Genera Pseudomonas and Xanthomonas include bacterial species that are etiological agents of several diseases of major vegetable crops, such as tomato, pepper, bean, cabbage and cauliflower. The bacterial pathogens of those genera may cause severe crop damage, leading to symptoms like leaf spots, wilting, blights, and rotting. These plant pathogens can affect propagation materials and spread rapidly through plant tissues, contaminated soils, or water sources, making them challenging to control using conventional chemical products alone. Biopesticides, such as essential oils (EOs), are nowadays studied, tested and formulated by employing nano- and micro-technologies as innovative biological control strategies to obtain more sustainable products using less heavy metal ions. Moreover, there is a growing interest in exploring new biological control agents (BCAs), such as antagonistic bacterial and fungal species or bacteriophages and understanding their ecology and biological mechanisms to control bacterial phytopathogens. These include direct competition for nutrients, production of antimicrobial compounds, quorum quenching and indirect induction of systemic resistance. Optimisation of the biocontrol potential goes through the development of nanoparticle-based formulations and new methods for field application, from foliar sprays to seed coatings and root inoculation, aimed to improve microbial stability, shelf life, controlled release and field performance. Overall, the use of biological control in horticultural crops is an area of research that continues to advance and shows promising potential. This review aims to provide an in-depth exploration of commercially accessible biocontrol solutions and innovative biocontrol strategies, with a specific focus on the management of bacterial diseases in vegetable crops caused by Pseudomonas and Xanthomonas species. In this article, we highlighted the advancements in the development and use of EOs and other BCAs, emphasizing their potential or shortcomings for sustainable disease management. Indeed, despite the reduced dependence on synthetic pesticides and enhanced crop productivity, variable regulatory frameworks, compatibility among different BCAs, and consistent performance under field conditions are among the current challenges to their commercialization and use. The review seeks to contribute valuable insights into the evolving landscape of biocontrol in vegetable crops and to provide guidance for more effective and eco-friendly solutions against plant bacterial diseases.

PurposeRot disease caused by Fusarium poses a formidable threat to the growth of saffron (Crocus sativus L.), resulting in substantial damage to both yield and quality. It is paramount to delve into the root causes of rot disease in saffron to optimize both yield and quality. Existing preventive and treatment modalities have exerted deleterious effects on corms and the natural environment. Consequently, the quest for efficacious and eco-friendly methods such as biological control agents has become an urgent imperative. MethodsThe disparate distribution of microbial communities between rhizospheric microorganisms and saffron serves as the foundational exploration for uncovering the underlying causes of rot disease. Samples from various saffron organs and rhizosphere soil were gathered, and the sequencing data from the microbial communities were interpreted using 16S rRNA and ITS gene sequencing methods. This facilitated an in-depth examination of the composition and changes of microorganisms in both healthy and diseased saffron plants. ResultsThe findings indicated rot disease reduced the abundance and diversity of microorganisms in saffron, and the fungal co-occurrence networks were less stable and their communities were more sensitive to rot disease than the bacterial community. Fusarium was the predominant genus in diseased samples, accounting for 99.19% and 89.77% of the communities in diseased leaves and corms. With corms and leaves displaying heightened susceptibility to infection compared to other plant organs. Some of the beneficial bacterial taxa enriched in the diseased plants were also identified in networks, they showed an antagonistic relationship with Fusarium, suggesting a potential for these bacteria to be used in biologically based control strategies against rot disease. These insights could prove invaluable for the development of biocontrol agents aimed at combating this plant ailment. ConclusionThese findings significantly advance our understanding of saffron-microbiome interactions and could provide fundamental and important data for improving saffron yield and quality in the process of sustainable development.

Crop plants are vulnerable to a variety of diseases, including anthracnose, caused by various species of Colletotrichum fungi that damages major crops, including apples and hot peppers. The use of chemical fungicides for pathogen control may lead to environmental pollution and disease resistance. Therefore, we conducted this research to develop a Bacillus subtilis-based biological control agent (BCA). B. subtilis GYUN-2311 (GYUN-2311), isolated from the rhizosphere soil of an apple orchard, exhibited antagonistic activity against a total of 12 fungal pathogens, including eight Colletotrichum species. The volatile organic compounds (VOCs) and culture filtrate (CF) from GYUN-2311 displayed antifungal activity against all 12 pathogens, with 81% control efficiency against Fusarium oxysporum for VOCs and 81.4% control efficacy against Botryosphaeria dothidea for CF. CF also inhibited germination and appressorium formation in Colletotrichum siamense and C. acutatum. The CF from GYUN-2311 showed antifungal activity against all 12 pathogens in different media, particularly in LB medium. It also exhibited plant growth-promoting (PGP) activity, lytic enzyme activity, siderophore production, and the ability to solubilize insoluble phosphate. In trials on apples and hot peppers, GYUN-2311 effectively controlled disease, with 75 and 70% control efficacies against C. siamense in wounded and unwounded apples, respectively. Similarly, the control efficacy of hot pepper against C. acutatum in wounded inoculation was 72%. Combined application of GYUN-2311 and chemical suppressed hot pepper anthracnose to a larger extent than other treatments, such as chemical control, pyraclostrobin, TK (R), GYUN-2311 and cross-spraying of chemical and GYUN-2311 under field conditions. The genome analysis of GYUN-2311 identified a circular chromosome comprising 4,043 predicted protein-coding sequences (CDSs) and 4,096,969 bp. B. subtilis SRCM104005 was the strain with the highest average nucleotide identity (ANI) to GYUN-2311. AntiSMASH analysis identified secondary metabolite biosynthetic genes, such as subtilomycin, bacillaene, fengycin, bacillibactin, pulcherriminic acid, subtilosin A, and bacilysin, whereas BAGEL analysis confirmed the presence of competence (ComX). Six secondary metabolite biosynthetic genes were induced during dual culture in the presence of C. siamense. These findings demonstrate the biological control potential of GYUN-2311 against apple and hot pepper anthracnose.

This review examines natural pests, competitors of the Heracleum sosnowsky. Special attention is paid to the role of mutualism in the invasiveness of hogweed. the parsnip yellow spot virus, larvae of the weevil ( Lixus iridis (Olivier, 1807)), agromyzid flies ( Phytomyza pastinacae (Hendel, 1923)), umbrella moth ( Epermenia chaerophyllella (Goeze, 1783)), scoops ( Dasypolia temple (Thunberg, 1792)), depressariids ( Depressaria radiella (Goeze, 1783)), celery fly ( Euleia heraclei (Linnaeus, 1758)), lamellate beetles ( Oxythyrea funesta (Poda, 1761)), caterpillars of the Kamchatka Swallowtail ( Papiliomachaon (Linnaeus, 1758)) significantly damaged Heracleum sosnowsky. Thrips vulgatissimus (Haliday, 1836) feeds on the sap, while Lixus iridis eat leaves and stems of the above mentioned hogweed. Phoma complanate (Tode) (= Calophoma complanate) is a phytopathogenic fungi that damage Heracleum sosnowsky. Powdery mildew, ascochitosis and cylindrosporosis are most common fungal diseases of the giant hogweed. Shellfish farming and livestock grazing curb the spread of hogweed. Due to the lack of competition in the environment, the importance of its artificial creation is discussed. The fast-growing perennial grasses create dense turf that prevents germinating of hogweed seeds. Poapratensis L., Alopecuruspratensis L., Bromus inermis Leyss., Festuca rubra L., Phlumpratense L., Loliumperenne L., Helianthus tuberosus L., and Galega orientalis Lam. are among them. Replacement crops, such as Picea abies (L.) Karst. and Pinus sylvestris L., can compete in vacant lots and abandoned lands. The success of the hogweed populations introduction depends on the presence of pollinators, the spread of its seeds by animals and humans; symbiosis with fungi and bacteria. The possibility of limiting the spread of hogweed through the absence of species that improve its adaptability is discussed. It was concluded that biological control agents are promising to use and additional studies is needed to reduce the number of Heracleum sosnowsky and eliminate negative consequences for the environment.