Tissue water relations for Brigalow and Mulga

1968 ◽  
Vol 16 (3) ◽  
pp. 487 ◽  
Author(s):  
DJ Connor ◽  
BR Tunstall
Keyword(s):  
Drought Tolerance ◽  
Water Potential ◽  
Water Content ◽  
Water Relations ◽  
Relative Water Content ◽  
Arid Zone ◽  
Tissue Water ◽  
Relative Water ◽  
The Relationship ◽  
Arid Zone Plants

The relationship between the relative water content and the water potential of the phyllodes in brigalow and mulga is compared. It is shown that brigalow phyllode tissue is more resistant to desiccation than that of mulga. This is of interest because mulga has previously been considered to represent an extreme in drought tolerance of Australian arid zone plants.

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.

Leaf and root osmotic adjustment in drought-stressed Quercusalba, Q. macrocarpa, and Q. stellata seedlings

1988 ◽  
Vol 18 (1) ◽  
pp. 1-5 ◽  
Author(s):  
William C. Parker ◽  
Stephen G. Pallardy
Keyword(s):  
Water Potential ◽  
Water Content ◽  
Water Relations ◽  
Osmotic Adjustment ◽  
Osmotic Potential ◽  
Root Tissue ◽  
Tissue Elasticity ◽  
Tissue Water ◽  
Before And After ◽  
Relative Water

The leaf and root tissue water relations of Quercusalba L., Quercusmacrocarpa Michx., and Quercusstellata Wang. seedlings before and after drought were examined to evaluate the occurrence and comparative extent of osmotic adjustment in seedlings of these species. Drought resulted in active osmotic adjustment in leaves of all three species, with decreases in osmotic potential at full tissue hydration and at the turgor loss point from 0.25 to 0.60 MPa. Active osmotic adjustment in Q. stellata, and increased root tissue elasticity in Q. macrocarpa and Q. alba, resulted in turgor loss of roots occurring at a water potential 0.36 to 0.66 MPa lower in drought-stressed than in well-watered seedlings. Species differed in tissue water relations only before drought, with Q. stellata exhibiting lower osmotic potentials than Q. alba and Q. macrocarpa. Estimates of the osmotic potential at full saturation were generally lower in leaves than in roots, but the osmotic potential at turgor loss was similar. Roots exhibited turgor loss at lower values of relative water content and experienced a more gradual decrease in water potential per unit water content during dehydration than did leaves. This response indicates greater relative tissue capacitance in roots than in leaves in these species.

Changes in Water Relations Associated With Infection by Phytophthora cinnamomi

1982 ◽  
Vol 30 (4) ◽  
pp. 393 ◽  
Author(s):  
P Dawson ◽  
G Weste
Keyword(s):  
Water Potential ◽  
Water Content ◽  
Water Relations ◽  
Relative Water Content ◽  
Phytophthora Cinnamomi ◽  
Stomatal Closure ◽  
Leaf Conductance ◽  
Eucalyptus Species ◽  
Significant Difference ◽  
Relative Water

Changes in water relations associated with infection by Phytophthora cinnamomi were measured for three native species from the Brisbane Ranges forest. Measurements included leaf conductance, stomatal aperture, transpiration, water potential and relative water content in container-grown plants of Isopogon ceratophyllus (highly susceptible), Eucalyptus macrorhyncha (field-susceptible) and E. goniocalyx (field-resistant) maintained in a glasshouse. I. Ceratophyllus showed a large and highly significant difference in water relations between infected and control plants. Infection was associated with stomatal closure, reduced transpiration, reduced relative water content and leaf water potential. These reactions to infection were not observed for either of the glasshouse-reared Eucalyptus species. In the forest diseased E. macrorhyncha showed significant differences in leaf conductance compared with healthy trees, whereas E. goniocalyx forest trees showed less infection-associated variation. This variation in leaf conductance was not associated with water stress.

Some Aspects of the Water Relations of the Lichen Parmotrema Tinctorum Measured Using Thermocouple Psychrometry

1996 ◽  
Vol 28 (3) ◽  
pp. 257-266 ◽  
Author(s):  
R. P. Beckett
Keyword(s):  
Bulk Modulus ◽  
Water Potential ◽  
Water Content ◽  
Water Relations ◽  
Osmotic Potential ◽  
Relative Water Content ◽  
Thermocouple Psychrometer ◽  
Relative Water ◽  
Parmotrema Tinctorum

AbstractThe thermocouple psychrometer was used to determine water potential, Ψ and its components in the lichen Parmotrema tinctorum. Data suggested that using conventional pressure-volume curves to study the water relations of lichens may give anomalous results, possibly because lichens may contain appreciable amounts of intercellular water. A way of correcting pressure-volume curves to remove the effect of intercellular water is discussed. Parmotrema tinctorum had a very low osmotic potential at full turgor (c. −2.5 MPa), and a low bulk modulus of elasticit (c. 2.1 MPa). As a result, P. tinctorum lost turgor only when the relative water content dropped below 0.47. Likely benefits of this for the lichen are discussed.

scholarly journals Animal anti-apoptotic genes ameliorate the loss of turgor in water-stressed transgenic tobacco

2003 ◽  
Vol 83 (3) ◽  
pp. 499-506 ◽  
Author(s):  
T. Awada ◽  
D. D. Dunigan ◽  
M. B. Dickman
Keyword(s):  
Drought Tolerance ◽  
Water Potential ◽  
Water Content ◽  
Relative Water Content ◽  
Water Deprivation ◽  
Tobacco Plants ◽  
Transformed Plants ◽  
Moisture Deficit ◽  
Relative Water ◽  
Apoptotic Genes

Nicotiana tabacum L. ‘Glurk’ plants were transformed with antiapoptotic animal genes [chicken Bcl-xl; nematode CED-9; chicken Bcl-xl(GA) a mutant of Bcl-xl ; and a 3’ non-coding region of human Bcl-2, referred to as 161-1]. Our objectives were to determine whether plant transformation with anti-apoptotic genes ameliorates drought tolerance in tobacco plants by subjecting the plants to a dry-down period. The non-transformed Glurk and the transgenic Glurk harboring G115, which expresses β-glucuronidase, served as controls. Transformation of tobacco plants with animal anti-apoptotic genes significantly impacted the rates of photosynthesis (A) and stomatal conductance (gs), but not to the same extent in every line. Controls generally exhibited higher A and gs than the transformed plants under well-watered conditions. Photosynthesis and stomatal conductance declined significantly on the 3rd day, and approached zero on the 11th day of water deprivation. Differences among controls and transformed tobacco plants disappeared as soil moisture deficit increased. Relative water content (RWC) and leaf water potential (ψw) remained relatively high in the first 3 d of water deprivation, while a dramatic reduction occurred in all plants on the 6th day. Relative water content did not differ between controls and transformed plants. Water potential declined significantly (became more negative) with the increase in soil moisture deficit. Evident differences among transformed and control plants appeared on the 6th day of water deprivation. The controls, Glurk and G115 generally maintained a higher water potential between days 6 and 11 compared to the transformed tobacco plants. Osmotic adjustment occurred in transformed plants but not in the controls, in response to drought. Relative water content at turgor loss point (RWCtlp) and osmotic potential at turgor loss point (ψπtlp) provided a measure of drought tolerance in plants. G115, Glurk and Bcl-xl plants lost turgor at a higher relative water content than Bcl-xl(GA), CED-9 and 161-1. ψπtlp in the controls G115 and Glurk were relatively higher compared to the transformed plants. We concluded that transgenic plants with anti-apoptotic genes resulted in moderate amelioration of drought tolerance in tobacco plants. Key words: Anti-apoptotic genes, programmed cell death, genetic engineering, Nicotiana tabaccum, drought tolerance, gas exchange, photosynthesis, turgor, osmotic adjustment

scholarly journals Growth and physiological response of two biomass sorghum (Sorghum bicolor (L.) Moench) genotypes bred for different environments, to contrasting levels of soil moisture

2015 ◽  
Vol 10 (4) ◽  
pp. 208 ◽  
Author(s):  
Lorenzo Barbanti ◽  
Ahmad Sher ◽  
Giuseppe Di Girolamo ◽  
Elio Cirillo ◽  
Muhammad Ansar
Keyword(s):  
Soil Moisture ◽  
Stomatal Conductance ◽  
Water Potential ◽  
Water Content ◽  
Aboveground Biomass ◽  
Relative Water Content ◽  
Physiological Response ◽  
Field Capacity ◽  
Biomass Sorghum ◽  
Relative Water

A better understanding of plant mechanisms in response to drought is a strong premise to achieving high yields while saving unnecessary water. This is especially true in the case of biomass crops for non-food uses (energy, fibre and forage), grown with limited water supply. In this frame, we investigated growth and physiological response of two genotypes of biomass sorghum (<em>Sorghum bicolor</em> (L.) Moench) to contrasting levels of soil moisture in a pot experiment carried out in a greenhouse. Two water regimes (high and low water, corresponding to 70% and 30% field capacity) were applied to JS-2002 and Trudan-8 sorghum genotypes, respectively bred for dry sub-tropical and mild temperate conditions. Two harvests were carried out at 73 and 105 days after seeding. Physiological traits (transpiration, photosynthesis and stomatal conductance) were assessed in four dates during growth. Leaf water potential, its components and relative water content were determined at the two harvests. Low watering curbed plant height and aboveground biomass to a similar extent (ca. 􀀀70%) in both genotypes. JS-2002 exhibited a higher proportion of belowground to aboveground biomass, <em>i.e</em>., a morphology better suited to withstand drought. Despite this, JS-2002 was more affected by low water in terms of physiology: during the growing season, the average ratio in transpiration, photosynthesis and stomatal conductance between droughty and well watered plants was, respectively, 0.82, 0.80 and 0.79 in JS-2002; 1.05, 1.08 and 1.03 in Trudan-8. Hence Trudan-8 evidenced a ca. 20% advantage in the three traits. In addition, Trudan-8 could better exploit abundant moisture (70% field capacity), increasing aboveground biomass and water use efficiency. In both genotypes, drought led to very low levels of leaf water potential and relative water content, still supporting photosynthesis. Hence, both morphological and physiological characteristics of sorghum were involved in plant adaptation to drought, in accordance with previous results. Conversely, the common assumption that genotypes best performing under wet conditions are less suited to face drought was contradicted by the results of the two genotypes in our experiment. This discloses a potential to be further exploited in programmes of biomass utilization for various end uses, although further evidence at greenhouse and field level is needed to corroborate this finding.

Relative water content and water potential of tissue 1

1995 ◽  
Vol 46 (1) ◽  
pp. 111-118 ◽  
Author(s):  
J.C. Diaz-Pérez ◽  
K.A. Shackel ◽  
E.G. Sutter
Keyword(s):  
Water Potential ◽  
Water Content ◽  
Relative Water Content ◽  
Relative Water

Studies on the Status of Unburnt Eucalyptus Woodland at Ocean Grove, Victoria. V. The Interactive Effects of Droughting and Shading on Seedlings Under Competition.

1979 ◽  
Vol 27 (3) ◽  
pp. 285 ◽  
Author(s):  
JR Withers
Keyword(s):  
Water Potential ◽  
Water Content ◽  
Drought Resistance ◽  
Relative Water Content ◽  
Height Growth ◽  
Interactive Effects ◽  
Wide Range ◽  
Relative Water ◽  
Pre Treatment ◽  
Grass Sward

Casuarina littoralis seedlings are inherently more drought-resistant than Eucalyptus ovata seedlings over a wide range of environmental conditions. Moderate shade pre-treatment (30% of full daylight) decreased the drought resistance of seedlings of E. ovata, Acacia pycnantha and C. stricta but not that of C. littoralis seedlings. Deep shade pre-treatment (8 % of full daylight) decreased the drought resistance of all species and was associated with decreased rootlshoot ratios. Both shaded and non-shaded C. littoralis seedlings closed stomata at higher relative water contents (about 80% and 88 % respectively) than did E. ovata seedlings (about 36 % and 63 % respectively). Shading decreased the relative water content at which E. ovata closed stomata and reduced the relative decrease in water potential which occurred with unit decreases in relative water content. When E. ovata and C. littoralis seedlings were grown in competition, the larger E. ovata dominated the drought response of plants under both high and low light conditions. E. ovata rapidly depleted moisture supplies thereby subjecting C. littoralis to greater stress and earlier death than it experienced in monoculture. C. littoralis seedlings grown and droughted in competition with E. ovata exhibited smaIIer decreases in water potential per unit decrease in relative water content than seedlings grown in monoculture. The height growth of E. ovata grown in monoculture and in competition with C. littoralis was reduced for at least 10-15 weeks after the wilting treatment, but height growth of C. littoralis was not affected. Eucalypts wilted at higher water potentials (-4.3 MPa) than did C. littoralis seedlings (- 6.3 MPa). It is suggested that the replacement of E. ovata by C. littoralis at Ocean Grove, Vic. may be partly due to the differential effects of shading on the drought resistance of seedlings which become established in the grass sward of canopy gaps.

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