Osmotic potential at full turgor: an easily measurable trait to help breeders select for drought tolerance in wheat

2016 ◽  
Vol 135 (3) ◽  
pp. 279-285 ◽  
Author(s):  
Kyle B. Mart ◽  
Erik J. Veneklaas ◽  
Helen Bramley
Keyword(s):  
Drought Tolerance ◽  
Osmotic Potential

scholarly journals Responses of Parameters for Electrical Impedance Spectroscopy and Pressure–Volume Curves to Drought Stress in Pinus bungeana Seedlings

Forests ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 359
Author(s):  
Ai-Fang Wang ◽  
Bao Di ◽  
Tapani Repo ◽  
Marja Roitto ◽  
Gang Zhang
Keyword(s):  
Drought Stress ◽  
Impedance Spectroscopy ◽  
Drought Tolerance ◽  
Osmotic Potential ◽  
Electrical Impedance ◽  
Electrical Impedance Spectroscopy ◽  
Tree Seedlings ◽  
Intracellular Resistance ◽  
Pinus Bungeana ◽  
Extracellular Resistance

Background and Objectives: Drought occurs more frequently in Northern China with the advent of climate change, which might increase the mortality of tree seedlings after afforestation due to hydraulic failure. Therefore, investigating water relations helps us understand the drought tolerance of tree seedlings. Electrical impedance spectroscopy (EIS) is widely used to assess the responses of plant tissues to stress factors and may potentially reveal the water relations of cells. The aim of this study is to reveal the relationships between EIS and water related parameters, produced by pressure–volume (PV) curves in lacebark pine (Pinus bungeana Zucc.) seedlings reacting to drought stress. Materials and Methods: Four-year-old pot seedlings were divided into three parts (0, 5, and 10 days of drought) before planting, the treated seedlings were then replanted, and finally exposed to post-planting drought treatments with the following soil relative water contents: (i) adequate irrigation (75%–80%), (ii) light drought (55%–60%), (iii) moderate drought (35%–40%), and (iv), severe drought (15%–20%). During the post-planting growth phase, the EIS parameters of needles and shoots, and the parameters of PV curves, were measured coincidently; thus, the correlations between them could be obtained. Results: The extracellular resistance (re) of needles and shoots were substantially reduced after four weeks of severe post-planting drought stress. Meanwhile, the osmotic potential at the turgor-loss point (ψtlp) and the saturation water osmotic potential (ψsat) of shoots decreased after drought stress, indicating an osmotic adjustment in acclimating to drought. The highest correlations were found between the intracellular resistance (ri) of the shoots and ψtlp and ψsat. Conclusions: EIS parameters can be used as a measure of drought tolerance. The change in intracellular resistance is related to the osmotic potential of the cell and cell wall elasticity. Extracellular resistance is a parameter that shows cell membrane damage in response to drought stress in lacebark pine seedlings.

Specific leaf metabolic changes that underlie adjustment of osmotic potential in response to drought by four Quercus species

2020 ◽  
Author(s):  
Ismael Aranda ◽  
Estrella Cadahía ◽  
Brígida Fernández de Simón
Keyword(s):  
Drought Tolerance ◽  
Osmotic Adjustment ◽  
Osmotic Potential ◽  
Quinic Acid ◽  
Molecular Processes ◽  
Leaf Habit ◽  
Leaf Osmotic Potential ◽  
Quercus Species ◽  
Metabolic Basis ◽  
Watering Treatment

Abstract Osmotic adjustment is almost ubiquitous as a mechanism of response to drought in many forest species. Recognized as an important mechanism of increasing turgor under water stress, the metabolic basis for osmotic adjustment has been described in only a few species. We established an experiment with four species of the genus Quercus ranked according to drought tolerance and leaf habit from evergreen to broad-leaved deciduous. A cycle of watering deprivation was imposed on seedlings, resulting in well-watered (WW) and water-stressed (WS) treatments, and their water relations were assessed from pressure-volume (P-V) curves. Leaf predawn water potential (Ψpd) significantly decreased in WS seedlings which was followed by a drop in leaf osmotic potential at full turgor (Ψπ100). The lowest values of Ψπ100 followed the ranking of decreasing drought tolerance: Q. ilex < Q. faginea < Q. pyrenaica < Q. petraea. The leaf osmotic potential at the turgor loss point (ΨTLP) followed the same pattern as Ψπ100 across species and treatments. The pool of carbohydrates, some organic acids, and cyclitols were the main osmolytes explaining osmotic potential across species, likewise to the osmotic adjustment assessed from the decrease in leaf Ψπ100 between WW and WS seedlings. Amino-acids were very responsive to WS, particularly γ-aminobutyric acid (GABA) in Q. pyrenaica, but made a relatively minor contribution to osmotic potential compared with other groups of compounds. In contrast, the cyclitol proto-quercitol made a prominent contribution to the changes in osmotic potential regardless of watering treatment or species. However, different metabolites such as quinic acid, played a more important role in osmotic adjustment in Q. ilex, distinguishing it from the other species studied. In conclusion, while osmotic adjustment was present in all four Quercus species, the molecular processes underpinning this response differed according to their phylogenetic history and specific ecology.

scholarly journals PHYSIOLOGICAL CHARACTERIZATION OF SIX WHEAT GENOTYPES FOR DROUGHT TOLERANCE

2016 ◽  
Vol 4 (2) ◽  
pp. 184-196
Author(s):  
HanifChachar Muhammad ◽  
Nazir Ahmed Chachar ◽  
Qamaruddin Chachar ◽  
Mujtaba Sheikh Muhammad ◽  
Sadaruddin Chachar ◽  
...  
Keyword(s):  
Water Stress ◽  
Drought Tolerance ◽  
Osmotic Potential ◽  
Glycine Betaine ◽  
Global Climate ◽  
Reductase Activity ◽  
Current Data ◽  
Wheat Genotypes ◽  
Physiological Characterization ◽  
Terminal Drought

Pakistan is one of the most severely affected countries by Global climate change, it is an agriculture based country and its economy (21%) mainly depend on agriculture production. Wheat is the major staple food crop in Pakistan and takes key position in the national economy. It contribute 12.5% share in agriculture and 2.9% in the country’s GDP. Frequent droughts and scarcity of the water severely affecting the wheat production. To fulfill the feed requirements of rapidly growing population, it is necessary to explore the advanced genetic resource that can be able to perform better in changing climate. Six wheat genotypes were tested for their early seedling and physiological performance under different water stress environments. The seeds of six wheat genotypes (Khirman, Chakwal-86, MSH-36, DH-3/48, NIA Amber and NIA-10 10/8) were tested for physiological characterization under pot house experiment for individual genotypic response to water stress. The variance of analysis shows two-way interaction water stress [Control (normal four irrigations) and terminal drought (Soaking dose) and wheat genotypes (P≤ 0.05). Seven physiological indices, including Proline content, Glycine-betaine, Total sugars, Total chlorophyll, Nitrate Reductase Activity ((NRA), Potassium (K+) content, and Osmotic potential (OP) were used to evaluate the drought tolerance of six wheat genotypes. From the current data it was illustrated that, MSH-36 and DH-3/48 exhibited the tolerance followed by, Khirman and Chakwal-86 by maintaining their osmotic potential and accumulation of higher proline and glycine-betaine content that helpful for plant to enhancing their tolerance under water stress and to maintain their growth and development, whereas NIA Amber and NIA-10 10/8 are the drought sensitive genotypes as they could not maintain their osmotic potential under drought stress environment.

scholarly journals Which way forward in the quest for drought tolerance in perennial ryegrass?

2012 ◽  
pp. 195-200 ◽  
Author(s):  
C. Matthew ◽  
A. Van der Linden ◽  
S. Hussain ◽  
H.S. Easton ◽  
J.-H B. Hatier ◽  
...  
Keyword(s):  
New Zealand ◽  
Drought Tolerance ◽  
Water Deficit ◽  
Water Use ◽  
Perennial Ryegrass ◽  
Osmotic Potential ◽  
Water Extraction ◽  
Conservation Strategy ◽  
Weather Data ◽  
Rooting Depth

Pasture moisture stress for "summer" (November to March) was calculated for five main pastoral regions of New Zealand, and 9 or 10 years' weather data were modelled in each case. Amelioration of water deficit with deeper rooting, stronger plant tissue osmotic potential for greater water extraction, or increased photosynthetic water use efficiency (WUE) was also modelled. Regional mean summer moisture deficits ranged from 34 mm in Taranaki to 447 mm in Canterbury. For a 10-cm increase in rooting depth, the model predicted an additional 16 mm water extraction. Increased plant osmotic potential was predicted to only slightly increase water extraction and paradoxically reduce yield. The assumed increase in photosynthetic WUE improved production by 240 kg DM ha-1 for the same water use. Drought tolerance traits exhibited by a range of ryegrass cultivars were measured in a series of glasshouse experiments and the potential to improve New Zealand ryegrass drought tolerance by introgression with germplasm originating from North Africa was assessed. North African germplasm possesses a trait of deep rootedness but has low summer productivity as a soil moisture conservation strategy and a high percentage of tillers flowering, so initial evaluations of this material for suitability for use in New Zealand are not promising. Ryegrass cultivars incorporating germplasm of Spanish origin appear to maintain summer production with enhanced WUE. Keywords: drought tolerance, root depth, Lolium perenne, perennial ryegrass, water deficit

Seasonal and clonal variations in drought tolerance of Populusdeltoides

1991 ◽  
Vol 21 (6) ◽  
pp. 910-916 ◽  
Author(s):  
G. Michael Gebre ◽  
Michael R. Kuhns
Keyword(s):  
Drought Tolerance ◽  
Osmotic Potential ◽  
Weight Fraction ◽  
Dry Weight ◽  
Weather Conditions ◽  
Injury Index ◽  
Eastern Cottonwood ◽  
Leaf Osmotic Potential ◽  
Favorable Weather ◽  
Osmotic Potentials

Water relations of three field-grown eastern cottonwood (Populusdeltoides Bartr.) clones were compared for the 1989 growing season. Clonal and seasonal variations in leaf water potential, leaf osmotic potential, dry weight fraction, and injury index were measured. The injury index was calculated from conductivity changes due to electrolyte leakage during rehydration of dehydrated and nondehydrated leaves. When samples were measured after dry periods, dry weight fraction increased and injury index and predawn osmotic potential declined. There were significant negative correlations between dry weight fraction and osmotic potential for all clones. There were no significant differences between clones from Nebraska (Platte) and Indiana (Tippecanoe) throughout the season in osmotic potential and injury index. The clones Platte and Tippecanoe had significantly lower osmotic potentials than a clone from Ohio (Ohio Red) on most sample dates. When injury index values increased following favorable weather conditions, Platte and Tippecanoe had a significantly lower injury index than Ohio Red. Since all clones had lower osmotic potential, higher dry weight fraction, and lower injury index during dry periods, it was concluded that all had drought hardened during the period, indicating that all clones have some degree of drought tolerance.

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