Although temperature is an important driver of seasonal changes in photosynthetic physiology, photoperiod also regulates leaf activity. Climate change will extend growing seasons if temperature cues predominate, but photoperiod-controlled species will show limited responsiveness to warming. We show that photoperiod explains more seasonal variation in photosynthetic activity across 23 tree speci...

Soybean plants (Glycine max var. Ransom) were grown at light intensities of 850 and 250 mueinsteins m(-2) sec(-1) of photosynthetically active radiation. A group of plants was shifted from each environment into the other environment 24 hours before the beginning of the experiment. Net photosynthetic rates and stomatal conductances were measured at 2,000 and 100 mueinsteins m(-2) sec(-1) photosy...

nitric oxide (no) is a bioactive molecule, which was found to have several physiological roles, including antioxidant. to have a better understanding of the effects of no concentrations (0, 0.1 and 0.2 mm) on germination, growth, photosynthetic pigments, lipid peroxidation and antioxidant activity of basil (ocimum basilicum l.) under different salinity concentrations (0, 100 and 200 mm of nacl)...

Diphenylamines, Inhibitors, Photosynthetic Electron Transport A number of 16 substituted diphenylamines have been tested for their inhibitory activity on photosynthetic NADP reduction and photophosphorylation. The most active compounds exhibited p l50 values of 6.0 in photosynthetic electron transport and 6.8 in cyclic photophosphorylation, respectively. The inhibition site in electron flow of ...

Pyrrolones, Site of Action, Structure-Activity Relations, Photosynthetic Electron Transport, Herbi­ cidal Action Substituted phenyl-hydroxy pyrrolone derivatives are potential herbicides and are found to be effective inhibitors of photosynthetic electron flow in chloroplasts. Their site of inhibition is localized at the acceptor side of photosystem II similar to DCMU. They have no effect on pho...

The synthesis of chlorophyll and ribulose diphosphate carboxylase as well as the development of Hill reaction activity were followed in expanding Populus deltoides leaves and related to photosynthetic patterns. Total chlorophyll, which was not correlated with photosynthetic rate in expanding leaves, decreased slightly with age in very young leaves, due to a decrease in chlorophyll b, but then i...

The photosynthetic activity of the green alga Scenedesmus quadricauda was investigated during synchronous growth in light/dark cycles. The rate of O2 evolution increased 2-fold during the first 3 to 4 h of the light period, remained high for the next 3 to 4 h, and then declined during the last half of the light period. During cell division, which occurred at the beginning of the dark period, th...