Water Status and ABA Content of Floral Organs in Drought-Stressed Wheat

1996 ◽  
Vol 23 (6) ◽  
pp. 763 ◽  
Author(s):  
ME Westgate ◽  
JB Passioura ◽  
R Munns
Keyword(s):  
Soil Water ◽  
Water Deficit ◽  
Water Status ◽  
Reproductive Development ◽  
Controlled Environment ◽  
Soil Water Deficit ◽  
Floral Organs ◽  
Boot Stage ◽  
Root Signals ◽  
Aba Content

Chemical signals from roots have been shown to mediate the response of vegetative shoots to drought. Our objective was to test whether root signals such as abscisic acid (ABA) affect grain set in wheat. Uniculm wheat was grown in a controlled environment and exposed to a water deficit from pollen mother cell meiosis to late boot stage-a period of reproductive development very sensitive to drought. The water deficit decreased grain numbers per spike up to 70%. As soil moisture was depleted, leaf, glume, ovary and anther water potential (Ψw) decreased with leaf Ψw. Turgor decreased in the leaves, but remained at or above control levels in all floral organs examined. Free ABA content of leaves increased 30-fold as leaf turgor declined, while ABA in floral organs increased 10-15-fold. To separate the effects of shoot and root water status on grain set, plants were pressurised to maintain leaf Ψw at control levels as the soil dried. Pressurisation increased flowers and grains per spike over that of droughted plants at comparable soil water suctions, but not to control levels. Free ABA content in leaves and floral organs increased only about 3-fold when leaves were maintained at high Ψw. Shoot water status had a greater effect on grain set than did soil water status. In both pressurised and unpressurised plants, grains per spike and percentage grain set decreased with increasing ABA content in ovaries and anthers. The results indicate that maintenance of a high shoot water status reduces the effect of soil water deficit on grain set by reducing the accumulation of ABA.

Water Consumption of Potato (Solanum Tuberosum) Grown under Water Deficit Regulated with Mulched Drip Irrigation

2013 ◽  
Vol 405-408 ◽  
pp. 2273-2276
Author(s):  
Heng Jia Zhang ◽  
Jing Li
Keyword(s):  
Soil Water ◽  
Water Deficit ◽  
Water Consumption ◽  
Drip Irrigation ◽  
Water Status ◽  
Starch Accumulation ◽  
Growth Stages ◽  
Soil Water Deficit ◽  
Crop Water Consumption ◽  
Mulched Drip Irrigation

An experiment was conducted to determine the effect of mulched drip irrigation under water deficit on soil water content (SWC), stored soil water (SSW), daily water consumption (DWC) and ratio of water consumption in total water use (RWC) of potato in an arid area. Five water deficit treatments designed to subject potato to various levels of soil water deficit at different crop growth stages and a full irrigation control were established. The result indicated that the maximum SWC was at 20 cm depth in soil profile and that in 10 to 40 cm increment varied sharply during potato growing season. The SWC, SSW, DWC and RWC were significantly affected by mulched drip irrigation at water deficit regulation stages except at starch accumulation. Therefore, proper levels of soil water deficit regulated with mulched drip irrigation at proper plant growth stages could be used to regulate soil water status, stored soil water and crop water consumption effectively.

Comparison of Stomatal Action of Orange, Soybean and Wheat Under Field Conditions

1981 ◽  
Vol 8 (1) ◽  
pp. 65 ◽  
Author(s):  
WS Meyer ◽  
GC Green
Keyword(s):  
Water Potential ◽  
Soil Water ◽  
Water Deficit ◽  
Water Status ◽  
Radiant Energy ◽  
Plant Water ◽  
Soil Water Deficit ◽  
Late Afternoon ◽  
Constant Rate ◽  
Orange Trees

Diurnal trends in leaf diffusive conductance, Cs, leaf water potential ΨL and rates of evapotranspiration E*T were monitored on orchard-grown orange trees and field-grown crops of soybeans and wheat. Changes in these measurements were observed on soybeans and wheat as the soil water deficit increased. Maximum values of Cs of well watered plants differed between the three species (soybeans > wheat >> orange) probably as a result of different stomatal sizes and densities. Diurnal trends in Cs were common for all species, with maximum values occurring during midmorning followed by slightly lower midday values. The reduction in Cs around midday became much more pronounced as the soil water deficit increased. Slight increases in Cs values of soybeans and wheat were recorded during late afternoon. This pattern of stomatal aperture change can reasonably be explained in terms of responses to both radiant energy and plant water status. The pattern also seems to comply with the premise that stomates interact to optimize the rate of assimilation while minimizing the rate of transpiration in a given environment. Stomatal action appeared to have little effect on daily ET in soybeans under well watered conditions; ET was closely related to incoming radiant energy. The low midday values of Cs apparently caused a midday plateau in the rate of CT in wheat while even lower daytime Cs values for orange seemed to cause a low and fairly constant rate of ET which was relatively insensitive to changes in incoming radiant energy. The value of ΨL attained during mid morning at which Cs initially began to decline was fairly constant for soybeans (-0.9 to -1.1 MPa) as the predawn ΨL decreased from -0.1 to -0.8 MPa. A similar decline in predawn ΨL for wheat caused a change in the value of ΨL at which initial decreases in Cs were observed from - 1.3 MPa to -2.4 MPa. Thus there appeared to be little adjustment of stomatal action in soybeans but considerable adjustment in wheat.

Soil–Root Interface Water Potential in Sweet Corn Affected by Organic Fertilizations and Effective Microbe Applications

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 491c-491
Author(s):  
H.L. Xu ◽  
H. Umemura ◽  
T. Higa
Keyword(s):  
Water Potential ◽  
Soil Water ◽  
Water Deficit ◽  
Organic Materials ◽  
Sweet Corn ◽  
Water Status ◽  
Root Activity ◽  
Plant Water ◽  
Soil Water Deficit ◽  
Chemical Fertilizers

We examined effects of organic fertilizations and effective microbes (EM, mainly Lactobacillus, Rhodopseudomonas, Streptomyces, and Aspergillus) applications on soil-root interface water potential Ψs-r of `Honey-Bantam' sweet corn. The contributions to Ψs-r from root amount and root activity were analyzed using the Ohm's law. Plants were grown in 1/5000 a Wagner's pots filled with Andosol and six treatments were made as follows: 1) organic materials fermented anaerobically with EM added; 2) anaerobic organic materials; 3) organic materials fermented aerobically with EM added; 4) aerobic organic materials; 5) chemical fertilizers with EM applied, and 6) chemical fertilizers. One month after sowing, as soil water decreased, Ψs-r was maintained higher in organic fertilized plants than chemical fertilized ones and also higher in plants with EM applications than those without EM. The relatively high Ψs-r was contributed by both their large root amount and high root activity. As a consequence, photosynthesis under soil water deficit conditions were also maintained relatively high in these plants. Maintenance of a high Ψs-r favored plants to resist against water deficits. Moreover, the Ψs-r analysis is a practicable additional means to examine the soil-plant water status under undisturbed conditions.

Differential effects of soil water deficit on the basic plant functions and their significance to analyse crop responses to water deficit in indeterminate plants

2005 ◽  
Vol 56 (11) ◽  
pp. 1201 ◽  
Author(s):  
Jacques Wery
Keyword(s):  
Exchange Rate ◽  
Soil Water ◽  
Water Deficit ◽  
Root Zone ◽  
Water Status ◽  
Large Set ◽  
Soil Water Deficit ◽  
Carbon Exchange ◽  
Differential Effects ◽  
Basic Plant

On the basis of a large set of experiments conducted on legumes, cotton, and vineyards, we propose a framework to analyse the functioning of an indeterminate crop in response to soil water deficit. Indicators of basic plant functions (e.g. leaf carbon exchange rate as an indicator of production of assimilates) have been correlated with soil water status in the root zone (quantified with the fraction of transpirable soil water, FTSW), across a range of soil water deficit. Leaf area development was the most sensitive process to soil water deficits, with branching being more sensitive than leaf emission and growth on the main stem. Net carbon exchange rate and the various steps of reproductive development were less sensitive to drought, thereby explaining why grain/fruit yield can be increased by a moderate drought in indeterminate plants. Other traits of plant adaptation to drought at the crop level, such as reduction of flowering duration and increase of harvest index (in case of early drought), can be explained by the observed differential effects of soil dehydration on the various plant functions. These results have been used to develop regulated deficit irrigation strategies using tensiometers and tools for in-field diagnosis, especially for seed production and grape production.

Relation of Soil Water Deficit, Involved by Precipitation and Corn Yield on Vinkovci Area (Eastern Croatia)

1998 ◽  
Vol 26 (3) ◽  
pp. 289-296
Author(s):  
M. Jurišić ◽  
Ž. Vidaček ◽  
Ž. Bukvić ◽  
D. Brkić ◽  
R. Emert
Keyword(s):  
Soil Water ◽  
Water Deficit ◽  
Corn Yield ◽  
Soil Water Deficit

Water use by winter wheat as affected by soil management

1984 ◽  
Vol 103 (1) ◽  
pp. 189-199 ◽  
Author(s):  
M. J. Goss ◽  
K. R. Howse ◽  
Judith M. Vaughan-Williams ◽  
M. A. Ward ◽  
W. Jenkins
Keyword(s):  
Winter Wheat ◽  
Soil Water ◽  
Water Deficit ◽  
Water Use ◽  
Management Practices ◽  
Soil Management ◽  
Maximum Depth ◽  
Water Extraction ◽  
Soil Water Deficit ◽  
Potential Yield

SummaryIn each of the years from September 1977 to July 1982 winter wheat was grown on one or more of three clay soil sites (clay content 35–55%) in Oxfordshire where the climate is close to the average for the area of England growing winter cereals.The effects on crop water use of different soil management practices, including ploughing, direct drilling and subsoil drainage, are compared. Cultivation treatment had little effect on the maximum depth of water extraction, which on average in these clay soils was 1·54 m below the soil surface. Maximum soil water deficit was also little affected by cultivation; the maximum recorded value was 186±7·6 mm. Subsoil drainage increased the maximum depth of water extraction by approximately 15 cm and the maximum soil water deficit by about 17 mm.Generally soil management had little effect on either total water use by the crop which was found to be close to the potential evaporation estimated by the method of Penman, or water use efficiency which for these crops was about 52 kg/ha par mm water used.Results are discussed in relation to limitations to potential yield.

The Effect of Dry Pegging Zone Soil on Pod Formation of Florunner Peanut1

1997 ◽  
Vol 24 (1) ◽  
pp. 19-24 ◽  
Author(s):  
P. J. Sexton ◽  
J. M. Bennett ◽  
K. J. Boote
Keyword(s):  
Drought Stress ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Deficit ◽  
Growth Rates ◽  
Root Zone ◽  
Soil Water Deficit ◽  
Seed Growth ◽  
Pod Development

Abstract Peanut (Arachis hypogaea L.) fruit growth is sensitive to surface soil (0-5 cm) conditions due to its subterranean fruiting habit. This study was conducted to determine the effect of soil water content in the pegging zone (0-5 cm) on peanut pod growth rate and development. A pegging-pan-root-tube apparatus was used to separately control soil water content in the pegging and root zone for greenhouse trials. A field study also was conducted using portable rainout shelters to create a soil water deficit. Pod phenology, pod and seed growth rates, and final pod and seed dry weights were determined. In greenhouse studies, dry pegging zone soil delayed pod and seed development. In the field, soil water deficits in the pegging and root zone decreased pod and seed growth rates by approximately 30% and decreased weight per seed from 563 to 428 mg. Pegs initiating growth during drought stress demonstrated an ability to suspend development during the period of soil water deficit and to re-initiate pod development after the drought stress was relieved.

scholarly journals Increased Tolerance of Citrus (Citrus tangerina) Seedlings to Soil Water Deficit after Mycorrhizal Inoculation: Changes in Antioxidant Enzyme Defense System

2013 ◽  
Vol 41 (2) ◽  
pp. 524 ◽  
Author(s):  
Qiu-Dan NI ◽  
Ying-Ning ZOU ◽  
Qiang-Sheng WU ◽  
Yong-Ming HUANG
Keyword(s):  
Antioxidant Enzyme ◽  
Soil Water ◽  
Water Deficit ◽  
Mycorrhizal Fungi ◽  
Enzyme System ◽  
Arbuscular Mycorrhizal ◽  
Temporal Variations ◽  
Soil Drying ◽  
Soil Water Deficit ◽  
Antioxidant Enzyme System

Arbuscular mycorrhizal fungi (AMF) can enhance tolerance of plants to soil water deficit, whereas morphological observations of reactive oxygen species and antioxidant enzyme system are poorly studied. The present study thereby evaluated temporal variations of the antioxidant enzyme system in citrus (Citrus tangerina) seedlings colonized by Glomus etunicatum and G. mosseae over a 12-day period of soil drying. Root colonization by G. etunicatum and G. mosseae decreased with soil drying days from 32.0 to 1.0% and 50.1 to 4.5% in 0-day to 12-day, respectively. Compared to the non-AM controls, the AMF colonized plants had significantly lower tissue (both leaves and roots) hydrogen peroxide (H2O2) and superoxide anion radical (O2•–) concentrations during soil water deficit, whereas 1.03–1.92, 1.25–1.84 and 1.18–1.69 times higher enzyme activity in superoxide dismutase, peroxidase (POD) and catalase. In situ leaf H2O2 and root POD location also showed that AM seedlings had less leaf H2O2 but higher root POD accumulation. Furthermore, significantly higher root infection and antioxidant enzymatic activities in plants colonized with G. mosseae expressed than with G. etunicatum during the soil drying. These results demonstrated that the AMs could confer greater tolerance of citrus seedlings to soil water deficit through an enhancement in their antioxidant enzyme defence system whilst an decrease level in H2O2 and O2•–.

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