Instruct: Identify the main category of Biorxiv papers based on the titles and abstracts
Query: Abscisic Acid Increases Hydrogen Peroxide in Multiple Subcellular Compartments to Drive Stomatal Closure Abscisic acid (ABA) closes stomata to minimize transpiration and gas exchange in response to drought. ABA signaling increases accumulation of reactive oxygen species (ROS) in guard cells to drive stomatal closure. We used chemical dyes and genetically-encoded biosensors to identify the subcellular localizations where ABA increases hydrogen peroxide (H2O2) in guard cells. The general redox sensor, dichlorofluorescein (DCF), revealed ABA-driven ROS increases in distinct subcellular locations including chloroplasts, cytosol, and nuclei. ABA also increased fluorescence of both DCF and an H2O2-selective probe, Peroxy Orange 1, in mitochondria, which colocalize with Mitotracker Red. Whole cell and mitochondrial localized ABA-increased ROS signals were lost in an ABA-insensitive quintuple ABA receptor mutant and accentuated in an ABA-hypersensitive mutant. The ABA-induced ROS accumulation in mitochondria was lost in guard cells of mutants with defects in genes encoding H2O2 elevating respiratory burst oxidase homolog (RBOH) enzymes and reduced by treatment with the RBOH inhibitor VAS2870. ABA treatment of guard cells transformed with the genetically-encoded H2O2 reporter targeted to the cytoplasm, roGFP2-Orp1, and the mitochondrial targeted, mt-roGFP2-Orp1, revealed significant ABA-induced H2O2 increases. Furthermore, H2O2 treatment is sufficient to close stomata. These results reveal that ABA elevates H2O2 accumulation in guard cell cytosol and mitochondria to drive stomatal closure.

One sentence summaryGenetically encoded biosensors and chemical probes revealed ABA-dependent increases in hydrogen peroxide, a reactive oxygen species with signaling activity, in guard cell cytoplasm and mitochondria.
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The categories of this paper are: microbiology
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The categories of this paper are: genetics
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The categories of this paper are: scientific
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The categories of this paper are: animal
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The categories of this paper are: neuroscience
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The categories of this paper are: ecology
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The categories of this paper are: behavior
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The categories of this paper are: education
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The categories of this paper are: systems
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The categories of this paper are: cell
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The categories of this paper are: bioinformatics
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The categories of this paper are: biochemistry
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The categories of this paper are: developmental
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The categories of this paper are: biophysics
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The categories of this paper are: physiology
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The categories of this paper are: immunology