The circadian system allows plants to coordinate metabolic and physiological functions with predictable environmental variables such as dusk and dawn. This endogenous oscillator is comprised of biochemical and transcriptional rhythms that are synchronized with a plant's surroundings via environmental signals, including light and temperature. We have used chlorophyll fluorescence techniques to d...

Traditional Chinese medicine relies heavily on herbs, yet there is no information on how these herb plants would respond to climate change. In order to gain insight into such response, we studied the effect of elevated [CO2] on Isatis indigotica Fort, one of the most popular Chinese herb plants. The changes in leaf photosynthesis, chlorophyll fluorescence, leaf ultrastructure and biomass yield ...

extended abstract background and objectives sugarcane (saccharum officinarum l.) is from poaceae trible and perennial native plant of asia continent warm areas. ratio fv/fm estimates the maximum quantum yield of photosystem ii. under conditions of stress fv/fm decreased, this decreasing is due to low activity of reaction of photosynthesis centers and reducing of proteins that are responsible fo...

Previous heat tolerance tests of higher plants have been mostly performed with darkened leaves. However, under natural conditions, high leaf temperatures usually occur during periods of high solar radiation. In this study, we demonstrate small but significant increases in the heat tolerance of illuminated leaves. Leaf disks of mature sun leaves from two neotropical tree species, Ficus insipida ...

measurement of chlorophyll fluorescence is noninvasive, highly sensitive, fast and easy way to give important information about the photosynthetic apparatus. chlorophyll fluorescence parameters and kautsky curves of wild oat and wild mustard sprayed by clodinafop and dicamba+2, 4-d respectively was investigated at two green house experiments. the results indicated significant reduction at trend...

to evaluate the effects of methanol and drought stress on chlorophyll fluorescence parameters, chlorophyll and relative water content in sugar beet, a study was conducted in 2008 in maahdasht (karaj, iran). aqueous solutions of 0 (control), 7, 14, 21, 28, 35% (v/v) methanol with each solution containing 0.2% glycine and a second factor, namely drought stress (irrigation after 70% depletion of a...

Under apparently similar field conditions individual plants of Cistus creticus turn transiently red during winter, while neighbouring plants remain green. These two phenotypes provide a suitable system for comparing basic photosynthetic parameters and assessing critically two hypotheses, i.e. anthocyanins afford photoprotection and anthocyanins induce shade characteristics on otherwise exposed ...

This experiment was carried out to evaluate the effect of silver nanoparticles pulsing treatment (0, 25, 75 and 125 mg L−1) on vase life and some postharvest physiological parameters of cut rose flower ʻHigh & Magicʼ in sucrose solution (0, 2 and 3%). This research performed as a factorial experiment based on a completely randomized design with three replications under 23 ± 2 °C, 60 ± 5% RH and...

In the present study, we investigated changes in chlorophyll fluorescence, photosynthetic parameters and fruit yields, as well as fruit phytochemical accumulation of strawberry (Fragaria ananassa Duch.) that had been cultivated in a greenhouse under different combinations of light intensity and temperature. In plants grown with low light (LL) photosystem II chlorophyll fluorescence was found to...

Photoacclimation of photosynthesis was investigated in a tropical population of C. glomerata (São Paulo State, southeastern Brazil, 20 degrees 48' 24" S and 49 degrees 22' 24" W) by chlorophyll fluorescence parameters and chlorophyll a content. Plants were acclimated to two levels of irradiance: low (65 +/- 5 micromol.m(-2).s(-1)) and high (300 +/- 10 micromol.m(-2).s(-1)) and exposed short-ter...