Chloroplasts isolated by methods similar to that described by Arnon et al. (1) are capable of incorporating acetate carbon into both lipid and n)on-lipid materials when fortified with appropriate cofactors (2, 3,4, 5). The actual rate of incorporation of acetate carbon in these preparations was, however, very small compared with the normal rate of photosynthesis (1-2 jumoles/mg chlorophyll'hr) ...

the objective of this work was to study the responses of two baby lettuce (lactuca sativa l.) cultivars, namely, green paris island and red sanguine, to different nacl concentrations (0, 5, 10, and 20 mm). the study was conducted in a floating system and plants were harvested at the stage of 5-6 leaves, outside leaf 6-10 cm in length (25 and 31 days after sowing for green and red lettuce, respe...

To understand the physiological basis of genetic variation and resulting quantitative trait loci (QTLs) for photosynthesis in a rice (Oryza sativa L.) introgression line population, 13 lines were studied under drought and well-watered conditions, at flowering and grain filling. Simultaneous gas exchange and chlorophyll fluorescence measurements were conducted at various levels of incident irrad...

1. The effect of poisons upon the photoreduction with hydrogen in Scenedesmus and similar algae has been studied. The poisons used were cyanide, hydroxylamine, dinitrophenol, and carbon monoxide, substances known to inhibit more or less specifically certain enzymatic reactions. 2. It was found that quite generally one has to distinguish between the action of poisons upon the photoreduction in t...

Despite previous reports of no apparent photorespiration in C. , plants based on measurements of gas exchange under 2 versus 21% O, at varying [CO,], photosynthesis in maize (Zea mays) shows a dual response to varying [O,]. l h e maximum rate of photosynthesis in maize i s dependent on 0, (approximately 10Y0). lhis O2 dependence is not related to stomatal conductance, because measurements were...

The atmospheric concentration of CO2 will probably rise to about 700 micromol mol(-1) by the end of this century. The effects of elevated growth CO2 on photosynthesis are still not fully understood. Effects of elevated growth CO2 on the capacity for photosynthesis of a single leaf and a whole plant were investigated with the radish cultivar White Cherish. The plants were grown under ambient ( a...

The study to examine the calcification rate, adaptation, and biotic response of three tropical coccolithophorids (Emiliania huxleyi, Gephyrocapsa oceanica, Ochosphaera sp) changes in CO2 concentration. Three selected calcifying coccolitophorids were grown at batch culture with system two levels (385 1000 ppm) light dark periods. parameters measured calculation including growth particulate organ...

We present a simple method for describing the influence of variable attenuation of spectral irradiance, Kd(λ), on water-column photosynthesis and its inhibition by ultraviolet radiation (UV). The approach is based on weighted water transparency, a calculation introduced by Vincent et al. 1998 (Ann Glaciol 27:691–696). Key results of a depthand spectrally-resolved model of photosynthesis can be ...

The effects of 2 nitrate levels, 14 (CK) and 140 mmol L (T), on the leaf gas exchange variables of cucumber (Cucumis sativus L. cv. Xintaimici) seedlings grown in hydroponic culture were investigated. Photosynthetic lightand CO2-response curves from CK and T seedlings were determined and used for the analysis of photosynthetic capacity. The results showed that nitrate stress resulted in a signi...