Photosynthetic Activity and Osmotic Volumes of Isolated Intact Chloroplasts and of Cells in Leaf Tissue from Various Plants Under Osmotic Stress

1983 ◽  
pp. 55-63 ◽  
Author(s):  
W. M. Kaiser
Keyword(s):  
Osmotic Stress ◽  
Photosynthetic Activity ◽  
Leaf Tissue ◽  
Intact Chloroplasts

Contribution of Chlorophyll Fluorescence to the Reflectance of Leaves in Stressed Plants as Determined with the VIRAF-Spectrometer

1999 ◽  
Vol 54 (9-10) ◽  
pp. 849-857 ◽  
Author(s):  
Claus Buschmann ◽  
Hartmut K. Lichtenthaler
Keyword(s):  
Chlorophyll Fluorescence ◽  
Early Detection ◽  
Inflection Point ◽  
Photosynthetic Activity ◽  
Leaf Tissue ◽  
Blue Shift ◽  
Tissue Structure ◽  
Red Edge ◽  
Chl Fluorescence ◽  
Bean Leaves

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

Endogenous biosynthetic precursors of (+)-abscisic acid. VI. Carotenoids and ABA are formed by the ‘non-mevalonate’ triose-pyruvate pathway in chloroplasts

1998 ◽  
Vol 25 (5) ◽  
pp. 507 ◽  
Author(s):  
B.V. Milborrow ◽  
H.-S. Lee
Keyword(s):  
Abscisic Acid ◽  
Leaf Tissue ◽  
Isopentenyl Diphosphate ◽  
Free System ◽  
Cell Free System ◽  
Avocado Fruit ◽  
Intact Chloroplasts ◽  
A Cell ◽  
Spinach Leaf ◽  
Leaf Protoplasts

A cell-free system from avocado fruit which routinely incorporated [14C]mevalonate into ABA (1000 dpm per 5 mL of preparation), and into carotenoids, has now been shown to incorporate [14C]pyruvate even more successfully (1620 dpm). Intact chloroplasts from spinach leaf protoplasts incorporated 2990 dpm of [14C]pyruvate (from 2 x 106 dpm) into ABA compared with 990 dpm from [3-R-5-14C]mevalonate (also from 2 x 106 dpm). The intact chloroplasts also produced [14C]ABA (1575 dpm) when supplied with [14C]isopentenyl diphosphate. This result establishes that the whole pathway of biosynthesis of ABA can occur within chloroplasts. Little [14C]acetate or [14C]alanine was incorporated into ABA by avocado fruit mesocarp. Most of the ABA in leaf tissue now appears to be formed by the triose-pyruvate pathway in chloroplasts and incorporation of [14C]mevalonate occurs after activation in the cytoplasm and importation of a later intermediate into the plastids.

scholarly journals A Cytosolic Heat Shock Protein Expressed in Carrot (Daucus carota L.) Enhances Cell Viability under Oxidative and Osmotic Stress Conditions

HortScience ◽  
2012 ◽  
Vol 47 (1) ◽  
pp. 143-148 ◽  
Author(s):  
Yeh-Jin Ahn ◽  
Na-Hyun Song
Keyword(s):  
Heat Shock ◽  
Osmotic Stress ◽  
Heat Shock Protein ◽  
Cell Viability ◽  
Daucus Carota ◽  
Leaf Tissue ◽  
Small Heat Shock Protein ◽  
Stress Conditions ◽  
Daucus Carota L ◽  
And Function

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.

scholarly journals ADAPTIVE CAPACITY OF SOME LAVENDER AND LAVANDIN CULTIVARSIN VITRO AND IN SITU

AGROFOR ◽  
2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Oksana GREBENNIKOVA ◽  
Anfisa PALIY ◽  
Valentina BRAILKO ◽  
Olga MITROFANOVA ◽  
Valery RABOTYAGOV ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Photosynthetic Activity ◽  
Bound Water ◽  
Leaf Tissue ◽  
Viral Pathogens ◽  
Intact Plants ◽  
Seed Propagation ◽  
Proline Concentration

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.

Occurrence and identification of jasmonic acid and its amino acid conjugates induced by osmotic stress in barley leaf tissue

1995 ◽  
Vol 14 (1) ◽  
pp. 29-36 ◽  
Author(s):  
R. Kramell ◽  
R. Atzorn ◽  
G. Schneider ◽  
O. Miersch ◽  
C. Brückner ◽  
...  
Keyword(s):  
Amino Acid ◽  
Osmotic Stress ◽  
Jasmonic Acid ◽  
Leaf Tissue ◽  
Amino Acid Conjugates ◽  
Barley Leaf

scholarly journals Adaptation Strategies of Halophytic Barley Hordeum marinum ssp. marinum to High Salinity and Osmotic Stress

2020 ◽  
Vol 21 (23) ◽  
pp. 9019
Author(s):  
Stanislav Isayenkov ◽  
Alexander Hilo ◽  
Paride Rizzo ◽  
Yudelsy Antonia Tandron Moya ◽  
Hardy Rolletschek ◽  
...  
Keyword(s):  
Plant Growth ◽  
Osmotic Stress ◽  
Photosynthetic Activity ◽  
High Salinity ◽  
Adaptation Strategies ◽  
Fine Tuning ◽  
Energy Costs ◽  
Effective Management ◽  
Resonance Imaging ◽  
Species Production

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.

scholarly journals Mechanisms of Low-temperature Tolerance in Cucumber Leaves of Various Ages

2007 ◽  
Vol 132 (3) ◽  
pp. 294-301 ◽  
Author(s):  
Yong In Kuk ◽  
Ji San Shin
Keyword(s):  
Lipid Peroxidation ◽  
Low Temperature ◽  
Photosynthetic Activity ◽  
Leaf Tissue ◽  
Temperature Tolerance ◽  
Antioxidant Protection ◽  
Tissue Lipid ◽  
Low Temperature Tolerance ◽  
Paraquat Tolerance ◽  
Tissue Lipid Peroxidation

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.

Influence of short-term osmotic stress on the photosynthetic activity of barley seedlings

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