REVIEW article Front. Plant Sci., 01 May 2013Sec. Physiology Volume 4 - 2013 | https://doi.org/10.3389/fpls.2013.00106

In many plant species that remain leafless part of the year, CO2 fixation occurring in green stems represents an important carbon gain. Traditionally, a distinction has been made between stem photosynthesis and corticular photosynthesis. All is, sensu stricto, cortical, since it is carried out largely by cortex. We proposed following nomenclature: net (SNP), which includes with stomata epidermis suberized stems, recycling (SRP), defines ling stems. The terms should reflect differences...

Seasonal changes in water relations, net photosynthetic rate (PN), and fluorescence of chlorophyll (Chl) a two perennial C3 deciduous shrubs, Ipomoea carnea Jatropha gossypifolia, growing thorn scrub Venezuela were studied order to establish the possible occurrence photoinhibition during dry season determine whether photochemical activity photosystem 2 (PS2) may explain variations PN these species. Leaf potential (ψ) decreased from -0.2 -2.1 MPa drought both The with ψ I. J. gossypifolia by...

Trees in the flooded forest of Mapire River Venezuela suffer a decrease photosynthetic rate (A) when flood begins, which is reverted at maximum flood. Changes A are accompanied by similar changes stomatal conductance (g s ), and possibility capacity not ruled out. In order to understand how relative non‐stomatal limitations photosynthesis affected flooding, we studied seasonal its response intercellular CO 2 concentration trees Campsiandra laurifolia , Symmeria paniculata Acosmium nitens...

Abstract In order to assess the response of cocoa trees drought, changes in water status, gas exchange, leaf carbon isotopic ratio ( δ 13 C), photochemical activity, and N chlorophyll content during rainy dry season were measured 31 Venezuelan clones (17 Trinitarios, 6 Criollos, 8 Modern Criollos) grown a common garden. Drought caused 40% decrease potential ψ ) all but reduction net photosynthetic rate A stomatal conductance g s without an increase instantaneous use efficiency (WUE) 93%...

In order to determine whether stomatal closure alone regulates photosynthesis during drought under natural conditions, seasonal changes in leaf gas exchange were studied plants of five species differing life form and carbon fixation pathway growing a thorn scrub Venezuela. The were: Ipomoea carnea, Jatropha gossypifolia, (C3 deciduous shrubs), Alternanthera crucis (C4 herb), Prosopis juliflora Capparis odoratissima (evergreen phreatophytic trees). Xylem water potential (Ψ) all followed very...

Journal Article Occurrence of Inducible Crassulacean Acid Metabolism in Leaves Talimum triangulare (Portulacaceae) Get access A. HERRERA, HERRERA 1 Universidad Central de Venezuela, Escuela Biologia, Centro Botánica TropicalApartado 47114, Caracas 104 1A, Venezuela To whom correspondence should be addressed Search for other works by this author on: Oxford Academic PubMed Google Scholar J. DELGADO, DELGADO I. PARAGUATEY Experimental Botany, Volume 42, Issue 4, April 1991, Pages 493–499,...

We studied the seasonal changes in water relations, chlorophyll a fluorescence, and leaf saccharide contents of tropical flood-tolerant trees Acosmium nitens, Campsiandra laurifolia, Eschweilera tenuifolia, Symmeria paniculata, Psidium ovatifolium. Xylem potential increased with flooding to larger extent than sap osmotic all species, soluble sugars contributed up 66 % at maximum flooding. Starch was accumulated leaves. Maximum quantum yield photosystem 2 decreased emerged leaves, values...

We studied the flood tolerance of five tree species growing in flooded forest adjacent to Mapire river, SW Venezuela. Mean photosynthetic rate and leaf conductance were 11 μmol m−2 s−1 700 mmol s−1, respectively. Xylem water potential ranged from –0.08 –1.15 MPa. Based on gas exchange as a criterion flooding, two response patterns identified: (1) decreasing with increasing flooding (Psidium ovatifolium Berg. ex Desc., Campsiandra laurifolia Benth., Symmeria paniculata Benth. Acosmium nitens...

The mechanisms underlying the drought tolerance of Peperomia carnevalii Steyermark (Piperaceae), a succulent herb growing in understorey seasonally dry forests, were examined. Crassulacean acid metabolism (CAM) was studied field and laboratory, measurements water status made plants subjected to greenhouse. Nocturnal accumulation day night-time CO 2 assimilation rates greatest watered decreased drought. proportion recycled through CAM droughted plants, with nocturnal uptake close zero, higher...

Cocoa grows under shade, but some cultivars develop successfully in full sunlight. In order to characterize the response photosynthetic photon flux density (PPFD) of a Modern Criollo cocoa clone, gas exchange, photochemical activity and leaf traits, their relation growth were measured seedlings growing greenhouse at three different values PPFD, as well adults sunlight shade field. Plants showed changes physiological, biochemical, morpho-anatomical traits light conditions, phenotypic...

In trees of the seasonally flooded forest Mapire River in Venezuela, early flooding induces a reversible diminution leaf conductance and photosynthetic rate. With aim finding an anatomical explanation for observed responses gas exchange, characteristics emerged leaves developed under drainage or after three months were examined tree species Acosmium nitens, Campsiandra laurifolia, Duroia fusifera, Eschweilera tenuifolia, Pouteria orinocoensis Symmeria paniculata only Inga spuria Tachigali...

Nicotiana glauca, a shrub native to southern South America, is widely distributed in the Americas, from Patagonia USA, zero up 3,700 m; it rapidly invades disturbed environments. In Venezuela, has been reported 2,000 m growing contrasting conditions of relative humidity, temperature, rainfall, and salinity. order gain insight into extent mode resistance drought salinity N. we studied effect these factors on water relations photosynthesis under both natural greenhouse conditions. field,...

Crassulacean acid metabolism (CAM) occurs in many Euphorbiaceae, particularly Euphorbia, a genus with C3 and C4 species as well. With the aim of contributing to our knowledge evolution CAM this genus, study examined possible occurrence Euphorbia milii, leaf succulence drought tolerance suggestive carbon fixation pathway. Leaf anatomy consisted palisade parenchyma, spongy parenchyma bundle sheath chloroplasts, which indicates functioning C2 photosynthesis. No evidence nocturnal CO2 was found...

It is commonly accepted that the leaf of a crassulacean acid metabolism (CAM) plant thick, with large mesophyll cells and vacuoles can accommodate malic produced during night. The link between characteristics CAM mode, whether obligate or C3/CAM, was evaluated.

We evaluated the effects of an elevated [CO2] on photosynthesis and growth cassava plants grown in open-top chambers with adequate supply water N a sufficient rooting volume. Cassava (Manihot esculenta Crantz. cv. Motilona) showed higher photosynthetic rates (Pn) when measured at (680 µmol mol-1) than ambient (480 mol-1). No downregulation due to was found, since carboxylation efficiency increased after 220 d spite decrease leaf soluble protein, Rubisco, content. Soluble sugar starch...

Crassulacean acid metabolism (CAM) is currently viewed as an adaptation to water deficit. In plants of Clusia minor, which grow mostly on acidic, P-deficient soils, CAM induced by The symbiosis between and mycorrhizal fungi alleviates the symptoms P deficiency may influence drought resistance. Therefore, effect supply, modified three different experimental treatments, induction in C. minor was investigated test hypothesis that will produce greater activity and, addition, treatment modify...

Crassulacean acid metabolism (CAM) can be induced by salinity, thus conferring the plant higher water-use efficiency. Talinum triangulare does not frequently encounter salt in its natural habitat but is cultivated soils that may become salinized. Here we examined whether plants of T. grow saline and show salt-induced CAM.Leaf gas exchange, carbon isotopic ratio (δ13C), nocturnal accumulation (ΔH+), water relations, photosynthetic pigment mineral contents, leaf anatomy growth were determined...

The effect of a very high CO 2 mole fraction (27000–35000 μmol mol −1 ) on photosynthesis and water relations was studied during the dry rainy season in plants Spatiphylum cannifolium (Dryand.) Schott Bauhinia multinervia (H.B.K.) DC. growing near natural cold springs. Xylem potential both species lowered by drought, growth‐concentration decreasing it further S. . In under concentration photosynthetic rates measured at 1000 were higher than ambient 350 response result direct machinery....