Euglena gracilis was found to contain a peroxidase that specifically require L-ascorbic acid as the natural electron donor in cytosol. The presence of an oxidation-reduction system metabolizing demonstrated cells. Oxidation by peroxidase, and absence ascorbic oxidase activity, suggests functions remove H2O2 E. gracilis, which lacks catalase.

The purified glutathione reductase was homogeneous on polyacrylamide-gel electrophoresis. It had an Mr of 79,000 and consisted two subunits with a 40,000. activity maximum at pH 8.2 52 degrees C. specific for NADPH but not NADH as the electron donor; reverse reaction observed. Km values GSSG were 14 55 microM respectively. enzyme markedly inhibited by thiol inhibitors metal ions such Hg2+, Cu2+ Zn2+. Euglena cells contained total millimolar concentration. GSH constituted more than 80% in...

Pyruvate:NADP+ oxidoreductase was homogeneously purified from crude extract of Euglena gracilis.The M, the enzyme estimated to be 309,000 by gel filtration.The migrated as a single protein band with 166,000 sodium dodecyl sulfatepolyacrylamide electrophoresis, suggesting that consists two identical polypeptides.The absorption spectrum native exhibited maxima at 278, 380, and 430 nm, broad shoulder observed around 480 nm; maximum nm eliminated reduction dithionite.Reduction pyruvate CoA...

Amino acid utilization by Euglena gracilis strains z and SM-ZK (a streptomycin-bleached mutant) was studied in the presence or absence of ethanol as a carbon source. Among 21 amino acids examined, glutamate most effective nutrient for both under all conditions. Methionine, cysteine, threonine, leucine phenylalanine inhibited growth E. on nitrogen source, but neither transport nor respiration these acids. The inhibition methionine, threonine were specifically relieved glycine, valine...

The hybrid larch F1 (Larix gmelinii var. japonica × Larix kaempferi) is considered one of the most important tree species not only for timber production but also as an afforestation material severe conditions such infertile soil. To predict ability under potential climates in future, it to understand response elevated CO2 concentration ([CO2]) low nutrient availability. Three-year-old seedlings were grown two different levels [CO2], 360 (ambient) and 720 µmol mol−1 (elevated), combination...

We have studied how tree seedlings with differing leaf phenological traits change their nitrogen allocation in seasonally changing light environments. Specifically, we investigated seasonal changes maximum photosynthetic rates situ, and nitrogen, chlorophyll ribulose‐1,5‐bisphosphate carboxylase oxygenase (Rubisco) content. also estimated characteristics from to proteins, light‐harvesting protein other proteins four successional species growing a larch plantation. The gap phase species,...

The partially purified monodehydroascorbate reductase (EC 1.6.5.4) from Euglena gracilis Z showed a pH optimum of 7·0 and temperature 41 °C, had an M r 52000. Activity was threefold higher with NADPH than N ADH; the K m values for ADPH NADH were 7 210 μm, respectively. dehydroascorbate 1.8.5.1) 7·0, 38 °C 28000. enzyme specific reduced glutathione as electron donor, 0·85 mm, dehydroascorbate, 0·26 mm. reaction proceeded in either ordered or random manner. Both reductases markedly inhibited...

We examined the effects of elevated CO2 (eCO2) on growth and photosynthetic responses deciduous trees using a Free Air Enrichment (FACE). In FACE, photosynthesis was down-regulated in several but not alder. Except alder, leaf nitrogen concentration decreased eCO2. Alder underwent symbiosis with N-fixing micro-organisms (Frankia sp.) roots, which act as sink photosynthates. Leaves alder had intensively been grazed by beetles eCO2, due to enhanced N concentration; leaves died later. The area...

Growth characteristics of Picea glehnii Masters, P. jezoensis (Sieb. et Zucc) Carr., var. hondoensis (Mayr) Rehder and shirasawae Hayashi from Japan, abies (L.) Karst. Europe glauca Voss, mariana Britt., Sterns Pogg. rubens Sarg. North America were compared. The trees grown in similar conditions at the Tomakomai Experimental Forest Hokkaido University northern Japan. Tree growth, needle biomass, longevity, photosynthetic rate, nitrogen concentration specific leaf area (SLA) measured,...

As photoinhibition primarily reduces the photosynthetic light use efficiency at low light, sunfleck-induced might result in a fatal loss of carbon gain shade leaves within canopy with barely positive balance. We hypothesized that lower retain certain amount leaf nitrogen (NL) to maintain energy consumption via electron transport, which contributes circumventing during sunflecks keep efficient utilization rest period daytime. investigated excess production, potential measure susceptibility...

To test the hypothesis that mesophyll conductance (g m ) would be reduced by leaf starch accumulation in plants grown under elevated CO 2 concentration [ ], we investigated g seedlings of Japanese white birch ambient and ] with an adequate limited nitrogen supply using simultaneous gas exchange chlorophyll fluorescence measurements. Both decreased area‐based N accompanied a decrease maximum rate Rubisco carboxylation (V c,max on at chloroplast stroma (C c basis. Conversely, only had...

Several deciduous broad-leaved tree species, differing in leaf phenology, invade larch (Larix kaempferii (Lamb.) Carrière) plantations Japan. The understory light environment of forests changes drastically between the leafy and leafless periods. To determine how invading seedlings exploit changing environment, if phenological differences reflect light- nitrogen-use traits seedlings, we measured seasonal light-saturated photosynthetic rate (Psat), nitrogen (N) content (Narea),...

We examined the effects of aortic input impedance alteration on left ventricular pressure, flow and ejected volume (integral value flow), in an isolated blood perfused ejecting canine heart, with special reference to end-systolic values. A hydraulic model which stimulates was attached root excised heart. Left end-diastolic pressure kept constant by electrical pacing. Three coronary arteries were arterial from support dogs. When peripheral resistance changed, there inverse linear...

Abstract Ground-level ozone (O 3 ) concentrations are expected to increase over the 21 st century, especially in East Asia. However, impact of O has not been directly assessed at forest level this region. We performed flux-based risk assessments carbon sequestration capacity an old cool temperate deciduous forest, consisting -sensitive Japanese beech ( Fagus crenata ), and a warm evergreen dominated by -tolerant Konara oak Quercus serrata based on long-term CO 2 flux observations. On basis...

We compared shoot and needle morphology photosynthesis in Picea glehnii (Friedr. Schmidt) M.T. Mast. jezoensis (Sieb. et Zucc.) Carr. trees planted on immature volcanic ash well-developed brown forest soils to investigate whether species differences morphological physiological plasticity affected tree growth different soil types. Height of P. was reduced by about 10% with soil, whereas that more than 60%. Needle unaffected type. In contrast, needles growing were shorter, narrower thicker,...

The objective of this paper is to clarify the effects multiple environmental conditions, elevated atmospheric CO2 concentration ([CO2]) and soil conditions on physiological morphological properties Alnus hirsuta Turcz., an N2-fixing species, predict its responses changes. We examined photosynthetic properties, leaf characteristics, biomass N allocation A. [CO2], phosphorus availability, drought by using results two experiments. P availability were more marked than those drought. [CO2] under...

Abstract We measured leaf photosynthetic traits in shade‐grown seedlings of four tree species native to northern Japan, raised under an elevated CO 2 condition, investigate the effects on shade tolerance deciduous broadleaf with different successional traits. considered Betula platyphylla var. japonica and maximowicziana as pioneer species, Quercus mongolica crispula a mid‐successional Acer mono climax species. The plants were grown conditions (10% full sunlight) ‐regulated phytotron. Light...

Ground level ozone (O3) is rapidly increasing in Asia and penetrates plants via stomata. Atmospheric carbon dioxide (CO2) has also been global short term may promote plant growth photosynthetic enhancement. Oaks are representative deciduous broadleaved trees native to northeastern Asia. In this study, we focused on the effects of elevated O3 and/or CO2 leaf nutrients status (phosphorous, nitrogen, potassium, magnesium, etc.) two oak species: Konara (Quercus serrata) Mizunara mongolica var....

As climate change progresses, it is becoming more crucial to understand how timber species respond increased drought frequency and severity. Photosynthetic traits in a 40-year-old clonal Japanese cedar (Cryptomeria japonica) plantation were assessed under artificial stress using roof exclude rainfall control with no exclusion. C. japonica commercial tree that native Japan has high growth on mesic sites. The maximum carboxylation rate (Vcmax), electron transfer (Jmax), dark respiration (Rd)...

Euglena aquacobalamin reductase (NADPH EC 1 .6 .9 9 ~) was purified, and its subcellular distribution studied to elucidate the mechanism of conversion hydroxocobalamin 6'-deoxyadenosylcobalamin. The enzyme found in mitochondria.It purified about 150-fold over mitochondrial extract a yield 38%.The homogeneous polyacrylamide gel electrophoresis.Spectra showed that it flavoprotein.The molecular weight calculated be 66,000 by Sephadex G- 100 filtration 65,000 sodium dodecyl...