Background and Aims In photosynthetic organisms exposure to high light induces the production of reactive oxygen species (ROS), such as hydrogen peroxide (H2O2), which in part is prevented by non-photochemical quenching (NPQ). As one of the most stable and longest-lived ROS, H2O2 is involved in key signalling pathways in development and stress responses, although in excess it can induce damage....

As part of a program to select maritime pine (Pinus pinaster Ait.) genotypes for resistance to low winter temperatures, we examined variation in photosystem II activity by chlorophyll fluorescence. Populations and families within populations from contrasting climates were tested during two consecutive winters through two progeny trials, one located at a continental and xeric site and one at a m...

The concept of plant memory triggers a quite controversial dispute on the definition, extent or even existence of such. Because plants are permanently exposed to rapidly changing environments it is evident that they had to evolve mechanisms enabling them to dynamically adapt to such fluctuations. Recognizing memory as a timed response to changes of external inputs through amplification and inte...

Polyamines are small, ubiquitous, nitrogenous compounds that scavenge reactive oxygen species and stabilize the structure and function of the photosynthetic apparatus in response to abiotic stresses. Molecular details underlying polyamine-mediated photoprotective mechanisms are not completely resolved. This study investigated the role of spermidine (Spd) in the structure and function of the pho...

There remains limited information to characterize the solar-induced chlorophyll fluorescence (SIF)-gross primary production (GPP) relationship in C4 cropping systems. The annual crop corn and perennial miscanthus differ phenology, canopy structure leaf physiology. Investigating SIF-GPP relationships these species could deepen our understanding of within crops. Using situ SIF GPP measurements fo...

Aristotelia chilensis (Mol.) Stuntz is an evergreen species endemic to Chile. It grows in open areas or under tree canopy, and its leaves emerge early spring summer. The objective of this study was determine changes photosynthetic parameters, total phenol content (TPC), antioxidant activity, anatomy apical basal A. during the year. Photosynthesis performance determined by measuring electron tra...

A new imaging system capable of simultaneously measuring stomatal conductance and fluorescence parameters, non-photochemical quenching (NPQ) and photochemical yield of photosystem II (Phi(PSII)), in intact leaves under aerobic conditions by both thermal imaging and chlorophyll fluorescence imaging was developed. Changes in distributions of stomatal conductance and fluorescence parameters across...

The light-harvesting complexes of plants have evolved the ability to switch between efficient light harvesting and quenching forms to optimize photosynthesis in response to the environment. Several distinct mechanisms, collectively termed "nonphotochemical quenching" (NPQ), provide flexibility in this response. Here we report the isolation and characterization of a mutant, suppressor of quenchi...

KEA3 is a thylakoid membrane localized K+ /H+ antiporter that regulates photosynthesis by modulating two components of proton motive force (pmf), the proton gradient (∆pH) and the electric potential (∆ψ). We identified a mutant allele of KEA3, disturbed proton gradient regulation (dpgr) based on its reduced non-photochemical quenching (NPQ) in artificial (CO2 -free with low O2 ) air. This pheno...

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...