A meta-analysis of responses of C plants to atmospheric CO : dose-response curves for 85 traits ranging from the molecular to the whole-plant level.

Generalised dose-response curves are essential to understand how plants acclimate to atmospheric CO . We carried out a meta-analysis of 630 experiments in which C plants were experimentally grown at different [CO ] under relatively benign conditions, and derived dose-response curves for 85 phenotypic traits. These curves were characterised by form, plasticity, consistency and reliability.

Crassulacean acid metabolism species differ in the contribution of C and C carboxylation to end of day CO fixation.

Crassulacean acid metabolism (CAM) is a photosynthetic pathway that temporally separates the nocturnal CO uptake, via phosphoenolpyruvate carboxylase (PEPC, C carboxylation), from the diurnal refixation by Rubisco (C carboxylation). At the end of the day (CAM-Phase IV), when nocturnally stored CO has depleted, stomata reopen and allow additional CO uptake, which can be fixed by Rubisco or by PEPC. This work examined the CO uptake via C and C carboxylation in phase IV in the CAM species Phalaenopsis "Sacramento" and Kalanchoe blossfeldiana "Saja.

CAM-physiology and carbon gain of the orchid Phalaenopsis in response to light intensity, light integral and CO.

The regulation of photosynthesis and carbon gain of crassulacean acid metabolism (CAM) plants has not yet been disclosed to the extent of C3-plants. In this study, the tropical epiphyte Phalaenopsis cv. "Sacramento" was subjected to different lighting regimes.

Frequently asked questions about in vivo chlorophyll fluorescence: practical issues.

The aim of this educational review is to provide practical information on the hardware, methodology, and the hands on application of chlorophyll (Chl) a fluorescence technology. We present the paper in a question and answer format like frequently asked questions. Although nearly all information on the application of Chl a fluorescence can be found in the literature, it is not always easily accessible.

Photosynthetic quantum yield dynamics: from photosystems to leaves.

The mechanisms underlying the wavelength dependence of the quantum yield for CO(2) fixation (α) and its acclimation to the growth-light spectrum are quantitatively addressed, combining in vivo physiological and in vitro molecular methods. Cucumber (Cucumis sativus) was grown under an artificial sunlight spectrum, shade light spectrum, and blue light, and the quantum yield for photosystem I (PSI) and photosystem II (PSII) electron transport and α were simultaneously measured in vivo at 20 different wavelengths. The wavelength dependence of the photosystem excitation balance was calculated from both these in vivo data and in vitro from the photosystem composition and spectroscopic properties.

Differential tomato transcriptomic responses induced by pepino mosaic virus isolates with differential aggressiveness.

Pepino mosaic virus (PepMV) is a highly infectious potexvirus and a major disease of greenhouse tomato (Solanum lycopersicum) crops worldwide. Damage and economic losses caused by PepMV vary greatly and can be attributed to differential symptomatology caused by different PepMV isolates. Here, we used a custom-designed Affymetrix tomato GeneChip array with probe sets to interrogate over 22,000 tomato transcripts to study transcriptional changes in response to inoculation of tomato seedlings with a mild and an aggressive PepMV isolate that share 99.

Photosynthetic acclimation in relation to nitrogen allocation in cucumber leaves in response to changes in irradiance.

Leaves deep in canopies can suddenly be exposed to increased irradiances following e.g. gap formation in forests or pruning in crops.

Blue light dose-responses of leaf photosynthesis, morphology, and chemical composition of Cucumis sativus grown under different combinations of red and blue light.

The blue part of the light spectrum has been associated with leaf characteristics which also develop under high irradiances. In this study blue light dose-response curves were made for the photosynthetic properties and related developmental characteristics of cucumber leaves that were grown at an equal irradiance under seven different combinations of red and blue light provided by light-emitting diodes. Only the leaves developed under red light alone (0% blue) displayed dysfunctional photosynthetic operation, characterized by a suboptimal and heterogeneously distributed dark-adapted F(v)/F(m), a stomatal conductance unresponsive to irradiance, and a relatively low light-limited quantum yield for CO(2) fixation.

Disruption of plant carotenoid biosynthesis through virus-induced gene silencing affects oviposition behaviour of the butterfly Pieris rapae.

Optical plant characteristics are important cues to plant-feeding insects. In this article, we demonstrate for the first time that silencing the phytoene desaturase (PDS) gene, encoding a key enzyme in plant carotenoid biosynthesis, affects insect oviposition site selection behaviour. Virus-induced gene silencing employing tobacco rattle virus was used to knock down endogenous PDS expression in three plant species (Arabidopsis thaliana, Brassica nigra and Nicotiana benthamiana) by its heterologous gene sequence from Brassica oleracea.

An artificial solar spectrum substantially alters plant development compared with usual climate room irradiance spectra.

Plant responses to the light spectrum under which plants are grown affect their developmental characteristics in a complicated manner. Lamps widely used to provide growth irradiance emit spectra which are very different from natural daylight spectra. Whereas specific responses of plants to a spectrum differing from natural daylight may sometimes be predictable, the overall plant response is generally difficult to predict due to the complicated interaction of the many different responses.

The responses of light interception, photosynthesis and fruit yield of cucumber to LED-lighting within the canopy.

Mathematical models of light attenuation and canopy photosynthesis suggest that crop photosynthesis increases by more uniform vertical irradiance within crops. This would result when a larger proportion of total irradiance is applied within canopies (interlighting) instead of from above (top lighting). These irradiance profiles can be generated by Light Emitting Diodes (LEDs).

Insights on the development, kinetics, and variation of photoinhibition using chlorophyll fluorescence imaging of a chilled, variegated leaf.

The effect of chilling on photosystem II (PSII) efficiency was studied in the variegated leaves of Calathea makoyana, in order to gain insight into the causes of chilling-induced photoinhibition. Additionally, a relationship was revealed between (chilling) stress and variation in photosynthesis. Chilling treatments (5 degrees C and 10 degrees C) were performed for different durations (1-7 d) under a moderate irradiance (120 micromol m-2 s-1).