Transcriptome Analyses and Antioxidant Activity Profiling Reveal the Role of a Lignin-Derived Biostimulant Seed Treatment in Enhancing Heat Stress Tolerance in Soybean

Green-synthesized lignin nanoparticles enhance Zea mays resilience to salt stress by improving antioxidant metabolism and mitigating ultrastructural damage

Soil salinity poses a substantial threat to agricultural productivity, resulting in far-reaching consequences. Green-synthesized lignin nanoparticles (LNPs) have emerged as significant biopolymers which effectively promote sustainable crop production and enhance abiotic stress tolerance. However, the defensive role and underlying mechanisms of LNPs against salt stress in Zea mays remain unexplored. The present study aims to elucidate two aspects: firstly, the synthesis of lignin nanoparticles from alkali lignin, which were characterized using Field Emission Scanning Electron Microscopy (FE-SEM), Transmission Electron Microscopy (TEM), Fourier Infrared Spectroscopy (FT-IR) and Energy Dispersive X-Ray Spectroscopy (EDX). The results confirmed the purity and morphology of LNPs. Secondly, the utilization of LNPs (200 mg/L) in nano priming to alleviate the adverse effects of NaCl (150 mM) on Zea mays seedlings. LNPs significantly reduced the accumulation of Na+ (17/21%) and MDA levels (21/28%) in shoots/roots while increased lignin absorption (30/31%), resulting in improved photosynthetic performance and plant growth. Moreover, LNPs substantially improved plant biomass, antioxidant enzymatic activities and upregulated the expression of salt-tolerant genes (ZmNHX3 (1.52 & 2.81 FC), CBL (2.83 & 3.28 FC), ZmHKT1 (2.09 & 4.87 FC) and MAPK1 (3.50 & 2.39 FC) in both shoot and root tissues. Additionally, SEM and TEM observations of plant tissues confirmed the pivotal role of LNPs in mitigating NaCl-induced stress by reducing damages to guard cells, stomata and ultra-cellular structures. Overall, our findings highlight the efficacy of LNPs as a practical and cost-effective approach to alleviate NaCl-induced stress in Zea mays plants. These results offer a sustainable agri-environmental strategy for mitigating salt toxicity and enhancing crop production in saline environments.

Biostimulants: A sufficiently effective tool for sustainable agriculture in the era of climate change?

Climate change is currently considered as one of the main concerns of the agriculture sector, as it limits crop production and quality. Furthermore, the current context of global crisis with international political instability and war conflicts over the world is pushing the agriculture sector even more to urgently boost productivity and yield and doing so in a sustainable way in the current frame of climate change. Biostimulants can be an effective tool in alleviating the negative effects of environmental stresses to which plants are exposed, such as drought, salinity, heavy metals and extreme temperatures etc. Biostimulants act through multiple mechanisms, modifying gene expression, metabolism and phytohormone production, promoting the accumulation of compatible solutes and antioxidants and mitigating oxidative stress. However, it is important to keep in mind that the use and effect of biostimulants has limitations and must be accompanied by other techniques to ensure crop yield and quality in the current frame of climate change, such as proper crop management and the use of other sustainable resources. Here, we will not only highlight the potential use of biostimulants to face future agricultural challenges, but also take a critical look at their limitations, underlining the importance of a broad vision of sustainable agriculture in the context of climate change.

Plant-Based Biostimulants for Seeds in the Context of Circular Economy and Sustainability

Plant-based biostimulants (PBs), agents rich in bioactive compounds, are emerging as key players able to sustainably improve plant growth and crop productivity to address food security. PBs are generally applied as foliar spray or soil irrigation, while more recently, the application as seed priming treatments is being envisaged as a highly sustainable method to also improve seed quality and germination. Therefore, this review proposes to explore the use of PBs for the seeds industry, specifically discussing about the relevance of product market values, sustainable methods for their production, why and how PBs are used for seed priming, and pinpointing specific strengths and challenges. The collected research studies indicate that PBs applied to seeds result in improved germination, seedling growth, and stress tolerance, although the molecular mechanisms at work are still largely overlooked. The high variability of bioactive molecules and used sources point towards a huge reservoir of nature-based solutions in support of sustainable agriculture practices.

Plant breeding for harmony between sustainable agriculture, the environment, and global food security: an era of genomics-assisted breeding

MAIN CONCLUSION

Genomics-assisted breeding represents a crucial frontier in enhancing the balance between sustainable agriculture, environmental preservation, and global food security. Its precision and efficiency hold the promise of developing resilient crops, reducing resource utilization, and safeguarding biodiversity, ultimately fostering a more sustainable and secure food production system. Agriculture has been seriously threatened over the last 40 years by climate changes that menace global nutrition and food security. Changes in environmental factors like drought, salt concentration, heavy rainfalls, and extremely low or high temperatures can have a detrimental effects on plant development, growth, and yield. Extreme poverty and increasing food demand necessitate the need to break the existing production barriers in several crops. The first decade of twenty-first century marks the rapid development in the discovery of new plant breeding technologies. In contrast, in the second decade, the focus turned to extracting information from massive genomic frameworks, speculating gene-to-phenotype associations, and producing resilient crops. In this review, we will encompass the causes, effects of abiotic stresses and how they can be addressed using plant breeding technologies. Both conventional and modern breeding technologies will be highlighted. Moreover, the challenges like the commercialization of biotechnological products faced by proponents and developers will also be accentuated. The crux of this review is to mention the available breeding technologies that can deliver crops with high nutrition and climate resilience for sustainable agriculture.

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.

Improvement of heat stress tolerance in soybean (Glycine max L), by using conventional and molecular tools

The soybean is a significant legume crop, providing several vital dietary components. Extreme heat stress negatively affects soybean yield and quality, especially at the germination stage. Continuous change in climatic conditions is threatening the global food supply and food security. Therefore, it is a critical need of time to develop heat-tolerant soybean genotypes. Different molecular techniques have been developed to improve heat stress tolerance in soybean, but until now complete genetic mechanism of soybean is not fully understood. Various molecular methods, like quantitative trait loci (QTL) mapping, genetic engineering, transcription factors (TFs), transcriptome, and clustered regularly interspaced short palindromic repeats (CRISPR), are employed to incorporate heat tolerance in soybean under the extreme conditions of heat stress. These molecular techniques have significantly improved heat stress tolerance in soybean. Besides this, we can also use specific classical breeding approaches and different hormones to reduce the harmful consequences of heat waves on soybean. In future, integrated use of these molecular tools would bring significant results in developing heat tolerance in soybean. In the current review, we have presented a detailed overview of the improvement of heat tolerance in soybean and highlighted future prospective. Further studies are required to investigate different genetic factors governing the heat stress response in soybean. This information would be helpful for future studies focusing on improving heat tolerance in soybean.

Combining metabolite doping and metabolic engineering to improve 2-phenylethanol production by engineered cyanobacteria

2-Phenylethanol (2-PE) is a rose-scented aromatic compound, with broad application in cosmetic, pharmaceutical, food and beverage industries. Many plants naturally synthesize 2-PE via Shikimate Pathway, but its extraction is expensive and low-yielding. Consequently, most 2-PE derives from chemical synthesis, which employs petroleum as feedstock and generates unwanted by products and health issues. The need for “green” processes and the increasing public demand for natural products are pushing biotechnological production systems as promising alternatives. So far, several microorganisms have been investigated and engineered for 2-PE biosynthesis, but a few studies have focused on autotrophic microorganisms. Among them, the prokaryotic cyanobacteria can represent ideal microbial factories thanks to their ability to photosynthetically convert CO2 into valuable compounds, their minimal nutritional requirements, high photosynthetic rate and the availability of genetic and bioinformatics tools. An engineered strain of Synechococcus elongatus PCC 7942 for 2-PE production, i.e., p120, was previously published elsewhere. The strain p120 expresses four heterologous genes for the complete 2-PE synthesis pathway. Here, we developed a combined approach of metabolite doping and metabolic engineering to improve the 2-PE production kinetics of the Synechococcus elongatus PCC 7942 p120 strain. Firstly, the growth and 2-PE productivity performances of the p120 recombinant strain were analyzed to highlight potential metabolic constraints. By implementing a BG11 medium doped with L-phenylalanine, we covered the metabolic burden to which the p120 strain is strongly subjected, when the 2-PE pathway expression is induced. Additionally, we further boosted the carbon flow into the Shikimate Pathway by overexpressing the native Shikimate Kinase in the Synechococcus elongatus PCC 7942 p120 strain (i.e., 2PE_aroK). The combination of these different approaches led to a 2-PE yield of 300 mg/gDW and a maximum 2-PE titer of 285 mg/L, 2.4-fold higher than that reported in literature for the p120 recombinant strain and, to our knowledge, the highest recorded for photosynthetic microorganisms, in photoautotrophic growth condition. Finally, this work provides the basis for further optimization of the process aimed at increasing 2-PE productivity and concentration, and could offer new insights about the use of cyanobacteria as appealing microbial cell factories for the synthesis of aromatic compounds.

Rhizobium inoculation and exogenous melatonin synergistically increased thermotolerance by improving antioxidant defense, photosynthetic efficiency, and nitro-oxidative homeostasis in Medicago truncatula

Global warming negatively affects plant growth due to the detrimental effects of high temperature-induced heat stress. Rhizobium inoculation (RI) and exogenous melatonin (MT) have shown a positive role in resisting abiotic stress. However, their synergistic effect on avoiding heat-induced damages in Medicago truncatula has not been studied yet. Hence, the objective of the present study was to evaluate the impact of these amendments (RI and MT) to ameliorate the heat damages in Medicago truncatula. The study was comprised of two factors: (1) heat-induced stress: (i) optimum temperature (26 ± 1°C): (23 ± 1°C) (day: night), (ii) moderate heat (35 ± 1°C): (28 ± 1°C), and (iii) severe heat (41 ± 1°C): (35 ± 1°C) for 72 h, and (2) amendments: (i) no RI + no MT (NRI + NMT), (ii) Rhizobium inoculation (RI), (iii) 60 μM melatonin (MT), and (iii) RI + MT. Results showed that the combined application of RI and MT was better than their individual applications, as it prevented heat-induced membrane damages by declining the hydrogen peroxide (34.22% and 29.78%), superoxide anion radical (29.49% and 26.71%), malondialdehyde contents (26.43% and 21.96%), and lipoxygenase activity (44.75% and 25.51%) at both heat stress levels as compared to NRI + NMT. Moreover, RI + MT treated plants showed higher antioxidative and methylglyoxal detoxification enzymes (Gly I and Gly II) activities under heat stress. While, NRI + NMT treated plants showed a higher level of methylglyoxal contents (47.99% and 46.71%) under both levels of heat stress. Relative to NRI + NMT plants, RI + MT pretreated plants exhibited improved heat tolerance as indicated by higher chlorophyll (37.42% and 43.52%), carotenoid contents (32.41% and 47.08%), and photosynthetic rate (42.62% and 64.63%), under moderate and severe heat stress, respectively. Furthermore, RI + MT pretreated plants had considerably higher indole-3 acetic acid and abscisic acid concentrations under moderate (54.02% and 53.92%) and severe (68.36% and 64.61%) heat stress conditions. Similarly, plant dry biomass, NPK uptake, nitric oxide, and nitrate reductase activity were high in RI + MT treated plants, under both levels of stress. Therefore, this study advocates the positive synergistic effect of RI and MT pretreatment against moderate and severe heat-induced stress and for possible maintenance of plant growth under changing scenarios of global warming.

Bioactive Compounds and Antioxidant Properties with Involved Mechanisms of Eugenia involucrata DC Fruits

In this study, the phytochemical profile and the antioxidative properties of Eugenia involucrata fruits were evaluated. Spectrophotometric assays indicated that these berries are a rich source of polyphenols with very high radical-scavenging and metal-reducing activities. High-performance liquid chromatography–Orbitrap analysis was able to carry out the annotation of 36 different compounds, mainly belonging to the flavonol, flavan-3-ol, and anthocyanin families. Antioxidant activity of the fruit extract was evaluated in a cell-based lipid peroxidation model. Obtained data showed that the extract, at very low concentration, was able to prevent oxidative damage in HepG2 cells exposed to oxidative stimuli. Moreover, the evaluation of the gene expression of the most important antioxidant enzymes suggested that the observed antioxidant protection in cells also involves an improvement in enzymatic antioxidant defenses. Finally, the collected data show that E. involucrata fruits are a good source of natural antioxidant molecules and provide evidence of their potential application in the nutraceutical field.

Phytochemical Profile and Antioxidant, Antiproliferative, and Antimicrobial Properties of Rubus idaeus Seed Powder

In the context of the contemporary research on sustainable development and circular economy, the quest for effective strategies aimed at revaluation of waste and by-products generated in industrial and agricultural production becomes important. In this work, an ethanolic extract from red raspberry (Rubus idaeus) seed waste (WRSP) was evaluated for its phytochemical composition and functional properties in term of antioxidative, antiproliferative, and antimicrobial activities. Chemical composition of the extract was determined by both HPLC-ESI-MS/MS and spectrophotometric methods. Phytochemical analysis revealed that flavan-3-ols and flavonols were the major phenolic compounds contained in WRSP. The extract demonstrated very high radical-scavenging (4.86 ± 0.06 µmol TE/DW) and antioxidant activity in a cell-based model (0.178 ± 0.03 mg DW/mL cell medium). The WRSP extract also exhibited antiproliferative activity against three different epithelial cancer cell lines (MCF-7, HepG2, and HeLa cells) in a dose-dependent manner. Finally, microbiological assays showed the absence of colonies of bacteria and microscopic fungi (yeasts and molds) and revealed that the WRSP extract has a large inhibition spectrum against spoilage and pathogenic bacteria, without inhibitory activity against pro-technological bacteria. In conclusion, the obtained results show that WRSP is a rich source of phytochemical compounds exerting interesting biological activities. For these reasons WRSP could find applications in the nutritional, nutraceutical, and pharmacological fields.

Growth-Promoting Endophytic Fungus (Stemphylium lycopersici) Ameliorates Salt Stress Tolerance in Maize by Balancing Ionic and Metabolic Status

Climate change is a major cause of the world's food security problems, and soil salinity is a severe hazard for a variety of crops. The exploitation of endophytic fungi that are known to have a positive association with plant roots is preferred for improving plant growth, yield, and overall performance under salt stress. The current study thus rationalized to address how salt stress affected the growth, biochemical properties, antioxidant capacity, endogenous indole-3-acetic acid (IAA), and the ionic status of maize associated with endophytic fungus (Stemphylium lycopersici). According to the findings, salt stress reduced chlorophyll a and b, total chlorophyll, total protein, sugars, lipids, and endogenous IAA levels. Enhanced values of chlorophyll a/b ratio, carotenoids, secondary metabolites (phenol, flavonoids, and tannins), antioxidant enzyme activity (catalase, ascorbate peroxidase), proline, and lipid peroxidation were noticed in maize plants under salt stress. Increased ionic content of Na+, Cl-, Na+/K+, and Na+/Ca2+ ratio, as well as decreased Ca2+, K+, Mg2+, N, and P contents, were also found in salt-stressed maize plants. In comparison to the non-saline medium, endophytic association promoted the antioxidant enzyme activities (798.7 U/g protein; catalase activity, 106 U/g protein; ascorbate peroxidase activity), IAA content (3.47 mg/g FW), and phenolics and flavonoids (88 and 1.68 μg/g FW, respectively), and decreased MDA content (0.016 nmol/g FW), Na+ ion content (18 mg/g dry weight), Cl- ion (16.6 mg/g dry weight), and Na+/K+ (0.78) and Na+/Ca2+ (1.79) ratios, in maize plants under salt stress, whereas Ca2+, K+, Mg2+, N, and P contents were increased in maize plants associated with S. lycopersici under salt stress. Current research exposed the role of S. lycopersici as an effective natural salt stress reducer and maize growth promoter; hence, it can be used as a biofertilizer to ameliorate salt stress tolerance in crops along with better growth performance in saline regions.

Can Agri-Food Waste Be a Sustainable Alternative in Aquaculture? A Bibliometric and Meta-Analytic Study on Growth Performance, Innate Immune System, and Antioxidant Defenses

The agri-food industry generates a large amount of waste every year, which is both an environmental and economic problem, especially for the countries in charge of its disposal. Over the years, there has been a growing interest especially in plant waste, since they are rich in compounds with high nutritional and nutraceutical value. As a result, several scientific disciplines are investigating their alternative use in the formulation of dietary supplements for human or animal use, or as biostimulants for agricultural purposes. In this review, using a meta-analytical approach, we summarize the main and most recent findings related to the use of plant waste as potential ingredients in dietary supplementation for fish grown under controlled experimental conditions. In particular, in this review, it has been highlighted that plant waste may have not only positive effects on growth performance, but also beneficial effects on modulation of the innate immune system and antioxidant defenses. Finally, the bibliometric study and a mapping provide an overview of the recent publications, showing the research strength across the country, the number of potential collaborations among institutions, and the main research focus, demonstrating how this topic is growing in interest, especially in Europe.

Strategies and prospects for biostimulants to alleviate abiotic stress in plants

Global climate change-induced abiotic stresses (e.g., drought, salinity, extreme temperatures, heavy metals, and UV radiation) have destabilized the fragile agroecosystems and impaired plant performance and thereby reducing crop productivity and quality. Biostimulants, as a promising and eco-friendly approach, are widely used to address environmental concerns and fulfill the need for developing sustainable/modern agriculture. Current knowledge revealed that plant and animal derived stimulants (e.g., seaweeds and phytoextracts, humic substances, and protein hydrolysate) as well as microbial stimulants (e.g., plant beneficial bacteria or fungi) have great potential to elicit plant tolerance to various abiotic stresses and thus enhancing plant growth and performance-related parameters (such as root growth/diameter, flowering, nutrient use efficiency/translocation, soil water holding capacity, and microbial activity). However, to successfully implement biostimulant-based agriculture in the field under changing climate, the understanding of agricultural functions and action mechanism of biostimulants coping with various abiotic stresses at physicochemical, metabolic, and molecular levels is needed. Therefore, this review attempts to unravel the underlying mechanisms of action mediated by diverse biostimulants in relation to abiotic stress alleviation as well as to discuss the current challenges in their commercialization and implementation in agriculture under changing climate conditions.

R, Choudhary AK, Salam MD, Sahoo MR, Bhutia TL, Devi SH, Thounaojam AS, Behera C, M. N. H, Kumar A, Dasgupta M, Devi YP, Singh D, Bhagowati S, Devi CP, Singh HR, Khaba CI. Role of biostimulants in mitigating the effects of climate change on crop performance

Climate change is a critical yield-limiting factor that has threatened the entire global crop production system in the present scenario. The use of biostimulants in agriculture has shown tremendous potential in combating climate change-induced stresses such as drought, salinity, temperature stress, etc. Biostimulants are organic compounds, microbes, or amalgamation of both that could regulate plant growth behavior through molecular alteration and physiological, biochemical, and anatomical modulations. Their nature is diverse due to the varying composition of bioactive compounds, and they function through various modes of action. To generate a successful biostimulatory action on crops under different parameters, a multi-omics approach would be beneficial to identify or predict its outcome comprehensively. The 'omics' approach has greatly helped us to understand the mode of action of biostimulants on plants at cellular levels. Biostimulants acting as a messenger in signal transduction resembling phytohormones and other chemical compounds and their cross-talk in various abiotic stresses help us design future crop management under changing climate, thus, sustaining food security with finite natural resources. This review article elucidates the strategic potential and prospects of biostimulants in mitigating the adverse impacts of harsh environmental conditions on plants.

Adaptation Strategies to Improve the Resistance of Oilseed Crops to Heat Stress Under a Changing Climate: An Overview

Temperature is one of the decisive environmental factors that is projected to increase by 1. 5°C over the next two decades due to climate change that may affect various agronomic characteristics, such as biomass production, phenology and physiology, and yield-contributing traits in oilseed crops. Oilseed crops such as soybean, sunflower, canola, peanut, cottonseed, coconut, palm oil, sesame, safflower, olive etc., are widely grown. Specific importance is the vulnerability of oil synthesis in these crops against the rise in climatic temperature, threatening the stability of yield and quality. The natural defense system in these crops cannot withstand the harmful impacts of heat stress, thus causing a considerable loss in seed and oil yield. Therefore, a proper understanding of underlying mechanisms of genotype-environment interactions that could affect oil synthesis pathways is a prime requirement in developing stable cultivars. Heat stress tolerance is a complex quantitative trait controlled by many genes and is challenging to study and characterize. However, heat tolerance studies to date have pointed to several sophisticated mechanisms to deal with the stress of high temperatures, including hormonal signaling pathways for sensing heat stimuli and acquiring tolerance to heat stress, maintaining membrane integrity, production of heat shock proteins (HSPs), removal of reactive oxygen species (ROS), assembly of antioxidants, accumulation of compatible solutes, modified gene expression to enable changes, intelligent agricultural technologies, and several other agronomic techniques for thriving and surviving. Manipulation of multiple genes responsible for thermo-tolerance and exploring their high expressions greatly impacts their potential application using CRISPR/Cas genome editing and OMICS technology. This review highlights the latest outcomes on the response and tolerance to heat stress at the cellular, organelle, and whole plant levels describing numerous approaches applied to enhance thermos-tolerance in oilseed crops. We are attempting to critically analyze the scattered existing approaches to temperature tolerance used in oilseeds as a whole, work toward extending studies into the field, and provide researchers and related parties with useful information to streamline their breeding programs so that they can seek new avenues and develop guidelines that will greatly enhance ongoing efforts to establish heat stress tolerance in oilseeds.

Melatonin and Phytomelatonin: Chemistry, Biosynthesis, Metabolism, Distribution and Bioactivity in Plants and Animals-An Overview

Melatonin is a ubiquitous indolamine, largely investigated for its key role in the regulation of several physiological processes in both animals and plants. In the last century, it was reported that this molecule may be produced in high concentrations by several species belonging to the plant kingdom and stored in specialized tissues. In this review, the main information related to the chemistry of melatonin and its metabolism has been summarized. Furthermore, the biosynthetic pathway characteristics of animal and plant cells have been compared, and the main differences between the two systems highlighted. Additionally, in order to investigate the distribution of this indolamine in the plant kingdom, distribution cluster analysis was performed using a database composed by 47 previously published articles reporting the content of melatonin in different plant families, species and tissues. Finally, the potential pharmacological and biostimulant benefits derived from the administration of exogenous melatonin on animals or plants via the intake of dietary supplements or the application of biostimulant formulation have been largely discussed.

Anti-Cancer Activity and Phenolic Content of Extracts Derived from Cypriot Carob (Ceratonia siliqua L.) Pods Using Different Solvents

Extracts derived from the Ceratonia siliqua L. (carob) tree have been widely studied for their ability to prevent many diseases mainly due to the presence of polyphenolic compounds. In this study, we explored, for the first time, the anti-cancer properties of Cypriot carobs. We produced extracts from ripe and unripe whole carobs, pulp and seeds using solvents with different polarities. We measured the ability of the extracts to inhibit proliferation and induce apoptosis in cancer and normal immortalized breast cells, using the MTT assay, cell cycle analysis and Western Blotting. The extracts’ total polyphenol content and anti-oxidant action was evaluated using the Folin–Ciocalteu method and the DPPH assay. Finally, we used LC-MS analysis to identify and quantify polyphenols in the most effective extracts. Our results demonstrate that the anti-proliferative capacity of carob extracts varied with the stage of carob maturity and the extraction solvent. The Diethyl-ether and Ethyl acetate extracts derived from the ripe whole fruit had high Myricetin content and also displayed specific activity against cancer cells. Their mechanism of action involved caspase-dependent and independent apoptosis. Our results indicate that extracts from Cypriot carobs may have potential uses in the development of nutritional supplements and pharmaceuticals.

Microbial Biostimulants as Response to Modern Agriculture Needs: Composition, Role and Application of These Innovative Products

An increasing need for a more sustainable agriculturally-productive system is required in order to preserve soil fertility and reduce soil biodiversity loss. Microbial biostimulants are innovative technologies able to ensure agricultural yield with high nutritional values, overcoming the negative effects derived from environmental changes. The aim of this review was to provide an overview on the research related to plant growth promoting microorganisms (PGPMs) used alone, in consortium, or in combination with organic matrices such as plant biostimulants (PBs). Moreover, the effectiveness and the role of microbial biostimulants as a biological tool to improve fruit quality and limit soil degradation is discussed. Finally, the increased use of these products requires the achievement of an accurate selection of beneficial microorganisms and consortia, and the ability to prepare for future agriculture challenges. Hence, the implementation of the microorganism positive list provided by EU (2019/1009), is desirable.

Lignin Nanoparticles: A Promising Tool to Improve Maize Physiological, Biochemical, and Chemical Traits

Lignin, and its derivatives, are the subject of current research for the exciting properties shown by this biomass. Particularly attractive are lignin nanoparticles for their eco- and biocompatibility compared to other nanomaterials. In this context, the effect of nanostructured lignin microparticles (LNP), obtained from alkaline lignin by acid treatment, on maize plants was investigated. To this end, maize seeds were primed with LNP at five concentrations: 80 mg L-1 (T80), 312 mg L-1 (T312), 1250 mg L-1 (T1250), 5000 mg L-1 (T5000) and 20,000 mg L-1 (T20000). Concerning the dose applied, LNP prompted positive effects on the first stages of maize development (germination and radicle length). Furthermore, the study of plant growth, biochemical and chemical parameters on the developed plants indicated that concerning the dose applied. LNP stimulated beneficial effects on the seedlings (fresh weight and length of shoots and roots). Besides, specific treatments increased the content of chlorophyll (a and b), carotenoid, and anthocyanin. Finally, the soluble protein content showed a positive trend in response to specific dosages. These effects are significant, given the essential biological function performed by these biomolecules. In conclusion, this research indicates as the nanostructured lignin microparticles can be used, at appropriate dosages, to induce positive biological responses in maize. This beneficial action deserves attention as it candidates LNP for biostimulating a crop through seed priming.

Bioactive Triterpenes of Protium heptaphyllum Gum Resin Extract Display Cholesterol-Lowering Potential

Hypercholesterolemia is one of the major causes of cardiovascular disease, the risk of which is further increased if other forms of dyslipidemia occur. Current therapeutic strategies include changes in lifestyle coupled with drug administration. Statins represent the most common therapeutic approach, but they may be insufficient due to the onset of resistance mechanisms and side effects. Consequently, patients with mild hypercholesterolemia prefer the use of food supplements since these are perceived to be safer. Here, we investigate the phytochemical profile and cholesterol-lowering potential of Protium heptaphyllum gum resin extract (PHE). Chemical characterization via HPLC-APCI-HRMS² and GC-FID/MS identified 13 compounds mainly belonging to ursane, oleanane, and tirucallane groups. Studies on human hepatocytes have revealed how PHE is able to reduce cholesterol production and regulate the expression of proteins involved in its metabolism. (HMGCR, PCSK9, LDLR, FXR, IDOL, and PPAR). Moreover, measuring the inhibitory activity of PHE against HMGR, moderate inhibition was recorded. Finally, molecular docking studies identified acidic tetra- and pentacyclic triterpenoids as the main compounds responsible for this action. In conclusion, our study demonstrates how PHE may be a useful alternative to contrast hypercholesterolemia, highlighting its potential as a sustainable multitarget natural extract for the nutraceutical industry that is rapidly gaining acceptance as a source of health-promoting compounds.

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.

The application of a biostimulant based on tannins affects root architecture and improves tolerance to salinity in tomato plants

Roots have important roles for plants to withstand adverse environmental conditions, including salt stress. Biostimulant application was shown to enhance plant resilience towards abiotic stresses. Here, we studied the effect of a tannin-based biostimulant on tomato (Solanum lycopersicum L.) grown under salt stress conditions. We investigated the related changes at both root architecture (via imaging and biometric analysis) and gene expression (RNA-Seq/qPCR) levels. Moreover, in order to identify the main compounds potentially involved in the observed effects, the chemical composition of the biostimulant was evaluated by UV/Vis and HPLC-ESI-Orbitrap analysis. Sixteen compounds, known to be involved in root development and having a potential antioxidant properties were identified. Significant increase of root weight (+ 24%) and length (+ 23%) was observed when the plants were grown under salt stress and treated with the biostimulant. Moreover, transcriptome analysis revealed that the application of the biostimulant upregulated 285 genes, most of which correlated to root development and salt stress tolerance. The 171 downregulated genes were mainly involved in nutrient uptake. These data demonstrated that the biostimulant is able not only to restore root growth in salty soils, but also to provide the adequate plant nourishment by regulating the expression of essential transcription factors and stress responsive genes.

The Application of a Plant Biostimulant Based on Seaweed and Yeast Extract Improved Tomato Fruit Development and Quality

Plant biostimulants are under investigation as innovative products to improve plant production and fruit quality, without resulting in environmental and food contaminations. Here, the effects of the application of Expando, a biostimulant based on seaweed and yeast extracts, on plant productivity, fruit ripening times, and fruit quality of Solanum lycopersicum var. Micro-Tom were evaluated. After biostimulant treatment, a two-week reduction of ripening times and a concomitant enhancement of the production percentage during the earliest ripening times, in terms of both fruit yield (+110%) and size (+85%), were observed. Concerning fruit quality, proximate analysis showed that tomatoes treated with the biostimulant had better nutritional composition compared to untreated samples, since both the quality of unsatured fatty acids (C16:3ω3: +328%; C18:2ω6: -23%) and micronutrients essential for human health (Fe: +14%; Cu: +21%; Zn: +24%) were increased. From a nutraceutical point of view, despite strong changes in bioactive compound profile not being observed, an increase of the antioxidant properties was recorded in fruits harvested by plants treated with the biostimulant (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS): +38%; 2,2-diphenyl-1-picrylhydrazyl (DPPH): +11%). In conclusion, the biostimulant application was able to reduce the ripening times and fruit size, while slightly increasing nutritional and nutraceutical values, leading to more marketable tomato fruits.