Water relations in Azospirillum-inoculated wheat seedlings under osmotic stress

1998 ◽  
Vol 76 (2) ◽  
pp. 238-244 ◽  
Author(s):  
Cecilia M Creus ◽  
Rolando J Sueldo ◽  
Carlos A Barassi
Keyword(s):  
Cell Wall ◽  
Osmotic Stress ◽  
Water Relations ◽  
Osmotic Potential ◽  
Modulus Of Elasticity ◽  
Growth Promotion ◽  
Water Status ◽  
Water Volume ◽  
Wheat Seedlings ◽  
Water Fraction

Azospirillum has been shown to improve coleoptile growth in seedlings growing in darkness under osmotic stress. However, the changes in water relations that may occur in this experimental system have not yet been studied. Two-centimetre long Triticum aestivum cv. Buck Pucará and Triticum durum cv. Balcarceño-INTA seedlings were inoculated with viable or autoclaved (control) Azospirillum brasilense Sp. 245 bacteria, at approximately 108 cells per seedling. Three days after inoculation, seedlings were exposed to osmotic stress by immersing their roots in 20% polyethylene glycol 6000 for up to 72 h. Germination and seedling growth were at 20°C in darkness. Shoots were excised after 72 h of stress, and water-status parameters were determined through pressure-volume analyses. While osmotic potential at full turgor remained constant, Azospirillum-stimulated growth in Buck Pucará seedlings was accompanied by significant decreases in osmotic potential and relative water content at zero turgor, in volumetric cell wall modulus of elasticity, and in absolute symplastic water volume and by a significant rise in apoplastic water fraction parameters. Except for a constant volumetric cell wall modulus of elasticity, similar results were obtained with Balcarceño-INTA seedlings. However, bacterial growth promotion was evident only in the less tolerant cv. Buck Pucará. Turgor at low water potential was higher in inoculated seedlings in both wheat cultivars under osmotic stress. These results are consistent with a better water status in Azospirillum-inoculated wheat seedlings under water stress, where both effects on cell wall elasticity and (or) apoplastic water are evident.Key words: Azospirillum, drought, seedlings, water status, wheat.

Water relations and yield inAzospirillum-inoculated wheat exposed to drought in the field

2004 ◽  
Vol 82 (2) ◽  
pp. 273-281 ◽  
Author(s):  
Cecilia M Creus ◽  
Rolando J Sueldo ◽  
Carlos A Barassi
Keyword(s):  
Grain Yield ◽  
Water Potential ◽  
Water Content ◽  
Water Relations ◽  
Relative Water Content ◽  
Mineral Content ◽  
Water Status ◽  
Water Fraction ◽  
Relative Water ◽  
And Control

There are scarce data connecting water relations in Azospirillum-inoculated wheat suffering drought during anthesis with the yield and mineral content of grains. Azospirillum brasilense Sp245-inoculated seeds of Triticum aestivum 'Pro INTA Oasis' were sown in nonirrigated and control plots. Water potential, water content, and relative water content were determined on flag leaves. Plant water status was calculated from pressure–volume curves. At maturity, grain yield and its components were determined. P, Ca, Mg, K, Fe, Cu, and Zn were determined in dried grains. Even though the cultivar underwent osmotic adjustment, significantly higher water content, relative water content, water potential, apoplastic water fraction, and lower cell wall modulus of elasticity values were obtained in Azospirillum-inoculated plants suffering drought. Grain yield loss to drought was 26.5% and 14.1% in noninoculated and Azospirillum-inoculated plants, respectively. Grain Mg and K diminished in nonirrigated, noninoculated plots. However, grains harvested from Azospirillum-inoculated plants had significantly higher Mg, K, and Ca than noninoculated plants. Neither drought nor inoculation changed grain P, Cu, Fe, and Zn contents. A better water status and an additional "elastic adjustment" in Azospirillum-inoculated wheat plants could be crucial in promoting higher grain yield and mineral quality at harvest, particularly when drought strikes during anthesis.Key words: Azospirillum, wheat, drought, pressure–volume curves, yield, mineral content.

Water Relations of Laticifers in Nerium oleander

1981 ◽  
Vol 8 (3) ◽  
pp. 329 ◽  
Author(s):  
WJS Downton
Keyword(s):  
Water Potential ◽  
Water Relations ◽  
Osmotic Potential ◽  
Water Status ◽  
Turgor Pressure ◽  
Death Valley ◽  
Nerium Oleander ◽  
Laboratory Measurements ◽  
Hydrocarbon Sources ◽  
Daily Changes

The water relations of laticifers in N. oleander were examined for plants growing in Death Valley, California, USA. Osmotic potential of laticifers in well watered plants paralleled the daily changes in leaf water potential. The turgor pressure of laticifers was usually less than bulk leaf turgor. Laticifer turgor was maintained in the absence of positive leaf turgor in severely water stressed plants (Ψw ͭ6 -7.0 MPa) and latex exuded when leaves were cut. The recovery in water status of leaves and laticifers following watering of the plants is described. Laboratory measurements confirmed that laticifer turgor differed from bulk leaf turgor and that it was maintained over a range of water potentials. These observations may have relevance for some of the latex-bearing plants currently being considered as future hydrocarbon sources.

The relationship between plant sugar concentration, osmotic potential, and frost tolerance in Kharkov MC22 winter wheat. Sugar and frost tolerance

1972 ◽  
Vol 50 (3) ◽  
pp. 677-680 ◽  
Author(s):  
D. G. Green
Keyword(s):  
Winter Wheat ◽  
Osmotic Potential ◽  
Reducing Sugars ◽  
Water Status ◽  
Frost Tolerance ◽  
Leaf Water Content ◽  
Total Carbohydrate ◽  
Wheat Seedlings ◽  
The Relationship ◽  
Individual Importance

Increased frost survival after exposure of winter wheat seedlings to solutions of glucose, sucrose, or mannitol was not explained simply by changes in the osmotic potential of the leaves. In some cases either an increase in percentage total carbohydrate and reducing sugars, or a slight decrease in leaf water content increased frost survival. Because of the dependency of osmotic potential and percentage total carbohydrate and reducing sugars on the plant's water status, it is difficult to evaluate their individual importance to frost survival. Because maleic hydroxide is residual it does not have application as a short-term (1-week) growth retardant for increasing frost tolerance in winter wheat.

Physiological and anatomical responses of wheat to induced dehydration and rehydration

2013 ◽  
Vol 8 (5) ◽  
pp. 499-503
Author(s):  
Konstantina Kocheva ◽  
Peter Petrov ◽  
Georgi Georgiev
Keyword(s):  
Hydrogen Peroxide ◽  
Lipid Peroxidation ◽  
Osmotic Stress ◽  
Water Content ◽  
Relative Water Content ◽  
Water Status ◽  
Free Proline ◽  
Leaf Water Status ◽  
Wheat Seedlings ◽  
Relative Water

AbstractHydroponically grown wheat seedlings of two prominent Bulgarian cultivars (Katya and Prelom) were subjected to 48 h osmotic stress with PEG 8000 and were then rehydrated. The degree of stress was evaluated by monitoring relative water content, lipid peroxidation level, and accumulation of free proline and hydrogen peroxide in the leaves. Anatomy and ultrastructure of leaf tissue were observed under light microscopy. After imposition of stress, drought tolerant cultivar Katya displayed higher free proline content and significantly lower malondialdehyde and peroxide concentration in leaves than in the leaves of susceptible cultivar Prelom. After 24 h of rehydration Katya showed better ability to restore leaf water status and an apparent tendency towards recovery, whereas Prelom sustained higher levels of hydrogen peroxide, lipid peroxidation products and free proline and markedly low relative water content. Here, we have uncovered some of the characteristics displayed by cultivar Katya that enable it to survive and recover from severe osmotic stress. Interestingly, there was congruence between our results and the high level of cultivar Katya drought tolerance observed in the field.

scholarly journals Cell water content and lignification in maize regulated by rhizobacteria under salinity

2017 ◽  
Vol 4 (7) ◽  
pp. 9-18 ◽  
Author(s):  
Yachana Jha
Keyword(s):  
Cell Wall ◽  
Plant Growth ◽  
Water Content ◽  
Growth Promotion ◽  
Lignin Content ◽  
Water Status ◽  
Physiological Mechanism ◽  
Cell Permeability ◽  
Maize Plant ◽  
Cell Water

Inoculation of plant growth promoting rhizobacteria (PGPR) Pseudomonas aeruginosa and Bacillus megaterium in maize plant under salinity stress was analyzed for its growth promotion efficacy and induction of physiological mechanism. In this study effect of these isolates were focused on the cellular level as with lignin deposition, cell wall lignin content and cell water status of maize under salinity. Maize plants get protected from the salinity induced injury by enhancing the plant growth, regulating relative water content, enhancing phenols, flavonoids as well as lignification of cell and antioxidant enzymes also. The study states that, PGPR helps in maize plant under salinity to increase the cell membrane stability, plays a significant action in the directive of cell permeability for the survival of plants. Nevertheless, the cell wall bounded peroxidase and phenylalanine ammonia-lyase (PAL) activity reduced with gradual increase soil in non-inoculated plants. So plants inoculated with selected root-associated bacteria has a positive response on cell content and water status in maize under salinity.

Variation of Leaf Characteristics With Level of Insertion on a Grass Tiller. III. Tissue Water Relations

1977 ◽  
Vol 4 (5) ◽  
pp. 733 ◽  
Author(s):  
JR Wilson
Keyword(s):  
Water Content ◽  
Water Relations ◽  
Osmotic Potential ◽  
Water Status ◽  
Physiological Age ◽  
Wall Material ◽  
Panicum Maximum ◽  
Stomatal Frequency ◽  
Matric Potential ◽  
Potential Component

Plants of a grass, green panic (Panicum maximum var. trichoglume) were grown under controlled environmental and nutritional regimes. Throughout the growth of the plants, leaves from varying levels of insertion on the main stem were sampled at comparable physiological age (viz, when just fully expanded) and their water relations characteristics measured over a range from full turgidity to a moderately stressed condition to determine whether there were inherent differences between leaves on the shoot. Leaf water potential, osmotic potential, and pressure potential fell in a similar manner for the leaves from each insertion level as leaf relative water content declined. A small increase in the average water and osmotic potential, and also in the average matric potential component, estimated for a common reIative water content, was evident with increasingly higher level of leaf insertion. Despite marked increases in the proportion of cell wall material and a trend towards increasing lignification in leaves of higher insertion, the bulk coefficient of elasticity of the tissues showed no gradient of change, and the overall change in the matric potential component was small. Various other chemical and morphological characteristics showed definite gradients with insertion level: for example, stomatal frequency increased from 91 to 287 mm-2 from leaf 5 to the flag leaf. There was no evidence of a progressive variation with insertion level in the water status of leaves sampled fresh from the plants, and thus no support for the theory that upper leaves on a tiller develop under inherently higher water stress, which could account for their xeromorphic chemical, anatomical and morphological features. It appears that in green panic at least, the water relations characteristics measured, with the exception of stomatal frequency, exhibit no strong inherent gradients with insertion level of leaves which could seriously confound comparisons of water status between plants in different treatments.

Water relations in Azospirillum-inoculated wheat seedlings under osmotic stress

1998 ◽  
Vol 76 (2) ◽  
pp. 238-244 ◽  
Author(s):  
Cecilia M. Creus ◽  
Rolando J. Sueldo ◽  
Carlos A. Barassi
Keyword(s):  
Osmotic Stress ◽  
Water Relations ◽  
Wheat Seedlings

scholarly journals Growth Promotion or Osmotic Stress Response: How SNF1-Related Protein Kinase 2 (SnRK2) Kinases Are Activated and Manage Intracellular Signaling in Plants

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1443
Author(s):  
Yoshiaki Kamiyama ◽  
Sotaro Katagiri ◽  
Taishi Umezawa
Keyword(s):  
Protein Kinase ◽  
Plant Growth ◽  
Osmotic Stress ◽  
Protein Function ◽  
Intracellular Signaling ◽  
Growth Promotion ◽  
Research Field ◽  
Dependent Manner ◽  
Related Protein ◽  
Wide Range

Reversible phosphorylation is a major mechanism for regulating protein function and controls a wide range of cellular functions including responses to external stimuli. The plant-specific SNF1-related protein kinase 2s (SnRK2s) function as central regulators of plant growth and development, as well as tolerance to multiple abiotic stresses. Although the activity of SnRK2s is tightly regulated in a phytohormone abscisic acid (ABA)-dependent manner, recent investigations have revealed that SnRK2s can be activated by group B Raf-like protein kinases independently of ABA. Furthermore, evidence is accumulating that SnRK2s modulate plant growth through regulation of target of rapamycin (TOR) signaling. Here, we summarize recent advances in knowledge of how SnRK2s mediate plant growth and osmotic stress signaling and discuss future challenges in this research field.

scholarly journals Optimal Nitrogen Supply Ameliorates the Performance of Wheat Seedlings under Osmotic Stress in Genotype-Specific Manner

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 493 ◽  
Author(s):  
Tania Kartseva ◽  
Anelia Dobrikova ◽  
Konstantina Kocheva ◽  
Vladimir Alexandrov ◽  
Georgi Georgiev ◽  
...  
Keyword(s):  
Osmotic Stress ◽  
Stress Tolerance ◽  
Wheat Variety ◽  
Growth And Yield ◽  
Physiological Status ◽  
Wheat Seedlings ◽  
Modern Variety ◽  
N Supply ◽  
N Assimilation ◽  
N Deficiency

Strategies and coping mechanisms for stress tolerance under sub-optimal nutrition conditions could provide important guidelines for developing selection criteria in sustainable agriculture. Nitrogen (N) is one of the major nutrients limiting the growth and yield of crop plants, among which wheat is probably the most substantial to human diet worldwide. Physiological status and photosynthetic capacity of two contrasting wheat genotypes (old Slomer and modern semi-dwarf Enola) were evaluated at the seedling stage to assess how N supply affected osmotic stress tolerance and capacity of plants to survive drought periods. It was evident that higher N input in both varieties contributed to better performance under dehydration. The combination of lower N supply and water deprivation (osmotic stress induced by polyethylene glycol treatment) led to greater damage of the photosynthetic efficiency and a higher degree of oxidative stress than the individually applied stresses. The old wheat variety had better N assimilation efficiency, and it was also the one with better performance under N deficiency. However, when both N and water were deficient, the modern variety demonstrated better photosynthetic performance. It was concluded that different strategies for overcoming osmotic stress alone or in combination with low N could be attributed to differences in the genetic background. Better performance of the modern variety conceivably indicated that semi-dwarfing (Rht) alleles might have a beneficial effect in arid regions and N deficiency conditions.

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