating stress effects. However, the multi-molecular nature and varying composition of commercially available biostimulants presents challenges when attempting to elucidate their underlying mechanisms. While most research has focused on the broad effects of biostimulants in crops, recent studies at the molecular level have started to unravel the pathways triggered by certain products at the cellular and gene level. Understanding the molecular influences involved could lead to further refinement of these treatments. This review comprises the most recent findings regarding the use of biostimulants in plants, with particular focus on reports of their molecular influence.

The Effect of Ascophyllum nodosum Extract on the Nutraceutical Antioxidant Potential of Vigna radiata Sprout under Salt Stress

Mung bean (Vigna radiata L.) sprout is a popular fresh vegetable, tasty and high in antioxidants. To increase yield and quality after the occurrence of both abiotic and biotic stresses, the application of seaweed extracts is of great importance. Hence, this study was conducted to determine the effect of Ascophyllum nodosum extract (ANE) in the presence of salt on the antioxidant potential of V. radiata sprouts. Different concentrations of ANE viz. 0.00, 0.01, 0.05, 0.10, and 0.50% and NaCl 0, 25, 50, 75, and 100 mM alone and in combinations were tested for researching the antioxidant potential of V. radiata sprouts at 0, 24, and 36 h of sprouting. The DPPH free-radical-scavenging activity of sprouts of V. radiata was found to increase with time and peaked at 24 h of treatment. The A. nodosum extract (0.01%) could reverse the ill effect of the low level of salinity posed by up to 25 mM NaCl. The increasing salinity deteriorated the antioxidant activity using ABTS method of sprouts down to 20.45% of the control at 100 mM NaCl. The total phenolic content (TPC), total flavonoid content (TFC), and reducing power of V. radiata sprouts was found to increase till 36 h of sprouting. A slight increase in TPC, TFC and reducing power was observed when seeds were treated with low concentrations of ANE. The elevation in TPC, TFC and reducing power upon treatment with low concentrations of ANE was also noticed in sprouts in saline combinations. Alpha amylase inhibition activity was found to reach a (67.16% ± 0.9) maximum at 24 h of sprouting at a 0.01% concentration of ANE. Tyrosinase inhibition and alpha glucosidase inhibition was 88.0% ± 2.11 and 84.92% ± 1.2 at 36 h of sprouting, respectively, at 0.01% concentration of ANE. A. nodosum extract is natural, environmentally friendly, and safe, and could be used as one of the strategies to decline stress at a low level and enhance the antioxidant activities in V. radiata sprouts, thus increasing its potential to be developed as an antioxidant-based functional food.

Biostimulants Application: A Low Input Cropping Management Tool for Sustainable Farming of Vegetables

Biostimulants, are a diverse class of compounds including substances or microorganism which have positive impacts on plant growth, yield and chemical composition as well as boosting effects to biotic and abiotic stress tolerance. The major plant biostimulants are hydrolysates of plant or animal protein and other compounds that contain nitrogen, humic substances, extracts of seaweeds, biopolymers, compounds of microbial origin, phosphite, and silicon, among others. The mechanisms involved in the protective effects of biostimulants are varied depending on the compound and/or crop and mostly related with improved physiological processes and plant morphology aspects such as the enhanced root formation and elongation, increased nutrient uptake, improvement in seed germination rates and better crop establishment, increased cation exchange, decreased leaching, detoxification of heavy metals, mechanisms involved in stomatal conductance and plant transpiration or the stimulation of plant immune systems against stressors. The aim of this review was to provide an overview of the application of plant biostimulants on different crops within the framework of sustainable crop management, aiming to gather critical information regarding their positive effects on plant growth and yield, as well as on the quality of the final product. Moreover, the main limitations of such practice as well as the future prospects of biostimulants research will be presented.

The Interplay between Light Quality and Biostimulant Application Affects the Antioxidant Capacity and Photosynthetic Traits of Soybean (Glycine max L. Merrill)

This paper evaluates the combined effect of biostimulant and light quality on bioactive compound production and seedling growth of soybean (Glycine max L. Merrill) plants. Germinated seeds pre-treated with different concentrations (0.01%, 0.05%, 0.5%) of an amino acid-based biostimulant were grown for 4 days at the dark (D), white fluorescent light (FL), full-spectrum LED (FS), and red-blue (RB) light. Potential changes in the antioxidant content of sprouts were evaluated. Part of the sprouts was left to grow at FL, FS, and RB light regimes for 24 days to assess modifications in plants' anatomical and physiological traits during the early developmental plant stage. The seed pre-treatment with all biostimulant concentrations significantly increased sprout antioxidant compounds, sugar, and protein content compared to the control (seeds treated with H₂O). The positive effect on bioactive compounds was improved under FS and RB compared to D and FL light regimes. At the seedling stage, 0.05% was the only concentration of biostimulant effective in increasing the specific leaf area (SLA) and photosynthetic efficiency. Compared to FL, the growth under FS and RB light regimes significantly enhanced the beneficial effect of 0.05% on SLA and photosynthesis. This concentration led to leaf thickness increase and shoot/root ratio reduction. Our findings demonstrated that seed pre-treatment with proper biostimulant concentration in combination with specific light regimes during plant development may represent a useful means to modify the bioactive compound amount and leaf structural and photosynthetic traits.

Wuxal amino (Bio stimulant) improved growth and physiological performance of tomato plants under salinity stress through adaptive mechanisms and antioxidant potential

In the present study, ameliorative capabilities of wuxal amino (bio stimulant) under salt stress has been investigated through adaptive mechanisms and antioxidant potential in tomato plants. In the experiment, two different concentrations (2 cm L^-1 and 3 cm L^-1) of wuxal amino through foliar application and soil irrigation were applied to the salt (150 mM) treated tomato plants and then morphological traits, photosynthetic pigments, osmolytes, secondary metabolites, oxidative stress and antioxidant enzymes activity were assessed at 60 days after planting. The results revealed that salt stress decreased the growth parameters, photosynthetic pigments, soluble sugars and soluble protein whereas, content of proline, ascorbic acid, total phenols, malondialdehyde, hydrogen peroxide and the activity of antioxidant enzymes activity increased under salt stress. Moreover, Wuxal amino application through foliar or soil to salt stressed plants improved morphological traits, photosynthetic pigments, osmolytes, total phenol and antioxidant enzymes activity. Interestingly, the deleterious impact of salinity on tomato plants were significantly reduced and it can be evident from reduced MDA and H₂O₂ levels. These responses varied with the mode (foliar or soil) of application of Wuxal amino under different concentrations (2 cm L^-1 and 3 cm L^-1). It was concluded that application of Wuxal amino (2 cm L^-1, foliar) and (3 cm L^-1; soil) proved best and could be commercially used as eco-friendly tool for the protection of tomato plants grown under salinity stress.

Effect of Botanical Extracts on the Growth and Nutritional Quality of Field-Grown White Head Cabbage (Brassica oleracea var. capitata)

Nutraceuticals and functional foods are gaining more attention amongst consumers interested in nutritious food. The consumption of foodstuffs with a high content of phytochemicals has been proven to provide various health benefits. The application of biostimulants is a potential strategy to fortify cultivated plants with beneficial bioactive compounds. Nevertheless, it has not yet been established whether the proposed higher plants (St. John’s wort, giant goldenrod, common dandelion, red clover, nettle, and valerian) are appropriate for the production of potential bio-products enhancing the nutritional value of white cabbage. Therefore, this research examines the impact of botanical extracts on the growth and nutritional quality of cabbage grown under field conditions. Two extraction methods were used for the production of water-based bio-products, namely: ultrasound-assisted extraction and mechanical homogenisation. Bio-products were applied as foliar sprays to evaluate their impact on total yield, dry weight, photosynthetic pigments, polyphenols, antioxidant activity, vitamin C, nitrates, micro- and macroelements, volatile compounds, fatty acids, sterols, and sugars. Botanical extracts showed different effects on the examined parameters. The best results in terms of physiological and biochemical properties of cabbage were obtained for extracts from common dandelion, valerian, nettle, and giant goldenrod. When enriched with nutrients, vegetables can constitute a valuable component of functional food.

A Beginner's Guide to Osmoprotection by Biostimulants

Water is indispensable for the life of any organism on Earth. Consequently, osmotic stress due to salinity and drought is the greatest threat to crop productivity. Ongoing climate change includes rising temperatures and less precipitation over large areas of the planet. This is leading to increased vulnerability to the drought conditions that habitually threaten food security in many countries. Such a scenario poses a daunting challenge for scientists: the search for innovative solutions to save water and cultivate under water deficit. A search for formulations including biostimulants capable of improving tolerance to this stress is a promising specific approach. This review updates the most recent state of the art in the field.