Genotype identification for a water saving trait: Exploring early stomatal closure under soil drying among Mid‐South soybeans

2021 ◽  
Author(s):  
Sam Purdom ◽  
Avat Shekoofa ◽  
Angela McClure ◽  
Vince Pantalone ◽  
Prakash Arelli
Keyword(s):  
Stomatal Closure ◽  
Water Saving ◽  
Soil Drying ◽  
Genotype Identification

Soil water matric potential rather than water content determines drought responses in field-grown lupin (Lupinus angustifolius)

1998 ◽  
Vol 25 (3) ◽  
pp. 353 ◽  
Author(s):  
C.R. Jensen ◽  
V.O. Mogensen ◽  
H.-H. Poulsen ◽  
I.E. Henson ◽  
S. Aagot ◽  
...  
Keyword(s):  
Water Potential ◽  
Water Content ◽  
Soil Water ◽  
Stomatal Closure ◽  
Soil Water Potential ◽  
Root Surface ◽  
Lupinus Angustifolius ◽  
Soil Drying ◽  
Matric Potential ◽  
Aba Content

Drought responses in leaves of lupin (Lupinus angustifolius L., cv. Polonez) were investigated in plants grown in lysimeters either in a sand or in a loam soil in the field. Abscisic acid (ABA) content, water potential (ψl) and conductance to water vapour (gH2O) were determined in leaves of both irrigated plants and in plants exposed to gradual soil drying. Amorning-peak of leaf ABA content was found in both fully watered and droughted plants. During soil drying which, on both soils types, only decreased soil water potential of the upper soil layers, mid-day leaf ABA content increased relative to that in fully irrigated plants before any appreciable decreases occurred in ψl. In the part of the soil profile from which water was taken up (0–60 cm depth), gH2O decreased when the relative available soil water content (RASW) on sand was below 12% and RASW on loam, below 30%. At this point the average soil water matric potential (ψsoil) on sand was less than –0.13 MPa and the fraction of roots in ‘wet’ soil was 0.12, while on loam, the fraction of roots in ‘wet’ soil was 0.44 while y soil was similar to that on sand. A critical leaf ABA content of 300–400 ng/g FW was associated with the onset of stomatal closure on both soil types. We suggest that the initial stomatal closure is controlled by ABA which originates from the roots where its production is closely related to ψsoiland the water potential of the root surface and that ψsoil is a more important parameter than RASW or the fraction of roots in ‘wet’ soil for affecting leaf gas exchange. Further drying on both soils led to further increases in leaf ABA and declines in ψl and gH2O. In order to gain further insight, experiments should be designed which combine signalling studies with simulation studies, which take account of soil water potential, root contact area and water flux when calculating the water status at the root surface in the soil-plant-atmosphere-continuum.

A modelling framework to predict transpiration reductions during drought based on soil hydraulics 

2021 ◽  
Author(s):  
Andrea Carminati ◽  
Mathieu Javaux
Keyword(s):  
Hydraulic Conductivity ◽  
Stomatal Conductance ◽  
Water Potential ◽  
Soil Water ◽  
Stomatal Closure ◽  
Soil Water Potential ◽  
Soil Drying ◽  
Soil Hydraulic Conductivity ◽  
Plant Hydraulics ◽  
Soil Hydraulic

<p>There is increasing need for mechanistic and predictive models of transpiration and stomatal response to drought. Global measurements of transpiration showed that the decrease in soil moisture is a primary constrain on transpiration. Additionally, a recent meta-analysis indicated that stomatal closure is explained by the loss in soil hydraulic conductivity, more than that of the xylem. Despite these evidences on the role of soil drying as a key driver of transpiration reduction, the mechanisms by which soil drying impacts transpiration, including the effect of different soil hydraulic properties, are not fully understood.</p><p>Here, we propose that stomata regulate transpiration in such a way that the relation between transpiration and the difference in water potential between soil and leaves remains linear during soil drying and increasing vapor pressure deficit (VPD). The onset of hydraulic nonlinearity sets the maximum stomatal conductance at a given soil water potential and VPD. The resulting trajectory of the stomatal conductance for varying soil water potentials and VPD depends on soil and plant hydraulics, with the soil hydraulic conductivity and root length being the most sensitive parameters.</p><p>From this hydraulic framework it follows that stomatal closure is not simply a function of soil moisture, soil water potential or leaf water potential. Instead, it depends on transpiration demand and soil-plant hydraulics in a predictable way. The proposed concept allows to predict transpiration reductions during drought with a limited number of parameters: transpiration demand, plant hydraulic conductivity, soil hydraulic conductivity and active root length. In conclusion, this framework highlights the role of the soil hydraulic conductivity as primary constrain on transpiration, and thus on stomatal conductance and photosynthesis.</p>

A review of drought adaptation in crop plants: changes in vegetative and reproductive physiology induced by ABA-based chemical signals

2005 ◽  
Vol 56 (11) ◽  
pp. 1245 ◽  
Author(s):  
Fulai Liu ◽  
Christian R. Jensen ◽  
Mathias N. Andersen
Keyword(s):  
Drought Stress ◽  
Stomatal Closure ◽  
Xylem Sap ◽  
Reproductive Development ◽  
Leaf Expansion ◽  
Rhizobium Japonicum ◽  
Soil Drying ◽  
Drought Adaptation ◽  
Chemical Signalling

This review discusses the role of abscisic acid (ABA)-based drought stress chemical signalling in regulating crop vegetative and reproductive development and its contributions to crop drought adaptation. Increased concentrations of ABA in the root induced by soil drying may maintain root growth and increase root hydraulic conductivity; both lead to an increase in water uptake and thereby postpone the development of water deficit in the shoot. Root ABA is also transported in the xylem to the shoot and is perceived at the acting sites, where it causes stomatal closure and reduced leaf expansion, thereby preventing dehydration of leaf tissues and enhancing the chance for survival under prolonged drought. ABA-based chemical signalling can be amplified by several factors, particularly increased pH in the xylem/apoplast, which retains anionic ABA. Such an increase in xylem pH detected in field-grown maize might have been brought about by reduced nitrate uptake by plants during soil drying. In contrast, xylem sap alkalinisation was not found in soybeans, which depend on fixing nitrogen through their association with Rhizobium japonicum. Evidence has also shown that the xylem-borne ABA can be transported to plant reproductive structures and influence their development, presumably by regulating gene expression that controls cell division and carbohydrate metabolic enzyme activity under drought conditions. The possible involvement of ABA in the up- and down-regulation of acid invertase in crop source (adult leaves) v. sink (young ovaries) organs indicates a crucial role of the hormone in balancing source and sink relationship in plants according to the availability of water in the soil. A novel irrigation technique named partial root-zone drying (PRD), has been developed to allow exploitation of ABA-based drought stress signalling to improve water-use efficiency (WUE) based on its roles in regulating stomatal aperture and leaf expansion. However, little is known about how crop reproductive development is regulated when irrigated under PRD. We suggest that more attention should be paid to the latter aspect as it directly relates to crop yield and quality.

Early signals in field grown wheat in response to shallow soil drying

1998 ◽  
Vol 25 (8) ◽  
pp. 871 ◽  
Author(s):  
M. Ali ◽  
C.R. Jensen ◽  
V.O. Mogensen
Keyword(s):  
Stomatal Conductance ◽  
Stomatal Closure ◽  
Soil Water Potential ◽  
Leaf Water ◽  
Soil Types ◽  
Extension Rate ◽  
Soil Drying ◽  
Stem Extension ◽  
Aba Content ◽  
Leaf Extension

The aim of the present work was to test under field condition earlier climate room findings that root-borne signals may control stomatal closure and leaf extension rate during mild soil drying. Stomatal conductance (g H2O) of flag leaves, leaf and stem extension rates, leaf water relations, leaf ABA content and predawn xylem [ABA] were measured daily in wheat grown in two soil types (sand and loam) in lysimeters in the field during a period of soil drying with high and low evaporative demands. At 3 days after withholding irrigation (DAI) on both soil types, when soil water potential (Ψsoil) in the upper soil profile of the droughted treatment had dropped to –70 kPa and with the lower layers still at field capacity, predawn xylem [ABA] increased. At 4 DAI the leaf extension rate decreased and midday leaf ABA content increased. Stem extension rates decreased at 5 DAI in loam and 7 DAI in sand. g H2O started to decrease 6 DAI in loam and 9 DAI in sand. These responses were observed before any detectable decrease in the midday leaf water status of the droughted plants had occurred relative to well- watered plants. The responses were closely related to Ψsoil and independent of evaporative demand. We conclude that, in wheat, root-borne signals probably control stomatal conductance and leaf extension rate during mild soil drying in the field.

Towards a conceptual ABA ideotype in plant breeding for water limited environments

2015 ◽  
Vol 42 (6) ◽  
pp. 502 ◽  
Author(s):  
Abraham Blum
Keyword(s):  
Drought Stress ◽  
Plant Breeding ◽  
Drought Resistance ◽  
Stomatal Closure ◽  
Field Research ◽  
Water Saving ◽  
Stress Profile ◽  
Negative Effects ◽  
Plant Model ◽  
Plant Hydraulics

A huge amount of information had been accumulated on abscisic acid (ABA). Laboratory and some field research with ABA-enhanced transgenic plants generally conclude that ABA is a drought resistance hormone, since it causes stomatal closure, reduces transpiration and results in ‘water saving’ under drought stress. This recurring conclusion is hard to accept in the agronomic domain considering the many direct and indirect negative effects of ABA on plant growth and reproduction. In order to formulate a conceptual phenotypic ABA ideotype for plant breeding, this paper begins by briefly reviewing the phenomics of ABA relative to plant function and productivity. Consequently, it is recognised that ABA enhancement is important in controlling the isohydric (‘water saving’) plant model, whereas plant hydraulics are more important in controlling the anisohydric (‘water spending’) plant model. Subsequently, the respective isohydric and anisohydric ideotypes appropriate to specific dryland crop drought stress scenarios are proposed. It is concluded that ABA can by no means be universally defined as a ‘drought resistance hormone’. Its benefit or damage depends on the crop drought stress profile and the dynamics of the seasonal regimen of ABA in the plant. The isohydric ideotype might have an advantage in the harshest environments, whereas the anisohydric one will perform relatively better under more moderate drought conditions.

scholarly journals Declining soil-root hydraulic conductance drives stomatal closure of tomato under drought 

2021 ◽  
Author(s):  
Mohanned Abdalla ◽  
Andrea Carminati ◽  
Gaochao Cai ◽  
Mathieu Javaux ◽  
Mutez Ahmed
Keyword(s):  
Water Potential ◽  
Stomatal Closure ◽  
Soil Water Potential ◽  
Hydraulic Conductance ◽  
Soil Drying ◽  
Xylem Water Potential ◽  
Hydraulic Limitation ◽  
Shoot Hydraulic Conductance ◽  
Root Conductance ◽  
Response To Water

<p>The fundamental question as to what triggers stomatal closure during soil drying remains contentious. Thus, we urgently need to improve our understanding of stomatal response to water deficits in soil and atmosphere.<strong> </strong>Here, we investigated the role of soil-plant hydraulic conductance (K<sub>sp</sub>) on transpiration (E) and stomata regulation. We used a root pressure chamber to measure the relation between E, leaf xylem water potential (ψ<sub>leaf-x</sub>) and soil water potential (ψ<sub>soil</sub>) in tomato. Additional measurements of ψ<sub>leaf-x</sub> were performed with unpressurized plants. A soil-plant hydraulic model was used to simulate E(ψ<sub>leaf-x</sub>) for decreasing ψ<sub>soil</sub>. In wet soils, E(ψ<sub>leaf-x</sub>) had a constant slope while in dry soils the slope decreased, with ψ<sub>leaf-x</sub> rapidly and nonlinearly decreasing for moderate increases in E. The ψ<sub>leaf-x</sub> measured in pressurized and unpressurized plants matched well, which indicates that the shoot hydraulic conductance did not decrease during soil drying and that the decrease in K<sub>sp</sub> is caused by a decrease in soil-root conductance. The decrease of E matched well the onset of hydraulic nonlinearity. Our findings demonstrate that stomatal closure prevents the drop in ψ<sub>leaf-x</sub> caused by a decrease in K<sub>sp</sub> and elucidate a strong correlation between stomatal regulation and belowground hydraulic limitation.</p>

scholarly journals Ethylene limits abscisic acid- or soil drying-induced stomatal closure in aged wheat leaves

2013 ◽  
Vol 36 (10) ◽  
pp. 1850-1859 ◽  
Author(s):  
LIN CHEN ◽  
IAN C. DODD ◽  
WILLIAM J. DAVIES ◽  
SALLY WILKINSON
Keyword(s):  
Abscisic Acid ◽  
Stomatal Closure ◽  
Soil Drying ◽  
Wheat Leaves

scholarly journals Water-Saving Traits Can Protect Wheat Grain Number Under Progressive Soil Drying at the Meiotic Stage: A Phenotyping Approach

2019 ◽  
Vol 38 (4) ◽  
pp. 1562-1573 ◽  
Author(s):  
Michele Faralli ◽  
Kevin S. Williams ◽  
Jiwan Han ◽  
Fiona M. K. Corke ◽  
John H. Doonan ◽  
...  
Keyword(s):  
Water Saving ◽  
Soil Drying ◽  
Meiotic Stage ◽  
Wheat Grain ◽  
Grain Number
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