Femtosecond excitation of the red edge of the chlorophyll a Q(Y) transition band in photosystem I (PSI), with light of wavelength > or = 700 nm, leads to wide transient (subpicosecond) absorbance changes: positive DeltaA between 635 and 665 nm, and four negative DeltaA bands at 667, 675, 683, and 695 nm. Here we compare the transient absorbance changes after excitation at 700, 705, and 710 nm a...

5-aminolevulinic acid (ALA) is a precursor in the biosynthesis of tetrapyrroles including chlorophylls and heme. The formation of ALA involves two enzymatic steps which take place in the chloroplast in plants. The first enzyme, glutamyl-tRNA reductase, and the second enzyme, glutamate-1-semialdehyde-2,1-aminomutase, are encoded by the nuclear HEMA and GSA genes, respectively. To assess the sign...

The siphonaxanthin-siphonein-chlorophyll-a/b-binding protein (SCP), a trimeric light-harvesting complex isolated from photosystem II of the siphonous green alga Codium fragile, binds carotenoid siphonaxanthin (Sx) and/or its ester siphonein in place lutein, addition to chlorophylls a/b and neoxanthin. SCP exhibits higher content chlorophyll b (Chl-b) than counterpart plants, (LHCII), increasing...

The response of sugar beet (Beta vulgaris L.) leaves to iron deficiency can be described as consisting of two phases. In the first phase, leaves may lose a large part of their chlorophyll while maintaining a roughly constant efficiency of photosystem II photochemistry; ratios of variable to maximum fluorescence decreased by only 6%, and photon yields of oxygen evolution decreased by 30% when ch...

Changes occurring in several chloroplast components during Norflurazon-induced photobleaching of Pisum sativum seedlings were investigated. mRNA steady state levels of the chlorophyll a/b-binding protein of photosystem II, ferredoxin I, the small and large subunits of ribulose 1,5-bisphosphate carboxylase, and pEA214 and pEA207, two other light-responsive genes, were determined during chlorophy...

The aggregation dependent correlation between fluorescence quenching and the electronic carotenoid– chlorophyll interactions, / S1 Chl Coupling , as measured by comparing chlorophyll fluorescence observed after twoand one-photon excitation, has been investigated using native LHC II samples as well as mutants lacking Chl 2 and Chl 13. For native LHC II the same linear correlation between / S1 Ch...

In 1844 Verdeill reported that acid treatment of chlorophyll or haem yielded apparently similar red compounds; he even postulated that chlorophylls would contain iron. Hoppe-Seyler2 confirmed the apparent similarity of acid derivatives of haems and chlorophylls from their light absorption characteristics, a point rather overshadowing the discovery at the same time by McMunn3 of cytochromes, ano...

Species of genus Hippophae commonly called Sea buckthorn grow in more than 30 countries of the world. Belonging to the family of Elaeagnaceae, each and every part of the plant is a source of about 190 bioactive substances which include many antioxidants. Different populations of Hippophae rhamnoides L. growing in Kargil district of Ladakh region of J&K (India) were subjected to the quantificati...

PROSPECT, a widely-used leaf directional-hemispherical reflectance and transmittance model, currently treats the behaviour of chlorophylls a, b, carotenoids, and anthocyanins uniformly, leading to errors. A finer discrimination among these pigments in lightabsorbing plant tissues should improve the model. In this paper, a new calibration and validation phase of PROSPECT is performed using two c...