scholarly journals The assessment of vine water uptake conditions by 13c/12c discrimination in grape sugar

OENO One ◽  
2001 ◽  
Vol 35 (4) ◽  
pp. 195 ◽  
Author(s):  
Jean-Pierre Gaudillère ◽  
Cornelis Van Leeuwen ◽  
Olivier Trégoat
Keyword(s):  
Water Potential ◽  
Water Uptake ◽  
Leaf Water Potential ◽  
Carbon Isotope Discrimination ◽  
Low Cost ◽  
Leaf Water ◽  
Plant Water ◽  
Plant Water Uptake ◽  
Primary Products ◽  
Heavy Equipment

<p style="text-align: justify;">Carbon isotope discrimination in primary products of photosynthesis varies with plant water uptake conditions. This property was used to show that the <sup>13</sup>C/<sup>12</sup>C ratio (called ΔC13) in grape sugars and tartrate measured at ripeness can be a valuable indicator of vine water deficit. Correlation between ΔC13 in grape sugar and minimum pre-dawn leaf water potential is excellent (R<sup>2</sup> = 0,81; n = 36). A statistically significant effect of soil and vintage is pointed out. When measured on a great number of plots of an estate, ΔC13 varies with the soil type. This proves ΔC13 can be a valuable tool in « terroir » studies. ΔC13 measured on phenolic compounds in wine is also significantly correlated to minimum pre-dawn leaf water potential as well as to ΔC13 in grape sugar. ΔC13 is actually the only tool capable to assess global vine water uptake conditions between veraison and harvest at a low cost, without the installation of heavy equipment in the vineyard.</p>

THE WATER RELATIONS AND IRRIGATION REQUIREMENTS OF COCONUT (Cocos nucifera): A REVIEW

2011 ◽  
Vol 47 (1) ◽  
pp. 27-51 ◽  
Author(s):  
M. K. V. CARR
Keyword(s):  
Water Potential ◽  
Water Use ◽  
Water Relations ◽  
Leaf Water Potential ◽  
Water Productivity ◽  
Chloride Ions ◽  
Leaf Water ◽  
Flower Initiation ◽  
Plant Water ◽  
Drought Mitigation

SUMMARYThe results of research on the water relations and irrigation needs of coconut are collated and summarized in an attempt to link fundamental studies on crop physiology to drought mitigation and irrigation practices. Background information on the centres of origin and production of coconut and on crop development processes is followed by reviews of plant water relations, crop water use and water productivity, including drought mitigation. The majority of the recent research published in the international literature has been conducted in Brazil, Kerala (South India) and Sri Lanka, and by CIRAD (France) in association with local research organizations in a number of countries, including the Ivory Coast. The unique vegetative structure of the palm (stem and leaves) together with the long interval between flower initiation and the harvesting of the mature fruit (44 months) mean that causal links between environmental factors (especially water) are difficult to establish. The stomata play an important role in controlling water loss, whilst the leaf water potential is a sensitive indicator of plant water status. Both stomatal conductance and leaf water potential are negatively correlated with the saturation deficit of the air. Although roots extend to depths >2 m and laterally >3 m, the density of roots is greatest in the top 0–1.0 m soil, and laterally within 1.0–1.5 m of the trunk. In general, dwarf cultivars are more susceptible to drought than tall ones. Methods of screening for drought tolerance based on physiological traits have been proposed. The best estimates of the actual water use (ETc) of mature palms indicate representative rates of about 3 mm d−1. Reported values for the crop coefficient (Kc) are variable but suggest that 0.7 is a reasonable estimate. Although the sensitivity of coconut to drought is well recognized, there is a limited amount of reliable data on actual yield responses to irrigation although annual yield increases (50%) of 20–40 nuts palm−1 (4–12 kg copra, cultivar dependent) have been reported. These are only realized in the third and subsequent years after the introduction of irrigation applied at a rate equivalent to about 2 mm d−1 (or 100 l palm−1 d−1) at intervals of up to one week. Irrigation increases female flower production and reduces premature nut fall. Basin irrigation, micro-sprinklers and drip irrigation are all suitable methods of applying water. Recommended methods of drought mitigation include the burial of husks in trenches adjacent to the plant, mulching and the application of common salt (chloride ions). An international approach to addressing the need for more information on water productivity is recommended.

scholarly journals The importance of cuticular permeance in assessing plant water–use strategies

2020 ◽  
Vol 40 (4) ◽  
pp. 425-432
Author(s):  
Matthew Lanning ◽  
Lixin Wang ◽  
Kimberly A Novick
Keyword(s):  
Water Stress ◽  
Water Potential ◽  
Water Use ◽  
Leaf Water Potential ◽  
Stress Responses ◽  
Leaf Water ◽  
Plant Water ◽  
Stomatal Control ◽  
Plant Water Use ◽  
The Impact

Abstract Accurate understanding of plant responses to water stress is increasingly important for quantification of ecosystem carbon and water cycling under future climates. Plant water-use strategies can be characterized across a spectrum of water stress responses, from tight stomatal control (isohydric) to distinctly less stomatal control (anisohydric). A recent and popular classification method of plant water-use strategies utilizes the regression slope of predawn and midday leaf water potentials, σ, to reflect the coupling of soil water availability (predawn leaf water potential) and stomatal dynamics (daily decline in leaf water potential). This type of classification is important in predicting ecosystem drought response and resiliency. However, it fails to explain the relative stomatal responses to drought of Acer sacharrum and Quercus alba, improperly ranking them on the spectrum of isohydricity. We argue this inconsistency may be in part due to the cuticular conductance of different species. We used empirical and modeling evidence to show that plants with more permeable cuticles are more often classified as anisohydric; the σ values of those species were very well correlated with measured cuticular permeance. Furthermore, we found that midday leaf water potential in species with more permeable cuticles would continue to decrease as soils become drier, but not in those with less permeable cuticles. We devised a diagnostic parameter, Γ, to identify circumstances where the impact of cuticular conductance could cause species misclassification. The results suggest that cuticular conductance needs to be considered to better understand plant water-use strategies and to accurately predict forest responses to water stress under future climate scenarios.

scholarly journals A minimally disruptive method for measuring water potential in planta using hydrogel nanoreporters

2021 ◽  
Vol 118 (23) ◽  
pp. e2008276118
Author(s):  
Piyush Jain ◽  
Weizhen Liu ◽  
Siyu Zhu ◽  
Christine Yao-Yun Chang ◽  
Jeff Melkonian ◽  
...  
Keyword(s):  
Water Potential ◽  
Leaf Water Potential ◽  
Water Status ◽  
Resonance Energy ◽  
Field Measurements ◽  
Leaf Water ◽  
Plant Water Status ◽  
Plant Water ◽  
In Planta

Leaf water potential is a critical indicator of plant water status, integrating soil moisture status, plant physiology, and environmental conditions. There are few tools for measuring plant water status (water potential) in situ, presenting a critical barrier for developing appropriate phenotyping (measurement) methods for crop development and modeling efforts aimed at understanding water transport in plants. Here, we present the development of an in situ, minimally disruptive hydrogel nanoreporter (AquaDust) for measuring leaf water potential. The gel matrix responds to changes in water potential in its local environment by swelling; the distance between covalently linked dyes changes with the reconfiguration of the polymer, leading to changes in the emission spectrum via Förster Resonance Energy Transfer (FRET). Upon infiltration into leaves, the nanoparticles localize within the apoplastic space in the mesophyll; they do not enter the cytoplasm or the xylem. We characterize the physical basis for AquaDust’s response and demonstrate its function in intact maize (Zea mays L.) leaves as a reporter of leaf water potential. We use AquaDust to measure gradients of water potential along intact, actively transpiring leaves as a function of water status; the localized nature of the reporters allows us to define a hydraulic model that distinguishes resistances inside and outside the xylem. We also present field measurements with AquaDust through a full diurnal cycle to confirm the robustness of the technique and of our model. We conclude that AquaDust offers potential opportunities for high-throughput field measurements and spatially resolved studies of water relations within plant tissues.

Water uptake depth is coordinated with leaf water potential, water‐use efficiency and drought vulnerability in karst vegetation

2020 ◽  
Vol 229 (3) ◽  
pp. 1339-1353
Author(s):  
Yali Ding ◽  
Yunpeng Nie ◽  
Hongsong Chen ◽  
Kelin Wang ◽  
José I. Querejeta
Keyword(s):  
Water Use Efficiency ◽  
Water Potential ◽  
Water Use ◽  
Water Uptake ◽  
Leaf Water Potential ◽  
Leaf Water ◽  
Drought Vulnerability ◽  
Use Efficiency

Impact of soil water potential pattern on root water uptake distribution and leaf water potential

2021 ◽  
Author(s):  
Ali Mehmandoost Kotlar ◽  
Mathieu Javaux
Keyword(s):  
Water Potential ◽  
Root System ◽  
Soil Water ◽  
Water Flow ◽  
Water Uptake ◽  
Leaf Water Potential ◽  
Root Water Uptake ◽  
Leaf Water ◽  
Hydraulic Lift ◽  
Water Potentials

&lt;p&gt;Root water uptake is a major process controlling water balance and accounts for about 60% of global terrestrial evapotranspiration. The root system employs different strategies to better exploit available soil water, however, the regulation of water uptake under the spatiotemporal heterogeneous and uneven distribution of soil water is still a major question. To tackle this question, we need to understand how plants cope with this heterogeneity by adjustment of above ground responses to partial rhizosphere drying. Therefore, we use R-SWMS simulating soil water flow, flow towards the roots, and radial and the axial flow inside the root system to perform numerical experiments on a 9-cell gridded rhizotrone (50 cm&amp;#215;50 cm). The water potentials in each cell can be varied and fixed for the period of simulation and no water flow is allowed between cells while roots can pass over the boundaries. Then a static mature maize root architecture to different extents invaded in all cells is subjected to the various arrangements of cells' soil water potentials. R-SWMS allows determining possible hydraulic lift in drier areas. With these simulations, the variation of root water and leaf water potential will be determined and the role of root length density in each cell and corresponding average soil-root water potential will be statistically discussed.&lt;/p&gt;

The effect of root hairs under drought in open field conditions

2021 ◽  
Author(s):  
Maria Marin ◽  
Deborah S Feeney ◽  
Lawrie K Brown ◽  
Muhammad Naveed ◽  
Siul Ruiz ◽  
...  
Keyword(s):  
Water Potential ◽  
Water Deficit ◽  
Open Field ◽  
Leaf Water Potential ◽  
Root Hair ◽  
Root Hairs ◽  
Leaf Water ◽  
Plant Water ◽  
Clay Loam ◽  
Wild Type

&lt;p&gt;Root hairs represent an attractive target for future crop breeding, to improve resource use efficiency and stress tolerance. Most studies investigating root hairs have focused on plant tolerance to phosphorus deficiency and rhizosheath formation under controlled conditions. However, data on the interplay between root hairs and open-field systems, under contrasting soils and climate conditions, are limited. Although root hairs and rhizosphere are assumed to play a key role in regulating plant water relations, their effect on plant water uptake has been rarely investigated. As such, this study aimed to experimentally elucidate some of the impacts that root hairs have on plant performance under field conditions and water deficit. A field experiment was set up in Scotland for two consecutive years, in 2017 (a typical year) and 2018 (the driest growing season ever recorded at this site), under different soil textures (i.e., clay loam vs. sandy loam). Five barley (Hordeum vulgare) genotypes exhibiting variation in root hair length and density were used in the study. Measurements of root hair density, length and its correlation with rhizosheath weight highlighted trait robustness in the field under variable environmental conditions. Root hairs did not confer a notable advantage to barley under optimal conditions, but under soil water deficit root hairs enhanced plant water status and stress tolerance. This resulted in less negative leaf water potential and lower leaf abscisic acid concentration, while promoting shoot phosphorus accumulation. Specifically, minimum leaf water potential differed significantly (P = 0.021) between the wild type (-1.43 MPa) and its hairless mutant (-1.76 MPa) grown in clay loam, with the mutant exhibiting greater water stress. In agreement with leaf water potential measurements, at the peak of water stress, leaf abscisic acid concentration was significantly (P = 0.023) greater for the hairless mutant (394 ng g&lt;sup&gt;-1&lt;/sup&gt;) than the wild type (250 ng g&lt;sup&gt;-1&lt;/sup&gt;) grown in clay loam soil. Under water deficit conditions, in clay loam soil, shoot phosphorus accumulation in the wild type (2.49 mg P shoot&lt;sup&gt;-1&lt;/sup&gt;) was over twice that in the hairless mutant (1.10 mg P shoot&lt;sup&gt;-1&lt;/sup&gt;). Furthermore, the presence of root hairs did not decrease yield under optimal conditions, while root hairs enhanced yield stability under drought. While yield of the hairless mutant significantly (P = 0.012) decreased from 2017 to 2018 in both clay (-26%) and sandy (-33%) loam soils, no significant differences were found between years in the yield of the wild type. Therefore, selecting for beneficial root hair traits can enhance yield stability without diminishing yield potential, overcoming the breeder&amp;#8217;s dilemma of trying to simultaneously enhance both productivity and resilience. To our knowledge, the present findings provide the first evidence of the effect of root hairs under drought in open field conditions (i.e., real agricultural system). Therefore, along with the well-recognized role for P uptake, maintenance or enhancement of root hairs can represent a key trait for breeding the next generation of crops for improved drought tolerance in relation to climate change.&lt;/p&gt;

Quantifying how plants with different species-specific water-use strategies cope with the same drought-prone hydro-ecological conditions

2020 ◽  
Author(s):  
Deepanshu Khare ◽  
Gernot Bodner ◽  
Mathieu Javaux ◽  
Jan Vanderborght ◽  
Daniel Leitner ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Drought Stress ◽  
Water Potential ◽  
Water Uptake ◽  
Hydraulic Properties ◽  
Root Water Uptake ◽  
Leaf Water ◽  
Plant Water ◽  
Soil Hydraulic Properties ◽  
Stomatal Control

&lt;p&gt;Plant transpiration and root water uptake are dependent on multiple traits that interact with site soil characteristics and environmental factors such as radiation, atmospheric temperature, relative humidity, and soil-moisture content. Models of root architecture and functions are increasingly employed to simulate root-soil interactions. Root water uptake is thereby affected by the root hydraulic architecture, soil moisture conditions, soil hydraulic properties, and the transpiration demand as controlled by atmospheric conditions. Stomatal conductance plays a vital role in regulating transpiration in plants. We performed simulations of plant water uptake for plants having different mechanisms to control transpiration, spanned by isohydric/anisohydric spectrum. Isohydric plants follow the strategy to close their stomata in order to maintain the leaf water potential at a constant level, while anisohydric plants leave their stomata open when leaf water potentials fall due to drought stress. Modelling the stomatal regulation effectively will result in a more reliable model that will regulate the excessive loss of water. We implemented hydraulic and chemical stomatal control&lt;br&gt;of root water uptake following the current approach where stomatal control is regulated by simulated water potential and/or chemical signal concentration. In order to maintain water uptake from dry soil, low plant water potentials are required, which may lead to reversible or permanent cavitation. We parameterise our model with field data, including climate data and soil hydraulic properties under different tillage conditions. This helps us to understand the behaviour of different crops under drought conditions and predict at which growing stage the stress hits the plant. We conducted the simulations for different scenarios to study the effect of hydraulic and chemical regulation on root system performance under drought stress.&lt;/p&gt;

Seasonal Variation in the Water Uptake and Leaf Water Potential of Intercropped and Monocropped Chillies

1987 ◽  
Vol 23 (3) ◽  
pp. 273-282 ◽  
Author(s):  
N. R. Hulugalle ◽  
S. T. Willatt
Keyword(s):  
Water Potential ◽  
Water Uptake ◽  
Leaf Water Potential ◽  
Growing Season ◽  
Leaf Water ◽  
Irrigation Regime ◽  
Use Patterns ◽  
Capsicum Annum ◽  
Water Use Patterns ◽  
Seasonal Water Use

SUMMARYThe seasonal water use patterns and leaf water potential of chillies (Capsicum annum var. annum) grown as a monocrop and as an intercrop between soyabeans (Glycine max) were studied under a weekly and two weekly irrigation regime on a red duplex soil in Northern Victoria, Australia. Irrigation at two weekly intervals resulted in a temporal stratification of water extraction over the growing season, the soyabeans making their maximum demand during the reproductive phase. Senescence of the soyabeans at the R6–R7, growth stage was accompanied by an increase in water uptake by the intercropped chillies. No corresponding increase in water uptake was observed in monocropped chillies irrigated every two weeks or in intercropped or monocropped chillies irrigated weekly. Leaf water potential of the intercropped chillies was, for the most part, greater than that of the corresponding monocrops.

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