Influence of rate of change in stomatal conductance to fluctuating irradiance on estimates of daily water use by Pinus taeda leaves

Different light qualities affect plant growth and physiological responses, including stomatal openings. However, most researchers have focused on stomatal responses to red and blue light only, and the direct measurement of evapotranspiration has not been examined. Therefore, we quantified the evapotranspiration of sweet basil under various red (R), green (G), and blue (B) combinations using light-emitting diodes (LEDs) and investigated its stomatal responses. Seedlings were subjected to five different spectral treatments for two weeks at a photosynthetic photon flux density of 200 µmol m−2 s−1. The ratios of the RGB light intensities were as follows: R 100% (R100), R:G = 75:25 (R75G25), R:B = 75:25 (R75B25), R:G:B = 60:20:20 (R60G20B20), and R:G:B = 31:42:27 (R31G42B27). During the experiment, the evapotranspiration of the plants was measured using load cells. Although there were no significant differences in growth parameters among the treatments, the photosynthetic rate and stomatal conductance were higher in plants grown under blue LEDs (R75B25, R60G20B20, and R31G42B27) than in the R100 treatment. The amount of water used was different among the treatments (663.5, 726.5, 728.7, 778.0, and 782.1 mL for the R100, R75G25, R60G20B20, R75B25, and R31G42B27 treatments, respectively). The stomatal density was correlated with the blue light intensity (p = 0.0024) and with the combined intensity of green and blue light (p = 0.0029); therefore, green light was considered to promote the stomatal development of plants together with blue light. Overall, different light qualities affected the water use of plants by regulating stomatal conductance, including changes in stomatal density.

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Boron Supply and Water Deficit Consequences in Young ParicÃ¡ (Schizolobium parahyba var. amazonicum) Plants

Notulae Botanicae Horti Agrobotanici Cluj-Napoca ◽

10.15835/nbha44110136 ◽

2016 ◽

Vol 44 (1) ◽

pp. 250-256 ◽

Cited By ~ 1

Author(s):

Bianca do Carmo SILVA ◽

PÃªola Reis de SOUZA ◽

Daihany Moraes CALLEGARI ◽

Vanessa Ferreira ALVES ◽

Allan Klynger da Silva LOBATO ◽

...

Keyword(s):

Hydrogen Peroxide ◽

Stomatal Conductance ◽

Gas Exchange ◽

Water Use Efficiency ◽

Water Deficit ◽

Water Use ◽

Electrolyte Leakage ◽

Tolerance Mechanism ◽

Schizolobium Parahyba ◽

Use Efficiency

Boron (B) is a very important nutrient required by forest plants; when supplied in adequate amounts, plants can ameliorate the negative effects of abiotic stresses. The objective of this study was to (i) investigate gas exchange, (ii) measure oxidant and antioxidant compounds, and (iii) respond how B supply acts on tolerance mechanism to water deficit in young Schizolobium parahyba plants. The experiment employed a factorial that was entirely randomised, with two boron levels (25 and 250 Âµmol L-1, simulating conditions of sufficient B and high B, respectively) and two water conditions (control and water deficit). Water deficit induced negative modifications on net photosynthetic rate, stomatal conductance and water use efficiency, while B high promoted intensification of the effects on stomatal conductance and water use efficiency. Hydrogen peroxide and electrolyte leakage of both tissues suffered non-significant increases after B high and when applied water deficit. Ascorbate levels presented increases after water deficit and B high to leaf and root. Our results suggested that the tolerance mechanism to water deficit in young Schizolobium parahyba plants is coupled to increases in total glutathione and ascorbate aiming to control the overproduction of hydrogen peroxide and alleviates the negative consequences on electrolyte leakage and gas exchange. In relation to B supply, this study proved that sufficient level promoted better responses under control and water deficit conditions.

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Gas exchanges and photosynthetic efficiency in sub-forest species from Atlantic Forest

Research Society and Development ◽

10.33448/rsd-v9i5.2870 ◽

2020 ◽

Vol 9 (5) ◽

pp. e43952870

Author(s):

Magnólia Martins Alves ◽

Manoel Bandeira de Albuquerque ◽

Renata Ranielly Pedroza Cruz ◽

Mário Luiz Farias Cavalcanti

Keyword(s):

Stomatal Conductance ◽

Gas Exchange ◽

Water Use ◽

Co2 Concentration ◽

Time Of Day ◽

Forest Understory ◽

Forest Species ◽

Gas Exchanges ◽

Endogenous Factors ◽

Intrinsic Efficiency

The availability of light is one of the factors that most limits the photosynthesis of juvenile trees in the understory of the forest. The study was carried out in the Mata do Pau-Ferro State Park, located in the city of Areia, PB. The objective of this study was to evaluate how gas exchanges occur in individuals of Psychotria colorata (Willd. Ex Roem & Schult.), Senna georgica Irwin & Barneby, Himatanthus phagedaenicus (Mart.) Woodson, Solanum swartzianum Roem. & Schult, Psychotria carthagenensis Jacq.e Psychotria hoffmannseggiana (Willd. ex Schult.) in the understory of a remnant of Mata Atlântica. The rate of photosynthesis (A), transpiration (E), stomatal conductance (Gs), internal CO2 concentration (Ci) leaf temperature-air temperature (°C), and internal carbon (Ci), instantaneous efficiency of water use (EUA) (A/E), Intrinsic efficiency of water use (EiUC) (A/Gs) and the intrinsic efficiency of carboxylation (ratio A/Ci). The rates of maximum photosynthesis (A), photosynthesis (E) and stomatal conductance (Gs) were shown to be influenced by the time of day, as there was no interference of external factors in the diurnal patterns of gas exchange, variations are due to endogenous factors, probably due to the circadian rhythm. The parameter of the gas exchange of sub-forest species responds differently, in the small variations in the luminosity levels of the forest understory

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Trehalose induces tomato defenses and increases drought tolerance and bacterial wilt disease resistance

10.1101/2021.07.26.453814 ◽

2021 ◽

Author(s):

April M MacIntyre ◽

Valerian Meline ◽

Zachary Gorman ◽

Steven P Augustine ◽

Carolyn J Dye ◽

...

Keyword(s):

Disease Resistance ◽

Stomatal Conductance ◽

Water Use ◽

Bacterial Wilt ◽

Xylem Sap ◽

Wilt Disease ◽

Tomato Plants ◽

Bacterial Wilt Disease ◽

Infected Tomato ◽

Use Efficiency

Ralstonia solanacearum causes plant bacterial wilt disease, leading to severe crop losses. Xylem sap from R. solanacearum-infected tomato is enriched in host produced trehalose. Water stressed plants accumulate the disaccharide trehalose, which increases drought tolerance via abscisic acid (ABA) signaling networks. Because infected plants have reduced water flow, we hypothesized that bacterial wilt physiologically mimics drought stress, which trehalose could mitigate. Transcriptomic responses of susceptible vs. resistant tomato plants to R. solanacearum infection revealed differential expression of drought-associated genes, including those involved in ABA and trehalose metabolism. ABA was enriched in xylem sap from R. solanacearum-infected plants. Treating roots with ABA lowered stomatal conductance and reduced R. solanacearum stem colonization. Treating roots with trehalose increased ABA in xylem sap and reduced plant water use by reducing stomatal conductance and temporarily improving water use efficiency. Further, trehalose-treated plants were more resistant to bacterial wilt disease. Trehalose treatment also upregulated expression of salicylic acid (SA)-dependent defense genes, increased xylem sap levels of SA and other antimicrobial compounds, and increased wilt resistance of SA-insensitive NahG tomato plants. Additionally, trehalose treatment increased xylem concentrations of jasmonic acid and related oxylipins. Together, these data show that exogenous trehalose reduced both water stress and bacterial wilt disease and triggered systemic resistance. This suite of responses revealed unexpected linkages between plant responses to biotic and abiotic stress and suggests that that R. solanacearum-infected tomato plants produce more trehalose to improve water use efficiency and increase wilt disease resistance. In turn, R. solanacearum degrades trehalose as a counter-defense.

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Shade Intensity Influences Water Use and Growth of Three Viburnum Species

Journal of Environmental Horticulture ◽

10.24266/0738-2898.31.4.259 ◽

2013 ◽

Vol 31 (4) ◽

pp. 259-266 ◽

Cited By ~ 1

Author(s):

Arjina Shrestha ◽

Janet C. Cole

Keyword(s):

Plant Growth ◽

Water Use ◽

Dry Weight ◽

Curvilinear Relationship ◽

Total Water ◽

Shoot Ratio ◽

Daily Water ◽

Use Efficiency ◽

Leaf Necrosis ◽

Growth Quality

Water use, growth, and leaf necrosis of Burkwood viburnum, Korean spice viburnum, and leatherleaf viburnum were evaluated on plants grown in 0 (full sun), 30, or 60% shade during 2010 and 2011. In both years, total water use of Burkwood viburnum decreased with increased shade intensity. Water use of leatherleaf viburnum was lowest in 0% and highest in 30% shade. Daily water use was lower in 0% than in 30 or 60% shade for leatherleaf viburnum plants in August of both years and September of 2010 due to greater leaf necrosis, leaf abscission, and less growth in height and width. In both years, growth in height and width, and leaf number at harvest generally increased in all three species with increased shade intensity. All species had a larger leaf area, stem dry weight, and root dry weight in 30 and 60% than in 0% shade. Shade intensity did not influence root to shoot (R/S) ratio in Burkwood viburnum in 2010, but in 2011, a curvilinear relationship occurred between R/S ratio and shade intensity. Root to shoot ratio of Korean spice and leatherleaf viburnum decreased linearly in 2010 but curvilinearly in 2011 with increasing shade. Leaf necrosis ratings were lower in shaded plants of all three species in both years. Results indicate that greater plant growth, quality, and water use efficiency occurs when these three viburnum species are grown in shade than when they are grown in full sun.

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Apparent Tolerance of Low Water Availability in Temperate Asian Bamboos1

Journal of Environmental Horticulture ◽

10.24266/jeh-d-17-00009.1 ◽

2018 ◽

Vol 36 (1) ◽

pp. 7-13

Author(s):

Melissa C. Smith ◽

Richard N. Mack

Keyword(s):

Stomatal Conductance ◽

Water Use Efficiency ◽

Water Use ◽

North American ◽

Water Availability ◽

Irrigation Treatment ◽

Bamboo Species ◽

Intrinsic Water Use Efficiency ◽

Use Efficiency ◽

Pleioblastus Chino

Abstract Suitable plant water dynamics and the ability to withstand periods of low moisture input facilitate plant establishment in seasonally arid regions. Temperate bamboos are a major constituent of mixed evergreen and deciduous forests throughout temperate East Asia but play only an incidental role in North American forests and are altogether absent in the Pacific Northwest forest. Many bamboo species are classified as mesic or riparian, but none are considered drought tolerant. To assess their ability to withstand low water, we subjected five Asian temperate and one North American temperate bamboo species to three irrigation treatments: 100%, 50%, and 10% replacement of water lost through evapotranspiration. Plants were irrigated every four days over a 31-day period. Plant response to treatments was measured with stomatal conductance, leaf xylem water potentials, and intrinsic water use efficiency (iWUE). Pleioblastus distichus and Pseudosasa japonica showed significant reductions in conductance between high and low irrigation treatments. Sasa palmata had significantly lower stomatal conductance in all treatments. Pleioblastus chino displayed significantly higher iWUE in the mid irrigation treatment and Arunindaria gigantea displayed significantly lower iWUE than P. chino and S. palmata in the low irrigation treatment. The Asian bamboo species examined here tolerate low water availability and readily acclimate to different soil moisture conditions. Index words: Temperate bamboos, irrigation response, stomatal conductance, intrinsic water use efficiency. Species used in this study: Giant Cane [Arundinaria gigantea (Walt.) Muhl.]; Pleioblastus chino (Franchet & Savatier) Makino; Pleioblastus distichus (Mitford) Nakai; Pseudosasa japonica (Makino); Sasa palmata (Bean) Nakai.

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Assessing variation in the radial profile of sap flux density in Pinus species and its effect on daily water use

Tree Physiology ◽

10.1093/treephys/24.3.241 ◽

2004 ◽

Vol 24 (3) ◽

pp. 241-249 ◽

Cited By ~ 133

Author(s):

C. R. Ford ◽

M. A. McGuire ◽

R. J. Mitchell ◽

R. O. Teskey

Keyword(s):

Flux Density ◽

Water Use ◽

Radial Profile ◽

Sap Flux ◽

Sap Flux Density ◽

Pinus Species ◽

Daily Water

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Influence of biochar and microorganisms co-application on the remediation and maize productivity in cadmium-contaminated soil.

10.21203/rs.3.rs-927778/v1 ◽

2021 ◽

Author(s):

Fasih Ullah Haider ◽

Muhammad Farooq ◽

Muhammad Naveed ◽

Sardar Alam Cheema ◽

Noor ul Ain ◽

...

Keyword(s):

Stomatal Conductance ◽

Water Use Efficiency ◽

Water Use ◽

Transpiration Rate ◽

Synergistic Effects ◽

Photosynthesis Rate ◽

Cow Manure ◽

Cd Uptake ◽

Spad Value ◽

Use Efficiency

Abstract The synergistic effects of biochar and microorganisms on the adsorption of Cd and on cereal plant physiology remained unclear. Therefore, this experiment was performed to evaluate the combined effects of biochar pyrolyzed from (maize-straw (BC1), cow-manure (BC2), and poultry-manure (BC3), and microorganisms including (T. harzianum L. and B. subtilis L.), to evaluate, how incorporation of biochar positively influences microorganisms growth and nutrients uptake in plant, and how it mitigates under various Cd-stress levels (0, 10, and 30ppm). Cd2 (30 ppm) had the highest reduction in the intercellular CO2, SPAD value, transpiration rate, water use efficiency, stomatal conductance, and photosynthesis rate, which were 22.36, 34.50, 40.45, 20.66, 29.07, and 22.41% respectively lower than control Cd0 (0 ppm). Sole application BC, resulted in enhanced intercellular CO2, SPAD value, transpiration rate, water use efficiency, stomatal conductance, and photosynthesis rate were recorded in BC2, which were 7.27, 20.54, 23.80, 5.96, 13.37, and 13.50% respectively greater as compared to control and decreased the Cd-concentration in root and shoot of maize by 34.07 and 32.53%, respectively as compared to control. Similarly, among sole microorganism’s inoculation, minimized the Cd-concentration in shoot, root, and soil by 23.77, 20.15, and 10.35% respectively than control. These results suggested that integrated application of cow manure biochar BC2 and inoculation of microorganisms MI3 as soil amendments had synergistic effects in improving the adsorption of nutrients and decreasing the Cd-uptake in maize, and enhancing the physiology of plant grown in Cd-polluted soils as opposed to using either biochar or inoculating microorganisms alone.

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