Fluorescence Emission Spectra of Paraquat ResistantConyza canadensis During the Chlorophyll Fluorescence Induction as Determined by the CCD-OMA System

1996 ◽  
Vol 148 (5) ◽  
pp. 574-578 ◽  
Author(s):  
Zoltán Szigeti ◽  
Peter Richter ◽  
Hartmut K. Lichtenthaler
1975 ◽  
Vol 30 (9-10) ◽  
pp. 689-690 ◽  
Author(s):  
Ulrich Schreiber ◽  
Konrad Colbow ◽  
William Vidaver

In contrast to slower heating rates, a temperature jump reveals complex rise phases in the heat induced chlorophyll fluorescence emission increase in intact plants. Three rise phases have been detected which indicate the stepwise loss of different quenching mechanism of system II fluorescence. Two of the phases appear to reflect heat deactivation of the system II reaction centers, while the other may be associated with the induction of hydrogenase activity. Variations in Tmax of the jump, for the increase in different plant varieties, suggest a correlation with membrane lipid phase transitions affecting thylakoid membrane structure and the fluorescence increase.


1984 ◽  
Vol 39 (5) ◽  
pp. 455-458 ◽  
Author(s):  
K. H. Grumbach

Plants grown in the presence of the herbicides assayed synthesized chlorophylls during growth at low fluence rates. Subsequent irradiation with higher fluence rates of red light induced a strong chlorosis with SAN 6706 being a much stronger herbicide than J 852 or amino-triazole. All herbicides assayed also changed the content and composition of chlorophylls, carotenoids and pigment-protein-complexes of the thylakoid membrane and therefore the pigment excitation and chlorophyll fluorescence emission spectra of the plastid. With increasing herbicide toxicity the main characteristic emission bands at 690 and 730 nm disappeared and new emission bands at 715 (J 852) and 700 nm (SAN 6706) appeared. Such “artificial” membranes with a changed pigment composition were very susceptible to light. Presented data may be taken as evidence, that the lack of photoprotective cyclic carotenoids caused by the specific action of a bleaching herbicide is the primary event that may lead to a disturbed formation of the thylakoid membrane and its destruction by light and oxygen.


2014 ◽  
Vol 940 ◽  
pp. 11-15
Author(s):  
Jun Qin Feng ◽  
Jun Fang Chen

Zinc nitride films were deposited by ion sources-assisted magnetron sputtering with the use of Zn target (99.99% purity) on 7059 glass substrates. The films were characterized by XRD, SEM and EDS, the results of which show that the polycrystalline zinc nitride thin film can be grown on the glass substrates, the EDS spectrum confirmed the chemical composition of the films and the SEM images revealed that the zinc nitride thin films have a dense structure. Ultraviolet-visible-near infrared spectrophotometer was used to study the transmittance behaviors of zinc nitride thin films, which calculated the optical band gap by Davis Mott model. The results of the fluorescence emission spectra show the zinc nitride would be a direct band gap semiconductor material.


2010 ◽  
Vol 12 (4) ◽  
pp. 546-563 ◽  
Author(s):  
Esa Tyystjärvi ◽  
Michael Nørremark ◽  
Heta Mattila ◽  
Mika Keränen ◽  
Marja Hakala-Yatkin ◽  
...  

1985 ◽  
Vol 104 (3) ◽  
pp. 501-504 ◽  
Author(s):  
M. Havaux ◽  
R. Lannoye

SummaryDisks of hard wheat (Triticum durum Desf.) leaves subjected to rapid desiccation over 4 h showed noticeable changes in the shape of the in vivo chlorophyll fluorescence induction curves. In drought-sensitive varieties (such as Claridoc), water stress resulted in a strong inhibition of the slow fluorescence induction transients. In particular, the fluorescence quenching rate was markedly decreased in water-stressed leaf disks. In contrast, leaves of drought-resistant varieties (such as Aouedj) showed only minor changes in chlorophyll fluorescence. The results of this investigation suggest that the slow transient of the in vivo chlorophyll fluorescence induction phenomenon may provide a simple method for selecting drought-tolerant wheats.


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