Subpicosecond fluorescence upconversion has been used to measure the rate of chlorophyll b to chlorophyll a electronic energy transfer in situ within the LHC pigment proteins of Chlamydomonas reinhardtii mutant C2. The time scale of energy transfer is 0.5 & 0.2 ps as determined from the rise time of chlorophyll a fluorescence following chlorophyll b excitation. Estimates of the energy-transfer ...

The reaction of several plant chlorophyll-protein complexes with NaBH, has been studied by absorption spectroscopy. In all the complexes studied, chlorophyll b is more reactive than Chl a , due to preferential reaction of its formyl substituent at C-7. The complexes also show large variations in reactivity towards NaBH, and the order of reactivity is: LHCI > PSI1 complex > LHCII > PSI > P700 (i...

The content of individual chlorophyll and carotenoid pigments is determined in three spinach varieties (Lorelei, Springfield, and Ballet) after processing. Raw spinach and spinach that is steam-blanched for 3, 9, or 15 min is stored frozen at -24 degrees C for 6 months. In addition, spinach is air-dried at 75 degrees C, packed in atmospheric air or nitrogen, and stored at ambient temperature fo...

The aim of the study was to compare two ozone exposure patterns with different peak concentrations under equal dose conditions. Spring wheat (Triticum aestivum cv. ‘Nandu’) was ‘pre-cultivated’ under glasshouse conditions and exposed to two different ozone exposure scenarios (A: 1700–0900 h: 20 ppb, 0900–1700 h: 65 ppb; B: 1600–1200 h: 20 ppb, 1200–1600 h: 110 ppb) in large fumigation chambers ...

We have investigated the photosynthetic properties of Acaryochloris marina, a cyanobacterium distinguished by having a high level of chlorophyll d, which has its absorption bands shifted to the red when compared with chlorophyll a. Despite this unusual pigment content, the overall rate and thermodynamics of the photosynthetic electron flow are similar to those of chlorophyll a-containing specie...

Tonnage (T), Simmonds (S) avocado trees, and TxS crosses were evaluated for differences in chlorophyll content and maximal quantum yield of photosystem II in sun and shade-type leaves. Total chlorophyll content by area (Chl a+bar) ranged from 984 mg m in TxS240 to 4320 mg m in Simmonds. Chlorophyll a/b ratio (Chl a/b) ranged from 9.8 to 5.5 in TxS238 and TxS243, respectively. Tonnage and Simmon...

in this study, the effect of four citrus rootstocks {sour orange (citrus aurantium), bakraeii (c. reticulata × c. aurantium, mexican lime (c. aurantifolia) and volkamerlemon (c. volkameriana)} on orlando tangelo leaf chlorophyll content and mineral element concentrations (n, p, k, ca, na, mg, fe, zn, mn, cl, cu, and b) have been evaluated in completely randomized design with four replications. ...

7. DEKOCK, P. C., K. COMMISIONG, V. C. FARMER, AND R. H. E. 1NKSON. 1960. Interrelationships of catalase, peroxidase, hematin, and chlorophyll. Plant Physiol. 35: 599-604. 8. DEKOCK, P. C. AND R. I. MORRISON. 1958. The metabolism of chlorotic leaves. 2. Organic acids. Biochem. J. 70: 272-77. 9. DICKMAN, S. R. AND A. A. CLOUTIER. 1951. Factors affecting the activity of aconitase. J. Biol. Chem. ...

The effect of different growth light intensities (60 W • m -2, 6 W • m -2) on the performance of the photosynthetic apparatus of mustard plants (Sinapis alba L.) was studied. A distinct decrease in photosystem II content per chlorophyll under low-light conditions compared to high-light condi­ tions was found. For P-680 as well as for QA and Q B protein the molar ratio between high-light and low...