C(4) photosynthesis has evolved more than 60 times as a carbon-concentrating mechanism to augment the ancestral C(3) photosynthetic pathway. The rate and the efficiency of photosynthesis are greater in the C(4) than C(3) type under atmospheric CO(2) depletion, high light and temperature, suggesting these factors as important selective agents. This hypothesis is consistent with comparative analy...

The relationship between loss of ribulose-1,5-bisphosphate carboxylase (RuBPCase) and the decline in photosynthesis during the senescence of barley primary leaves was assessed. Loss of RuBPCase accounted for about 85% of the decrease in soluble protein. RuBPCase was highly correlated with in vitro RuBPCase activity (r = 0.95) and gross photosynthesis (r = 0.96). However, the rate of photosynthe...

pinto bean is a susceptible plant to drought stress. however, there is genotype variation for this trait in this plant. in order to investigate the effects of drought stress on physiological traits and grain yield of pinto bean genotypes cultivated in zanjan province, an experiment was conducted as spilt plot based on a completely randomized block design with four replications at zanjan univers...

Photosynthesis is the most important chemical reaction in the world. The measurement of plant photosynthesis rate plays an important role in agriculture. Light-induced delayed fluorescence (DF) in plants is an intrinsic label of the efficiency of charge separation at P680 in photosystem II (PS II). In this paper, we have developed a biosensor that can accurately measure the plant photosynthesis...

On the base of the physiological processes and according to the balance of the carbon, a simulation model for photosynthetic production and dry matter accumulation was established for the peanut. The photosynthesis rate of unit green leaf area was scribed by negative exponential function. By analyzing the characteristic of the shoots, the Gaussian integration method was used to calculate the ph...

Photosynthetic rate, ribulose 1,5-bisphosphate carboxylase activity, specific leaf weight, and leaf concentrations of carbohydrates, proteins, chlorophyll, and inorganic phosphate were determined periodically from midbloom until maturity in leaves of soybean plants (Glycine max L., var. Hodgson) from which reproductive and vegetative sinks had been removed 32 hours before measurement, or contin...

Individual leaves of potato (Solanum tuberosum L. W729R), a C(3) plant, were subjected to various irradiances (400-700 nm), CO(2) levels, and temperatures in a controlled-environment chamber. As irradiance increased, stomatal and mesophyll resistance exerted a strong and some-what paralleled regulation of photosynthesis as both showed a similar decrease reaching a minimum at about 85 neinsteins...

precedingw or following irrigations. No reduction in the rate of photosynthesis was cletected as soil moisture was extracted, until the approximate time the first visible signs of wilting appeared. As the severity of wilting increased, the photosynthetic rate declined rapidly. When the plants were (listinctly wilted, photosynthetic activity had been reduced to approximately 75 % of its maximum ...

Measurements of gross photosynthesis; respiration, rate of net oxygen diffusion, and organic storage are reported for 7 microcosms maintained over periods of 5 to 7 months. Average rates of gross photosynthesis ranged from 0.86 to 1.69 g Oz/m2/day and were related to the amounts of inorganic nutrients added. Average final organic storage was equal to 35.6% of gross photosynthesis. Assumed photo...