The influence of leaf water content and isoprenoids on flammability of some Mediterranean woody species

The impact of water content and isoprenoids on leaf flammability was studied. Field and laboratory experiments were carried out on monoterpene-emitting evergreen broad-leaved species (Quercus ilex, Quercus suber); a needle-leaved species (Pinus halepensis) that emits and stores monoterpenes; an evergreen species (Myrtus communis) that emits isoprene but stores monoterpenes; and a deciduous species (Quercus pubescens) that emits isoprene. Photosynthesis, leaf water content (LWC) and isoprenoid emission were measured. Isoprenoid content was calculated. Temperatures of visible smoke, incandescence and flame appearance were recorded. The LWC significantly correlated with both photosynthesis and isoprenoid emissions. Linear correlation and factorial analysis revealed a positive correlation between temperature of flame appearance and LWC and a negative relationship between temperature of flame appearance and isoprenoid emission. Multiple regression analysis indicated that the temperature of flame appearance was reduced in broadleaved monoterpene-emitting species. In monoterpene emitters, the temperature of flame appearance depended for ~65% on LWC, whereas monoterpene emissions explained ~35% of the dependency. P. halepensis and M. communis, storing high levels of isoprenoids, ignited at high humidity. The results may be explained if isoprenoids indeed facilitate leaf ignition but, being dissolved in water, isoprenoids are also an indicator of a high water content that decreases flammability.

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An Equilibrium Model of Leaf Water Potentials Which Separates Intra- and Extracellular Potentials

Functional Plant Biology ◽

10.1071/pp9750253 ◽

1975 ◽

Vol 2 (3) ◽

pp. 253 ◽

Cited By ~ 8

Author(s):

B Acock

Keyword(s):

Water Content ◽

Turgor Pressure ◽

Bound Water ◽

Leaf Tissue ◽

High Water ◽

Leaf Water ◽

High Water Content ◽

Pressure Potential ◽

Matrix Bound ◽

Water Contents

A model is proposed which makes it possible to estimate the intracellular turgor pressure potential, intracellular osmotic plus matric potential, and intra- and extracellular soIution fractions of water in leaf tissue at any water content. The model requires only the data normally collected with a thermocouple psychrometer: total water potential of live and dead (cells ruptured) tissue at various known water contents. The major assumptions are that (1) the total potential of water in the solution fraction in any part of the tissue multiplied by the volume of water is constant; (2) extracellular water experiences no pressure potential; (3) matrix-bound water is held only by matric forces and contains no solute; (4) the solution fraction of the intracellular water is constant at high water content; and (5) matrix-bound water content is constant over the range of leaf water contents normally examined. The models developed to deal with pressure bomb data are examined critically and doubts are cast on the validity of some of their assumptions.

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Osmotic Potential, Sucrose Level, and Activity of Sucrose Metabolic Enzymes in Tall Fescue in Response to Deficit Irrigation

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.135.6.506 ◽

2010 ◽

Vol 135 (6) ◽

pp. 506-510 ◽

Cited By ~ 22

Author(s):

Jinmin Fu ◽

Bingru Huang ◽

Jack Fry

Keyword(s):

Drought Stress ◽

Water Content ◽

Tall Fescue ◽

Osmotic Potential ◽

Deficit Irrigation ◽

Leaf Water ◽

Leaf Water Content ◽

Severe Drought ◽

The Impact ◽

Sucrose Level

Effects of deficit irrigation applied to home lawns, used as means of water conservation, are an important issue. However, the impact of deficit irrigation on sucrose metabolism in tall fescue (Festuca arundinacea) is unknown and important because sucrose is the dominant form of carbohydrate transported to developing plant organs. The objectives of this study were to investigate the effects of deficit irrigation on leaf water content, osmotic potential (ψS), sucrose level, and the activity of sucrose phosphate synthase (SPS; EC 2.4.1.14), sucrose synthase (SS; EC 2.4.1.13), and acid invertase (AI; EC 3.2.1.26) in tall fescue leaves. Sods of ‘Falcon II’ tall fescue were established in polyvinylchloride (PVC) tubes (10 cm diameter × 40 cm long) filled with a mixture of sand and fritted clay [9:1 (v:v)] and then placed in growth chambers. Reference evapotranspiration rate [ETo (millimeters of water per day)] was determined by weighing the PVC tubes containing well-watered turfgrass every 3 days to determine water loss on a daily basis as ETo. Deficit irrigation treatments were applied as follows: well-watered control, mild drought stress (60% ETo), and severe drought stress (20% ETo). Leaf water content was lower at 6, 12, and 20 days of treatment for the 20% ETo treatment and 20 days after treatment began for the 60% ETo treatment. Compared with the well-watered control, ψS was lower in the 60% ETo treatment on all three measurement dates. Sucrose was higher at 8 and 14 days after treatment began in the 60% ETo treatment and on all three measurement dates in the 20% ETo treatment relative to the well-watered control. No difference in sucrose level was observed between the 20% ETo and 60% ETo irrigation regimes at 8 and 14 days of treatment. Beginning 14 days after treatment, tall fescue had a higher level of SPS in the 60% ETo and 20% ETo treatments compared with the well-watered treatment. Tall fescue receiving 60% or 20% ETo had a lower level of AI activity on all measurement dates. Results suggest that the decrease in ψS was accompanied by higher sucrose levels, which were the result of the increased level of SPS and SS activity and a decline in AI activity.

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Analysis of heat energy in the drying process of Moringa Oleifera leaves using a greenhouse effect dryer (ERK)

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/913/1/012036 ◽

2021 ◽

Vol 913 (1) ◽

pp. 012036

Author(s):

Sukmawaty ◽

Murad ◽

Ansar ◽

H Kurniawan ◽

Z Fitri

Keyword(s):

Total Energy ◽

Water Content ◽

Greenhouse Effect ◽

Nutrient Content ◽

High Water ◽

Heat Energy ◽

High Water Content ◽

Leaf Water Content ◽

Drying Process ◽

Drying Efficiency

Abstract Moringa leaves have a high enough nutrient content so that they are used as a source of natural nutrients. Fresh moringa leaves have a high water content, so they need to be dried to reduce post-harvest loss. This study aims to analyze heat energy in the drying process of moringa leaves using a greenhouse effect type dryer (ERK). The study was an experimental method on drying of moringa leaves using a Greenhouse Effect (ERK) in the field and was analyzed using mass and energy equilibrium approaches. In this study, two different treatments were carried out i.e not crushed and crushed leaves. The result shows that the water content of the uncrushed and crushed leaves were 74.9%wb and 71.4%wb, dried moringa leaf water content was 4.8 %wb and 4.5%wb. Total energy entered by dryers 7415038.8 kJ and 7780575.4 kJ, Total useful energy of 767089.470 kJ and 2171369.143 kJ, total energy discharged through outlet/ventilation and lost through successive walls were is 4148.222 kJ, 5718.912 kJ, 8.924 kJ and 7.194 kJ as well as heat lost from opening consecutive doors of 771246.62 kJ and 2177095.25 kJ. The input masses were 0.75 kg and 1.35 kg, the output mass were 0.180 kg and 0.391 kg, the accumulated mass were 0.570 kg and 0.959 kg. Drying efficiency values were 18.25% and 29.26%.

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Isotopic and Water Relation Responses to Ozone and Water Stress in Seedlings of Three Oak Species with Different Adaptation Strategies

Forests ◽

10.3390/f11080864 ◽

2020 ◽

Vol 11 (8) ◽

pp. 864

Author(s):

Claudia Cocozza ◽

Elena Paoletti ◽

Tanja Mrak ◽

Saša Zavadlav ◽

Tom Levanič ◽

...

Keyword(s):

Water Stress ◽

Gas Exchange ◽

Water Content ◽

Leaf Gas Exchange ◽

Water Relation ◽

Adaptation Strategies ◽

Leaf Water ◽

Leaf Water Content ◽

Global Changes ◽

The Impact

The impact of global changes on forest ecosystem processes is based on the species-specific responses of trees to the combined effect of multiple stressors and the capacity of each species to acclimate and cope with the environment modification. Combined environmental constraints can severely affect plant and ecological processes involved in plant functionality. This study provides novel insights into the impact of a simultaneous pairing of abiotic stresses (i.e., water and ozone (O3) stress) on the responses of oak species. Water stress (using 40 and 100% of soil water content at field capacity—WS and WW treatments, respectively) and O3 exposure (1.0, 1.2, and 1.4 times the ambient concentration—AA, 1.2AA, and 1.4AA, respectively) were carried out on Quercus robur L., Quercus ilex L., and Quercus pubescens Willd. seedlings, to study physiological traits (1. isotope signature [δ13C, δ18O and δ15N], 2. water relation [leaf water potential, leaf water content], 3. leaf gas exchange [light-saturated net photosynthesis, Asat, and stomatal conductance, gs]) for adaptation strategies in a Free-Air Controlled Exposure (FACE) experiment. Ozone decreased Asat in Q. robur and Q. pubescens while water stress decreased it in all three oak species. Ozone did not affect δ13C, whereas δ18O was influenced by O3 especially in Q. robur. This may reflect a reduction of gs with the concomitant reduction in photosynthetic capacity. However, the effect of elevated O3 on leaf gas exchange as indicated by the combined analysis of stable isotopes was much lower than that of water stress. Water stress was detectable by δ13C and by δ18O in all three oak species, while δ15N did not define plant response to stress conditions in any species. The δ13C signal was correlated to leaf water content (LWC) in Q. robur and Q. ilex, showing isohydric and anisohydric strategy, respectively, at increasing stress intensity (low value of LWC). No interactive effect of water stress and O3 exposure on the isotopic responses was found, suggesting no cross-protection on seasonal carbon assimilation independently on the species adaptation strategy.

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Response of Selected Clones of Cocoa Seedlings in the Nursery Against High Soil Water Content

Pelita Perkebunan (a Coffee and Cocoa Research Journal) ◽

10.22302/iccri.jur.pelitaperkebunan.v21i2.17 ◽

2005 ◽

Vol 21 (2) ◽

Author(s):

Adi Prawoto ◽

Mohammad Zainunnuroni ◽

Slameto .

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Field Capacity ◽

Dry Weight ◽

High Water ◽

Stem Diameter ◽

High Water Content ◽

High Soil ◽

The Impact

Since 2001 to 2005, cocoa bean price is high, this condition accelerates farmers to plant and enlarger their cocoa areas. The impact of this euphoria is the possibility that the planting area will be more marginal, i.e. high water table or soil with continuously high water content. This study was to evaluate cocoa planting materials tolerant to those condition. The experiment was conducted in glass house of Indonesian Coffee and Cocoa Research Institute using RCBD, replicated 3 times. The treatments were factorial 10 x 4. The propelegitimate seedlings of 10 clones were the first factor, i.e. KW 165, KW 162, DR 2, DRC 16, GC 7, ICS 13, ICS 60, KW 163, Sca 12, and TSH 858. The second factor were soil water content, that were 100% (field capacity = control), 125%, 150%, and 175%. Watering method was gravimetric, once a month the volume was corrected by wet weight of the seedlings. The study was terminated after 5 month old. The result showed that growth of stem diameter, root dry weight and leaf number still normal until soil water content 25% above field capacity. At that condition, seedling dry weight dropped 13% below control, whereas at 175% treatment the decreasing of seedling dry weight was 34% below control. According to seedling and root dry weights, and chlorophyll content, by using cluster analysis it could be obtained a group of seedlings tolerant to high soil water content, i.e. DRC 16, GC 7, and ICS 60. Meanwhile, a group of seedlings susceptible to high water content, i.e. KW 165, KW 163, and DR 2. Stem diameter and chlorophyl content was good indicator for water logging tolerance reaction for cocoa seedling, its correlation to seedling dry weight were positive and tight. Key words: Theobroma cacao, seedlings, waterlogging, growth, chlorophyll.

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Plant Water Relation and Drought: Relationship Between Plant Water Potential and Relative Leaf Water Content in Different Tropical Plants

10.5194/egusphere-egu2020-12797 ◽

2020 ◽

Author(s):

Sydney Kerman ◽

Kinzie Bailey ◽

Joost van Haren ◽

Angelika Kübert ◽

Kathrin Kühnhammer ◽

...

Keyword(s):

Water Stress ◽

Water Potential ◽

Water Content ◽

Negative Relationship ◽

Leaf Water ◽

Leaf Water Content ◽

Plant Water ◽

Long Term Effects ◽

Tropical Plants ◽

Plant Water Potential

As global average temperature continues to increase and precipitation events become less predictable, understanding the long-term effects of drought on ecosystems is of increasing importance. However, it is difficult to study phenomena such as drought due to their unpredictable nature and the fact that it is difficult to tag and track the movement of water and carbon through an entire ecosystem. Within the framework of the controlled ecosystem manipulation experiment (WALD- Water, Atmosphere and Life Dynamics) at Biosphere 2, a deliberate drought in the enclosed tropical rainforest biome presented a unique opportunity to study responses in carbon and water cycling due to water stress. Within the scope of this study, the goal of this project was to examine the effect of prolonged water stress on different species within the rainforest and understand how the plants coped with the stress on an ecosystem level. This was accomplished by weekly plant water potential measurements (WP) before, during, and after the drought, as well as leaf sampling for relative leaf water content (RWC) and xylem sampling for water isotope measurements. For both predawn and midday WP, we found significantly different species responses; for Ceiba pentandra and Pachira aquatica, WP did not decrease during the drought, while for Hibiscus tiliaceus and Hibiscus rosa sinensis, WP decreased dramatically during the drought. After the additional of moisture from deeper depths, both C. pentandra and Hura crepitans (largest trees) responded the fastest by increasing in WP, while H. tiliaceus and H. rosa sinensis had the slowest recovery in WP, and only after rewetting from above had occurred. RWC also revealed different responses by different plant species, with Phytolacca dioica and H. rosa sinensis showing the highest RWC values throughout the experiment. The relationship between RWC and WP was also not consistent among species, with half of the species exhibiting a positive relationship, while the other half exhibiting a negative relationship. Other factors such as trunk capacitance and or leaf shedding during the drought might explain some of these contrasting relationships. Establishing such associations could lead to the development of tools that remotely assess average leaf water content of an area of forest via spectral reflectance and use those data to approximate the water stress of plants in that area, a very valuable asset when dealing with such geographically extensive phenomena as drought.&#160;

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Hydrogels as Antibacterial Biomaterials

Current Pharmaceutical Design ◽

10.2174/1381612824666180213122953 ◽

2018 ◽

Vol 24 (8) ◽

pp. 843-854 ◽

Cited By ~ 6

Author(s):

Weiguo Xu ◽

Shujun Dong ◽

Yuping Han ◽

Shuqiang Li ◽

Yang Liu

Keyword(s):

Mechanical Properties ◽

Drug Delivery ◽

Tissue Engineering ◽

Water Content ◽

Oxygen Permeability ◽

Structural Diversity ◽

High Water ◽

Clinical Applications ◽

High Water Content ◽

Biomedical Field

Hydrogels, as a class of materials for tissue engineering and drug delivery, have high water content and solid-like mechanical properties. Currently, hydrogels with an antibacterial function are a research hotspot in biomedical field. Many advanced antibacterial hydrogels have been developed, each possessing unique qualities, namely high water swellability, high oxygen permeability, improved biocompatibility, ease of loading and releasing drugs and structural diversity. In this article, an overview is provided on the preparation and applications of various antibacterial hydrogels. Furthermore, the prospects in biomedical researches and clinical applications are predicted.

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