Functional Characterization of Lobularia maritima LmTrxh2 Gene Involved in Cold Tolerance in Tobacco through Alleviation of ROS Damage to the Plasma Membrane.

Cold stress is a key environmental factor affecting plant growth and development, crop productivity, and geographic distribution. Thioredoxins (Trxs) are small proteins that are ubiquitously expressed in all organisms and implicated in several cellular processes, including redox reactions. However, their role in the regulation of cold stress in the halophyte plant Lobularia maritima remains unknown. We recently showed that overexpression of LmTrxh2, which is the gene that encodes the h-type Trx protein previously isolated from L. maritima, led to an enhanced tolerance to salt and osmotic stress in transgenic tobacco. This study functionally characterized the LmTrxh2 gene via its overexpression in tobacco and explored its cold tolerance mechanisms. Results of the RT-qPCR and western blot analyses indicated differential temporal and spatial regulation of LmTrxh2 in L. maritima under cold stress at 4 °C. LmTrxh2 overexpression enhanced the cold tolerance of transgenic tobacco, as evidenced by increased germination rate, fresh weight and catalase (CAT), superoxide dismutase (SOD) and peroxidase (POD) activities; reduced malondialdehyde levels, membrane leakage, superoxide anion (O2-), and hydrogen peroxide (H2O2) levels; and higher retention of chlorophyll than in non-transgenic plants (NT). Furthermore, the transcript levels of reactive oxygen species (ROS)-related genes (NtSOD and NtCAT1), stress-responsive late embryogenis abundant protein 5 (NtLEA5), early response to dehydration 10C (NtERD10C), DRE-binding proteins 1A (NtDREB1A), and cold-responsive (COR) genes (NtCOR15A, NtCOR47, and NtKIN1) were upregulated in transgenic lines compared with those in NT plants under cold stress, indicating that LmTrxh2 conferred cold stress tolerance by enhancing the ROS scavenging ability of plants, thus enabling them to maintain membrane integrity. These results suggest that LmTrxh2 promotes cold tolerance in tobacco and provide new insight into the improvement of cold-stress resistance to cold stress in non-halophyte plants and crops.

Lobularia maritima leave extract, a nutraceutical agent with antioxidant activity, protects against CCl4-induced liver injury in mice.

Lobularia maritima (Alyssum maritimum, Brassicaceae), commonly known as sweet alyssum, is an annual ornamental halophyte widely spread along the Tunisian seashore. Lobularia maritima leaf ethanol extract was tested in an experimental model of hepatotoxicity induced by carbon tetrachloride (CCl4). L. maritima extract was found to possess in vitro antioxidant activity by scavenging the DPPH radical (IC50= 45 µg/mL), reducing/chelating iron ions and inhibiting liver lipid peroxidation induced by FeSO4. The levels of total phenolics and flavonoids were 175 ± 2.66 mg GAE/g, and 35 ± 2.88 mg QE/g respectively. Moreover, HPLC analysis revealed six compounds, namely gallic, salicylic, ellagic and ferulic acids as well as catechin and quercetin. A mice model of acute liver injury was successfully established after a single intraperitoneal injection of CCl4, as evidenced by histological analysis, Masson trichrome and Sirius red staining. Compared with the CCl4 intoxicated group, the L. maritima treatment resulted to reduce the liver serum marker enzymes, lipid peroxidation and increased the activities of antioxidant enzymes with further amelioration in the oxidative stress. The present findings discover the therapeutic potentials of L. maritima empowered with promising natural leads for the treatment of oxidative stress associated health disorders by attenuating free radicals, inhibiting lipid peroxidation, and upregulating the tissue-specific antioxidant enzymes.

Novel non-specific lipid-transfer protein (TdLTP4) isolated from durum wheat: Antimicrobial activities and anti-inflammatory properties in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages.

Lipid transfer proteins (LTP) are members of the family of pathogenesis-related proteins (PR-14) that play a key role in plant defense mechanisms. In this study, a novel gene TdLTP4 encoding an antifungal protein from wheat (cv. Om Rabiaa) was cloned, overexpressed in Escherichia coli BL-21 (DE3) and enriched using ammonium sulfate fractionation. The TdLTP4 fusion protein was then tested against a panel of pathogens, food-borne and spoilage bacteria and fungi in order to evaluate the antimicrobial properties. TdLTP4 was applied to 0.5 µg/mL LPS-induced RAW 264.7 macrophages in vitro at different concentrations (5, 10, 20, 50 and 100 µg/mL). Levels of nitric oxide (NO), pro-inflammatory cytokines interleukin (IL)-1ß (IL-1 ß), interleukin (IL)-6 (IL-6), tumor necrosis factor (TNF-α) and anti-inflammatory cytokine IL-10 in the supernatant fraction were measured using enzyme-linked immunosorbent assay (ELISA). Expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) were detected via Western blot. The inhibition zones and minimal inhibitory concentration (MIC) values of bacterial strains were in the range of 14-26 mm and 62.5-250 µg/mL, respectively. Moreover, a remarkable activity against several fungal strains was revealed. TdLTP4 (5-100 µg/mL) decreased the production of NO (IC50 = 4.32 µg/mL), IL-6 (IC50 = 11.52 µg/mL), IL-1ß (IC50 = 7.87 µg/mL) and TNF-α (IC50 = 8.66 µg/mL) by lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. TdLTP4 could modulate the macrophages inflammatory mode by causing reduction in iNOS and COX-2. According to these findings, TdLTP4 fusion protein could be used as natural anti-inflammatory and antimicrobial agent in food preservation and human health.

A novel Triticum durum Annexin 12 protein: Expression, purification and biological activities against Listeria monocytogenes growth in meat under refrigeration.

The present study was undertaken to investigate the expression, purification and biological activities of a novel Triticum durum Annexin 12 protein (TdAnn12). The findings indicated that the molecular weight of the purified TdAnn12 was estimated to 35 kDa. The purified TdAnn12 protein was modulated by, Methyl-jasmonate, and ethephon treatments. The purified TdAnn12 protein displayed good antimicrobial activities against 9 tested pathogenic bacteria. The antioxidant activities showed that TdAnn12 displayed an excellent DPPH scavenging ability with an IC50 of 8.33 µg/ml and a strong Beta-carotene bleaching inhibition after 120 min of incubation with an IC50 of 2 µg/ml the cytotoxic effects of the TdAnn 12 showed that HepG2 and MCF-7 were examined by MTT assay. The IC50 values were 250.35 and 400.25 µg/ml for HepG2 and MCF-7 cells, respectively. The inhibitory effects of this TdAnn12 was assessed in vivo against Listeria monocytogenes, inoculated in minced beef meat at 6.105 CFU/g amended with different concentrations of the purified TdAnn12 and stored at 4 °C for 21 days. Results showed an excellent inhibitory effect of TdAnn12 of this pathogenic bacterium at 4 °C. Overall, the TdAnn12 have potential application as active ingredients in food and pharmaceutical industry.

Potential anti-inflammatory and antioxidant effects of Citrus aurantium essential oil against carbon tetrachloride-mediated hepatotoxicity: A biochemical, molecular and histopathological changes in adult rats.

The present study aimed (1) to investigate the chemical composition as well as the anti-inflammatory properties and in vitro antioxidant activity of Citrus aurantium peel essential oil (pEOCa) and (2) to evaluate its potential effect in vivo. The main results showed that the major components of pEOCa are Limonene and Linalool. Additionally, DPPH scavenging ability and ß-carotene bleaching inhibition tests confirmed the antioxidant capacity of pEOCa. Our oil reduced the production of NO by LPS-stimulated RAW264,7 macrophages in a concentration-dependent. This inhibition occurred at a transcriptional level. pEOCa in CCl4 treated rats alleviated hepatotoxicity as monitored by the improvement of hepatic oxidative stress biomarkers levels plasma biochemical parameters, and DNA molecule aspect. Furthermore, the mRNA gene expression of Cu-Zn SOD, CAT, and GPx increased under CCl4 + pEOCa exposure to reach the same value to the control. Similarly, antioxidant activities of these three enzymes changed in accordance with the mRNA levels. These results were confirmed by the histological results. It seems obvious that the treatment with pEOCa prevented liver damage induced by CCl4 , thus preventing the harmful effects of free radicals.

Ectopic Expression of Aeluropus littoralis Plasma Membrane Protein Gene AlTMP1 Confers Abiotic Stress Tolerance in Transgenic Tobacco by Improving Water Status and Cation Homeostasis.

We report here the isolation and functional analysis of AlTMP1 gene encoding a member of the PMP3 protein family. In Aeluropus littoralis, AlTMP1 is highly induced by abscisic acid (ABA), cold, salt, and osmotic stresses. Transgenic tobacco expressing AlTMP1 exhibited enhanced tolerance to salt, osmotic, H2O2, heat and freezing stresses at the seedling stage. Under greenhouse conditions, the transgenic plants showed a higher level of tolerance to drought than to salinity. Noteworthy, AlTMP1 plants yielded two- and five-fold more seeds than non-transgenic plants (NT) under salt and drought stresses, respectively. The leaves of AlTMP1 plants accumulated lower Na⁺ but higher K⁺ and Ca2+ than those of NT plants. Tolerance to osmotic and salt stresses was associated with higher membrane stability, low electrolyte leakage, and improved water status. Finally, accumulation of AlTMP1 in tobacco altered the regulation of some stress-related genes in either a positive (NHX1, CAT1, APX1, and DREB1A) or negative (HKT1 and KT1) manner that could be related to the observed tolerance. These results suggest that AlTMP1 confers stress tolerance in tobacco through maintenance of ion homeostasis, increased membrane integrity, and water status. The observed tolerance may be due to a direct or indirect effect of AlTMP1 on the expression of stress-related genes which could stimulate an adaptive potential not present in NT plants.

The promoter of the AlSAP gene from the halophyte grass Aeluropus littoralis directs a stress-inducible expression pattern in transgenic rice plants.

KEY MESSAGE: When fused to " Pr AlSAP " promoter, transcripts of gusA exhibited similar accumulation patterns in transgenic rice as AlSAP transcripts in A. littoralis. Pr AlSAP can be used for engineering abiotic stress tolerance. We previously showed that ectopic expression of a stress-associated protein gene from Aeluropus littoralis (AlSAP) enhances tolerance to multiple abiotic stresses in tobacco, wheat and rice. The ortholog of AlSAP in rice is OsSAP9. Here, we demonstrate that AlSAP transcripts accumulate in Aeleuropus in response to multiple abiotic stresses and at a higher level in roots, while those of OsSAP9 are preferentially induced by cold and heat treatments and accumulate preferentially in leaves of rice. In silico analysis of the AlSAP promoter "Pr AlSAP " predicted several cis-acting elements responsible for gene regulation by dehydration, salt, heat, ABA, SA, wounding and tissue-specific expression. The Pr AlSAP promoter was fused to the gusA gene and used to produce transgenic rice plants. Transcripts of gusA exhibited similar accumulation patterns in transgenic rice as AlSAP transcripts in A. littoralis. Indeed, accumulation of gusA transcripts was higher in roots than in leaves and induced by salt, drought, cold and heat treatments. GUS activity was confirmed in roots, coleoptiles, leaves and glumes, but absent in the root cell elongation zone and in dry seeds. A wound treatment strongly induced GUS accumulation in leaves and imbibed seeds. Altogether, these results indicate that the regulatory regions of two ortholog genes "AlSAP" and "OsSAP9" have diverged in the specificity of the signals promoting their induction, but that the trans-acting elements allowing the correct spatiotemporal regulation and stress induction of Pr AlSAP exist in rice. Therefore, the AlSAP promoter appears to be an interesting candidate for engineering abiotic stress tolerance in cereals.

Development of a marker-free engineered durum wheat overexpressing Lobularia maritima GASA1 with improved drought tolerance.

Due to their fixed lifestyle, plants must adapt to abiotic or biotic stresses by orchestrating various responses, including protective and growth control measures. Growth arrest is provoked upon abiotic stress and can impair plant production. Members of the plant-specific GASA (gibberellic acid-stimulated Arabidopsis) gene family play crucial roles in phytohormone responses, abiotic and biotic stresses, and plant growth. Here, we recognized and examined the LmGASA1 gene from the halophyte plant Lobularia maritima and developed marker-free engineered durum wheat plants overexpressing the gene. The LmGASA1 transcript profile revealed that it's induced by stressful events as well as by phytohormones including GA3, MeJA, and ABA, suggesting that the LmGASA1 gene may contribute to these stress and hormone signal transduction pathways. Transient expression of GFP-LmGASA1 fusion in onion epidermal cells indicated that LmGASA1 is localized to the cell membrane. Further analysis showed that overexpression of LmGASA1 in durum wheat plants enhanced tolerance to drought stress compared with that in non-transgenic (NT) plants, imposing no yield penalty and enabling seed production even following drought stress at the vegetative stage. Altogether, our data indicate that LmGASA1 regulates both the scavenging capacity of the antioxidant enzymatic system and the activation of at least six stress-related genes that function as positive regulators of drought stress tolerance. LmGASA1 appears to be a novel gene useful for further functional analysis and potential engineering for drought stress tolerance in crops.

Changes in inoculated Salmonella enterica subsp. enterica Serovar Enteritidis and other microbiological qualities of vacuum-packed carrot slices after treatment with aqueous extract of Lobularia maritima.

After harvesting, pathogens can infect fresh vegetables in different ways. Pathogenic bacteria associated with fresh vegetables can cause widespread epidemics associated with foodborne illness. The aim of this study was to assess the microbiological quality of carrot slices after treatment with aqueous extracts of Lobularia maritima (AELm) at different concentrations AELm1 (10 mg/mL), AELm2 (5 mg/mL), AELm3 (2.5 mg/mL) and AELm4 (1.25 mg/mL), and Salmonella enterica subsp. enterica serovar Enteritidis, along with vacuum packaging and storage of carrots for 7 days at 4 °C. On days 1. and 7., total viable counts (TVC), and coliforms bacteria (CB), and Salmonella count were all analysed. Microorganisms that were obtained from carrots were identified using MALDI-TOF MS Biotyper Mass Spectrometry. The total viable, coliform bacteria and Salmonella counts were varied by the group of treatment. Higher counts were found in the control group on both days. The most isolated species of bacteria were Salmonella enterica and Pantoea agglomerans on the 1. day and Klebsiella oxytoca on the 7. day. The current study adds useful information for a better understanding of how Salmonella enterica reacts to the effect of AELm and its potential use as a sustainable washing method to eliminate bacteria from freshly cut carrots.

Citrus limon Essential Oil: Chemical Composition and Selected Biological Properties Focusing on the Antimicrobial (In Vitro, In Situ), Antibiofilm, Insecticidal Activity and Preservative Effect against Salmonella enterica Inoculated in Carrot.

New goals for industry and science have led to increased awareness of food safety and healthier living in the modern era. Here, one of the challenges in food quality assurance is the presence of pathogenic microorganisms. As planktonic cells can form biofilms and go into a sessile state, microorganisms are now more resistant to broad-spectrum antibiotics. Due to their proven antibacterial properties, essential oils represent a potential option to prevent food spoilage in the search for effective natural preservatives. In this study, the chemical profile of Citrus limon essential oil (CLEO) was evaluated. GC-MS analysis revealed that limonene (60.7%), ß-pinene (12.6%), and γ-terpinene (10.3%) are common constituents of CLEO, which prompted further research on antibacterial and antibiofilm properties. Minimum inhibitory concentration (MIC) values showed that CLEO generally exhibits acceptable antibacterial properties. In addition, in situ antimicrobial research revealed that vapour-phase CLEO can arrest the growth of Candida and Y. enterocolitica species on specific food models, indicating the potential of CLEO as a preservative. The antibiofilm properties of CLEO were evaluated by MIC assays, crystal violet assays, and MALDI-TOF MS analysis against S. enterica biofilm. The results of the MIC and crystal violet assays showed that CLEO has strong antibiofilm activity. In addition, the data obtained by MALDI-TOF MS investigation showed that CLEO altered the protein profiles of the bacteria studied on glass and stainless-steel surfaces. Our study also found a positive antimicrobial effect of CLEO against S. enterica. The anti-Salmonella activity of CLEO in vacuum-packed sous vide carrot samples was slightly stronger than in controls. These results highlight the advantages of the antibacterial and antibiofilm properties of CLEO, suggesting potential applications in food preservation.

Mixture design of α-pinene, α-terpineol, and 1,8-cineole: A multiobjective response followed by chemometric approaches to optimize the antibacterial effect against various bacteria and antioxidant activity.

α-Pinene, α-terpineol, and 1,8-cineole are compounds naturally present in essential oils, although their amounts vary from oil to oil. Although several studies have reported their antibacterial and antioxidant effects, there are few reports on the synergistic or antagonistic effects of their combinations. The objective of this study was to investigate the combined antibacterial effect of these three compounds. To our knowledge, this is the first report on the prediction of their optimal combination using the mixture design approach. The experimental antibacterial activity of the α-pinene, α-terpineol, and 1,8-cineole mixtures depended on the proportion of each compound in the mixture and the target strain, with minimum inhibitory concentrations (MIC) ranging from 0.31 to 1.85 mg/mL. Using the increased simplex-centroid mixture design, the mixture containing 0.33% of each molecule proved to be the most effective against Bacillus cereus and had the lowest MIC values. In addition, α-pinene, α-terpineol, and 1,8-cineole showed significant antioxidant activity against 2,2-picryl-1-hydrazyl radical (DPPH), with IC50 values of 24.53 ± 0.05, 65.63 ± 0.71, and 63.58 ± 0.01 µg/mL, respectively. Statistical planning and the development of utility profiles of the substance mixtures can predict the optimal composition that will exhibit the highest antibacterial activity against B. cereus as well as antioxidant properties. Furthermore, the synergistic effect of the mixtures can contribute significantly to their successful use as natural preservatives in various applications.

Biological Activity and Phytochemical Characteristics of Star Anise (Illicium verum) Essential Oil and Its Anti-Salmonella Activity on Sous Vide Pumpkin Model.

Illicium verum, commonly known as star anise, represents one of the notable botanical species and is recognized for its rich reservoir of diverse bioactive compounds. Beyond its culinary application as a spice, this plant has been extensively utilized in traditional medicine. Given the contemporary emphasis on incorporating natural resources into food production, particularly essential oils, to enhance sensory attributes and extend shelf life, our study seeks to elucidate the chemical composition and evaluate the antibacterial (in vitro, in situ) and insecticidal properties of Illicium verum essential oil (IVEO). Also, microbiological analyses of pumpkin sous vide treated with IVEO after inoculation of Salmonella enterica were evaluated after 1 and 7 days of study. GC/MS analysis revealed a significantly high amount of (E)-anethole (88.4%) in the investigated EO. The disc diffusion method shows that the antibacterial activity of the IVEO ranged from 5.33 (Streptococcus constellatus) to 10.33 mm (Citrobacter freundii). The lowest minimal inhibition concentration was found against E. coli and the minimum biofilm inhibition concertation was found against S. enterica. In the vapor phase, the best antimicrobial activity was found against E. coli in the pears model and against S. sonei in the beetroot model. The application of the sous vide method in combination with IVEO application decreased the number of microbial counts and eliminated the growth of S. enterica. The most isolated microbiota identified from the sous vide pumpkin were Bacillus amyloliquefaciens, B. cereus, B. licheniformis, and Ralstonia picketii. Modifications to the protein composition of biofilm-forming bacteria S. enterica were suggested by the MALDI TOF MS instigations. The IVEO showed insecticidal potential against Harmonia axyridis. Thanks to the properties of IVEO, our results suggest it can be used in the food industry as a natural supplement to extend the shelf life of foods and as a natural insecticide.

Rosmarinus officinalis L. essential oil enhances salt stress tolerance of durum wheat seedlings through ROS detoxification and stimulation of antioxidant defense.

Salt-induced stress poses a significant barrier to agricultural productivity by impeding crop growth. Presently, environmentalists are dedicated to safeguarding food security by enhancing agricultural yields in challenging environments. Biostimulants play a crucial role in mitigating abiotic stresses in crop production, and among these, plant essential oils (EOs) stand out as organic substances with diverse biological effects on living organisms. Among the natural promoters of plant growth, Rosmarinus officinalis L. essential oil (RoEO) has gained considerable attention. Although the manifold effects of essential oils (EOs) on plant growth have been extensively demonstrated, their impact on salt stress tolerance in durum wheat seedlings remains unexplored. This investigation was undertaken to evaluate the biostimulatory capabilities of RoEO on the durum wheat cultivar "Mahmoudi." The effects of three RoEO concentrations (1, 2.5, and 5 ppm) on seed germination, growth establishment, and the induction of salt resistance under salinity conditions (150 mM NaCl) were tested. At 5 ppm, RoEO enhanced seedlings' tolerance to salinity by improving growth and reducing membrane deterioration and oxidative stress-induced damage. The expression profile analyses of seven stress-related genes (TdNHX1, TdSOS1, TdSOD, TdCAT, TdGA20-ox1, TdNRT2.1, and TdGS) using RT-qPCR showed enhancement of several important genes in durum wheat seedlings treated with 5 ppm RoEO, even under control conditions, which may be related to salt stress tolerance. The results indicate that the application of RoEO suggests a possible alternative strategy to increase salt tolerance in durum wheat seedlings towards better growth quality, thus increasing ROS scavenging and activation of antioxidant defense.

Effect of treated and untreated domestic wastewater on seed germination, seedling growth and amylase and lipase activities in Avena sativa L.

BACKGROUND: Oats (Avena sativa L.) are a potential economically viable source of lipids and starch for use in foods. The aim of this study was to determine the effect of treated and untreated urban wastewater on seed germination, growth parameters and lipase and amylase activities in A. sativa. RESULTS: Untreated wastewater was highly toxic in nature and had an inhibitory effect on seed germination and seedling growth. However, after bacterial treatment, its toxicity was significantly reduced and it showed improved seed germination. It was observed that treated wastewater had no inhibitory effect on seedling growth parameters. However, A. sativa seeds treated with untreated effluent showed reduced lipase and amylase activities. CONCLUSION: Treated wastewater could be used for irrigation purposes provided that it satisfies other conditions fixed by legislation.

Genome-wide characterization and expression profiling of GASA gene family in Triticum turgidum ssp. durum (desf.) husn. (Durum wheat) unveils its involvement in environmental stress responses.

Family members within the plant-specific gibberellic acid-stimulated Arabidopsis (GASA) gene serve a crucial role in plant growth and development, particularly in flower induction and seed development. Through a genome-wide analysis of Triticum turgidum ssp. Durum (durum wheat), we identified 19 GASA genes, designated as TdGASA1‒19. Moreover, the chromosomal locations, exon-intron distribution and the physiochemical properties of these genes were determined and the subcellular localization of their encoded proteins was estimated. Analyses of their domain structure, motif arrangements, and phylogeny revealed four distinct groups that share a conserved GASA domain. Additionally, a real-time q-PCR analysis revealed differential expression patterns of TdGASA genes in various tissues (including leaves, roots, stems, and seeds) and in response to salinity, osmotic stress, and treatment with exogenous phytohormones (abscisic and gibberellic acid), implying that these genes may play a role in the growth, development, and stress responses of Triticum turgidum. Heterologous expression of TdGASA1, TdGASA4, TdGASA14, and TdGASA19 in Saccharomyces cerevisiae improved its tolerance to salt, osmotic, oxidative, and heat stresses, which suggests the involvement of these genes in abiotic stress tolerance mechanisms. The present study is the first to identify and analyze the expression profile of T. turgidum GASA genes, therefore offering novel insights for their further functional characterization, which may serve as a novel resource for molecular breeding of durum wheat.

Biopreservative Effect of the Tunisian Halophyte Lobularia maritima Flavonoid Fraction, Used Alone and in Combination with Linalool in Stored Minced Beef Meat.

In the present study, Lobularia maritima (Lm) flavonoid extract (LmFV) was characterized by HPLC analyses and five compounds were detected. Further, to describe the chemical content of the matrix, GC-MS analyses after silylation were performed; the obtained results showed the presence of a large number of components belonging to several chemical classes, mostly sugar alcohols, sugars, fatty acids, and terpenes. Firstly, the antibacterial activities of this fraction and linalool (Lin) were evaluated against eight foodborne pathogenic strains with MIC values between 2.3 and 5.8 mg/mL and 0.23 and 0.7 mg/mL, respectively. Then, the antioxidant activity of both was evaluated by the DPPH antiradical test and the phosphomolybdenum test. Furthermore, the biopreservative effect of LmFV alone and in combination with Lin on minced beef stored at 4 °C for 14 days was evaluated using microbiological and physiochemical tests. LmFV at 4.6% alone significantly reduced microbial spoilage in ground meat (p < 0.05). The combination of LmFV (4.6%) and Lin (0.46%) was more effective than LmFV alone in inhibiting bacterial contamination, reducing TBARS values and the risk of bacterial contamination, and reducing the accumulation of Met myoglobin (MetMb). This combination, therefore, extends the shelf life of the product by about 10 days. Based on these microbiological results and physicochemical parameters, it can be stated that the addition of Lin potentiates the flavonoid fraction of L. maritima more strongly against the deterioration of meat quality by significantly improving its biopreservative effect as a natural conservative.

Recent Advances in the Incorporation of Polysaccharides with Antioxidant and Antibacterial Functions to Preserve the Quality and Shelf Life of Meat Products.

Meat and meat products are susceptible to various types of natural processes such as oxidative degradation due to their high content of protein and essential amino acids. However, finding solutions to maintain the nutritional and sensory quality of meat and meat products is unavoidable. Hence, there is a pressing need to investigate alternatives to synthetic preservatives, focusing on active biomolecules of natural provenance. Polysaccharides are natural polymers of various sources that exhibit antibacterial and antioxidant properties via a variety of mechanisms, owing to their diversity and structural variation. For this reason, these biomolecules are widely studied in order to improve texture, inhibit the growth of pathogens, and improve the oxidative stability and sensory characteristics of meat products. However, the literature has not addressed their biological activity in meat and meat products. This review summarizes the various sources of polysaccharides, their antioxidant and antibacterial activities (mainly against pathogenic food strains), and their use as natural preservatives to replace synthetic additives in meat and meat products. Special attention is given to the use of polysaccharides to improve the nutritional value of meat, resulting in more nutrient-rich meat products with higher polysaccharide content and less salt, nitrites/nitrates, and cholesterol.

Salvia officinalis L. and Salvia sclarea Essential Oils: Chemical Composition, Biological Activities and Preservative Effects against Listeria monocytogenes Inoculated into Minced Beef Meat.

In this study, Salvia officinalis L. and Salvia sclarea essential oils (EOs) were investigated using gas chromatography-mass spectrometry (GC-MS) to describe their chemical composition. The obtained results show, for both EOs, a profile rich in terpene metabolites, with monoterpenes predominating sesquiterpenes but with significant qualitative and quantitative differences. The main compound found in the Salvia officinalis EO (SOEO) was camphor (19.0%), while in Salvia sclarea EO (SCEO), it was linalyl acetate (59.3%). Subsequently, the in vitro antimicrobial activity of the EOs against eight pathogenic strains was evaluated. The disc diffusion method showed a significant lysis zone against Gram-positive bacteria. The minimum inhibitory concentrations (MICs) ranged from 3.7 mg/mL to 11.2 mg/mL, indicating that each EO has specific antimicrobial activity. Both EOs also showed significant antiradical activity against DPPH radicals and total antioxidant activity. In addition, the preservative effect of SOEO (9.2%) and SCEO (9.2%), alone or in combination, was tested in ground beef, and the inhibitory effect against Listeria monocytogenes inoculated into the raw ground beef during cold storage was evaluated. Although the effect of each individual EO improved the biochemical, microbiological, and sensory parameters of the samples, their combination was more effective and showed complete inhibition of L. monocytogenes after 7 days of storage at 4 °C. The results show that both EOs could be used as safe and natural preservatives in various food and/or pharmaceutical products.

GASA Proteins: Review of Their Functions in Plant Environmental Stress Tolerance.

Gibberellic acid-stimulated Arabidopsis (GASA) gene family is a class of functional cysteine-rich proteins characterized by an N-terminal signal peptide and a C-terminal-conserved GASA domain with 12 invariant cysteine (Cys) residues. GASA proteins are widely distributed among plant species, and the majority of them are involved in the signal transmission of plant hormones, the regulation of plant development and growth, and the responses to different environmental constraints. To date, their action mechanisms are not completely elucidated. This review reports an overview of the diversity, structure, and subcellular localization of GASA proteins, their involvement in hormone crosstalk and redox regulation during development, and plant responses to abiotic and biotic stresses. Knowledge of this complex regulation can be a contribution to promoting multiple abiotic stress tolerance with potential agricultural applications through the engineering of genes encoding GASA proteins and the production of transgenic plants.

Expression of the Aeluropus littoralis AlSAP gene in rice confers broad tolerance to abiotic stresses through maintenance of photosynthesis.

The expression of AlSAP, in rice cv. Nipponbare, enhances plant tolerance to cold, drought and salt stresses. AlSAP lines showed 100% survival rate and set seeds while control plants did not recover from the cold treatment. Under a severe drought stress treatment (fraction of transpirable soil water down to 0.1), AlSAP lines exhibited enhanced Transpiration Efficiency (TE) and maintained a high A (Assimilation rate) value (22 µmol·m(-2) s(-1) ) while these values dramatically decreased (A = 4 µmol·m(-2) s(-1) ) in control plants which were subsequently unable to recover from the stress. Of noteworthy is that AlSAP rice plants yielded a similar and a 60% seed set under control and stress conditions respectively, with regard to wild-type (WT) plants grown under control conditions. This indicates that AlSAP expression imposes no yield penalty and allows seed production even following a severe drought stress at the vegetative stage. Furthermore, AlSAP rice was shown to accumulate transcripts of a pilot set of eight stress-related genes at a significantly higher level than WT plants, both under control and stressed conditions. The results suggest that AlSAP expression generates stress tolerance in plants through maintenance of the photosynthetic apparatus integrity and by stimulating an endogenous adaptive potential which is not effectively accomplished in WT plants.