Correlation between changes in photosynthetic activity and changes in total protoplast volume in leaf tissue from hygro-, meso- and xerophytes under osmotic stress

Planta ◽  
1982 ◽  
Vol 154 (6) ◽  
pp. 538-545 ◽  
Author(s):  
Werner M. Kaiser
1999 ◽  
Vol 54 (9-10) ◽  
pp. 849-857 ◽  
Author(s):  
Claus Buschmann ◽  
Hartmut K. Lichtenthaler

Reflectance spectra allow the early detection of stressors causing differences in pigment content as well as changes of leaf tissue structure and photosynthetic activity. The reflectance decreased with increasing Chl content in greening bean leaves. In stressed leaves, in turn, the reflectance increased with decreasing Chl content. This also caused a shift of the red reflection rise (“red edge”) to shorter wavelengths (“blue shift”) associated with a blue shift of the inflection point of the red edge. The contribution of the red and far-red Chl fluorescence to the reflectance signal at the red edge of the spectrum and the shift of the wavelength position of the inflection point are demonstrated and discussed


HortScience ◽  
2012 ◽  
Vol 47 (1) ◽  
pp. 143-148 ◽  
Author(s):  
Yeh-Jin Ahn ◽  
Na-Hyun Song

The expression and function of DcHsp17.7, a small heat shock protein expressed in carrot (Daucus carota L.), was examined under oxidative and osmotic stress conditions. Comparative analysis revealed that DcHsp17.7 is a cytosolic Class I protein. Sequence alignment showed that DcHsp17.7 has the characteristic α-crystalline domain-containing consensus regions I and II. Under oxidative [hydrogen peroxide (H2O2)] and osmotic (polyethylene glycol) stress conditions, DcHsp17.7 accumulated in carrot leaf tissue. To examine its function under these abiotic stress conditions, the coding sequence of DcHsp17.7 was introduced into Escherichia coli and expressed by isopropyl β-D-1-thiogalactopyranoside treatment. Under both oxidative and osmotic stress conditions, heterologously expressed DcHsp17.7 enhanced bacterial cell viability. The expression level of soluble proteins was higher in transgenic cells expressing DcHsp17.7 when compared with controls under these stress conditions. These results suggest that DcHsp17.7 confers tolerance to both oxidative and osmotic stresses and thereby functions as a molecular chaperone during the stresses examined.


AGROFOR ◽  
2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Oksana GREBENNIKOVA ◽  
Anfisa PALIY ◽  
Valentina BRAILKO ◽  
Olga MITROFANOVA ◽  
Valery RABOTYAGOV ◽  
...  

Lavandula angustifolia Mill. and (LavandulaxintermediaEmericexLoisel) arepromising fragrant plants with medicinal, aromatic and ornamental properties.Since the collection plantations of these crops are very damaged with viralpathogens and there is lack of seed propagation in valuable cultivars 'Belyanka','Record' (lavender) and 'Rabat', 'Snezhnyi Bars' (lavandin), were introduced invitro. Chemotherapy was used for cleaning up. Regenerants were cultured (4-5months) on MS medium with 0. 3 mg L- Kinetin, 0. 025 mg L- NAA and 0. 25 mgL- GA3 at 25±1°C under 16-h photoperiod. Intact plants were studied during thegrowing season. In order to reveal plants` biotechnological and genetic capacitysome biochemical stress indicators, indexes of photosynthetic activity and waterregime were identified. Under the open field cultivation, tested plants were rich inascorbic acid, phenolic compounds, and redox enzymes (catalase, polyphenoloxidase, superoxide dismutase) were active. Leaf tissue hydration was 56-62%,with greater part of bound water. Photosynthetic activity was reduced only in thesamples with visible damages with viral pathogens. In plants cultured in vitro,amount of ascorbic acid and phenolic compounds were lower, so as enzymaticactivity and proline concentration were higher than in intact plants. The rate ofhydration was high (70-77%), with the same trend of water fractional composition.Photosynthetic activity and vitality index indicated no photoinhibition. It wasfound out the lavandin cultivars had better capacity for a wide use under variousculture conditions.


1995 ◽  
Vol 14 (1) ◽  
pp. 29-36 ◽  
Author(s):  
R. Kramell ◽  
R. Atzorn ◽  
G. Schneider ◽  
O. Miersch ◽  
C. Brückner ◽  
...  

2020 ◽  
Vol 21 (23) ◽  
pp. 9019
Author(s):  
Stanislav Isayenkov ◽  
Alexander Hilo ◽  
Paride Rizzo ◽  
Yudelsy Antonia Tandron Moya ◽  
Hardy Rolletschek ◽  
...  

The adaptation strategies of halophytic seaside barley Hordeum marinum to high salinity and osmotic stress were investigated by nuclear magnetic resonance imaging, as well as ionomic, metabolomic, and transcriptomic approaches. When compared with cultivated barley, seaside barley exhibited a better plant growth rate, higher relative plant water content, lower osmotic pressure, and sustained photosynthetic activity under high salinity, but not under osmotic stress. As seaside barley is capable of controlling Na+ and Cl− concentrations in leaves at high salinity, the roots appear to play the central role in salinity adaptation, ensured by the development of thinner and likely lignified roots, as well as fine-tuning of membrane transport for effective management of restriction of ion entry and sequestration, accumulation of osmolytes, and minimization of energy costs. By contrast, more resources and energy are required to overcome the consequences of osmotic stress, particularly the severity of reactive oxygen species production and nutritional disbalance which affect plant growth. Our results have identified specific mechanisms for adaptation to salinity in seaside barley which differ from those activated in response to osmotic stress. Increased knowledge around salt tolerance in halophytic wild relatives will provide a basis for improved breeding of salt-tolerant crops.


2007 ◽  
Vol 132 (3) ◽  
pp. 294-301 ◽  
Author(s):  
Yong In Kuk ◽  
Ji San Shin

To determine whether differential tolerance to paraquat among cucumber (Cucumis sativus L.) leaves of various ages correlates with low-temperature tolerance, leaves of three cultivars at the four-leaf stage were exposed to 5 °C. Leaves tolerant to paraquat were also tolerant to low temperature as indicated by electrolyte leakage changes in leaf tissue, lipid peroxidation, and photosynthesis measurements. The youngest leaf (leaves were numbered 1 to 4 with the youngest leaf given 4) on the same plant was more tolerant than older leaves to low temperature. During chilling, lipid peroxidation and H2O2 content increased in the oldest leaf when compared with the three younger leaves. Photosynthetic activity and chlorophyll a fluorescence (Fv/Fm) were significantly lower in leaf 1 than in leaf 4. There was no difference in superoxide dismutase, catalase, ascorbate peroxidase (APX), and glutathione reductase activities among various leaf ages in untreated plants. Induction of antioxidant activity in response to low temperature was higher in the youngest leaf than in the oldest leaf. Expression of APX isozymes increased in response to low temperature, and their expression was the highest in the youngest leaf. Current results support earlier findings that antioxidant protection also was a mechanism for paraquat tolerance.


2005 ◽  
Vol 49 (1) ◽  
pp. 145-148 ◽  
Author(s):  
K. V. Kocheva ◽  
M. C. Busheva ◽  
G. I. Georgiev ◽  
P. H. Lambrev ◽  
V. N. Goltsev

2020 ◽  
Vol 71 (4) ◽  
pp. 349
Author(s):  
Jingyun Li ◽  
Wenjing Jia ◽  
Huihui Wang ◽  
Yanqiu Zhu ◽  
Zhikun Duan ◽  
...  

The quality and yield of wheat (Triticum aestivum L.) are dramatically affected by drought. We used morphological and physiological characteristics and degree of DNA methylation to compare the responses of two wheat cultivars under osmotic stress, and found that the two cultivars behaved differently. Root development, leaf growth, and the accumulation of proline and soluble carbohydrate in wheat cv. AK58 all showed drought tolerance. Drought tolerance of wheat cv. XM13 was mainly improved by accumulation of proline and soluble carbohydrate. The degree of DNA methylation in wheat showed tissue specificity and increased significantly in leaf tissue with increasing osmotic stress, but decreased significantly in root tissue under mild osmotic stress. In addition, changes of DNA methylation differed between two wheat cultivars under osmotic stress, and this change was especially significant in AK58. Therefore, wheat AK58 may have stronger self-adjustment ability under osmotic stress compared with XM13, and might respond more rapidly to osmotic stress through the change of DNA methylation. This finding could be significant for revealing drought-tolerance mechanisms of plants.


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