Temperature-sensitive coupling and uncoupling of ATPase-mediated, nonradiative energy dissipation: Similarities between chloroplasts and leaves

Planta ◽  
1995 ◽  
Vol 197 (4) ◽  
Author(s):  
AdamM. Gilmore ◽  
Olle Bj�rkman
Keyword(s):  
Energy Dissipation ◽  
Temperature Sensitive ◽  
Nonradiative Energy Dissipation

Assessing the drought-resistance adaptive advantage of some anatomical and physiological features in Nicotiana tabacum

1994 ◽  
Vol 72 (10) ◽  
pp. 1445-1454 ◽  
Author(s):  
L. van Rensburg ◽  
G. H. J. Kruger ◽  
H. Krüger
Keyword(s):  
Drought Stress ◽  
Nicotiana Tabacum ◽  
Energy Dissipation ◽  
Drought Tolerance ◽  
Rate Constant ◽  
Drought Tolerant ◽  
Nicotiana Tabacum L ◽  
Carotenoid Composition ◽  
Leaf Movements ◽  
Nonradiative Energy Dissipation

As part of an extensive research programme that attempts to explain and quantify the known difference in drought tolerance of four Nicotiana tabacum L. cultivars, some aspects that may contribute towards the avoidance and tolerance of drought stress were investigated to evaluate overall resistance. The results presented emphasize the adaptive significance of effective leaf movements in determining drought tolerance, by reducing or preventing damage to the photosynthetic system caused by photoinhibition and direct heat damage. Leaf movement seemed to be achieved with greater efficiency by the drought-tolerant cultivars GS46 and Elsoma. Drought stress specifically influenced the carotenoid composition. A strong quantitative correlation existed between the formation of zeaxanthin in the xanthophyll cycle and the type of fluorescence quenching, which is indicative of nonradiative energy dissipation. The latter occurred to a lesser extent in the drought-tolerant cultivars GS46 and Elsoma. This phenomenon also indicated that the rate constant for nonradiative energy dissipation in tobacco remains relatively small in relation to the rate constant for fluorescence during drought stress. Furthermore, irrespective of their drought tolerance, it would seem that tobacco plants have a capability towards starch overproduction, though this was less pronounced in the drought-sensitive cultivars TL33 and CDL28. Owing to anatomical differences, resistance to water flow varied between the respective cultivars, as did the percentage intercellular spaces, both of which correlated positively with the slower decrease in water use efficiency and faster recovery upon rehydration of the drought-tolerant cultivars. Key words: carotenoid composition, chlorophyll a fluorescence, Nicotiana tabacum L., mesophyll surface area, leaf movements.

Oncogenesis and the Lucké Virus

1968 ◽  
Vol 26 ◽  
pp. 200-201
Author(s):  
A. E. Vatter ◽  
J. Zambernard
Keyword(s):  
Rna Viruses ◽  
Vegetative State ◽  
Temperature Sensitive ◽  
Structural Level ◽  
Oncogenic Viruses ◽  
Dna Viruses ◽  
Leopard Frogs ◽  
Renal Adenocarcinoma ◽  
Induced Tumors ◽  
Northern Leopard Frogs

Oncogenic viruses, like viruses in general, can be divided into two classes, those that contain deoxyribonucleic acid (DNA) and those that contain ribonucleic acid (RNA). The RNA viruses have been recovered readily from the tumors which they cause whereas, the DNA-virus induced tumors have not yielded the virus. Since DNA viruses cannot be recovered, the bulk of present day investigations have been concerned with RNA viruses.The Lucké renal adenocarcinoma is a spontaneous tumor which occurs in northern leopard frogs (Rana pipiens) and has received increased attention in recent years because of its probable viral etiology. This hypothesis was first advanced by Lucké after he observed intranuclear inclusions in some of the tumor cells. Tumors with inclusions were examined at the fine structural level by Fawcett who showed that they contained immature and mature virus˗like particles.The use of this system in the study of oncogenic tumors offers several unique features, the virus has been shown to contain DNA and it can be recovered from the tumor, also, it is temperature sensitive. This latter feature is of importance because the virus can be transformed from a latent to a vegetative state by lowering or elevating the environmental temperature.

THEORETICAL ELECTRON DENSITY AND TEMPERATURE SENSITIVE EMISSION LINE RATIOS FOR HELIUM-LIKE Si XIII COMPARED TO DITE TOKAMAK OBSERVATIONS

1989 ◽  
Vol 50 (C1) ◽  
pp. C1-559-C1-564
Author(s):  
F. P. KEENAN ◽  
R. BARNSLEY ◽  
J. DUNN ◽  
K. D. EVANS ◽  
S. M. McCANN ◽  
...  
Keyword(s):  
Emission Line ◽  
Electron Density ◽  
Temperature Sensitive ◽  
Electron Density And Temperature

Energy Dissipation Processes of Singlet Excited 1-Hydroxyfluorenone and its Hydrogen-Bonded Complex with N-Methylimidazole

2004 ◽  
Author(s):  
Krisztina Sebők-Nagy ◽  
László Biczók ◽  
Akimitsu Morimoto ◽  
Tetsuya Shimada ◽  
Haruo Inoue
Keyword(s):  
Energy Dissipation ◽  
Dissipation Processes ◽  
Hydrogen Bonded
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