NADPH oxidases (NOX) catalyze the production of superoxides, a type reactive oxygen species (ROS). The dramatic induction ROS by human NOX2 in activated blood phagocytic cells and its role promoting pathogen killing has long motivated research this area ([Babior et al., 2002][

Abstract Genes encoding homologs of the gp91phox subunit plasma membrane NADPH oxidase complex have been identified in plants and are hypothesized to be a source reactive oxygen species during defense responses. However, direct involvement gene products superoxide (O2 −) production has yet shown. A novel activity gel assay based on protein fractionation native or sodium dodecyl sulfate (SDS)-denaturing polyacrylamide gels was developed. In electrophoresis, one two major O2 −-producing...

Abstract Plant respiratory burst oxidase homologs (Rboh) are of the human neutrophil pathogen-related gp91phox. Antisense technology was employed to ascertain biological function Lycopersicon esculentum (tomato) Rboh. Lines with diminished Rboh activity showed a reduced level reactive oxygen species (ROS) in leaf, implying role for establishing cellular redox milieu. Surprisingly, antisense plants acquired highly branched phenotype, switched from indeterminate determinate growth habit, and...

Summary The plant molybdenum‐cofactor (Moco) and flavin‐containing enzymes, xanthine dehydrogenase (XDH; EC 1.2.1.37) aldehyde oxidase (AO; 1.2.3.1) are thought to play important metabolic roles in purine metabolism hormone biosynthesis, respectively. Their animal counterparts contribute reactive oxygen species (ROS) production numerous pathologies here we examined these enzymes as potential sources of ROS plants. Novel in‐gel assay techniques Moco sulfurase mutants, lacking a sulfur ligand...

Summary The remobilization of metabolites during stress and senescence plays an important role in optimal plant adaptation to the environment. molybdenum co‐factor (MoCo) flavin‐containing enzyme xanthine dehydrogenase (XDH; EC 1.2.1.37) are pivotal for purine remobilization, catalyze conversion catabolic products hypoxanthine uric acid, which is subsequently degraded ureides allantoin allantoate. We observed that wild‐type plants conditions extended darkness or increasing leaf age caused...

Abstract The identification and understanding of metabolic pathways is a key aspect in crop improvement drug design. common approach for their detection based on gene annotation ontology. Correlation-based network analysis, where metabolites are arranged into formation, used as complentary tool. Here, we demonstrate the correlation-based analysis combined with machine-learning techniques. Metabolites known tomato pathways, non-tomato random sets were mapped subgraphs onto metabolite...

Abstract Reactive oxygen species (ROS) play a crucial role in many cellular responses and signaling pathways, including the oxidative burst defense response to pathogens. We have examined very early events cryptogein-induced ROS production tobacco (Nicotiana tabacum) Bright Yellow-2 suspension cells. Using Amplex Red Ultra reagents, which report real-time H2O2 accumulation cell populations, we show that internal signal for develops more rapidly than external apoplastic signal. Subcellular of...

Summary The molybdenum cofactor (MoCo)‐containing enzymes aldehyde oxidase (AO; EC 1.2.3.1) and xanthine dehydrogenase (XDH; 1.2.1.37) require for activity a sulfuration step that inserts terminal sulfur ligand into the MoCo. tomato flacca mutation was originally isolated as wilty phenotype due to lack of abscisic acid (ABA) is related simultaneous loss AO XDH activities. An expressed sequence tag candidate from selected on basis homology sulfurases animals, fungi recently Arabidopsis genes...

The gaseous pollutant SO(2) readily reacts with water to form sulfite that impacts deleteriously on animal and plant health. By modulating the level of oxidase (SO) catalyzes transformation sulfites non-toxic sulfate, we show Arabidopsis tomato plants can be rendered resistant or susceptible SO(2)/sulfite. Plants in which expression was abrogated by RNA interference (RNAi) accumulated relatively less sulfate after application showed enhanced induction senescence wounding-associated...

The requirement for hydrogen peroxide (H2O2) generation and action during stomatal closure induced by darkness abscisic acid (ABA) was investigated in pea (Pisum sativum L.). Stomatal or ABA inhibited the H2O2-scavenging enzyme catalase antioxidant N-acetyl cysteine (NAC), diphenylene iodonium (DPI), an inhibitor of H2O2-generating NADPH oxidase. Exogenous H2O2 a dose- time-dependent manner, also required ABA-inhibition opening light. accumulation guard cells increased ABA, as assessed with...

Abstract Plant sulfite reductase (SiR; Enzyme Commission 1.8.7.1) catalyzes the reduction of to sulfide in reductive sulfate assimilation pathway. Comparison SiR expression tomato (Solanum lycopersicum ‘Rheinlands Ruhm’) and Arabidopsis (Arabidopsis thaliana) plants revealed that is expressed a different tissue-dependent manner likely reflects dissimilarity sulfur metabolism between plant species. Using mutants with modified expression, we show here resistance ectopically applied...

The fresh water shortage in agriculture is an increasing problem worldwide, therefore the possibility of cultivating crops under saline conditions high importance. Crithmum maritimum, a halophytic plant naturally found on rocky coastlines Atlantic Ocean and Mediterranean Sea, has long history human consumption was recently suggested as cash crop for biosaline agriculture. In present study, we compared responses different genotypes originating from France, Portugal Israel to moderate...

The Arabidopsis (Arabidopsis thaliana) aldehyde oxidases are a multigene family of four (AAO1–AAO4) that oxidize variety aldehydes, among them abscisic aldehyde, which is oxidized to the phytohormone acid. Toxic aldehydes generated in plants both under normal conditions and response stress. detoxification such by oxidation attributed dehydrogenases but never oxidases. feasibility siliques via AAO4 was demonstrated, first, its ability efficiently an array aromatic aliphatic including reactive...

Abstract The flacca tomato (Lycopersicon esculentum) mutant displays a wilty phenotype as result of abscisic acid (ABA) deficiency. Mo cofactor (MoCo)-containing aldehyde oxidases (AO; EC 1.2.3.1) are thought to play role in the final oxidation step required for ABA biosynthesis. AO and related MoCo-containing enzymes xanthine dehydrogenase (XDH; 1.2.1.37) nitrate reductase (EC 1.6.6.1) were examined extracts genotype wild-type (WT) roots shoots. levels MoCo found be similar both genotypes....

Abstract Little is known about the homeostasis of sulfite levels, a cytotoxic by-product plant sulfur turnover. By employing extended dark to induce catabolic pathways, we followed key elements network enzymes that include adenosine-5′-phosphosulfate reductase and scavengers oxidase (SO), reductase, UDP-sulfoquinovose synthase, β-mercaptopyruvate sulfurtransferases. During dark, SO was enhanced in tomato (Solanum lycopersicum) wild-type leaves, while other components were down-regulated. RNA...

The nitrogen (N)-rich ureides allantoin and allantoate, which are products of purine catabolism, play a role in N delivery Leguminosae. Here, we examined their as an source nonlegume plants using Arabidopsis (Arabidopsis thaliana) mutated XANTHINE DEHYDROGENASE1 (AtXDH1), catalytic bottleneck catabolism. Older leaves the Atxdh1 mutant exhibited early senescence, lower soluble protein, organic levels compared with wild-type older when grown 1 mm nitrate but were comparable to wild type under...

Pathogenic fungi cause major postharvest losses. During storage and ripening, fruit becomes highly susceptible to that disease. Fungicides are effective treatments limit However, due increased public concern for their possible side effects, there is a need develop new strategies control fungal pathogens. Botrytis cinerea, common pathogen, was shown uptake small double-stranded RNA (dsRNA) molecules from the host plant. Such dsRNA can regulate gene expression through interference system. This...

The Arabidopsis thaliana aldehyde oxidase 3 (AAO3) catalyzes the oxidation of abscisic (ABal) to acid (ABA). Besides ABal, plants generate other aldehydes that can be toxic above a certain threshold. AAO3 knockout mutants (aao3) exhibited earlier senescence but equivalent relative water content compared with wild-type (WT) during normal growth or upon application UV-C irradiation. Aldehyde profiling in leaves 24-day-old revealed higher accumulation acrolein, crotonaldehyde, 3Z-hexenal,...