Photosynthesis of an epiphytic resurrection fern Davallia angustata (Wall .ex Hook. & Grev.)

2017 ◽  
Vol 65 (4) ◽  
pp. 348 ◽  
Author(s):  
Rosanne Quinnell ◽  
Daniel Howell ◽  
Raymond J. Ritchie
Keyword(s):  
Photosynthetic Efficiency ◽  
Photosynthetic Electron Transport ◽  
Pulse Amplitude ◽  
Resurrection Plant ◽  
Simple Relationship ◽  
Chl A ◽  
Palm Trees ◽  
Titratable Acid ◽  
Cam Plant ◽  
Epiphytic Fern

Davallia (Pachypleuria) angustata (Wall. ex Hook. & Grev.) is a common epiphytic fern that grows on tree trucks and palm trees in south-east Asia. The plant is a resurrection plant, capable of rapid recovery from desiccation, but is not a CAM plant like some other epiphytic ferns. Under well-watered conditions Davallia shows a diurnal cycle of photosynthesis with maxima in mid-morning ~0900 hours (solar time). Under optimum conditions, the optimum irradiance (Eopt) = 879.3 ± 65.31 μmol photons m–2 s–1 or ~45% of full sunlight qualifying it as a sun plant. The maximum photosynthetic electron transport rate (ETRmax) was 77.77 ± 3.423 μmol e– m–2 s–1 or, on a Chl a basis 350 ± 36.0 μmol g–1 (Chl a) s–1. The photosynthetic efficiency (α0) is α0 = 0.2404 ± 0.02076 e– photon–1 or 1.082 ± 0.137 e– photon m2 g–1 (Chl a). Eopt and maximum photosynthesis (ETRmax) are directly proportional to one another (y = mx, r = 0.8813, P < <0.001). The slope of the line is the average photosynthetic efficiency at optimum irradiance (ETRmax/Eopt or αEopt = 0.07505 ± 0.00262 e– photon–1), equivalent to a mean asymptotic photosynthetic efficiency (α0) of 0.2040 ± 0.00712 e– photon–1. This simple relationship between ETRmax and Eopt does not appear to have been noted before. There is some accumulation of titratable acid in the morning but no accumulation of organic acids at night. Davallia is not a CAM plant. A simple pulse amplitude modulation (PAM) protocol shows that Davallia is a homiochlorophyllous resurrection plant.

Endolithic algae photoacclimate to increased irradiance during coral bleaching

2004 ◽  
Vol 55 (1) ◽  
pp. 115 ◽  
Author(s):  
Maoz Fine ◽  
Laura Steindler ◽  
Yossi Loya
Keyword(s):  
Chlorophyll Fluorescence ◽  
Photosynthetic Efficiency ◽  
Photosynthetic Electron Transport ◽  
Pulse Amplitude ◽  
Coral Tissue ◽  
Pam Fluorometry ◽  
Endolithic Algae ◽  
Symbiotic Dinoflagellates ◽  
Pam Chlorophyll Fluorescence

The photoacclimation of endolithic algae (of the genus Ostreobium) inhabiting the skeleton of the Mediterranean coral Oculina patagonica during a bleaching event was examined. Pulse amplitude modulated (PAM) chlorophyll fluorescence techniques in situ were used to assess the photosynthetic efficiency of endolithic algae in the coral skeleton and the symbiotic dinoflagellates (zooxanthellae) in the coral tissue. Relative photosynthetic electron transport rates (ETRs) of the endolithic algae under bleached areas of the colony were significantly higher than those of endolithic algae from a healthy section of the colony and those of zooxanthellae isolated from the same section. Endolithic algae under healthy parts of the colony demonstrated an ETRmax of 16.5% that of zooxanthellae from tissue in the same section whereas endolithic algae under bleached sections showed ETRmax values that were 39% of those found for healthy zooxanthellae. The study demonstrates that endolithic algae undergo photoacclimation with increased irradiance reaching the skeleton. As PAM fluorometry has become a major tool for assessing levels of stress and bleaching in corals, the importance of considering the contribution of the endolithic algae to the overall chlorophyll fluorescence measured is highlighted.

Monitoring of cold and light stress impact on photosynthesis by using the laser induced fluorescence transient (LIFT) approach

2010 ◽  
Vol 37 (5) ◽  
pp. 395 ◽  
Author(s):  
Roland Pieruschka ◽  
Denis Klimov ◽  
Zbigniew S. Kolber ◽  
Joseph A. Berry
Keyword(s):  
Photosynthetic Efficiency ◽  
Light Stress ◽  
Pulse Amplitude ◽  
Laser Induced Fluorescence ◽  
High Light Intensity ◽  
High Light ◽  
Persea Americana ◽  
Effective Quantum Yield ◽  
Fluorescence Transient ◽  
Fluorescence Measurements

Chlorophyll fluorescence measurements have been widely applied to quantify the photosynthetic efficiency of plants non-destructively. The most commonly used pulse amplitude modulated (PAM) technique provides a saturating light pulse, which is not practical at the canopy scale. We report here on a recently developed technique, laser induced fluorescence transient (LIFT), which is capable of remotely measuring the photosynthetic efficiency of selected leaves at a distance of up to 50 m. The LIFT approach correlated well with gas exchange measurements under laboratory conditions and was tested in a field experiment monitoring the combined effect of low temperatures and high light intensity on a variety of plants during the early winter in California. We observed a reduction in maximum and effective quantum yield in electron transport for Capsicum annuum L., Lycopersicon esculentum L. and Persea americana Mill. as the temperatures fell, while a grass community was not affected by combined low temperature and high light stress. The ability to make continuous, automatic and remote measurements of the photosynthetic efficiency of leaves with the LIFT system provides a new approach for studying and monitoring of stress effects on the canopy scale.

scholarly journals Slow induction of photosynthesis on shade to sun transitions in wheat may cost at least 21% of productivity

2017 ◽  
Vol 372 (1730) ◽  
pp. 20160543 ◽  
Author(s):  
Samuel H. Taylor ◽  
Stephen P. Long
Keyword(s):  
Photosynthetic Efficiency ◽  
Green Revolution ◽  
Photosynthetic Electron Transport ◽  
Yield Potential ◽  
Carbon Gain ◽  
Bisphosphate Carboxylase ◽  
Flag Leaves ◽  
Speed Of Adjustment ◽  
Typical Day

Wheat is the second most important direct source of food calories in the world. After considerable improvement during the Green Revolution, increase in genetic yield potential appears to have stalled. Improvement of photosynthetic efficiency now appears a major opportunity in addressing the sustainable yield increases needed to meet future food demand. Effort, however, has focused on increasing efficiency under steady-state conditions. In the field, the light environment at the level of individual leaves is constantly changing. The speed of adjustment of photosynthetic efficiency can have a profound effect on crop carbon gain and yield. Flag leaves of wheat are the major photosynthetic organs supplying the grain of wheat, and will be intermittently shaded throughout a typical day. Here, the speed of adjustment to a shade to sun transition in these leaves was analysed. On transfer to sun conditions, the leaf required about 15 min to regain maximum photosynthetic efficiency. In vivo analysis based on the responses of leaf CO 2 assimilation ( A ) to intercellular CO 2 concentration ( c i ) implied that the major limitation throughout this induction was activation of the primary carboxylase of C3 photosynthesis, ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). This was followed in importance by stomata, which accounted for about 20% of the limitation. Except during the first few seconds, photosynthetic electron transport and regeneration of the CO 2 acceptor molecule, ribulose-1,5-bisphosphate (RubP), did not affect the speed of induction. The measured kinetics of Rubisco activation in the sun and de-activation in the shade were predicted from the measurements. These were combined with a canopy ray tracing model that predicted intermittent shading of flag leaves over the course of a June day. This indicated that the slow adjustment in shade to sun transitions could cost 21% of potential assimilation. This article is part of the themed issue ‘Enhancing photosynthesis in crop plants: targets for improvement’.

Duststorm-Facilitated Improvement of the Photosynthetic Efficiency of Tamarix ramosissima L. in the Oasis-Desert Ecotone, Northwest China

2012 ◽  
Vol 518-523 ◽  
pp. 5035-5039
Author(s):  
Wei Han ◽  
Ling Cao ◽  
Haimid Yimit
Keyword(s):  
Photosynthetic Efficiency ◽  
Weather Conditions ◽  
Northwest China ◽  
Tamarix Ramosissima ◽  
Taklimakan Desert ◽  
Chl A ◽  
Fluorescence Parameters ◽  
Mature Leaves ◽  
Chl A Fluorescence ◽  
Maximum Period

The photosynthetic efficiency of Tamarix ramosissima Ledeb., one of the major natural plants in the southern oasis-desert ecotone of the Taklimakan Desert, was investigated to assess the ecological effects of duststorms on T ramosissima Ledeb. We measured daily chlorophyll a (Chl a) fluorescence parameters of mature leaves of healthy 10-years old T. ramosissima L. during months of July and August in 2008, using a portable modulated Chl a fluorometer PAM-2100 and three duststorm days were singled out to assess the affects of duststorms on the photosynthetic efficiency. Our results showed that duststorms increased the energy absorption and the increased absorption then enhanced the photosynthetic efficiency of T. ramosissima L. under duststorm weather conditions. Our results also showed that the qP (quenching coefficients for photosynthesis) was significantly decreased and qN (quenching coefficients for non-photosynthesis) was significantly increased during the maximum period of solar readiation between 14:00 and 16:00 under normal conditions, implying that stress might occur in normal weather conditions, but lowered stress to T ramosissima Ledeb. during duststorm weather conditions. In a word, duststorm-facilitated might provide favorable opportunities for constructing and expansing oasis-desert ecotone.

The Effect of Nano-ZnO on the Photosynthetic Capacity and Survival of Anabaena sp. and M. aeruginosa

2014 ◽  
Vol 1073-1076 ◽  
pp. 77-80
Author(s):  
Jian Fen Du ◽  
Yu Lin Tang ◽  
Qian Li
Keyword(s):  
Photosynthetic Efficiency ◽  
Photosynthetic Capacity ◽  
Electron Transport Rate ◽  
Pulse Amplitude ◽  
Maximal Effect ◽  
Effective Quantum Yield ◽  
Chlorophyll Fluorescence Parameters ◽  
Fluorescence Parameters ◽  
Malondialdehyde Content ◽  
Anabaena Sp

Anabaena sp. and M. aeruginosa were used to examine the toxic mechanism of nanoZnO to them, as well as the toxicity. Typical chlorophyll fluorescence parameters, including effective quantum yield, photosynthetic efficiency and maximum electron transport rate, were measured by a pulse amplitude modulated fluorometer. Results showed that nanoZnO could inhibit Anabaena sp. and M.aeruginosa growth with the EC50 (concentration for 50% of maximal effect) of 0.74±0.01 and 1.68±0.01 mg/L respectively. The toxicity of nanoZnO to Anabaena sp. is higher than that to M.aeruginosa, which can be proved by the malondialdehyde content in Anabaena sp. and M.aeruginosa cells.

scholarly journals Metabolic changes which form the basis of a microbiological assay of nicotinic acid

1949 ◽  
Vol 136 (882) ◽  
pp. 12-29 ◽  
Keyword(s):  
Catalytic Activity ◽  
Nicotinic Acid ◽  
Assay System ◽  
Microbiological Assay ◽  
Acid Formation ◽  
Present System ◽  
Simple Relationship ◽  
Bacterial Cells ◽  
Titratable Acid ◽  
Catalytic Capacity

The manner in which limitation of nicotinic acid in cultures of Lactobacillus arabinosus limited their formation of titratable acid has been examined. This system forms the basis of a much-used microbiological assay of nicotinic acid. During a large part of a normal assay, the rate of formation of titratable acid was pro­portional to the quantity of added nicotinic acid. The relationship between this rate and the quantities of nicotinic acid has been expressed as a ratio: mol. titrated acid/hr. /mol. bacterial nicotinic acid, which has been called the catalytic activity of nicotinic acid in the assay system. Its value was about 15 x 10 3 hr. -1 at pH 6·8, and fell with fall in pH to 5 x 10 3 hr. -1 at pH 5·0. The rate of acid formation during assay fell to a greater extent than could be accounted for by the change in pH which took place during the assay. Much of this fall was due to loss of nicotinic acid from the bacterial cells. During the first day’s growth the added, limiting, quantities of nicotinic acid were rapidly and completely removed from the culture fluid to the cells, but following this period the nicotinic acid was gradually lost. Loss of nicotinic acid from the cells bore a simple relationship to the quantity of titratable acid formed; for each 5 x 10 5 mol. of acid produced, 1 mol. of nicotinic acid was lost. This molar ratio has been called the catalytic capacity of nicotinic acid for the formation of titratable acid in the present system. Its value was independent of the changes in pH during assay and of the actual rate of acid formation. The use of the terms catalytic capacity and catalytic activity has been assessed, and relationships between them and the quantities of titratable acid produced at different times have been expressed mathematically. During the assay as it is ordinarily performed, only part of the catalytic capacity of the added nicotinic acid was found to be used. About half the acid remained in the cells, and these remained capable of the formation of titratable acid, after the 3 days at which the acid formed in assay cultures is commonly titrated. Because nicotinic acid was lost from the bacteria in proportion to their formation of titratable acid, the assay system could compensate for initial fluctuations in such circum­stances as temperature or the quantity of bacterial cells.

Toxicity of Nano-ZnO and Nano-TiO2 to M. aeruginosa

2014 ◽  
Vol 1073-1076 ◽  
pp. 278-281
Author(s):  
Zhe Hua Xue ◽  
Yu Lin Tang ◽  
Yu Hui Sun
Keyword(s):  
Photosynthetic Efficiency ◽  
Electron Transport Rate ◽  
Pulse Amplitude ◽  
Maximal Effect ◽  
Effective Quantum Yield ◽  
Nano Zno ◽  
Chlorophyll Fluorescence Parameters ◽  
Fluorescence Parameters ◽  
Malondialdehyde Content ◽  
Anabaena Sp

Anabaena sp.andM. aeruginosawere used to examine the toxic mechanism of nano-ZnO to them, as well as the toxicity. Typical chlorophyll fluorescence parameters, including effective quantum yield, photosynthetic efficiency and maximum electron transport rate, were measured by a pulse amplitude modulated fluorometer. Results showed that nano-ZnO could inhibitAnabaena sp.andM. aeruginosagrowth with the EC50(concentration for 50% of maximal effect) of 0.74±0.01 and 1.68±0.01 mg/L respectively. The toxicity of nano-ZnO toAnabaena sp.is higher than that toM. aeruginosa, which can be proved by the malondialdehyde content inAnabaena sp.andM. aeruginosacells.

scholarly journals Wastewater Biofilm Photosynthesis in Photobioreactors

2019 ◽  
Vol 7 (8) ◽  
pp. 252 ◽  
Author(s):  
Antonella Guzzon ◽  
Francesca Di Pippo ◽  
Roberta Congestri
Keyword(s):  
Treatment Plant ◽  
Environmental Parameters ◽  
Dry Weight ◽  
Pulse Amplitude ◽  
Photosynthetic Performance ◽  
Photosynthetic Parameters ◽  
Effective Quantum Yield ◽  
Chl A ◽  
Experimental Values ◽  
Over Time

Photosynthetic performance of algal-bacterial biofilms from an Italian wastewater treatment plant was studied in a flow-lane photobioreactor at different irradiances, temperatures, and flow regime to evaluate the effects of these environmental parameters on biofilms’ functioning, in view of application of these communities in wastewater biological treatment. Pulse amplitude modulated fluorescence was used to estimate the effective quantum yield of PSII (ΔF/Fm’) of the light-acclimated biofilms and to perform rapid light curves (RLCs) for the determination of the photosynthetic parameters (rel.ETRmax, α, Ik). Chl a, ash free dry weight (AFDW), and dry weight (DW) were measured to assess phototrophic and whole biofilm biomass development over time. From the analysis of photosynthetic parameter variation with light intensity, temperature and flow rate, it was possible to identify the set of experimental values favoring biofilm photosynthetic activity. Biomass increased over time, especially at the highest irradiances, where substrata were fastly colonized and mature biofilms developed at all temperatures and flow conditions tested.

scholarly journals Fast repetition rate and pulse amplitude modulation chlorophyllafluorescence measurements for assessment of photosynthetic electron transport in marine phytoplankton

2003 ◽  
Vol 38 (4) ◽  
pp. 371-384 ◽  
Author(s):  
David J Suggett ◽  
Kevin Oxborough ◽  
Neil R Baker ◽  
Hugh L MacIntyre ◽  
Todd M Kana ◽  
...  
Keyword(s):  
Electron Transport ◽  
Amplitude Modulation ◽  
Repetition Rate ◽  
Photosynthetic Electron Transport ◽  
Pulse Amplitude ◽  
Marine Phytoplankton ◽  
Pulse Amplitude Modulation

scholarly journals Diversity and host preferences of ferns and lycopods epiphytes on palm trees

2019 ◽  
Vol 20 (12) ◽  
Author(s):  
Titien Ngatinem Praptosuwiryo ◽  
SUMANTO SUMANTO ◽  
RIA CAHYANINGSIH
Keyword(s):  
Floristic Composition ◽  
Botanic Gardens ◽  
Tropical Rain Forests ◽  
Host Preferences ◽  
Palm Trees ◽  
Host Trees ◽  
Fern Species ◽  
Global Biodiversity ◽  
Epiphytic Fern ◽  
Pyrrosia Piloselloides

Abstract. Praptosuwiryo TN, Sumanto, Cahyaningsih. 2019. Diversity and host preferences of ferns and lycopods epiphytes on palm trees. Biodiversitas 20: 3731-3740. Epiphytic ferns contribute importantly to the global biodiversity of tropical rain forests. However, our knowledge of the ecology of epiphytic ferns is phenomenally still limited. Most studies on the ecology, floristic and diversity of epiphytic ferns and lycopods were reported outside of Malesian region. This study aimed: (i) to figure out the diversity of ferns and lycopods on palm trees of the lowland areas by analyzing its species richness and floristic composition, and (ii) to determine the host preferences of epiphytic ferns on palm trees. Twenty-eight phorophyte species belonging to 17 genera of palm trees, growing at Bogor Botanic Gardens, were observed. Trunk of palm trees was divided into three zones (basal, middle and upper). Individual numbers for each species of epiphytic fern growing on each zone were recorded. Epiphytic fern species which were most commonly found were analyzed statistically to determine their preference for the host trees. A total of 16 species of epiphytic ferns and lycopods were recorded. The greatest richness of species occurred in Polypodiaceae (50%). Habitual true epiphyte was the predominant ecological category, representing 75 % of the species. Caryota no Becc. hosted the greatest number of ferns and lycopods 8 species) while Attalea insignis (Mart.) Drude hosted the fewest (2 species). Individual numbers of six epiphytic fern species were significantly affected by palm trees species, namely Belvisia callifolia (Christ) Copel., Pyrrosia lanceolata (L.) Farwell, Pyrrosia piloselloides (L.) M.G. Price, Davallia denticulata (Burm.) Mett., Nephrolepis biserrata (Sw.) Schott, Vittaria ensiformis Sw. Individual numbers of five epiphytic fern species were significantly affected by zone of the host plant. Nephrolepis biserrata tends to grow well in the upper zone. Pyrrosia lanceolata tends to be abundant in the middle zone. B. callifolia, D. denticulata, and V. ensiformis grow well and make dense populations in the basal zone.

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