Many plant tissues fluoresce due to the natural fluorophores present in cell walls or within the cell protoplast or lumen. While lignin and chlorophyll are well-known fluorophores, other components are less well characterized. Confocal fluorescence microscopy of fresh or fixed vibratome-cut sections of radiata pine needles revealed the presence of suberin, lignin, ferulate, and flavonoids assoc...

This study pursues the detection of bruised areas caused by mechanical impact on Golden Delicious apples using chlorophyll fluorescence imagery. When a fruit is impacted by a mechanical force and a bruise occurs, the chlorophyll nuclei inside the peel are damaged, which causes a reduction in fluorescence excitation compared to non-impacted areas. This difference allows automated detection of br...

A phytoplankton bloom occurred in Ardley Cove, King George Island in January 2016, during which maximum chlorophyll-a reached 9.87 mg/m3. Records show that blooms have previously not occurred in this area prior to 2010 and the average chlorophyll-a concentration between 1991 and 2009 was less than 2 mg/m3. Given the lack of in situ measurements and the poor performance of satellite algorithms i...

The Stepanov equation, relating the intensity of emission, f(e)(v), at a given frequency, and that of absorption, k(v), at the same frequency, is applied, in its modified form (see equation 3 in text) to suspensions of Chlorella, Porphyridium, and Anacystis and to chlorophyll solutions. This application can reveal whether the yield of fluorescence, Phi(v), is constant, or changes with frequency...

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...

Salinity is one of major stresses which can severely limit plant production, especially in the arid and semi-arid regions. The present study was carried out to evaluate the impact of salinity stress on some physio-biochemical parameters in nitre bush plants (Nitraria schoberi). Thus, an experiment was carried out under natural conditions and salinity stress was induced by a combination of diffe...

Pathogen infection in plants induces complex responses ranging from gene expression to metabolic processes in infected plants. In spite of many studies on biotic stress-related changes in host plants, little is known about the metabolic and phenotypic responses of the host plants to Pseudomonas cichorii infection based on image-based analysis. To investigate alterations in tomato plants accordi...

UV excitation of green leaves induces two distinct, fundamentally different, but still complementary types of fluorescence: a blue-green fluorescence in the 400-630 nm range and the chlorophyll a fluorescence in the red to farred region (630-800 nm) of the spectrum. The relative intensities of these two types of fluorescence are highly sensitive to intrinsic leaf properties and environmental fa...

We have studied the time-resolved fluorescence properties of the light-harvesting complexes (Lhc) of photosystem II (Lhcb) in order to obtain information on the mechanism of energy dissipation (non-photochemical quenching) which is correlated to the conversion of violaxanthin to zeaxanthin in excess light conditions. The chlorophyll fluorescence decay of Lhcb proteins LHCII, CP29, CP26, and CP2...