ABSTRACT
The introductory chapter introduces aeromicrobiology as a part of aerobiology essentially concerned with aerosolization, transmission, and deposition of microorganisms. Differential characteristics of the various strata of the atmosphere are described. The various groups of microorganisms, namely bacteria, archaea, fungi, protozoans, algae, and viruses, are examined, with particular attention to the forms and functions and propensity to become airborne. The indoor and outdoor sources of microorganisms as well as the natural and anthropogenic factors that modulate their aerosolization and survival in the air are elucidated. Molecular approach to sampling and analysis of bioaerosols samples is highlighted as a game changer in our understanding of airborne microbes. While emphasizing the long history of control of microorganism in the air dating back to the infancy of knowledge of germs, human-made biological agents and biocontrol agents are identified as a major threat to human existence, deserving attention, even as various conspiracy theories as in the case of SARS-CoV-2 remain unverified. © 2023 Elsevier Inc. All rights reserved.
ABSTRACT
Introduction: Oomycetes cause several damaging diseases of plants and animals, and some species also act as biocontrol agents on insects, fungi, and other oomycetes. RNA silencing is increasingly being shown to play a role in the pathogenicity of Phytophthora species, either through trans-boundary movement of small RNAs (sRNAs) or through expression regulation of infection promoting effectors. Methods: To gain a wider understanding of RNA silencing in oomycete species with more diverse hosts, we mined genome assemblies for Dicer-like (DCL), Argonaute (AGO), and RNA dependent RNA polymerase (RDRP) proteins from Phytophthora plurivora, Ph. cactorum, Ph. colocasiae, Pythium oligandrum, Py. periplocum, and Lagenidium giganteum. Moreover, we sequenced small RNAs from the mycelium stage in each of these species. Results and discussion: Each of the species possessed a single DCL protein, but they differed in the number and sequence of AGOs and RDRPs. SRNAs of 21nt, 25nt, and 26nt were prevalent in all oomycetes analyzed, but the relative abundance and 5' base preference of these classes differed markedly between genera. Most sRNAs mapped to transposons and other repeats, signifying that the major role for RNA silencing in oomycetes is to limit the expansion of these elements. We also found that sRNAs may act to regulate the expression of duplicated genes. Other sRNAs mapped to several gene families, and this number was higher in Pythium spp., suggesting a role of RNA silencing in regulating gene expression. Genes for most effector classes were the source of sRNAs of variable size, but some gene families showed a preference for specific classes of sRNAs, such as 25/26 nt sRNAs targeting RxLR effector genes in Phytophthora species. Novel miRNA-like RNAs (milRNAs) were discovered in all species, and two were predicted to target transcripts for RxLR effectors in Ph. plurivora and Ph. cactorum, indicating a putative role in regulating infection. Moreover, milRNAs from the biocontrol Pythium species had matches in the predicted transcriptome of Phytophthora infestans and Botrytis cinerea, and L. giganteum milRNAs matched candidate genes in the mosquito Aedes aegypti. This suggests that trans-boundary RNA silencing may have a role in the biocontrol action of these oomycetes.
ABSTRACT
Immunobiotics, a group of probiotics, have the effect of anti-infection by regulating immune function, which can be added in in foods or used to make adjuvants or medicines (biologics). Immunobiotics can stimulate the mucosal immune system of the body, regulate innate and acquired immunity and exert non-specific anti-microbial (bacterial and viral) infection effects through oral, nasal mucosa, sublingual and other routes, but the immune regulation function of immunobiotics is species-specific. Oral administration of Lactobacillus plantarum GUANKE stimulated the increase and maintenance of SARS-CoV-2 neutralization antibodies in mice even 6 months after immunization. When L. plantarum GUANKE was given immediately after SARS-CoV-2 vaccination, the level of SARS-COV-2 specific neutralizing antibody in bronchoalveolar lavage increased by 8 times in mice, which improved the local and systematic cellular immune response to SARS-CoV-2 of mice. Clinical studies have found that immunobiotics have the auxiliary effect in the treatment of COVID-19 by mitigating the symptoms and increase the level of SARS-CoV-2 specific antibody of the patients. It is necessary to conduct research and evaluation for the appropriate guideline of immunobiotics use as erly as possible to provide a new option for the prevention and control of COVID-19.
ABSTRACT
Originally, the 17th Symposium on Insect-Plant Relationships (SIP-17) was scheduled to take place in Leiden, The Netherlands, in July 2020. However, due to the COVID-19 pandemic, the symposium was postponed to July 2021 and held in an exclusively online format. This exceptional edition has resulted in four strong contributions to the journal. It is with great pleasure that we now present a themed issue including the proceedings of SIP-17, supplemented with eight regular articles within the subject of insect-plant relationships.
ABSTRACT
Tomato (Solanum lycopersicum L.) production is constantly threatened by wide array of mycopathogens. Emmia lacerata has been investigated as an endophyte, a saprophyte, a respiratory pathogen, and presently, as a soil-borne mycopathogen of tomato. The disease caused by E. lacerata FMIB29 in tomato was characterised through phenotypic assessment and controlled with antifungal plant extracts, using soil amendment assay (0.2 g/plant). Pathogenesis of E. lacerata on tomato ranged from mild chlorosis to severe stunt, or plant death. The highest leaf number, plant height, and disease severity reduction of 17.33 cm, 39.00 and 43.80%, respectively were recorded on G. arborea treated plants. Aqueous extracts of these inhibitory plants are accessible, and could be further studied for their biocontrol potentials against mycopathogens like E. lacerata. This will encourage tomato production and prevent pathogen transfer to humans;essentially, to avoid complications in individuals suffering from COVID-19 and other respiratory diseases. [ FROM AUTHOR] Copyright of Archives of Phytopathology & Plant Protection is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)
ABSTRACT
Background: The fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), is an invasive alien species in Indonesia. This study aimed to assess the impact of its invasion in Indonesia by measuring the damaged area caused by the pest in maize fields located across East Java and simultaneously determine whether S. frugiperda outcompetes the native Asian armyworm Spodoptera litura (Fabricius). Secondly, the virulence of 14 entomopathogenic fungus (EPF) isolates against S. frugiperda larvae was evaluated in an effort to find effective biocontrol agent candidates. Results: The damaged area caused by S. frugiperda was generally higher than that caused by S. litura during the survey period from August 2019 to December 2021. It indicated that S. frugiperda may have dominated the native armyworm and become the primary key pest of maize in Indonesia. Based on a single-concentration assay (106 conidia ml−1), the tested EPF isolates displayed varying degrees of virulence against S. frugiperda larvae, causing larval mortality of 3.5 to 71% at 10-day post-treatment, with the highest mortality rates provided by Beauveria bassiana sensu lato and Trichoderma asperellum sensu lato. At a concentration of 108 conidia ml−1, B. bassiana s.l. and T. asperellum s.l. elicited high larval mortality of 76 and 81%, respectively, at 10-day post-treatment. Nevertheless, the probit analysis based on a concentration–response assay revealed that T. asperellum s.l. had lower LC50 and LC90 values than B. bassiana s.l. Conclusions: The attack and invasion of S. frugiperda seem to be a continual threat to the maize agro-ecosystem in Indonesia. As a consequence, Indonesia should mitigate and be well-prepared for future outbreaks of S. frugiperda. Indigenous EPF isolates used in this study may act as promising biocontrol agents of S. frugiperda, especially T. asperellum s.l. This study also serves as the first report documenting the direct lethality of Trichoderma fungus on S. frugiperda larvae. [ FROM AUTHOR] Copyright of Egyptian Journal of Biological Pest Control is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)