Leaf gas exchange capacity in relation to leaf position on the stem in field grown teak (Tectona grandis L.f.)

1998 ◽  
Vol 34 (1) ◽  
pp. 45-55 ◽  
Author(s):  
G. Rajendrudu ◽  
C.V. Naidu
Keyword(s):  
Gas Exchange ◽  
Leaf Gas Exchange ◽  
Tectona Grandis ◽  
Exchange Capacity ◽  
Leaf Position ◽  
Tectona Grandis L.F

scholarly journals Fossil evidence for low gas exchange capacities for Early Cretaceous angiosperm leaves

Paleobiology ◽  
2011 ◽  
Vol 37 (2) ◽  
pp. 195-213 ◽  
Author(s):  
Taylor S. Feild ◽  
Garland R. Upchurch ◽  
David S. Chatelet ◽  
Timothy J. Brodribb ◽  
Kunsiri C. Grubbs ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Early Cretaceous ◽  
Leaf Gas Exchange ◽  
Exchange Capacity ◽  
Basal Angiosperm ◽  
Photosynthetic Gas Exchange ◽  
Angiosperm Evolution ◽  
Early Angiosperm ◽  
Fossil Evidence ◽  
Functional Analyses

The photosynthetic gas exchange capacities of early angiosperms remain enigmatic. Nevertheless, many hypotheses about the causes of early angiosperm success and how angiosperms influenced Mesozoic ecosystem function hinge on understanding the maximum capacity for early angiosperm metabolism. We applied structure-functional analyses of leaf veins and stomatal pore geometry to determine the hydraulic and diffusive gas exchange capacities of Early Cretaceous fossil leaves. All of the late Aptian—early Albian angiosperms measured possessed low vein density and low maximal stomatal pore area, indicating low leaf gas exchange capacities in comparison to modern ecologically dominant angiosperms. Gas exchange capacities for Early Cretaceous angiosperms were equivalent or lower than ferns and gymnosperms. Fossil leaf taxa from Aptian to Paleocene sediments previously identified as putative stem-lineages to Austrobaileyales and Chloranthales had the same gas exchange capacities and possibly leaf water relations of their living relatives. Our results provide fossil evidence for the hypothesis that high leaf gas exchange capacity is a derived feature of later angiosperm evolution. In addition, the leaf gas exchange functions of austrobaileyoid and chloranthoid fossils support the hypothesis that comparative research on the biology of living basal angiosperm lineages reveals genuine signals of Early Cretaceous angiosperm ecophysiology.

scholarly journals IDENTIFIKASI KESESUAIAN LAHAN UNTUK JATI (Tectona grandis Linn.f) DI PT. MELAPI TIMBER, KALIMANTAN TIMUR Identify Suitable Land for Jati (Tectona grandis L.f) in PT. Melapi Timber, East Kalimantan

2018 ◽  
Vol 9 (1) ◽  
pp. 31-36
Author(s):  
Susanti . ◽  
Prijanto Pamoengkas ◽  
Cahyo Wibowo
Keyword(s):  
Soil Depth ◽  
Tectona Grandis ◽  
Exchange Capacity ◽  
Land Evaluation ◽  
Weight Factor ◽  
Plantation Forest ◽  
East Kalimantan ◽  
Study Results ◽  
Factor Matching ◽  
Tectona Grandis L.F

Land evaluation of a tract of land, for its suitability to be planted with a particular plantation species is an importantstep for species choice in plantation forest. A weight factor matching (WFM) approach of this study, was used to identifysuitable land for jati (Tectona grandis L.f) in PT. Melapi Timber, East Kalimantan. Land suitability is affected by climate,soil and topograph. According to WFM, the results indicated that important variables which limit T. grandis in theresearch area were pH, cation exchange capacity (CEC), potassium (P) and soil depth condition. The study results showthat 4 of 5 land units are marginally suitable (S3) for T. grandis cultivation in PT. Melapi Timber.Key words: Land evaluation, suitability, Tectona grandis L.f., weight factor matching (WFM)

scholarly journals A stomatal model of anatomical tradeoffs between gas exchange and pathogen colonization

2019 ◽  
Author(s):  
Christopher D. Muir
Keyword(s):  
Gas Exchange ◽  
Leaf Surface ◽  
Stomatal Density ◽  
Leaf Gas Exchange ◽  
Stomatal Closure ◽  
Exchange Capacity ◽  
Pathogen Defense ◽  
Stomatal Size ◽  
Scaling Relationships ◽  
Pathogen Colonization

ABSTRACTStomatal pores control both leaf gas exchange and are one route for infection of internal plant tissues by many foliar pathogens, setting up the potential for tradeoffs between photosynthesis and defense. Anatomical shifts to lower stomatal density and/or size may also limit pathogen colonization, but such developmental changes could permanently reduce the gas exchange capacity for the life of the leaf. I developed and analyzed a spatially explicit model of pathogen colonization on the leaf as a function of stomatal size and density, anatomical traits which partially determine maximum rates of gas exchange. The model predicts greater stomatal size or density increases the probability of colonization, but the effect is most pronounced when the fraction of leaf surface covered by stomata is low. I also derived scaling relationships between stomatal size and density that preserves a given probability of colonization. These scaling relationships set up a potential anatomical conflict between limiting pathogen colonization and minimizing the fraction of leaf surface covered by stomata. Although a connection between gas exchange and pathogen defense has been suggested empirically, this is the first mathematical model connecting gas exchange and pathogen defense via stomatal anatomy. A limitation of the model is that it does not include variation in innate immunity and stomatal closure in response to pathogens. Nevertheless, the model makes predictions that can be tested with experiments and may explain variation in stomatal anatomy among plants. The model is generalizable to many types of pathogens, but lacks significant biological realism that may be needed for precise predictions.

The Effects of Drought on Leaf Gas Exchange and Growth of Three Species of Herbaceous Perennials

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 540a-540
Author(s):  
K.J. Prevete ◽  
R.T. Fernandez
Keyword(s):  
Drought Stress ◽  
Stomatal Conductance ◽  
Gas Exchange ◽  
Drought Tolerance ◽  
Transpiration Rate ◽  
Leaf Gas Exchange ◽  
Gas Analysis ◽  
Herbaceous Perennials ◽  
Effects Of Drought ◽  
Analysis System

Three species of herbaceous perennials were tested on their ability to withstand and recover from drought stress periods of 2, 4, and 6 days. Eupatorium rugosum and Boltonia asteroides `Snowbank' were chosen because of their reported drought intolerance, while Rudbeckia triloba was chosen based on its reported drought tolerance. Drought stress began on 19 Sept. 1997. Plants were transplanted into the field the day following the end of each stress period. The effects of drought on transpiration rate, stomatal conductance, and net photosynthetic rate were measured during the stress and throughout recovery using an infrared gas analysis system. Leaf gas exchange measurements were taken through recovery until there were no differences between the stressed plants and the control plants. Transpiration, stomatal conductance, and photosynthesis of Rudbeckia and Boltonia were not affected until 4 days after the start of stress. Transpiration of Eupatorium decreased after 3 days of stress. After rewatering, leaf gas exchange of Boltonia and Rudbeckia returned to non-stressed levels quicker than Eupatorium. Growth measurements were taken every other day during stress, and then weekly following transplanting. Measurements were taken until a killing frost that occurred on 3 Nov. There were no differences in the growth between the stressed and non-stressed plants in any of the species. Plants will be monitored throughout the winter, spring, and summer to determine the effects of drought on overwintering capability and regrowth.

scholarly journals Grapevine species from varied native habitats exhibit differences in embolism formation/repair associated with leaf gas exchange and root pressure

2015 ◽  
Vol 38 (8) ◽  
pp. 1503-1513 ◽  
Author(s):  
THORSTEN KNIPFER ◽  
ASHLEY EUSTIS ◽  
CRAIG BRODERSEN ◽  
ANDREW M. WALKER ◽  
ANDREW J. MCELRONE
Keyword(s):  
Gas Exchange ◽  
Leaf Gas Exchange ◽  
Root Pressure ◽  
Native Habitats

scholarly journals An improved theory for calculating leaf gas exchange more precisely accounting for small fluxes

Nature Plants ◽  
2021 ◽  
Author(s):  
Diego A. Márquez ◽  
Hilary Stuart-Williams ◽  
Graham D. Farquhar
Keyword(s):  
Gas Exchange ◽  
Leaf Gas Exchange

Long-term liming improves soil fertility and soybean root growth, reflecting improvements in leaf gas exchange and grain yield

2021 ◽  
Vol 128 ◽  
pp. 126308
Author(s):  
João William Bossolani ◽  
Carlos Alexandre Costa Crusciol ◽  
José Roberto Portugal ◽  
Luiz Gustavo Moretti ◽  
Ariani Garcia ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Root Growth ◽  
Soil Fertility ◽  
Grain Yield ◽  
Leaf Gas Exchange ◽  
Soybean Root

scholarly journals Shading Effects on Leaf Gas Exchange, Leaf Pigments and Secondary Metabolites of Polygonum minus Huds., an Aromatic Medicinal Herb

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 608
Author(s):  
Fairuz Fatini Mohd Yusof ◽  
Jamilah Syafawati Yaacob ◽  
Normaniza Osman ◽  
Mohd Hafiz Ibrahim ◽  
Wan Abd Al Qadr Imad Wan-Mohtar ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Secondary Metabolites ◽  
Chlorophyll A ◽  
Leaf Gas Exchange ◽  
Photosynthesis Rate ◽  
Total Phenolic ◽  
Chlorophyll B ◽  
Low Light ◽  
Total Anthocyanin ◽  
Polygonum Minus

The growing demand for high value aromatic herb Polygonum minus-based products have increased in recent years, for its antioxidant, anticancer, antimicrobial, and anti-inflammatory potentials. Although few reports have indicated the chemical profiles and antioxidative effects of Polygonum minus, no study has been conducted to assess the benefits of micro-environmental manipulation (different shading levels) on the growth, leaf gas exchange and secondary metabolites in Polygonum minus. Therefore, two shading levels (50%:T2 and 70%:T3) and one absolute control (0%:T1) were studied under eight weeks and 16 weeks of exposures on Polygonum minus after two weeks. It was found that P. minus under T2 obtained the highest photosynthesis rate (14.892 µmol CO2 m−2 s−1), followed by T3 = T1. The increase in photosynthesis rate was contributed by the enhancement of the leaf pigments content (chlorophyll a and chlorophyll b). This was shown by the positive significant correlations observed between photosynthesis rate with chlorophyll a (r2 = 0.536; p ≤ 0.05) and chlorophyll b (r2 = 0.540; p ≤ 0.05). As the shading levels and time interval increased, the production of total anthocyanin content (TAC) and antioxidant properties of Ferric Reducing Antioxidant Power (FRAP) and 2,2-Diphenyl-1-picrylhydrazyl (DPPH) also increased. The total phenolic content (TPC) and total flavonoid content (TFC) were also significantly enhanced under T2 and T3. The current study suggested that P.minus induce the production of more leaf pigments and secondary metabolites as their special adaptation mechanism under low light condition. Although the biomass was affected under low light, the purpose of conducting the study to boost the bioactive properties in Polygonum minus has been fulfilled by 50% shading under 16 weeks’ exposure.

scholarly journals Ethylene enhances root water transport and aquaporin expression in trembling aspen (Populus tremuloides) exposed to root hypoxia

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xiangfeng Tan ◽  
Mengmeng Liu ◽  
Ning Du ◽  
Janusz J. Zwiazek
Keyword(s):  
Gas Exchange ◽  
Water Transport ◽  
Populus Tremuloides ◽  
Leaf Gas Exchange ◽  
Hydraulic Conductance ◽  
Root Hydraulic Conductance ◽  
Trembling Aspen ◽  
Expression Levels ◽  
Root Hypoxia ◽  
Exogenous Ethylene

Abstract Background Root hypoxia has detrimental effects on physiological processes and growth in most plants. The effects of hypoxia can be partly alleviated by ethylene. However, the tolerance mechanisms contributing to the ethylene-mediated hypoxia tolerance in plants remain poorly understood. Results In this study, we examined the effects of root hypoxia and exogenous ethylene treatments on leaf gas exchange, root hydraulic conductance, and the expression levels of several aquaporins of the plasma membrane intrinsic protein group (PIP) in trembling aspen (Populus tremuloides) seedlings. Ethylene enhanced net photosynthetic rates, transpiration rates, and root hydraulic conductance in hypoxic plants. Of the two subgroups of PIPs (PIP1 and PIP2), the protein abundance of PIP2s and the transcript abundance of PIP2;4 and PIP2;5 were higher in ethylene-treated trembling aspen roots compared with non-treated roots under hypoxia. The increases in the expression levels of these aquaporins could potentially facilitate root water transport. The enhanced root water transport by ethylene was likely responsible for the increase in leaf gas exchange of the hypoxic plants. Conclusions Exogenous ethylene enhanced root water transport and the expression levels of PIP2;4 and PIP2;5 in hypoxic roots of trembling aspen. The results suggest that ethylene facilitates the aquaporin-mediated water transport in plants exposed to root hypoxia.

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