Establishment of suppressive populations of bacterial biological control agents on aerial plant surfaces is a critical phase in biologically based management of floral diseases. Periodically, biocontrol agents encounter inhospitable conditions for growth on plants; consequently, tolerance of environmental stresses may contribute to their fitness. In many gram-negative bacteria, including strains of Pseudomonas spp., the capacity to survive environmental stresses is influenced by the stationary phase sigma factor RpoS. This study focused on the role of RpoS in stress response and epiphytic fitness of Pseudomonas fluorescens A506, a well-studied bacterial biological control agent. We detected a frameshift mutation in the rpoS of A506 and demonstrated that the mutation resulted in a truncated, nonfunctional RpoS. Using site-directed mutagenesis, we deleted a nucleotide from rpoS, which then encoded a full-length, functional RpoS. We compared the stress response and epiphytic fitness of A506 with derivative strains having the functional full-length RpoS or a disrupted, nonfunctional RpoS. RpoS had little effect on stress response of A506 and no consistent influence on epiphytic population size of A506 on pear or apple leaves or flowers. Although the capacity of strain A506 to withstand exposure to environmental stresses was similar to that of other fluorescent pseudomonads, this capacity was largely independent of rpoS.
Key Laboratory of Plant Nutrition and the Agro-Environment in Northwest China, Ministry of Agriculture and Rural Affairs, College of Natural Resources and Environment, Northwest A & F University, Yangling, Shaanxi 712100, China.
Microplastics (MPs) have been confirmed as a hotspot for antibiotic resistance genes (ARGs) in wastewater. However, the impact of MPs on the transfer of ARGs in wastewater treatment remains unclear. This study investigated the roles and mechanisms of conventional (polystyrene, PS) and biodegradable (polylactic acid, PLA) MPs in the conjugative transfer of ARGs during ultraviolet disinfection.
Pituitary adenylate cyclase-activating polypeptide (PACAP) affects rodents' stress-related behaviors, such as anxiety-like behavior or fear conditioning. However, previous studies have investigated the effect of intracerebroventricular, but not hippocampal, injection of this PAC1R-selective antagonist (PACAP-6-38) on anxiety-like behavior. However, it has been reported that administration of PACAP-6-38 to the dorsal hippocampus reduces the fear response in a fear conditioning test.
Changes to the composition of the microbiome in neoplasia, is termed oncobiosis, may affect tumor behavior through the changes to the secretion of bacterial metabolites. In this study we show, that ursodeoxycholic acid (UDCA), a bacterial metabolite, has cytostatic properties in pancreatic adenocarcinoma cell (PDAC) models. UDCA in concentrations corresponding to the human serum reference range suppressed PDAC cell proliferation.
Human Phenome Institute, Institute of Medical Genetics and Genomics, MOE Key Laboratory of Contemporary Anthropology, Zhangjiang Fudan International Innovation Center, Fudan University, 825 Zhangheng Road, Shanghai, 201203 China.
Unlabelled: () is a neuro-specific gene linked to neurodevelopmental disorders and has recently been reported to function as a bidirectional emotional regulator, highlighting its molecular roles in the nervous system. However, the connections between , brain architecture, and functionality remain to be fully elucidated. Our study utilized 11.
Research Group in Bioclimatology, Ethology and Animal Welfare (BioEt), Department of Animal Science, Federal University of Paraiba, Areia, Paraiba, Brazil.
The present study aimed to evaluate the effects of different nutritional plans on meat quails subjected to heat stress. A total of 324 quails male European quails () were used, with an average initial weight of 121.48 g ± 3.
