Effects of phosphorus supply and mycorrhizal status on the response of photosynthetic capacity to elevated CO(2) were investigated in loblolly pine (Pinus taeda L.) seedlings. Seedlings were grown in greenhouses maintained at either 35.5 or 71.0 Pa CO(2) in a full factorial experiment with or without mycorrhizal inoculum (Pisolithus tinctorius (Pers.) Coker & Couch) and with an adequate or a li...

Chloroplast suspensions from spinach (Spinacia oleracea L.) were clearly resolved into intact and stripped chloroplasts by isopycnic centrifugation in density gradients of silica sol ("Ludox") and polyethlene glycol. The intact chloroplasts fixed CO(2) and evolved O(2) more rapidly than the crude suspensions; the stripped chloroplasts were inactive. During the photosynthetic fixation of (14)CO(...

Life on earth is dependent on the photosynthetic conversion of light energy into chemical energy. However, absorption of excess sunlight can damage the photosynthetic machinery and limit photosynthetic activity, thereby affecting growth and productivity. Photosynthetic light harvesting can be down-regulated by nonphotochemical quenching (NPQ). A major component of NPQ is qE (energy-dependent no...

PAL is a peptidoglycan-associated lipoprotein found in the cell membranes of many Gramnegative bacteria. The presence of PAL has been demonstrated in Escherichia coli and many bacteria. In this paper, we show the presence of a gene coding for a PAL-like protein in C. vinosum, a photosynthetic bacteria and the partial sequence of the PAL gene.

The luminescent marine dinoflagellate, Gonyaulax polyedra, exhibits a diurnal rhythm in the rate of photosynthesis and photosynthetic capacity measured by incorporation of C(14)O(2), at different times of day. With cultures grown on alternating light and dark periods of 12 hours each, the maximum rate is at the 8th hour of the light period. Cultures transferred from day-night conditions to cont...

in order to evaluate the effect of piriformospora indica fungi inoculation on antioxidant systems and photosynthetic pigments of stevia under salt stress, an experiment was conducted in a factorial based completely randomized design with four replications under in vitro culture conditions. factors include salinity at six levels (0, 50, 100, 150, 200 and 250 mm of nacl) and inoculation of mycorr...

An 125iodine labelled 1,4-benzoquinone, an analogue of DBMIB, was studied for its interaction with the photosynthetic system of chloroplasts. It is not covalently bound to the thylakoid mem­ brane. Instead, chloroplasts slowly decompose it under release of 125iodine and formation of a quinone of only small inhibitory potency, i. e. photosynthetic activity is restored after a few minutes. The in...

We analyzed trends in a time series of photosynthetic activity across boreal North America over 22 years (1981 through 2003). Nearly 15% of the region displayed significant trends, of which just over half involved temperature-related increases in growing season length and photosynthetic intensity, mostly in tundra. In contrast, forest areas unaffected by fire during the study period declined in...

The impact of supplemental UV-B (sUV-B) radiation and heavy metals: Cd (68 μmol.kg-1 soil) and Ni (68 μmol.kg-1 soil) singly and in combination was studied on photosynthetic and non-photosynthetic pigments, metabolites, enzyme activities, biomass accumulation and the net primary productivity of spinach (Spinacia oleracea L. var. All Green), a common leafy vegetable plant. Both the stresses indi...

Seasonal changes in the biochemistry and photophysiology of the brown macroalga Cystoseira tamariscifolia was analyzed in southern Spain. Total carbon and nitrogen contents, phenolic compounds, antioxidant and photosynthetic activities were seasonally determined over two years. Carbon, nitrogen and photoprotective phenolic contents were higher in winter and spring than in summer and autumn. Ant...