Jasmonate synthesis and signalling are essential for plant defense upregulation upon herbivore or microbial attacks. Stress-induced accumulation of jasmonoyl-isoleucine (JA-Ile), the bioactive hormonal form triggering transcriptional changes, is dynamic and transient because of the existence of potent removal mechanisms. Two JA-Ile turnover pathways operate in Arabidopsis, consisting in cytochrome P450 (CYP94)-mediated oxidation and deconjugation by the amidohydrolases IAR3/ILL6. Understanding their impacts was previously blurred by gene redundancy and compensation mechanisms. Here we address the consequences of blocking these pathways on jasmonate homeostasis and defenses in double-2ah, triple-3cyp mutants, and a quintuple-5ko line deficient in all known JA-Ile-degrading activities. These lines reacted differently to either mechanical wounding/insect attack or fungal infection. Both pathways contributed additively to JA-Ile removal upon wounding, but their impairement had opposite impacts on insect larvae feeding. By contrast, only the ah pathway was essential for JA-Ile turnover upon infection by Botrytis, yet only 3cyp was more fungus-resistant. Despite building-up extreme JA-Ile levels, 5ko displayed near-wild-type resistance in both bioassays. Molecular analysis indicated that restrained JA-Ile catabolism resulted in enhanced defense/resistance only when genes encoding negative regulators were not simultaneously overstimulated. This occurred in discrete stress- and pathway-specific combinations, providing a framework for future defense-enhancing strategies.
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http://dx.doi.org/10.1111/pce.13753 | DOI Listing |
Sleep
January 2025
Postgraduate Program in Epidemiology, Federal University of Pelotas, Pelotas, RS, Brazil.
We aimed to test the association between sleep-related polygenic scores (PGSs) and accelerometer-based sleep metrics among Brazilian adolescents and to evaluate potential mechanisms underlying the association through the enrichment of obesity, and cortisol pathway-specific polygenic scores (PRSet). Utilizing data from The 2004 Pelotas (Brazil) Birth Cohort, sleep time window and sleep efficiency were measured at the 11-year-old follow-up using ActiGraph accelerometers. Three sleep PGSs were developed based on the most recent genome-wide association study of accelerometer-based sleep measures.
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September 2024
CERVO Brain Research Center, Department of Psychiatry and Neuroscience, Faculty of medicine, Université Laval, Quebec City, QC G1J 2G3, Canada
The lateral habenula (LHb) has emerged as a pivotal brain region implicated in depression, displaying hyperactivity in human and animal models of depression. While the role of LHb efferents in depressive disorders has been acknowledged, the specific synaptic alterations remain elusive. Here, employing optogenetics, retrograde tracing, and ex vivo whole-cell patch-clamp techniques, we investigated synaptic transmission in male mice subjected to chronic social defeat stress (CSDS) at three major LHb neuronal outputs: the dorsal raphe nucleus (DRN), the ventral tegmental area (VTA), and the rostromedial tegmental nucleus (RMTg).
View Article and Find Full Text PDFACS Omega
February 2024
Department of Functional Sciences, Faculty of Veterinary Medicine, Pharmacology and Toxicology, Fundamental and Applied Research for Animals & Health (FARAH), University of Liège, Sart Tilman, 4000 Liège 1, Belgium.
Equine atypical myopathy (AM) is a severe environmental intoxication linked to the ingestion of protoxins contained in seeds and seedlings of the sycamore maple () in Europe. The toxic metabolites cause a frequently fatal rhabdomyolysis syndrome in grazing horses. Since these toxic metabolites can also be present in cograzing horses, it is still unclear as to why, in a similar environmental context, some horses show signs of AM, whereas others remain clinically healthy.
View Article and Find Full Text PDFNeuroscience
March 2024
Department of Radiology, Gucheng County Hospital of Hebei Province, Hengshui 253800, Hebei, People's Republic of China.
Post-stroke depression (PSD) is a prevalent mental health issue, and resveratrol (RES) has been implicated in its management. This study aimed to elucidate the impact of RES on PSD. A PSD rat model was established through middle cerebral artery occlusion and chronic unpredictable mild stress.
View Article and Find Full Text PDFJ Vis Exp
December 2023
Department of Biochemistry and Molecular Pharmacology, NYU Grossman School of Medicine; The Laura and Isaac Perlmutter Cancer Center, NYU Langone Health; Howard Hughes Medical Institute, NYU Grossman School of Medicine; Institute of Enzymology, Centre of Excellence of the Hungarian Academy of Sciences, HUN-REN Research Centre for Natural Sciences;
DNA has dedicated cellular repair pathways capable of coping with lesions that could arise from both endogenous and/or exogenous sources. DNA repair necessitates collaboration between numerous proteins, responsible for covering a broad range of tasks from recognizing and signaling the presence of a DNA lesion to physically repairing it. During this process, tracks of single-stranded DNA (ssDNA) are often created, which are eventually filled by DNA polymerases.
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