Removal of Magnesium by Mg-dechelatase Is a Major Step in the Chlorophyll-Degrading Pathway in Ginkgo biloba in the Process of Autumnal Tints

2000 ◽  
Vol 55 (11-12) ◽  
pp. 923-926 ◽  
Author(s):  
Lei Tang ◽  
Atsushi Okazawa ◽  
Eiichiro Fukusaki ◽  
Akio Kobayashi
Keyword(s):  
Ginkgo Biloba ◽  
Hplc Analysis ◽  
Deciduous Trees ◽  
Natural Phenomena ◽  
Major Step ◽  
Pheophytin A ◽  
Chl A ◽  
Degrading Enzymes ◽  
Green Leaves ◽  
Related Compounds

Autumnal tints are one of the most manifest and fascinating natural phenomena, but the mechanism of chlorophyll (Chl)-breakdown in deciduous trees has not been fully elucidated. In this study, we analyzed the composition of Chl-related compounds and determined the activities of initial Chl-degrading enzymes in Ginkgo leaves at various stages in the process of autumnal coloring. Only pheophytin a (Pheo a, Mg-free Chl a) was detected in yellow leaves by HPLC analysis, and the activity of Mg-dechelatase in yellow leaves was found to be higher than in green leaves. These findings showed that the removal of magnesium from Chl a occurred in advance of dephytylation in the Ginkgo.

Characterization and Subcellular Localization of Chlorophyllase from Ginkgo biloba

2006 ◽  
Vol 61 (1-2) ◽  
pp. 111-117 ◽  
Author(s):  
Atsushi Okazawa ◽  
Lei Tang ◽  
Yoshiko Itoh ◽  
Ei’ichiro Fukusaki ◽  
Akio Kobayashi
Keyword(s):  
Subcellular Localization ◽  
Ginkgo Biloba ◽  
Fluorescent Protein ◽  
Initial Step ◽  
Subcellular Fractionation ◽  
Natural Phenomena ◽  
Chl A ◽  
Green Fluorescent ◽  
Common Understanding

Abstract Chlorophyllase (Chlase) catalyzes the initial step of chlorophyll (Chl)-degradation, but the physiological significance of this reaction is still ambiguous. Common understanding of its role is that Chlase is involved in de-greening processes such as fruit ripening, leaf senescence, and flowering. But there is a possibility that Chlase is also involved in turnover and homeostasis of Chls. Among the de-greening processes, autumnal coloration is one of the most striking natural phenomena, but the involvement of Chlase during autumnal coloration is not clear. Previously, it was shown that Chlase activity and expression level of the Chlase gene were not increased during autumnal coloration in Ginkgo biloba, indicating that Chlase does not work specially in the de-greening processes in G. biloba. In this study, we characterized the recombinant Chlase and analyzed its subcellular localization to understand the role of the cloned Chlase of G. biloba (GbCLH). GbCLH exhibited its highest activity at pH 7.5, 40 °C. Kinetic analysis revealed that GbCLH hydrolyzes pheophytin (Pheo) a and Chl a more rapidly than Pheo b and Chl b. Transient expression analysis of 40 N-terminus amino acids of GbCLH fused with GFP (green fluorescent protein) and subcellular fractionation showed that GbCLH localizes within chloroplasts. Together with our previous results, property of GbCLH and its location within the chloroplasts suggest that GbCLH plays a role in the turnover and homeostasis of Chls in green leaves of G. biloba

scholarly journals Study on the breeding ginkgo (ginkgo biloba l.) in Tashkent oasis

2021 ◽  
Vol 939 (1) ◽  
pp. 012058
Author(s):  
B Gafurdjanov ◽  
E Berdiev ◽  
U Xoliyorov
Keyword(s):  
Vitamin C ◽  
Human Body ◽  
Ginkgo Biloba ◽  
Biochemical Composition ◽  
Botanical Garden ◽  
Vital Activity ◽  
Green Leaves ◽  
Normal Metabolism ◽  
Macro And Micronutrients ◽  
Academy Of Sciences

Abstract This article presents the results of research on the biochemical composition of green and yellowing leaves of 64-year-old bipedal ginkgo (Ginkgo biloba L.) seed and pollen trees growing in the Botanical Garden of the Academy of Sciences of Uzbekistan, introduced to Uzbekistan in the last century. Biochemical analyzes recorded the presence of 6 types of vitamins and 44 macro- and micronutrients in the leaves of the ginkgo tree. Vitamin C levels were found to be lower in the seed tree than in the pollen tree. The amount was 35.8 mg/% in the green leaves of the seed tree and 34.4 mg/% in the yellowed leaves. Ginkgo leaves contain important macro-and micronutrients such as Ca, Mg, K, Al, Fe, Cu, Mn, Zn, Mo, Co, I, Se, which are necessary for the vital activity of the human body and normal metabolism. The green leaves of the two-leafed ginkgo pollen tree contained 27577.288 mg/l of calcium, 11562.299 mg/l of potassium, the leaves of the seed tree 13912.903 mg/l of calcium and 7491.462 mg/l of potassium. At the same time, the green leaves of ginkgo contain 3073.807 mg/l – 7977.459 mg/l magnesium, 4353.72-5003.88 mg/l phosphorus, 501.073-515.343 mg/l sodium, 779.750 mg/l– the presence of silicon in the amount of 844.039 mg/l and iron in the amount of 373.023 mg/l – 655.148 mg/l was determined.

Effect of pollutant gases on chlorophyll a multilayer

1981 ◽  
Vol 59 (15) ◽  
pp. 2402-2411 ◽  
Author(s):  
Camille Chapados ◽  
Denis Germain ◽  
Roger M. Leblanc
Keyword(s):  
Ir Spectra ◽  
Atomic Absorption ◽  
Chlorophyll A ◽  
Direct Effect ◽  
Time Effect ◽  
Reaction Products ◽  
Pheophytin A ◽  
Chl A ◽  
End Products ◽  
Pollutant Gases

The aim of this paper is to examine the direct effect of polluting gases on chlorophyll a (chl a) multilayer arrays. The pollutants studied are CO, CO2, SO2, H2S, NO, and NO2. Electronic and infrared spectroscopies were used to monitor the time effect of the polluting gases on chl a molecules. TLC, atomic absorption, and electronic spectroscopies were used to characterise the reaction products. The results show that neither CO nor CO2 affect the chl a molecules in the multilayer arrays. Upon exposure to SO2, we notice many modifications on the electronic and ir spectra. All the evidence confirms that one of the reaction products is pheophytin a. A mechanism is presented to explain the reaction of SO2 with chl a. The effect of H2S on chl a is less pronounced than that of SO2, but the end products are the same. NO and NO2 have exactly the same effect on the chl a multilayer. The reaction is much more drastic than the reaction of chl a with either SO2 or H2S. There is opening of the cycle and nitration of the chl a molecule.

Chlorophyll a epimer and pheophytin a in green leaves

1985 ◽  
Vol 807 (2) ◽  
pp. 110-117 ◽  
Author(s):  
Tadashiá Watanabe ◽  
Masataka Nakazato ◽  
Hitoshi Mazaki ◽  
Akinori Hongu ◽  
Mitsuo Konno ◽  
...  
Keyword(s):  
Chlorophyll A ◽  
Pheophytin A ◽  
Green Leaves

scholarly journals New Perspectives on Photosystem II Reaction Centres

2020 ◽  
Vol 73 (8) ◽  
pp. 669 ◽  
Author(s):  
Jeremy Hall ◽  
Rafael Picorel ◽  
Nicholas Cox ◽  
Robin Purchase ◽  
Elmars Krausz
Keyword(s):  
Photosystem Ii ◽  
Charge Separation ◽  
Cd Spectra ◽  
Negative Component ◽  
Ps Ii ◽  
Pheophytin A ◽  
Chl A ◽  
Special Pair ◽  
Reaction Centres ◽  
Weak Luminescence

We apply the differential optical spectroscopy techniques of circular polarisation of luminescence (CPL) and magnetic CPL (MCPL) to the study of isolated reaction centres (RCs) of photosystem II (PS II). The data and subsequent analysis provide insights into aspects of the RC chromophore site energies, exciton couplings, and heterogeneities. CPL measurements are able to identify weak luminescence associated with the unbound chlorophyll-a (Chl-a) present in the sample. The overall sign and magnitude of the CPL observed relates well to the circular dichroism (CD) of the sample. Both CD and CPL are reasonably consistent with modelling of the RC exciton structure. The MCPL observed for the free Chl-a luminescence component in the RC samples is also easily understandable, but the MCPL seen near 680nm at 1.8K is anomalous, appearing to have a narrow, strongly negative component. A negative sign is inconsistent with MCPL of (exciton coupled) Qy states of either Chl-a or pheophytin-a (Pheo-a). We propose that this anomaly may arise as a result of the luminescence from a transient excited state species created following photo-induced charge separation within the RC. A comparison of CD spectra and modelling of RC preparations having a different number of pigments suggests that the non-conservative nature of the CD spectra observed is associated with the ‘special pair’ pigments PD1 and PD2.

scholarly journals BN 52021 and related compounds: A new series of highly specific PAF-acether receptor antagonists isolated from Ginkgo biloba L.

1985 ◽  
Vol 16 (6) ◽  
pp. 558-572 ◽  
Author(s):  
Pierre G. Braquet ◽  
Brigitte Spinnewyn ◽  
Monique Braquet ◽  
René H. Bourgain ◽  
John E. Taylor ◽  
...  
Keyword(s):  
Ginkgo Biloba ◽  
Receptor Antagonists ◽  
Related Compounds

scholarly journals Isolation and characterization of 10,11-dihydroatlantone and related compounds from Ginkgo biloba L.

1975 ◽  
Vol 23 (8) ◽  
pp. 1892-1894 ◽  
Author(s):  
HIROSHI IRIE ◽  
KOSEI OHNO ◽  
YUKIE ITO ◽  
SHOJIRO UYEO
Keyword(s):  
Ginkgo Biloba ◽  
Isolation And Characterization ◽  
Related Compounds

Enzymatic and Immunological Approaches for the Quantitation and Confirmation of Ochratoxin A in Swine Kidneys

1997 ◽  
Vol 60 (2) ◽  
pp. 172-176 ◽  
Author(s):  
ANDREW A. FROHLICH ◽  
RONALD R. MARQUARDT ◽  
JAMES R. CLARKE
Keyword(s):  
Ochratoxin A ◽  
High Performance ◽  
Hplc Analysis ◽  
Linear Regression Analysis ◽  
Enzyme Linked Immunosorbent Assay ◽  
Enzymatic Method ◽  
Naturally Occurring ◽  
Related Compounds ◽  
Enzymatic Procedure ◽  
Swine Kidney

Several techniques for the quantitation and confirmation of ochratoxin A (OA) in swine kidneys were examined. Naturally and artificially contaminated swine kidneys were analyzed for OA by conventional high-performance liquid chromatography (HPLC) analysis. Samples were additionally tested by enzyme-linked immunosorbent assay (ELISA) or treated with carboxypeptidase A followed by HPLC analysis (enzymatic method). Correlations (r values) between the conventional HPLC procedure and the ELISA, using artificially contaminated samples, were 0.88 and 0.81 (P < 0.05) respectively, while the corresponding values between the conventional HPLC procedure and the enzymatic method were 0.89 and 0.98 (P < 0.05). The ELISA gave a more direct estimation of OA contamination than the enzymatic procedure. The enzymatic method also had a reproducible tendency to underestimate or overestimate the amounts of OA in kidney. This was found to be dependent on the source of contamination, as artificially and naturally contaminated kidney samples resulted in linear regression analysis slopes of 0.38 and 2.8, whereas the slopes for the ELISA method were 1.13 and 0.92, respectively. The results with the naturally contaminated kidneys suggest that other naturally occurring forms of OA also occurred in swine kidney. Regardless of this effect, the enzymatic method accurately confirms the presence of OA and related compounds in kidney. The techniques are simple and will complement conventional HPLC analysis for the detection, quantitation, and confirmation of OA in swine kidneys.

Chlorophyll a′/P-700 and pheophytin a/P-680 stoichiometries in higher plants and cyanobacteria determined by HPLC analysis

1988 ◽  
Vol 936 (1) ◽  
pp. 81-89 ◽  
Author(s):  
Masami Kobayashi ◽  
Tadashi Watanabe ◽  
Masataka Nakazato ◽  
Isamu Ikegami ◽  
Tetsuo Hiyama ◽  
...  
Keyword(s):  
Chlorophyll A ◽  
Hplc Analysis ◽  
Higher Plants ◽  
Pheophytin A
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