Abstract The light-saturated rate of photosynthetic O2 evolution in Chlamydomonas reinhardtii declined by approximately 75% on a per-cell basis after 4 d P starvation or 1 S starvation. Quantitation the partial reactions electron transport demonstrated that photosystem (PS) I activity was unaffected limitation, whereas PSII reduced more than 50%. This decline correlated with both maximal quantum efficiency and accumulation secondary quinone acceptor nonreducing centers (PSII capable...

Understanding the ways in which phosphorus metabolism is regulated photosynthetic eukaryotes critical for optimizing crop productivity and managing aquatic ecosystems can be a major source of pollution. Here we describe gene encoding regulator metabolism, designated Psr1 (phosphorus starvation response), from eukaryote. The protein acclimation unicellular green alga Chlamydomonas reinhardtii to starvation. N-terminal half contains region similar myb DNA-binding domains C-terminal possesses...

Cellular metabolism depends on the appropriate concentration of intracellular inorganic phosphate; however, little is known about how phosphate concentrations are sensed. The similarity Pho84p, a high-affinity transporter in Saccharomyces cerevisiae, to glucose sensors Snf3p and Rgt2p has led hypothesis that Pho84p an sensor. Furthermore, pho84Delta strains have defects signaling; they constitutively express PHO5, starvation-inducible gene. We began these studies determine role transporters...

Plants are continually subjected to ultraviolet-B (UV-B) irradiation (290 320 nanometers) as a component of sunlight, which induces variety types damage the plant DNA. Repair two major DNA photoproducts was analyzed in wild-type Arabidopsis thaliana and mutant derivative whose growth sensitive UV-B radiation. In seedlings, repair cyclobutane pyrimidine dimers occurred more slowly dark than light; this photoproduct not affected mutant. Repair, dark, pyrimidine-pyrimidinone(6-4) defective UV-sensitive

Symbiotic relationships between N2-fixing prokaryotes and their autotrophic hosts are essential in nitrogen (N)-limited ecosystems, yet the importance of this association pristine boreal peatlands, which store 25 % world's soil (C), has been overlooked. External inputs N to bogs predominantly atmospheric, given that regions Canada anchor some lowest rates found globally (~1 kg ha−1 year−1), biomass production is thought be limited primarily by N. Despite historically low deposition, we show...

Abstract Background Inorganic phosphate is an essential nutrient required by organisms for growth. During starvation, Saccharomyces cerevisiae activates the signal transduction (PHO) pathway, leading to expression of secreted acid phosphatase, PHO5 . The fission yeast, Schizosaccharomyces pombe , regulates ScPHO5 homolog ( pho1 + ) via a non-orthologous PHO pathway involving genetically identified positive pho7 and negative csk1 regulators. genes induced limitation molecular mechanism which...

A cell's ability to generate different responses levels of stimulus is an important component adaptive environmental response. Transcriptional are frequently controlled by transcription factors regulated phosphorylation. We demonstrate that differential phosphorylation the budding yeast factor Pho4 contributes gene expression. When cells grown in high-phosphate growth medium, phosphorylated on four critical residues cyclin–CDK complex Pho80–Pho85 and inactivated. starved for phosphate,...

Abstract We have examined the extracellular phosphatases produced by terrestrial green alga Chlamydomonas reinhardtii in response to phosphorus deprivation. Phosphorus-deprived cells increase alkaline phosphatase activity 300-fold relative unstarved cells. The are released into medium cell-wall-deficient strains and wild-type after treatment with autolysin, indicating that they localized periplasm. Anion-exchange chromatography analysis nondenaturing polyacrylamide gel electrophoresis...

A major challenge in the post-genomic era is development of experimental approaches to monitor properties proteins on a proteome-wide level. It would be particularly useful systematically assay protein subcellular localization, post-translational modifications and protein-protein interactions, both at steady state response environmental stimuli. Development new reagents methods will enhance our ability do so efficiently systematically. Here we describe construction two collections budding...

ABSTRACT The phosphate signal transduction (PHO) pathway, which regulates genes in response to starvation, is well defined Saccharomyces cerevisiae . We asked whether the PHO pathway was same distantly related fission yeast Schizosaccharomyces pombe screened a deletion collection for mutants aberrant phosphatase activity, primarily consequence of pho1 + transcription. identified novel zinc finger-containing protein (encoded by spbc27b12.11c ), we have named pho7 , that essential...

Abstract P-starved plants scavenge inorganic phosphate (Pi) by developing elevated rates of Pi uptake, synthesizing extracellular phosphatases, and secreting organic acids. To elucidate mechanisms controlling these acclimation responses in photosynthetic organisms, we characterized the green algaChlamydomonas reinhardtii to P starvation developed screens for isolating mutants (designated psr[phosphorus-stress response]) abnormal their environmental levels Pi. Thepsr1-1 mutant was identified...

Abstract Organisms exhibit a diverse set of responses when exposed to low-phosphate conditions. Some these are specific for phosphorus limitation, including that enable cells efficiently scavenge phosphate from internal and external stores via the production high-affinity transporters synthesis intracellular extracellular phosphatases. Other general occur under number different environmental stresses, helping coordinate cellular metabolism cell division with growth potential cell. In this...

Abstract Increasing temperatures and a reduction in the frequency severity of freezing events have been linked to species distribution shifts. Across globe, mangrove ranges are expanding toward higher latitudes, likely due diminishing associated with climate change. Continued warming will alter coastal wetland plant dynamics both above‐ belowground, potentially altering capacity keep up sea level rise. We conducted an situ experiment, northeast Florida, determine how increased temperature...

Comparative genomic analyses of Candida glabrata and Saccharomyces cerevisiae suggest many signal transduction pathways are highly conserved. Focusing on the phosphate (PHO) pathway C. glabrata, we demonstrate that components conserved confirm role CgPHO81, CgPHO80, CgPHO4, CgMSN5 in PHO through deletion analysis. Unlike S. cerevisiae, shows little dependence transcription factor, Pho2, for induction phosphate-regulated genes during limitation. We show CgPho4 protein is necessary sufficient...

In vivo assembly of plasmids has become an increasingly used process, as high throughput studies in molecular biology seek to examine gene function. this study, we investigated the plasmid construction technique called gap repair cloning (GRC) two closely related species yeast - Saccharomyces cerevisiae and Candida glabrata. GRC utilizes homologous recombination (HR) activity join a linear vector piece DNA that contains base pair homology. We demonstrate minimum 20 bp homology on each side...

The iprA gene (formerly known as yaiV or STM0374) is located in a two-gene operon the Salmonella enterica serovar Typhimurium genome and associated with altered expression during spaceflight rotating-wall-vessel culture conditions that increase virulence. However, uncharacterized literature. In this report, we present first targeted characterization of gene, which revealed highly conserved across Enterobacteriaceae We found S Typhimurium, Escherichia coli, Enterobacter cloacae ΔiprA mutant...

Evolution through natural selection suggests unnecessary genes are lost. We observed that the yeast Candida glabrata lost gene encoding a phosphate-repressible acid phosphatase (PHO5) present in many yeasts including Saccharomyces cerevisiae. However, C. still had phosphate starvation-inducible activity. Screening genomic library, we identified CgPMU2, member of three-gene family contains phosphomutase-like domain. This small-scale duplication event could allow for sub- or...

The phosphorylated form of thiamine (Vitamin B1), pyrophosphate (TPP) is essential for the metabolism amino acids and carbohydrates in all organisms. Plants microorganisms, such as yeast, synthesize de novo whereas animals do not. signal transduction (THI) pathway Saccharomyces cerevisiae well characterized. ~10 genes required biosynthesis uptake are transcriptionally upregulated during starvation by THI2, THI3, PDC2. Candida glabrata, a human commensal opportunistic pathogen, closely...

What steps are required for a promoter to acquire regulation by an environmental condition? We address this question examining in Candida glabrata that is regulated phosphate starvation and the transcription factor Pho4. The gene PMU2 encodes secreted acid phosphatase resulted from duplication events not present other Ascomycetes, only of three paralogs has acquired Pho4 regulation. observe C. functional Saccharomyces cerevisiae, which surprising because it Pho4, similar manner both species...