• Stomatal opening is caused by guard cell swelling due to an accumulation of osmotica. We investigated the release of carbon from guard cell chloroplasts as a source for the production of organic osmotica. • Photosynthetically active chloroplasts were isolated from guard cell protoplasts of Vicia faba. Export of metabolites into the surrounding medium was analyzed by silicone oil filtering centrifugation and spectrophotometrically by coupled metabolite assays. Effects of external oxaloacetate and 3-phosphoglycerate on photosynthetic electron transport were examined by recording chlorophyll fluorescence. • In the light, guard cell chloroplasts exported triose phosphates, glucose, maltose and hexose phosphates. The presence of phosphate in the medium was essential for the release of phosphorylated compounds and also strongly enhanced the export of glucose and maltose. Total efflux of carbon from illuminated guard cell chloroplasts was on average 486 µatom C (mg Chl) h , which was significant with respect to the carbon requirement for stomatal opening. • Metabolites released by illuminated guard cell chloroplasts originated predominantly from starch breakdown. Photosynthetic electron transport provided redox power for the reduction of oxaloacetate and 3-phosphoglycerate.
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http://dx.doi.org/10.1046/j.1469-8137.2003.00789.x | DOI Listing |
Int J Mol Sci
January 2025
Medical Research Core Facility and Platforms (MRCFP)-Drug Discovery Platform, King Abdullah International Medical Research Center (KAIMRC), King Saud Bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs (MNGHA), Riyadh 11481, Saudi Arabia.
Peroxisome proliferator-activated receptors (PPARs) are considered good drug targets for breast cancer because of their involvement in fatty acid metabolism that induces cell proliferation. In this study, we used the KAIMRC1 breast cancer cell line. We showed that the PPARE-Luciferase reporter gets highly activated without adding any exogenous ligand when PPAR alpha is co-transfected, and the antagonist GW6471 can inhibit the activity.
View Article and Find Full Text PDFGenes (Basel)
January 2025
Department of Biology and Biotechnology 'L. Spallanzani', University of Pavia, via Ferrata 9, 27100 Pavia, Italy.
DNA damage response (DDR) contributes to seed quality by guarding genome integrity in the delicate phases of pre- and post-germination. As a key determinant of stress tolerance and resilience, DDR has notable implications on the wider scale of the agroecosystems challenged by harsh climatic events. The present review focuses on the existing and documented links that interconnect DDR efficiency with an array of molecular hallmarks with biochemical, molecular, and physiological valence within the seed metabolic networks.
View Article and Find Full Text PDFAntibiotics (Basel)
December 2024
Nanomedicine Department, King Abdullah International Medical Research Center, King Saud Bin Abdulaziz University for Health Sciences, Riyadh 11481, Saudi Arabia.
The emergence of multidrug-resistant bacteria presents a significant global health threat. Liposomal antibiotics have shown a potential to improve antibiotic delivery and efficacy. This study aimed to develop liposomes encapsulating tobramycin (TOB) and methylglyoxal (MGO) to enhance TOB activity while reducing bacterial adhesion and biofilm formation.
View Article and Find Full Text PDFCancers (Basel)
January 2025
ARUP Laboratories, Department of Pathology, University of Utah, Salt Lake City, UT 84103, USA.
Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is an aggressive orphan hematopoietic malignancy characterized by cutaneous and systemic hematologic involvement. BPDCN is frequently misidentified, but early, accurate diagnosis is critical to extending patient survival using tagraxofusp, a first-in-class CD123-targeted therapy, and increasing their chances of receiving a potentially curative stem cell transplantation. Cases of BPDCN in countries of the Gulf Cooperation Council are lower than the extrapolated incidence from other geographic locations due to lack of awareness of key diagnostic features, lack of consensus on the minimal phenotype for diagnosis, and lack of local immunohistochemistry testing facilities, contributing to underdiagnosis in this region.
View Article and Find Full Text PDFPlant Physiol
January 2025
Laboratory of Plant Physiology and Biophysics, Bower Building, and.
Accelerating stomatal kinetics through synthetic optogenetics and mutations that enhance guard cell K+ flux has proven a viable strategy to improve water use efficiency and biomass production. Stomata of the model C4 species Gynandropsis gynandra, a relative of the C3 plant Arabidopsis thaliana, are similarly fast to open and close. We identified and cloned the guard cell rectifying outward K+ channel (GROK) of Gynandropsis and showed that GROK is preferentially expressed in stomatal guard cells.
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