The impact of sublethal heat on photosynthetic performance, photosynthetic pigments and free radical scavenging activity was examined in three high mountain species, Rhododendron ferrugineum, Senecio incanus and Ranunculus glacialis using controlled in situ applications of heat stress, both in darkness and under natural solar irradiation. Heat treatments applied in the dark reversibly reduced p...

Chlamydomonas reinhardtii cy6Nac2.49 is a genetically modified algal strain that activates photosynthesis in a cyclical manner, so that photosynthesis is not active constitutively in the presence of oxygen, but is turned on only in response to a metabolic trigger (anaerobiosis). Here, we further investigated hydrogen production by this strain comparing it with the parental wild-type strain unde...

Physical principles applied to remote sensing data are key to successfully quantifying vegetation physiological condition from the study of the light interaction with the canopy under observation. We used the fluorescence-reflectance-transmittance (FRT) and PROSPECT leaf models to simulate reflectance as a function of leaf biochemical and fluorescence variables. A series of laboratory measureme...

Currently there is no commonly accepted way to define, much less quantify, locomotor stability. In engineering, "orbital stability" is defined using Floquet multipliers that quantify how purely periodic systems respond to perturbations discretely from one cycle to the next. For aperiodic systems, "local stability" is defined by local divergence exponents that quantify how the system responds to...

The effects of cold acclimation of two ecotypes (Antarctic and Andes) of Colobanthus quitensis (Kunth) Bartl. Caryophyllaceae on their photosynthetic characteristics and performance under high light (HL) were compared. Non-acclimated plants of the Antarctic ecotype exhibited a higher (34%) maximal rate of photosynthesis than the Andes ecotype. In cold-acclimated plants the light compensation po...

Photoreduction of the artificial electron acceptor, cytochrome c, by isolated spinach chloroplasts in the absence of added catalyst has been found to be resistant to inhibition by 10 mM salicyl­ aldoxime. This contrasts with the pronounced inhibition of the photoreduction of both 2,6-dichlorophenolindophenol and ferricyanide over a range of electron flow rates, and indicates an inhibition on th...

The effects of water deficit modelling by polyethylene glycol (PEG), metal nanoparticles (NPs) and their combined action on status, chlorophyll fluorescence pigments composition in the leaves three drought tolerant wheat genotypes – Triticum aestivum L. (Trypilska Favorytka cultivars) dicoccum Schrank. (cv. Holikovska), have been studied. Water deficit, induced PEG, as well treatment with NPs (...

  Abstract Two experiments with factorial arrangements on the basis of randomized complete block design in three replications were conducted in 2007 and 2008, to evaluate chlorophyll content index (CCI), fluorescence of chlorophyll, proline content and grain yield of three soybean cultivars (Williams, Zan and L17) under a non-saline (control) and three saline (3, 6 and 9 ds/m NaCl) conditions...

Deer mice (Peromyscus maniculatus sonoriensis) populations in the White Mountains of Eastern California are found across a substantial range of partial pressures of oxygen (PO₂). Reduction in PO₂ at high altitude can have a negative impact on aerobic performance. We studied plastic changes in organ mass and volume involved in aerobic respiration in response to acclimation to high altitude, and ...