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Articles 1 - 5 of 5

Full-Text Articles in Biology

Phospholipase Dα1 And Phosphatidic Acid Regulate Nadph Oxidase Activity And Production Of Reactive Oxygen Species In Aba-Mediated Stomatal Closure In Arabidopsis, Xuemin Wang, Yanyan Zhang, Huiying Zhu, Qun Zhang, Maoyin Li, Min Yan, Rong Wang, Liling Wang, Ruth Welti, Wenhua Zhang Aug 2009

Phospholipase Dα1 And Phosphatidic Acid Regulate Nadph Oxidase Activity And Production Of Reactive Oxygen Species In Aba-Mediated Stomatal Closure In Arabidopsis, Xuemin Wang, Yanyan Zhang, Huiying Zhu, Qun Zhang, Maoyin Li, Min Yan, Rong Wang, Liling Wang, Ruth Welti, Wenhua Zhang

Biology Department Faculty Works

We determined the role of Phospholipase Dα1 (PLDα1) and its lipid product phosphatidic acid (PA) in abscisic acid (ABA)-induced production of reactive oxygen species (ROS) in Arabidopsis thaliana guard cells. The pldα1 mutant failed to produce ROS in guard cells in response to ABA. ABA stimulated NADPH oxidase activity in wild-type guard cells but not in pldα1 cells, whereas PA stimulated NADPH oxidase activity in both genotypes. PA bound to recombinant Arabidopsis NADPH oxidase RbohD (respiratory burst oxidase homolog D) and RbohF. The PA binding motifs were identified, and mutation of the Arg residues 149, 150, 156, and 157 in …


Allometry Of The Duration Of Flight Feather Molt In Birds, Sievert Rohwer, Robert Ricklefs, Vanya Rohwer, Michelle Copple Jun 2009

Allometry Of The Duration Of Flight Feather Molt In Birds, Sievert Rohwer, Robert Ricklefs, Vanya Rohwer, Michelle Copple

Biology Department Faculty Works

No abstract provided.


Evolutionary Ecology Of Microbial Wars: Within-Host Competition And (Incidental) Virulence, Sam Brown, R Inglis, François Taddei Feb 2009

Evolutionary Ecology Of Microbial Wars: Within-Host Competition And (Incidental) Virulence, Sam Brown, R Inglis, François Taddei

Biology Department Faculty Works

Invading an occupied niche is a formidable ecological challenge, and one of particular human importance in the context of food-borne microbial pathogens. We discuss distinct categories of invader-triggered environmental change that facilitate invasion by emptying their niche of competitors. Evidence is reviewed that gut bacteria use such strategies to manipulate their environment (via bacteriocins, temperate phage viruses or immuno-manipulation) at the expense of their competitors are reviewed. The possible virulence implications of microbial warfare among multiple co-infecting strains are diverse. Killing competitors can reduce virulence by reducing overall microbial densities, or increase virulence if for example the allelopathic mechanism involves …


Synthesis: Evolutionary Ecology Of Microbial Wars: Within-Host Competition And (Incidental) Virulence, Sam Brown, Fredrik Inglis, François Taddei Feb 2009

Synthesis: Evolutionary Ecology Of Microbial Wars: Within-Host Competition And (Incidental) Virulence, Sam Brown, Fredrik Inglis, François Taddei

Biology Department Faculty Works

Invading an occupied niche is a formidable ecological challenge, and one of particular human importance in the context of food-borne microbial pathogens. We discuss distinct categories of invader-triggered environmental change that facilitate invasion by emptying their niche of competitors. Evidence is reviewed that gut bacteria use such strategies to manipulate their environment (via bacteriocins, temperate phage viruses or immuno-manipulation) at the expense of their competitors are reviewed. The possible virulence implications of microbial warfare among multiple co-infecting strains are diverse. Killing competitors can reduce virulence by reducing overall microbial densities, or increase virulence if for example the allelopathic mechanism involves …


High-Resolution, Long-Term Characterization Of Bacterial Motility Using Optical Tweezers, Lon Chubiz, Taejin Min, Patrick Mears, Christopher Rao, Ido Golding, Yann Chemla Jan 2009

High-Resolution, Long-Term Characterization Of Bacterial Motility Using Optical Tweezers, Lon Chubiz, Taejin Min, Patrick Mears, Christopher Rao, Ido Golding, Yann Chemla

Biology Department Faculty Works

We present a single-cell motility assay, which allows the quantification of bacterial swimming in a well-controlled environment, for durations of up to an hour and with a temporal resolution greater than the flagellar rotation rates of ∼100 Hz. The assay is based on an instrument combining optical tweezers, light and fluorescence microscopy, and a microfluidic chamber. Using this device we characterized the long-term statistics of the run-tumble time series in individual Escherichia coli cells. We also quantified higher-order features of bacterial swimming, such as changes in velocity and reversals of swimming direction.