Mechanical stimulation of trigger hairs on the adaxial surface of the trap of Dionaea muscipula leads to the generation of action potentials and to rapid leaf movement. After rapid closure secures the prey, the struggle against the trigger hairs results in generation of further action potentials which inhibit photosynthesis. A detailed analysis of chlorophyll a fluorescence kinetics and gas exc...

A study was conducted over 2 years to determine whether growth under elevated CO(2) (700 μmol mol(-1) ) and temperature (ambient + 4 °C) conditions modifies photochemical efficiency or only the use of electron transport products in spring wheat grown in field chambers. Elevated atmospheric CO(2) concentrations increased crop dry matter at maturity by 12-17%, while above-ambient temperatures d...

Mass coral bleaching due to thermal stress represents a major threat to the integrity and functioning of coral reefs. Thermal thresholds vary, however, between corals, partly as a result of the specific type of endosymbiotic dinoflagellate (Symbiodinium sp.) they harbour. The production of reactive oxygen species (ROS) in corals under thermal and light stress has been recognised as one mechanis...

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 (...

Drought in heavy metal polluted arid and semiarid regions severely inhibits the plant growth phytoremediation potential by affecting photosynthesis, antioxidant defense mechanism, other biochemical processes. In present study, we explored role of growth-promoting bacteria (PGPB) on Zea mays efficiency Chromium (Cr) contaminated soils under drought stress assessing tolerance, photosynthetic gas ...

Phytoplankton in high-light, low-nutrient ocean environments are challenged with maintaining high photosynthetic efficiency and simultaneously preventing photodamage that results from low levels of electron acceptors downstream of photosystem II (PSII). Here, we identify a process in open ocean picophytoplankton that preserves PSII activity by diverting electrons from the photosystem I (PSI) co...

The efficiency of protective energy dissipation by non-photochemical quenching (NPQ) in photosystem II (PSII) has been recently quantified by a new non-invasive photochemical quenching parameter, qPd. PSII yield (ФPSII) was expressed in terms of NPQ, and the extent of damage to the reaction centres (RCIIs) was calculated via qPd as: ФPSII=qPd×(F v/F m)/{1+[1-(F v/F m)]×NPQ}. Here this approach ...

Variable fluorescence (Fv), i.e., Fv = Fm-Fo where Fo is the minimal fluorescence and Fm the maximum fluorescence, and difference Fourier transform infrared (FT-IR) spectroscopy were used to study the effect of heat stress in the 25-55 degrees C range on photosystem II (PSII) structure and function. First, the Fv intensity reflects accurately the changes in the number of open photochemical cent...

Hibiscus syriacus, a woody ornamental plant with great economic value, is vulnerable to salinity. Hence, its cultivation in saline areas severely restricted. Although grafting H. syriacus onto hamabo rootstock can greatly improve syriacus’s salt resistance, the photosynthetic response of and stress remains largely unknown. To address this question, self-rooted (Hs), self-grafted (Hs/Hs), hamabo...