Bacillus velezensis: a versatile ally in the battle against phytopathogens-insights and prospects.

The escalating interest in Bacillus velezensis as a biocontrol agent arises from its demonstrated efficacy in inhibiting both phytopathogenic fungi and bacteria, positioning it as a promising candidate for biotechnological applications. This mini review aims to offer a comprehensive exploration of the multifaceted properties of B. velezensis, with particular focus on its beneficial interactions with plants and its potential for controlling phytopathogenic fungi. The molecular dialogues involving B. velezensis, plants, and phytopathogens are scrutinized to underscore the intricate mechanisms orchestrating these interactions. Additionally, the review elucidates the mode of action of B. velezensis, particularly through cyclic lipopeptides, highlighting their importance in biocontrol and promoting plant growth. The agricultural applications of B. velezensis are detailed, showcasing its role in enhancing crop health and productivity while reducing reliance on chemical pesticides. Furthermore, the review extends its purview in the industrial and environmental arenas, highlighting its versatility across various sectors. By addressing challenges such as formulation optimization and regulatory frameworks, the review aims to chart a course for the effective utilization of B. velezensis. KEY POINTS: • B. velezensis fights phytopathogens, boosting biotech potential • B. velezensis shapes agri-biotech future, offers sustainable solutions • Explores plant-B. velezensis dialogue, lipopeptide potential showcased.

Lactic acid bacteria as an eco-friendly approach in plant production: Current state and prospects.

Since the late nineteenth century, the agricultural sector has experienced a tremendous increase in chemical use in response to the growing population. Consequently, the intensive and indiscriminate use of these substances caused serious damage on several levels, including threatening human health, disrupting soil microbiota, affecting wildlife ecosystems, and causing groundwater pollution. As a solution, the application of microbial-based products presents an interesting and ecological restoration tool. The use of Plant Growth-Promoting Microbes (PGPM) affected positive production, by increasing its efficiency, reducing production costs, environmental pollution, and chemical use. Among these microbial communities, lactic acid bacteria (LAB) are considered an interesting candidate to be formulated and applied as effective microbes. Indeed, these bacteria are approved by the European Food Safety Authority (EFSA) and Food and Drug Administration (FDA) as Qualified Presumption of Safety statute and Generally Recognized as Safe for various applications. To do so, this review comes as a road map for future research, which addresses the different steps included in LAB formulation as biocontrol, bioremediation, or plant growth promoting agents from the isolation process to their field application passing by the different identification methods and their various uses. The plant application methods as well as challenges limiting their use in agriculture are also discussed.

Unlocking Nature's Secrets: Molecular Insights into Postharvest Pathogens Impacting Moroccan Apples and Innovations in the Assessment of Storage Conditions.

Apple production holds a prominent position in Morocco's Rosaceae family. However, annual production can fluctuate due to substantial losses caused by fungal diseases affecting stored apples. Our findings emphasize that the pre-storage treatment of apples, disinfection of storage facilities, box type, and fruit sorting are pivotal factors affecting apple losses during storage. Additionally, the adopted preservation technique was significantly correlated with the percentage of damage caused by fungal infections. Blue mold accounts for nearly three-quarters of the diseases detected, followed by gray rot with a relatively significant incidence. This study has revealed several fungal diseases affecting stored apples caused by pathogens such as Penicillium expansum, Botrytis cinerea, Alternaria alternata, Trichothecium roseum, Fusarium avenaceum, Cadophora malorum, and Neofabraea vagabunda. Notably, these last two fungal species have been reported for the first time in Morocco as pathogens of stored apples. These data affirm that the high losses of apples in Morocco, attributed primarily to P. expansum and B. cinerea, pose a significant threat in terms of reduced production and diminished fruit quality. Hence, adopting controlled atmosphere storage chambers and implementing good practices before apple storage is crucial.

Nutrient and Bioactive Fraction Content of Olea europaea L. Leaves: Assessing the Impact of Drying Methods in a Comprehensive Study of Prominent Cultivars in Morocco.

This study explores the potential of olive leaves, long integral to Mediterranean traditional medicine, as a rich source of valuable compounds. The challenge lies in their considerable water content, hindering these compounds' full valorization. Four drying methods (air-drying, oven-drying, freeze-drying and solar-drying) were investigated for their impact on nutrient and bioactive compound content in the leaves of four olive varieties ("Arbequina", "Koroneiki", "Menara" and "Picholine Marocaine") cultivated in Morocco. In their fresh state, "Picholine Marocaine" exhibited the highest protein levels (6.11%), "Arbequina" had the highest phenolic content (20.18 mg gallic acid equivalents/g fresh weight (FW)), and "Koroneiki" and "Menara" were highest in flavonoids (3.28 mg quercetin equivalents/g FW). Specific drying methods proved optimal for different varieties. Oven-drying at 60 °C and 70 °C effectively preserved protein, while phenolic content varied with drying conditions. Air-drying and freeze-drying demonstrated effectiveness for flavonoids. In addition, an analytical approach using high-performance liquid chromatography and diode array detection (HPLC-DAD) was applied to investigate the effects of the different drying methods on the bioactive fraction of the analyzed samples. The results showed qualitative and quantitative differences depending on both the variety and the drying method used. A total of 11 phenolic compounds were tentatively identified, with oleuropein being the most abundant in all the samples analyzed. The freeze-dried samples showed the highest content of oleuropein in the varieties "Arbequina" and "Picholine Marocaine" compared to the other methods analyzed. In contrast, "Koroneiki" and "Menara" had higher oleuropein content when air dried. Overall, the obtained results highlight the importance of tailored drying techniques for the preservation of nutrients and bioactive compounds in olive leaves.

Chemical composition, antioxidant properties, and antifungal activity of wild Origanum elongatum extracts against Phytophthora infestans.

Introduction: Phytophthora infestans, the causative agent of late blight disease, has gained notoriety for its destructive potential, leading to substantial losses in potato yields. Although conventional systemic fungicides have been shown to be effective in controlling plant pathogens, growing environmental concerns have prompted the need for more integrated disease management approaches. Hence, in this study, the effectiveness of wild Origanum elongatum extracts as biopesticides was explored in controlling P. infestans and potentially mitigating its devastating impact in planta. Methods: The aerial parts of O. elongatum were subjected to sequential extraction using water, hexane, chloroform, and methanol. The obtained extracts were tested in vitro through the poisoned food procedure for their capacity to obstruct P. infestans growth and to defeat potato blight severity in vivo. The phyto-contents (total phenolic content (TPC) and total flavonoid content (TFC)), as well as the antioxidant activities, were spectrophotometrically determined in all extracts, and the phytoconstituents of the most active extract (methanolic extract) were profiled via high-performance liquid chromatography-photodiode array-tandem mass spectrometry (HPLC-PDA-MS/MS). Results: In vitro, the complete inhibition rate of the P. infestans was obtained using the methanolic extract at 5 mg/mL, followed by the hexane and chloroform extracts at 10 mg/mL. Interestingly, complete inhibition of the pathogen was achieved upon the application of the aqueous extract at 10 mg/mL. In vivo, the aqueous extract at 25 mg/mL reduced the P. infestans severity rate to 27.25%, while the methanolic extract at 20 mg/mL led to the lowest severity rate. Moreover, the hexane and chloroform extracts impaired the pathogen severity rate to 50% and 41% using 20 mg/mL, respectively. The TPC and TFC in the extracts were variable with high concentrations detected in the methanolic extract with 485.42 mg GAE/g and 58.24 mg QE/g, respectively. In addition, the methanolic extract showed the highest antioxidant activities, while the chloroform extract exhibited the lowest activity. Liquid chromatography (LC)-MS/MS analysis of the methanol extract revealed 56 components from diverse classes. These included organic acids, phenolic acids, flavonoids, tannins, and coumarins. Conclusion: These findings suggest that O. elongatum could be investigated as a potential source of antifungal compounds targeting different phytopathogens.

Evaluation of the impact of two citrus plants on the variation of Panonychus citri (Acari: Tetranychidae) and beneficial phytoseiid mites.

The abundance of Panonychus citri McGregor 1916 (Acari: Tetranychidae) and its associated enemies (Euseius stipulatus Athias-Henriot, 1960; Typhlodromus sp.; Phytoseiulus persimilis Athias-Henriot, 1957) was studied on two 12-year-old citrus cultivars, specifically Clementine "Nules" (Citrus Clementina) and Valencia (Citrus sinensis), in the Gharb region of Morocco. Throughout the entire monitoring period in the Valencia late cultivar, the density of the spider mite P. citri on leaves was notably higher at 38.0% (n = 1,212 mobile forms). Predator P. persimilis exhibited a leaf occupancy of 25.0% (n = 812), followed by Typhlodromus sp. at 20.0% (n = 643). Conversely, the abundance of E. stipulatus was lower at 17.0% (n = 538). In the Nules variety, P. citri abundance recorded a higher percentage at 48.0% (n = 1,922). E. stipulatus emerged as the most abundant predator at 23.0% (n = 898), followed by P. persimilis with 16.0% (n = 639). Meanwhile, the population of Typlodromus sp. remained notably low at 13.0% (n = 498). Regarding the fluctuation of the different mites studied on the two cultivars across monitoring dates, the period from May 4 to June 1 was characterized by low temperatures and a diminished presence of mite populations (P. citri, E. stipulatus, Typhlodromus sp., and P. persimilis). However, from June 7 to June 19, characterized by high temperatures, a notable increase in the presence of mite populations was observed. As regards the effect of the variety on the different mites studied, the varietal impact was significant.

Analysis of Primary and Secondary Metabolites, Physical Properties, Antioxidant and Antidiabetic Activities, and Chemical Composition of Rosmarinus officinalis Essential Oils under Differential Water Stress Conditions.

This study investigated the effects of varying water stress levels on Rosmarinus officinalis essential oils (EO). Three samples (S1, S2, and S3) were cultivated under different stress levels (40, 60, and 80%). Increased water stress led to changes in primary and secondary metabolites, EO contents, and physical properties. Antioxidant activity varied, with S2 exhibiting the highest IC50 value. In terms of antidiabetic activity, S2 showed robust α-amylase inhibition, while S3 displayed a commendable influence. For α-galactosidase inhibition, S3 had a moderate effect, and S2 stood out with increased efficacy. Gas chromatography-mass spectrometry analysis revealed stress-induced changes in major compounds. The study enhances the understanding of plant responses to water stress, with potential applications in antioxidant therapy and diabetes management. The findings emphasize the importance of sustainable water management for optimizing the EO quality in its various uses.

Comprehensive phytochemical and toxicological analysis of Chenopodium ambrosioides (L.) fractions.

Chenopodium ambrosioides aerial parts have been historically employed in traditional medicine for addressing various ailments such as headaches, abdominal discomfort, joint issues, and respiratory disorders, alongside treatments for lice and warts. This study aimed to conduct a comprehensive phytochemical analysis of C. ambrosioides and assess the acute and subacute toxicity of oral treatments using fractions in preclinical trials. Spectrophotometric analysis via LC-MS/MS was used to characterize the plant's chemical composition. Acute toxicity evaluation followed Organisation for Economic Co-operation and Development code 42 guidelines, conducted on adult male and female Wistar strain mice. Subsequently, Swiss mice were divided into six groups for the subacute toxicity study, receiving oral doses of 200 mg/kg extracts and fractions for 28 days. Daily observations and biochemical analyses were performed, with LC-MS/MS revealing a diverse array of compounds including organic acids, flavonoids, phenolic acids, rutin, hesperidin, nicotiflorine, and fumaric acid. Results indicated no lethality or alterations in body weight in treated groups, though some organ weight changes were noted. Biochemical analyses demonstrated values within the normal range for all groups, suggesting that the treatments did not induce adverse effects. Acute and subacute treatments with fractions did not result in lethality or toxic alterations at therapeutic doses, implying the safety of the product at appropriate levels. This study underscores the potential of C. ambrosioides as a safe therapeutic option warranting further exploration.

The Hidden World within Plants 2.0.

Interactions between plants and microorganisms are complex, with some microorganisms causing damage by employing strategies that hinder plant growth and reproduction, while others positively influence plant growth through various physiological activities [...].

Beneficial Microorganisms as Bioprotectants against Foliar Diseases of Cereals: A Review.

Cereal production plays a major role in both animal and human diets throughout the world. However, cereal crops are vulnerable to attacks by fungal pathogens on the foliage, disrupting their biological cycle and photosynthesis, which can reduce yields by 15-20% or even 60%. Consumers are concerned about the excessive use of synthetic pesticides given their harmful effects on human health and the environment. As a result, the search for alternative solutions to protect crops has attracted the interest of scientists around the world. Among these solutions, biological control using beneficial microorganisms has taken on considerable importance, and several biological control agents (BCAs) have been studied, including species belonging to the genera Bacillus, Pseudomonas, Streptomyces, Trichoderma, Cladosporium, and Epicoccum, most of which include plants of growth-promoting rhizobacteria (PGPRs). Bacillus has proved to be a broad-spectrum agent against these leaf cereal diseases. Interaction between plant and beneficial agents occurs as direct mycoparasitism or hyperparasitism by a mixed pathway via the secretion of lytic enzymes, growth enzymes, and antibiotics, or by an indirect interaction involving competition for nutrients or space and the induction of host resistance (systemic acquired resistance (SAR) or induced systemic resistance (ISR) pathway). We mainly demonstrate the role of BCAs in the defense against fungal diseases of cereal leaves. To enhance a solution-based crop protection approach, it is also important to understand the mechanism of action of BCAs/molecules/plants. Research in the field of preventing cereal diseases is still ongoing.