scholarly journals Stomatal behavior and components of the antioxidative system in coffee plants under water stress

2011 ◽  
Vol 68 (1) ◽  
pp. 77-85 ◽  
Author(s):  
Sidnei Deuner ◽  
José Donizeti Alves ◽  
Ilisandra Zanandrea ◽  
Patrícia de Fátima Pereira Goulart ◽  
Neidiquele Maria Silveira ◽  
...  
Keyword(s):  
Water Stress ◽  
Transpiration Rate ◽  
Vapor Pressure Deficit ◽  
Stomatal Closure ◽  
Field Capacity ◽  
Stomatal Resistance ◽  
Water Restriction ◽  
Coffee Plants ◽  
Hydrogen Peroxide Formation ◽  
In The Beginning

Coffee (Coffea arabica) plants show a positive relationship between stomatal closure and formation and accumulation of H2O2. However, for coffee plants under water restriction such relationship has never been studied. The objective of the present study was evaluate the stomatal movement and the antioxidant capacity of coffee seedlings under different water regimes. Eight months old coffee seedlings of cv. Catuaí IAC 99 were submitted to field capacity, gradual and total suspension of irrigation during a period of 21 days. Evaluations of leaf water potential (Ψw) were performed in the beginning of the morning, and stomatal resistance, transpiration rate and vapor pressure deficit were determined at 10 am and 5 pm. All biochemical and enzymatic determinations were performed in leaves collected at 5 pm. Evaluations and samplings were performed at three days intervals. There was no variation in Ψw during the evaluated period for plants in field capacity. However, an expressive decrease of Ψw following day 12, reaching values near -2.5 MPa at the end of the experiment was observed for plants submitted to gradual suspension of irrigation. For plants submitted to total suspension of irrigation, Ψw decreases after the sixth day, reaching -2.5 MPa at day 15. The decay of Ψw in plants submitted to gradual and total suspension of irrigation reflected in increased stomatal resistance and in a decreased transpiration rate leading to an increase in hydrogen peroxide formation and, on final stages, increase in lipid peroxidation. As a conclusion, an increase in the activity of antioxidant enzymes as well as in the levels of ascorbate and dehydroascorbate was observed, which act in the detoxification of free radicals formed as result of the water stress.

Verticillium wilt of chrysanthemum: quantitative relationship between increased stomatal resistance and local vascular dysfunction preceding wilt

1976 ◽  
Vol 54 (10) ◽  
pp. 1023-1034 ◽  
Author(s):  
William E. MacHardy ◽  
Lloyd V. Busch ◽  
Robert Hall
Keyword(s):  
Water Stress ◽  
Water Transport ◽  
Vascular Dysfunction ◽  
Stomatal Closure ◽  
Quantitative Relationship ◽  
Stomatal Resistance ◽  
Chrysanthemum Morifolium ◽  
Transport Pathways ◽  
Relative Water ◽  
Chrysanthemum Morifolium Ramat

The relationship between the development of water stress and foliar symptom expression within chrysanthemum (Chrysanthemum morifolium Ramat) cuttings infected with Verticillium dahliae Kleb. was examined using relative water content (RWC), diffusive resistance to water vapor loss (stomatal resistance), and dye distribution along water-transport pathways as indicators of water stress. The RWC remained at a normal level until symptoms appeared, but stomatal resistance increased beginning about 8 days before symptoms. Dye movement along xylem elements was uniform within uninoculated checks and also within infected plants until stomatal resistances increased. Veinal dye distribution was incomplete within tissue exhibiting increased stomatal resistances, and the extent of dye interruption was closely aligned to the magnitude of resistance increase. Apparently, stomatal closure effectively prevented tissue desiccation under conditions of high, localized internal water stress, but this mechanism could not prevent tissue from becoming flaccid or wilted when water transport became so limited that water was deficient even within the large veins.

scholarly journals Short-Term Exposure to High Atmospheric Vapor Pressure Deficit (VPD) Severely Impacts Durum Wheat Carbon and Nitrogen Metabolism in the Absence of Edaphic Water Stress

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 120
Author(s):  
Dorra Fakhet ◽  
Fermín Morales ◽  
Iván Jauregui ◽  
Gorka Erice ◽  
Pedro M. Aparicio-Tejo ◽  
...  
Keyword(s):  
Gene Expression ◽  
Water Stress ◽  
Vapor Pressure ◽  
Soil Water ◽  
Vapor Pressure Deficit ◽  
Stomatal Closure ◽  
Stress Conditions ◽  
Short Term Exposure ◽  
Young Leaves ◽  
N Metabolism

Low atmospheric relative humidity (RH) accompanied by elevated air temperature and decreased precipitation are environmental challenges that wheat production will face in future decades. These changes to the atmosphere are causing increases in air vapor pressure deficit (VPD) and low soil water availability during certain periods of the wheat-growing season. The main objective of this study was to analyze the physiological, metabolic, and transcriptional response of carbon (C) and nitrogen (N) metabolism of wheat (Triticum durum cv. Sula) to increases in VPD and soil water stress conditions, either alone or in combination. Plants were first grown in well-watered conditions and near-ambient temperature and RH in temperature-gradient greenhouses until anthesis, and they were then subjected to two different water regimes well-watered (WW) and water-stressed (WS), i.e., watered at 50% of the control for one week, followed by two VPD levels (low, 1.01/0.36 KPa and high, 2.27/0.62 KPa; day/night) for five additional days. Both VPD and soil water content had an important impact on water status and the plant physiological apparatus. While high VPD and water stress-induced stomatal closure affected photosynthetic rates, in the case of plants watered at 50%, high VPD also caused a direct impairment of the RuBisCO large subunit, RuBisCO activase and the electron transport rate. Regarding N metabolism, the gene expression, nitrite reductase (NIR) and transport levels detected in young leaves, as well as determinations of the δ15N and amino acid profiles (arginine, leucine, tryptophan, aspartic acid, and serine) indicated activation of N metabolism and final transport of nitrate to leaves and photosynthesizing cells. On the other hand, under low VPD conditions, a positive effect was only observed on gene expression related to the final step of nitrate supply to photosynthesizing cells, whereas the amount of 15N supplied to the roots that reached the leaves decreased. Such an effect would suggest an impaired N remobilization from other organs to young leaves under water stress conditions and low VPD.

Transpiration and leaf water potentials of wheat in relation to changing soil water potential

1977 ◽  
Vol 28 (3) ◽  
pp. 355 ◽  
Author(s):  
KA Seaton ◽  
JJ Landsberg ◽  
RH Sedgley
Keyword(s):  
Water Potential ◽  
Soil Water ◽  
Transpiration Rate ◽  
Water Conservation ◽  
Root Zone ◽  
Stomatal Closure ◽  
Soil Water Potential ◽  
Stomatal Resistance ◽  
Leaf Water ◽  
Water Potentials

Changes in the transpiration rate of wheat in drying soils were followed in experiments in which plants were grown in two small weighable lysimeters in a glasshouse. Hourly measurements of soil water potential (Ψs) were made at three depths in each lysimeter. The water potential of flag leaves was measured with a pressure chamber, and stomatal resistance with a pressure drop porometer. Data on root densities and distribution were also obtained. Transpiration rates fell below estimated potential levels when the average value of Ψs in the root zone was reduced to –1 to –5 bars, depending on soil storage, root distribution and potential transpiration rate. From this point Ψs fell rapidly in the surface layers, more slowly at depth. It was found that accurate calculations of daily water uptake could be made from changes in soil water content. The minimum value of leaf water potential (�1 )attained each day declined progressively through the drying cycle, but there was evidence that stomatal resistance (rs) is not uniquely related to Ψ1; initial stomatal closure occurred at Ψ1, values which decreased from –11 to –25 bars as drying progressed. This adaptive mechanism is related to changes in osmotic potential of the leaves. Whole plant resistances (Rp), derived from leaf water potentials and fluxes through individual stems, increased as stem populations increased. In the high population lysimeter Rp decreased from 300 to 100 bar sec mm-3 as canopy transpiration rates increased from 1.5 to 4.5 x 10-4 mm sec-1. In the low population lysimeter Rp decreased from 70 to 30 bar sec mm-3 as transpiration increased from about 2.2 to 4.5 x 10-4 mm sec-1. The higher resistances appear to confer significant advantages in terms of water conservation and adaptation to drought.

scholarly journals Atmospheric H2S exposure does not affect stomatal aperture in maize

Planta ◽  
2020 ◽  
Vol 252 (4) ◽  
Author(s):  
Ties Ausma ◽  
Jeffrey Mulder ◽  
Thomas R. Polman ◽  
Casper J. van der Kooi ◽  
Luit J. De Kok
Keyword(s):  
Hydrogen Sulfide ◽  
Transpiration Rate ◽  
Stomatal Density ◽  
Stomatal Closure ◽  
Stomatal Resistance ◽  
Stomatal Aperture ◽  
Sulfur Source ◽  
Growth Reduction ◽  
Signal Molecule ◽  
Lower Biomass

Abstract Main conclusion Stomatal aperture in maize is not affected by exposure to a subtoxic concentration of atmospheric H2S. At least in maize, H2S, thus, is not a gaseous signal molecule that controls stomatal aperture. Abstract Sulfur is an indispensable element for the physiological functioning of plants with hydrogen sulfide (H2S) potentially acting as gasotransmitter in the regulation of stomatal aperture. It is often assumed that H2S is metabolized into cysteine to stimulate stomatal closure. To study the significance of H2S for the regulation of stomatal closure, maize was exposed to a subtoxic atmospheric H2S level in the presence or absence of a sulfate supply to the root. Similar to other plants, maize could use H2S as a sulfur source for growth. Whereas sulfate-deprived plants had a lower biomass than sulfate-sufficient plants, exposure to H2S alleviated this growth reduction. Shoot sulfate, glutathione, and cysteine levels were significantly higher in H2S-fumigated plants compared to non-fumigated plants. Nevertheless, this was not associated with changes in the leaf area, stomatal density, stomatal resistance, and transpiration rate of plants, meaning that H2S exposure did not affect the transpiration rate per stoma. Hence, it did not affect stomatal aperture, indicating that, at least in maize, H2S is not a gaseous signal molecule controlling this aperture.

scholarly journals Mitigation of water restriction effects on soybean with biofertilizer: metabolic and stomatal conductance changes

2021 ◽  
Vol 10 (11) ◽  
pp. e11101119377
Author(s):  
Harielly Marianne Costa Marques ◽  
Ely Cristina Negrelli Cordeiro ◽  
Juliana de Oliveira Amatussi ◽  
Gabriel Bocchetti de Lara ◽  
Gilda Mógor ◽  
...  
Keyword(s):  
Water Stress ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Stomatal Resistance ◽  
Sugar Accumulation ◽  
Water Retention Capacity ◽  
Water Restriction ◽  
Retention Capacity ◽  
Bacterial Fermentation ◽  
Soybean Plants

The demand for soybean has increased in the international market, and water restriction is an important factor in reducing its yield. Therefore, the development of technologies aimed to reducing the damage caused by water stress becomes strategic. Thus, the objective was to demonstrate the role of the amino acid L-glutamic acid in mitigating water stress in soybean plants. A study was conducted in a greenhouse using soybean plants in vegetative stage subjected to water restriction and foliar applications of biofertilizer obtained from bacterial fermentation, containing 25% of the amino acid L-glutamic acid, sprayed three days before the imposition of water restriction and when the substrate moisture reached 50% of the water retention capacity (WRC).  Stomatal resistance was determined throughout the days and three collections of plant material were carried out: at the beginning of water restriction, one and four days after rehydration for biochemical and enzymatic analyses. Plants that were supplied with biofertilizer at the beginning of water restriction showed lower stomatal resistance, while plants that received application three days before 50% WRC showed increases in sugar accumulation, in free amino acids and proline content, and in nitrate reductase and peroxidase enzymes activity, consequently, reducing lipids peroxidation, mitigating the effects of oxidative stress.

scholarly journals Jenis Tumbuhan Bertahan Hidup di Lahan Kering

2018 ◽  
Vol 6 (02) ◽  
pp. 12
Author(s):  
Riri Yulianti Rusdi ◽  
A. R. Tolangara ◽  
Hasna Ahmad
Keyword(s):  
Water Stress ◽  
Research Result ◽  
Soil Surface ◽  
Field Capacity ◽  
Dry Land ◽  
Randomized Design ◽  
Number Of Leaves ◽  
Completely Randomized Design ◽  
Living Tissues ◽  
In The Beginning

AbstrakAir merupakan bagian terbesar penyusun jaringan tumbuh-tumbuhan. Air berfungsi  mengatur setiap proses metabolisme tanaman secara langsung atau tidak langsung. Air yang tersedia di dalam tanah berada pada kapasitas lapang. Air pada kapasitas lapang adalah air yang tetap tersimpan dalam tanah. Air dapat hilang dalam bentuk uap air dari jaringan hidup tanaman yang terletak di atas permukaan tanah, air tersebut daapt hilang melewati stomata, kutikula, dan lentisel disebut transpirasi. Air pun dapat hilang akibatnya tanah menjadi kering. Apabila tanaman hidup dalam kondisi ini,  maka tanaman akan mengalami cekaman air (Water stress) dan akhirnya mati. Penelitian ini bertujuan untuk mengetahui jenis tumbuhan yang mampu bertahan hidup di lahan kering beserta lamanya waktu tanaman dalam bertahan hidup.  Penelitian ini bersifat eksperimen yang menggunakan Rancangan Acak Lengkap (RAL) , dengan 4 perlakuan dan 5 kali ulangan. Pemberian air sekali dalam 9 bulan dan pengamatan dilakukan seminggu sekali dengan parameter tinggi tanaman dan jumlah daun. Sedangkan untuk faktor lingkungan berupa pH, suhu dan kelembaban tanah diukur pada awal penelitian dan akhir penelitian. Kemudian data tersebut dianalisis menggunakan uji Koefisien Variasi (KV). Hasil penelitian menunjukkan bahwa jenis tanaman yang mampu bertahan hidup di lahan kering adalah jagung dengan waktu 20 minggu (5 bulan).Kata Kunci : Jenis Tumbuhan, bertahan hidup, lahan kering Abstract Water is the biggest constituent of plant tissues. Water serves to regulate all plant metabolism processes, directly or indirectly. Water available in the soil is in field capacity, which is water that is kept in the soil. The water can be lost in form of vapor from plant living tissues located on the soil surface. The water can be lost through stomata, cuticle and lenticel and it is called transpiration. The loss of water causes soil to dry. If plant lives in this condition, the plant will experience water stress and eventually it will die. The research aimed to find out the type of plant that able to survive on dry land and the duration of the survival. The research was an experimental research using a completely randomized design (RAL) with four treatments and 5 repetitions. Watering was conducted once in 9 months and observation was conducted once in a week with parameters of plant height and number of leaves. Regarding the environmental factors, namely, pH, temperature and, soil humidity, they were measured in the beginning and end of the research. Data was analyzed using variance coefficient (KV) test. The research result indicated that type of plant that survived on dry land was corn with 20 weeks (5 months) of period.  Keywords: Type of plant, survival, dry land

scholarly journals DETECTING PEACH WATER STRESS THROUGH CHANGES IN FOLIAGE TEMPERATURE

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1136a-1136
Author(s):  
Roger Kjelgren ◽  
Bradley H. Taylor
Keyword(s):  
Water Stress ◽  
Water Potential ◽  
Air Temperature ◽  
Leaf Water Potential ◽  
Inverse Relationship ◽  
Vapor Pressure Deficit ◽  
Stomatal Closure ◽  
Leaf Water ◽  
Temperature Differential ◽  
Predawn Leaf Water Potential

The response of foliage-air temperature differential (Tl-Ta) to vapor-pressure deficit (VPD) as a means of detecting incipient water stress was investigated in the Illinois planting of the NC-140 Uniform Peach Rootstock Trial. Stomatal conductance, foliage temperature, leaf water potential, air temperature and VPD were followed diurnally on three dates in 1989 for mature `Redhaven' on six different rootstock. On two of three sampling dates where predawn leaf water potential was greater than -0.5 MPa there was no indication of midday stomatal closure and all rootstock exhibited an inverse relationship between T1-Ta and VPD. On the date with the most negative predawn leaf water potential, T1-Ta of two plum rootstock (GF-677 and GF-655-2) was observed to be significantly greater at VPD levels above 2 kPa than the remaining rootstock. All rootstock on this date exhibited greater T1-Ta than at similar VPD levels on the other two dates. These data suggest that transpirational cooling plays a large enough role in foliage temperature regulation of `Redhaven' peach such that incipient water stress and rootstock effects on water relations can be detected through increases in foliage temperature.

Relationships between weather patterns, Sitka spruce (Piceasitchensis) stress, and possible tip weevil (Pissodesstrobi) infestation levels

1992 ◽  
Vol 22 (5) ◽  
pp. 667-673 ◽  
Author(s):  
Dennis L. Warkentin ◽  
D.L. Overhulser ◽  
R.I. Gara ◽  
T.M. Hinckley
Keyword(s):  
Water Stress ◽  
Vapor Pressure Deficit ◽  
Stomatal Closure ◽  
Sitka Spruce ◽  
Washington State ◽  
Host Defenses ◽  
Pressure Potential ◽  
Olympic Peninsula ◽  
Weather Patterns ◽  
Xylem Pressure Potential

Vapor pressure deficit (VPD) regimes were determined for Sitka spruce (Piceasitchensis (Bong.) Carr.) plantations growing in coastal and inland sites of the Olympic Peninsula of Washington State. Relationships between VPD regimes on patterns of stomatal conductance, stem hydration, and xylem pressure potential were examined in Sitka spruce saplings growing on these two sites. These patterns and VPD regimes were analyzed in relation to areas known to sustain either low or high infestation levels of the tip weevil (Pissodesstrobi (Peck) (Coleoptera: Curculionidae)). High VPD regimes of inland Sitka spruce plantations were frequently observed in the summers and were associated with clear days and on-shore breezes; in synchrony with high VPD regimes, the trees of these areas exhibited water stress and decreased photosynthesis. In turn, these factors might contribute to lowered host defenses against tip weevil attacks. Coastal sites generally experienced lower VPD regimes and, consequently, infrequent water stress and stomatal closure, and spruces growing near the coast were mostly associated with low tip weevil attack.

Soil Moisture Deficits in South-Central Sweden

1989 ◽  
Vol 20 (2) ◽  
pp. 109-122 ◽  
Author(s):  
Lotta Andersson
Keyword(s):  
Soil Moisture ◽  
Field Capacity ◽  
Interannual Variations ◽  
Neutron Probe ◽  
South Central ◽  
Normal Ranges ◽  
Moisture Fluxes ◽  
In The Beginning ◽  
Probe Measurements ◽  
Different Parts

Some commonly used assumptions about climatically induced soil moisture fluxes within years and between different parts of a region were challenged with the help of a conceptual soil moisture model. The model was optimised against neutron probe measurements from forest and grassland sites. Five 10 yrs and one 105 yrs long climatic records, from the province of Östergötland, situated in south-central Sweden, were used as driving variables. It was concluded that some of the tested assumptions should not be taken for granted. Among these were the beliefs that interannual variations of soil moisture contents can be neglected in the beginning of the hydrological year and that soils usually are filled up to field capacity after the autumn recharge. The calculated climatic induced dryness was estimated to be rather insensitive to the choice of climatic stations within the region. Monthly ranges of soil moisture deficits (1883-1987) were shown to be skewed and it is therefore recommended to use medians and standard deviations in statistical analyses of “normal” ranges of soil moisture deficits.

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