Throughout history, plant diseases have posed significant challenges to agricultural progress, driven by both abiotic and biotic factors. Abiotic factors include wind, salt damage, freezing, girdling roots and compacted soil, while biotic factors encompass bacteria, nematodes, fungi and viruses. Plants have evolved diverse defense strategies to counter pathogen attacks, one of which involves chitinases, a subset of pathogenesis-related proteins. Chitinases are hydrolytic enzymes that degrade chitin, a high-molecular-weight linear polymer of N-acetylD-glucosamine, which is a crucial component of fungal cell walls and septa. These enzymes are produced by a wide range of organisms, including plants, animals, insects, fungi and microorganisms. In plants, chitinases are strongly expressed under pathogenic stress, primarily targeting fungal pathogens by breaking down their cell walls. They also contribute to cell wall remodeling and degradation during growth and defense processes. Numerous studies have demonstrated that the antifungal activity of chitinases is influenced by the chitin concentration and surface microstructure of different fungal species. Research has highlighted their role in protecting plants like mango, cucumber, rye, tomato, grapevine and other plants from various fungal diseases. These findings underscore the critical role of chitinases in plant defense mechanisms, showcasing their importance in mitigating fungal infections and supporting plant health.

Spent mushroom substrate (SMS), a waste product from mushroom cultivation, in addition to being rich in essential nutrients for crop growth, contains actively growing mushroom mycelia and metabolites that suppress some plant pathogens and pests. SMS thus has potential for fostering the suppressiveness of soil-borne pathogens of farms. This study determined the potential of using the spent Pleurotus ostreatus substrate (SPoS) to suppress the plant-parasitic nematode Radopholus similis in bananas. R. similis is the most economically important nematode in bananas worldwide. The effect of SPoS on R. similis was assessed through two in vivo (potted plants) experiments between May 2023 and June 2024. Five-month-old East African highland banana (genome AAA) plantlets that are highly susceptible to R. similis were used. In the first experiment, the plantlets were established in 3 L pots containing (i) pre-sterilized soil, (ii) pre-sterilized soil inoculated with nematodes, (iii) pre-sterilized soil mixed with 30% (v/v) SPoS, (iv) pre-sterilized soil mixed with 30% (v/v) SPoS followed by nematode inoculation, (v) SPoS without soil, and (vi) SPoS without soil inoculated with nematodes. The SPoS was already decomposed; thus, it may or may not have contained active mycelia. The nematodes were introduced two weeks after the SPoS application. In the second experiment, SPoS was introduced two weeks after nematode inoculation. The SPoS treatments without soil were not evaluated in the second experiment. Both experiments were monitored over a three-month period. Each screenhouse treatment contained four plants and was replicated thrice. In the first experiment, data were collected on changes in soil nutrient content, below- and aboveground biomass, root deaths, root necrosis due to nematode damage, and R. similis population in root tissues and soil. In the second experiment, data were collected on root deaths and the number of nematodes in root tissues and the soil. The SPoS improved crop biomass yield, reduced root damage, and colonization by R. similis. The potential of SPoS to improve the management of R. similis and banana production under field conditions needs to be determined.

Compost tea is widely recognized for its beneficial effects on crop growth and soil health. However, its efficacy varies depending on the composition of the feedstock and brewing conditions. This study investigates the chemical composition and agronomic impact of compost tea prepared from a commercial mixture of plant residues and animal manure. Standard chemical analyses, combined with solid-state 13C CPMAS NMR spectroscopy, were employed to characterize the organic chemistry of the feedstock. High-throughput sequencing of bacterial and eukaryotic rRNA gene markers was used to profile the microbiota. Compost tea was applied to three crops, Allium cepa, Beta vulgaris, and Lactuca sativa, grown in protected Mediterranean environments on volcanic soils. The 13C CPMAS NMR analysis revealed that the feedstock is predominantly composed of plant-derived tissues, including grass straw, nitrogen-fixing hay, and animal manure, with a significant presence of O-alkyl-C and di-O-alkyl-C regions typical of sugars and polysaccharides. Additionally, the chemical profile indicated the presence of an aliphatic fraction (alkyl-C), characteristic of lipids such as waxes and cutins. The compost tea microbiome was dominated by Pseudomonadota, with Pseudomonas, Massilia, and Sphingomonas being the most prevalent genera. Compost tea application resulted in significant yield increases, ranging from +21% for lettuce to +58% for onion and +110% for chard. Furthermore, compost tea application reduced slug damage and enhanced the shelf life of lettuce. These findings highlight the bio-stimulant potential of this standardized compost tea mixture across different vegetable crops.

This study focuses on developing an encapsulated and dehydrated formulation of vegetative actinobacteria cells for an efficient application in sustainable agriculture, both as a fungicidal agent in crop protection and as a growth-stimulating agent in plants. Three strains of actinobacteria were used: one from a collection (Streptomyces sp.) and two natives to agricultural soil, which were identified as S3 and S6. Vegetative cells propagated in a specific liquid medium for mycelium production were encapsulated in various alginate-chitosan composites produced by extrusion. Optimal conditions for cell encapsulation were determined, and cell damage from air-drying at room temperature was evaluated. The fresh and dehydrated composites were characterized by porosity, functional groups, size and shape, and their ability to protect the immobilized vegetative cells' viability. Actinomycetes were immobilized in capsules of 2.1-2.7 mm diameter with a sphericity index ranging from 0.058 to 0.112. Encapsulation efficiency ranged from 50% to 88%, and cell viability after drying varied between 44% and 96%, depending on the composite type, strain, and airflow. Among the three immobilized and dried strains, S3 and S6 showed greater resistance to encapsulation and drying with a 4 Lmin-1 airflow when immobilized in coated and core-shell composites. Encapsulation in alginate-chitosan matrices effectively protects vegetative actinobacteria cells during dehydration, maintaining their viability and functionality for agricultural applications.

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.Graphical AbstractThe different processes involved in LAB use as biofertilizers or biocontrol agents.

Soil-borne pathogens have economic significance regarding the damage they cause to crop production worldwide. Arid lands are even more susceptible to soil-borne pathogens damage due to climate extremes such as high temperature and evapotranspiration to precipitation ratio that limits the diversity of crops. More so, some soil-borne pathogens are highly adapted to arid lands' high soil temperature and water limitations. Chemical controls like fungicides and bactericides are widely used in managing soil-borne diseases, but they come at a significant environmental, health, and agricultural cost. On the other hand, biological control of soil-borne pathogens is relatively environment-friendly, safe, has no reported effect on human and animal health, and can improve soil health for optimum ecosystem functioning. Thus, this review presents an overview of soil-borne pathogens infestation in arid lands and the potential of using biological control agents (BCAs) in managing plant disease outbreaks. Some common pathogens in arid lands include Fusarium spp. (pathogenic), Pythium spp., Rhizoctonia solani, and Meloidogyne incognita. Investigations have, however, revealed effective BCAs against soil-borne pathogens, and some examples include Bacillus cereus, Streptomyces atrovirens, Phlebiopsis gigantea, Pseudomonas putida, Trichoderma harzianum, Pythium oligandrum, and Enterobacter amnigenus. The most common mechanisms used by BCAs for controlling soil-borne pathogens include antibiosis, induced systemic resistance, parasitism (mycoparasitism), antagonism, competition for nutrients and space, and indirect plant growth promotion. Recent advances in molecular biology, such as metabarcoding and biomarker transformation, offer promising ways to increase the success rates with the use of BCAs under field conditions. This study suggests that the effectiveness of BCAs can be further enhanced with the addition of soil organic amendments coupled with the cultivation of arid lands adapted crops such as agave and Opuntia spp.

Controlling Salmonella contamination in dry food processing environments represents a significant challenge due to their tolerance to desiccation stress and enhanced thermal resistance. Blue light is emerging as a safer alternative to UV irradiation for surface decontamination. In the present study, the antimicrobial efficacy of ultra-high irradiance (UHI) blue light, generated by light-emitting diodes (LEDs) at wavelengths of 405 nm (841.6 mW/cm(2)) and 460 nm (614.9 mW/cm(2)), was evaluated against a five-serovar cocktail of Salmonella enterica dry cells on clean and soiled stainless steel (SS) surfaces. Inoculated coupons were subjected to blue light irradiation treatments at equivalent energy doses ranging from 221 to 1106 J/cm(2). Wheat flour was used as a model food soil system. To determine the bactericidal mechanisms of blue light, the intracellular concentration of reactive oxygen species (ROS) in Salmonella cells and the temperature changes on SS surfaces were also measured. The treatment energy dose had a significant effect on Salmonella inactivation levels. On clean SS surfaces, the reduction in Salmonella counts ranged from 0.8 to 7.4 log CFU/cm(2), while, on soiled coupons, the inactivation levels varied from 1.2 to 4.2 log CFU/cm(2). Blue LED treatments triggered a significant generation of ROS within Salmonella cells, as well as a substantial temperature increase in SS surfaces. However, in the presence of organic matter, the oxidative stress in Salmonella cells declined significantly, and treatments with higher energy doses (>700 J/cm(2)) were required to uphold the antimicrobial effectiveness observed on clean SS. The mechanism of the bactericidal effect of UHI blue LED treatments is likely to be a combination of photothermal and photochemical effects. These results indicate that LEDs emitting UHI blue light could represent a novel cost- and time-effective alternative for controlling microbial contamination in dry food processing environments.

The study was conducted within the Longstanding Stationary Fertilizer Experiment (LSFE) in IASS Obraztsov Chiflik, Rousse with the aim of establishing the influence of different options of mineral fertilization on yield and resistance to environmental stress and the development of phytopathogens in common wheat.It was found that the highest yield for the period - 6,080 kg ha(-1), was obtained in the experimental plot with full mineral fertilization (N-15 & Rcy;(12)& Kcy;(7)), which represents more than a two-fold increase compared to the average yield obtained from the control. Phytopathological analysis shows that the seeds obtained from the variant with full mineral fertilization have the lowest percentage of phytopathogens (0.75-2.00%) while 22% of the seeds in the control was damaged by Tilletia. The variants with potassium fertilization (K-7) stand out as the most resistant to atmospheric drought during the four-year research period, with the reported values - 58.61 mu S cm(-1), being 12% lower, compared to the control. The highest resistance to soil drought was established for the variants with potassium (K-7) and phosphorus (P-12) fertilization, respectively 83.02 mu S cm(-1) and 83.05 mu S cm(-1).

Context. The South American grass Nassella trichotoma (serrated tussock) is widely distributed in central Argentina and one of the most damaging invasive species in Australia, New Zealand, and South Africa. In Australia, it is a weed of national significance. Aims. Our aim was to characterise the fungi able to colonise N. trichotoma seeds buried at a site in south-western Buenos Aires province, Argentina, and measure their impact on seed survival and germination. Methods. We tested the germination of healthy seeds at the beginning of the experiment (control). We buried 10 mesh bags containing 100 disinfected N. trichotoma seeds each, during 3 months in spring and autumn. At the end of each experiment, the contents of five of the bags were counted and classified as germinated, healthy, damaged, or disintegrated. Germination tests were then conducted with seeds of the latter three categories. The remaining seeds were used for recording fungal signs/symptoms, and the isolation of fungi. Key results. We identified and described a diverse group of fungi associated with the seeds and a seasonal variation in the specific composition. Seeds showing fungal signs and/or symptoms germinated less than the control. Conclusions. This is the first study on fungi associated with seeds of this species in the native range, which can affect their survival and longevity. Implications It is expected that studies on the seed microbiome may help us understand the differences in behaviour of the plant between ranges, and test the enemy-release hypothesis.

- Bacteria of genus Bradyrhisobium form a symbiotic relationship with legumes, promoting biological nitrogen fixation (BNF). However, their effect on the biological control of disease has not been investigated. The aim of this study was to evaluate the effect of four strains of Bradyrhisobium spp., namely SEMIA 5080, SEMIA 5079, SEMIA 5019 and SEMIA 587, on the in -vitro control of four soil phytopathogens: Fusarium crassistipitatum , Macrophomina phaseolina , Rhisoctonia solani and Sclerotinia sclerotiorum , which cause root rot in the soybean. All the strains of Bradyrhisobium spp. and of the phytopathogens were obtained from Embrapa Soja in Londrina, Paran & aacute;. In -vitro tests were conducted using the circle method (adapted), and comparing soybean seeds inoculated with the bacteria and the phytopathogens. The dishes subjected to the circle test were evaluated using a scanning electron microscope (SEM). Two tests of antibiosis were conducted using filtrates of metabolites from Bradyrhisobium spp.: assessment of the minimum inhibitory concentration (MIC) and of the antibiosis in Petri (R) dishes. The results were submitted to the Lilliefors test of normality, followed by ANOVA and regression analysis using the Genes software. The comparison showed that the SEMIA 5080 and SEMIA 5019 strains achieved the best control of the four phytopathogens, with a good performance by the SEMIA 5079 strain; however, the SEMIA 587 strain showed no control over the pathogens. There was morphological damage to the hyphae of each of the phytopathogens subjected to the circle method. There was no antibiosis from the filtered or volatile metabolites.