Intensity Of Photosynthesis Research Articles

Metabolite profiling during cold acclimation of Lolium perenne genotypes distinct in the level of frost tolerance.

Abiotic stresses, including low temperature, can significantly reduce plant yielding. The knowledge on the molecular basis of stress tolerance could help to improve its level in species of relatively high importance to agriculture. Unfortunately, the complex research performed so far mainly on model species and also, to some extent, on cereals does not fully cover the demands of other agricultural plants of temperate climate, including forage grasses. Two Lolium perenne (perennial ryegrass) genotypes with contrasting levels of frost tolerance, the high frost tolerant (HFT) and the low frost tolerant (LFT) genotypes, were selected for comparative metabolomic research. The work focused on the analysis of leaf metabolite accumulation before and after seven separate time points of cold acclimation. Gas chromatography-mass spectrometry (GC/MS) was used to identify amino acids (alanine, proline, glycine, glutamic and aspartic acid, serine, lysine and asparagine), carbohydrates (fructose, glucose, sucrose, raffinose and trehalose) and their derivatives (mannitol, sorbitol and inositol) accumulated in leaves in low temperature. The observed differences in the level of frost tolerance between the analysed genotypes could be partially due to the time point of cold acclimation at which the accumulation level of crucial metabolite started to increase. In the HFT genotype, earlier accumulation was observed for proline and asparagine. The increased amounts of alanine, glutamic and aspartic acids, and asparagine during cold acclimation could be involved in the regulation of photosynthesis intensity in L. perenne. Among the analysed carbohydrates, only raffinose revealed a significant association with the acclimation process in this species.

Determination of the tolerance of sunflower to lead-induced stress

Six-week old sunflower seedlings, cv. Ogrodowy, were treated with 0, 15, 45 and 60 mg Pb dm-3, and then the content of lead and selected physiological and biochemical parameters were measured. Photosynthesis efficiency, water relations (intensity of transpiration, relative water content (RWC)) and gene-encoding metallothionein were measured three times after 24, 48 and 72 hours of exposure to Pb. The content of glutathione and lead was analysed after 72 hours’ exposure to Pb. Most of the lead uptake was accumulated in the roots, then in the stems and leaves, but when re-calculated per plant dry weight, the uptake of the metal did not depend on the lead dose applied. The highest 60 mg Pb dm-3 treatment was accompanied by a significant decrease in dry weight content. Moreover, most of the lead taken up in these plants was transported to the stems and leaves (23.6% of total lead uptake). The lead doses used in this study did not affect the intensity of photosynthesis, but a decrease in transpiration and relative water content was observed. The glutathione level in the plants varied depending on the organ examined and the Pb concentration in the treatment. The expression of the metallothionein gene HaMT1 was observed in the stems only. These results indicate that the sunflower cultivar Ogrodowy is a promising plant for phytoremediation of lead-polluted soils.

Sustainable Approach to Mitigation of CO2 Emission

Abstract The discussion about greenhouse gases emission mitigation focuses on the reduction of fossil fuels usage, which is extremely costly from the economic and social viewpoint. The analyses of CO2 and CH4 fluxes in the environment showed that intensifying natural photosynthesis and respiration process may significantly contribute to the mitigation of greenhouse gases emission. It has been proven that the intensity of photosynthesis in land ecosystems could compensate for the increase of CO2 emission from anthropological sources.

Uticaj preparata ishrane na sadržaj fotosintetičkih pigmenata juvenilnih sadnica crnog oraha (Juglans nigra L.)

The paper presents the results of the effect of different fertilizers on concentration of photosynthetic pigments in leaves of juvenile seedlings of Eastern black walnut (Juglans nigra L.). The seedlings were produced in 2014 in the seedling nursery of Institute of forestry in Belgrade. The trial was set up in a random block system with three types of fertilizers and a control in three replications. Three types of pigments have been examined: chlorophyll a, chlorophyll b and carotenoids. The leaf sampling was carried out in the beginning of June 2014. The highest concentration of photosynthetic pigments was found in the leaves of seedlings treated with the preparation Osmocote® Exact Standard 5-6 M and the lowest in the seedlings which were not treated. The highest mean value had chlorophyll a (0.522mg/g) in treatment with Osmocote® Exact Standard 5-6 M and the lowest mean value had chlorophyll b (0.213mg/g) in the control sample. The results showed that the concentration of photosynthetic pigments in leaves of Eastern black walnut juvenile seedlings varied depending on the fertilizer that was applied. Based on the obtained results it can be concluded that the proper fertilizer can increase the concentration of photosynthetic pigments in leaves and therefore the intensity of photosynthesis which contributes to increasing the biomass production.

Features of Ontogeny of Wheat Hybrid of Type Dwarf II

The genes of hybrid depression widely spread in the genus Triticum lead to inviability of hybrid plants and prevent the successful implementation of breeding programs. At the same time the phenomenon of hybrid depression serves as a basic model for the study of profound changes in hybrid plants resulting of expression of various genes. Research of the intensity and orientation of these changes and regularities of ontogenetic development of wheat is necessary to evaluate the viability of hybrids. We have investigated the influence of complementary genes of hybrid dwarfism on the root system, intensity of photosynthesis and the activity of catalase. It was shown that the interaction of complementary dominant genes of hybrid dwarfism has multilateral impact on the ontogenetic development of wheat hybrid Dwarf II. Depression in above ground and underground plant organs was manifested. Photosynthesis in Dwarf II hybrids proceeded more intensively than in the parental forms, but the catalase activity was interrupted in leaves and roots. Notable decrease of the volume and total absorbency of the root surface was detected.

Wpływ biostymulatorów Asahi SL i Siapton 10 L na zdolność roślin ogórka do tolerancji uszkodzeń wywołanych żerowaniem wciornastka zachodniego (Frankliniella occidentalis Pergande)

Summary The studies were conducted on cucumber cultivar Aramis, treated and not treated with biostimulants: Asahi SL and Siapton 10 L in the glasshouse of the Warsaw University of Life Sciences and in the Laboratory of Entomology Department. Plants were cultivated in two glasshouse chambers and western flower thrips (Frankliniella occidentalis Pergande) was introduced to one of the chambers. The aim of the study was to evaluate if application of biostimulants to cucumber crop can increase the level of plant tolerance to thrips. Intensity of growth, photosynthesis and yield were compared in the plants treated and not treated with biostimulants. Cucumber plants tolerated injuries caused by thrips. They accelerated the growth and photosynthesis intensity in the first 4 weeks of pest feeding. This phenomenon was more evident in the plants treated with biostimulants, especially with Siapton 10 L. The yield was not significantly affected by thrips and biostimulants after 4 as well as after 6 weeks of thrips feeding.

The assessment of physiology parameters of willow plants as a criterion for selection of prospective clones

Bioenergy production based on short rotation coppice willow plantations (SRC) is an effective direction both for economic and environment profit. The yield of willow wood can amount to 10-15 tons per hectare of dry biomass per year and the cost of thus obtained energy is lower in comparison with other energy crops. In order to achieve high yield and profitability, the use of special willow clones is necessary. Species most often used in selection for biomass production are shrub type willows: Salix viminalis, Salix dasyclados and Salix schwerini, while the clones tested in this paper were also of tree species Salix alba. The productivity and some physiology characteristics of Serbian selection clones of Salix alba (Backa, Volmianka and Drina) and Swedish selection clone Jorr (Salix viminalis) were investigated in greenhouses and in field conditions. As the result of testing three clones of Salix alba - Backa, Volmianka and Drina, having special preferences and adaptability to different environmental conditions, these were included in State register of Republic of Belarus in 2013. In our experiment it was also satisfactory that specific properties of willows (intensity of transpiration and photosynthesis, water use efficiency and others), were conserved both in greenhouses and in field conditions. This factor gives opportunity to select prospective clones of willows at an early stage of ontogenesis for further testing.

Changes in 14CO2 absorption rates by the successive leaves in buckwheat and white mustard plants of various ages

The experiments with different-aged buckwheat (<i>Fagopyrum esculentum</i> Mnch.) and white mustard (<i>Sinapis alba</i> L.) plants showed that the sub-apical and middle leaves, before they had reached their approximate final sizes, had the highest rates of <sup>14</sup>CO<sub>2</sub> absorption. The intensity of this process decreases in each leaf with age of the plant. White mustard leaves showed a little higher absorption rate of <sup>14</sup>CO<sub>2</sub> than analogous leaves of buckwheat plants. In the investigated leaves no close relationship between the intensity of <sup>14</sup>CO<sub>2</sub> assimilation and chlorophyll a and b concentration was observed. Some possible reasons for the higher intensity of photosynthesis in the sub-apical leaves are discussed.

Wpływ IAA i GA3 na natężenie fotosyntezy, oddychania i transpiracji siewek pszenicy jarej i kukurydzy w warunkach niedostatku wody w glebie [The effect of IAA and GA3 on photosynthesis, respiration and transpiration of spring wheat and corn seedlings under conditions of insufficient water in the soil

It was found that IAA and GA3 distinctly increase the intensity of photosynthesis of the grain seedlings under 30% capillary water capacity. At 60% of capillary water capacity this effect is smaller. The effect of the applied substances on respiration and transpiration is pronounced in spring wheat and only slight in corn.

The effect of nitrogen fertilization on flag leaf and ear photosynthesis and grain yield of spring wheat

In a three-year field experiment the assessment of leaves and ears photosynthesis rate in spring wheat was made using a LI-COR 6400 portable photosynthesis system. The photosynthetic rate of spring wheat was affected by cultivars, nitrogen fertilization and weather conditions. We generally found a negative correlation between the yield of spring wheat and the rate of photosynthesis in flag leaves in phases 39–55 BBCH (the strength of this effect depended on the level of nitrogen fertilization). Strong negative correlation occurred for cv. Bryza in phases:  39–51 BBCH in treatment fertilized with lower dose of nitrogen and in phase 39–41 BBCH for dose 120 kg/ha. There was a significant negative correlation for cv. Tybald only in phase 39–41 BBCH for higher dose of nitrogen and 52–55 BBCH for lower dose. Our studies show that the photosynthetic activity of flag leaves decreased from the booting (39–41 BBCH) to heading stage (52–55 BBCH), and their function was taken over by ears. Contrary to flag leaf, in wheat ears the intensity of photosynthesis correlated positively with grain yield for most of the studied period (52–65 BBCH, with highly significant correlation at 56–57 BBCH and – only for high nitrogen treatments – at 59–61 BBCH; a negative correlation was generally observed at a later phase, i.e. at 65–69 BBCH). Contrary to flag leaf photosynthesis, the intensity of this process in wheat ears (at the heading and flowering stages) seems highly relevant for grain yield. High positive correlation was noted in 56–57 BBCH and 61–65 BBCH. However, the study was done in field conditions and for definitive conclusions observations over a longer period would be desirable.

Effects of temperature on the astaxanthin productivity and light harvesting characteristics of the green alga Haematococcus pluvialis

The green alga Haematococcus pluvialis, which accumulates astaxanthin at an optimal temperature of 20°C, was cultivated under temperatures of 20°C, 23.5°C, 27°C, and 30.5°C, in order to assess the effects on algal metabolism during the growth phase. The culture growth rate declined with above-optimal increases in temperature, and the final maximum cell concentration at 30.5°C reached only 35% of that attained at 20°C. On the contrary, the biomass productivity was increased under all the high-temperature conditions, probably reflecting the metabolism switch from cell duplication to energy accumulation that is typically observed in algal cultures subjected to environmental stress. Moreover, an increase in the light-harvesting capability of the alga was observed by means of the total pigment balance and the photosynthesis-intensity (PI) curve measured under the different cultivation conditions. Cultures kept at higher temperatures were able to better harvest and utilize the impinging light due to photo-acclimation. Finally, the differences in the astaxanthin metabolism were elucidated by subjecting the cultures to nitrogen starvation at 20°C and 27°C. In the culture at 27°C, a 1.4-fold increase in the astaxanthin productivity was observed when compared to that at 20°C, and the latter required almost two-fold more energy for the astaxanthin production compared with the 27°C culture.

Effect of peat on the accumulation and translocation of heavy metals by maize grown in contaminated soils.

Incorporation of organic materials into soil improves the soil sorption capacity, while limiting the mobility of metals in soil and their availability to plants. These effects can be taken advantage for remediation of soils polluted with heavy metals. The objective of this study is to assess the remediatory potential of peat applied to soils with concomitant pollution with Cd, Pb, and Zn. Two 1-year experiments were run in microplots in which maize was grown as the test plant. The following treatments were compared on two soils (sandy soil and loess): (1) control, (2) heavy metals (HM), (3) HM + peat in a single dose, and (4) HM + peat in a double dose. Maize was harvested in the maturity stage; the biomass of roots and aerial parts, including grain and cobs, was measured. Besides, concentration of metals in all those plant parts and the net photosynthetic rate and transpiration rate were determined. The approach of using peat in soil remediation led to satisfactory results on sandy soil only. The application of peat to sandy soil caused significant changes in the accumulation of the metals and their translocation from roots to other parts of plants, which resulted in a higher intensity of photosynthesis and an increase in the maize biomass compared to the HM treatment.

Effect of nitrophenolates on pod damage caused by the brassica pod midge on the photosynthetic apparatus and yield of winter oilseed rape

Oil seed rape (Brassica napus L.) is one of the most commonly grown crops in Central Europe, and the brassica pod midge (Dasineura brassicae Winn.) is one of the most important pests there. Insecticides against this pest applied during flowering may harm bees and other bene- ficial insects. The use of biostimulants such as nitrophe- nolates, which are not harmful to beneficial insects, can be an environmentally friendly way to control this pest. Nitrophenolates activate lignin synthesis in rape pods so the brassica pod midge is not able to penetrate pods. Nitrophenolates also regulate the efficiency of the photo- synthetic apparatus, thus increasing yield. For these reasons nitrophenolates were tested in field conditions in Central Europe in 2005, 2007 and 2008. Nitrophenolates were applied on 10-m 2 plots, and their effect was compared to that of conventional insecticides. The number of damaged pods and yield parameters were assessed; the lignin content as well as photosynthetic rate was measured. Expression of genes related to lignin biosynthesis was examined in Arabidopsis thaliana L. The application of nitrophenolates decreased pod damage caused by the brassica pod midge. Expression levels of four genes related to lignin biosyn- thesis were increased after the application of nitropheno- lates. The yield was higher in nitrophenolate-treated plots, which was attributed to an increase in the intensity of photosynthesis, higher chlorophyll content and improved chlorophyll a fluorescence parameters. The results showed that nitrophenolates have potential as a protective agent, but a further study is required. The application of nitro- phenolates holds promise for reducing chemical input into the environment.

Impact of subgrid-scale vegetation heterogeneity on the simulation of carbon-cycle characteristics

The carbon cycle module of the global climate model developed at the Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences (IAP RAS CM) has been extended by implementing the subgrid-scale heterogeneity (SH) of plant functional types (PFTs). It is found that subgrid-scale PFT heterogeneity enhances the photosynthesis intensity and increases vegetation and soil carbon stocks in grass-dominated regions. In forest-dominated regions, photosynthesis is suppressed and vegetation and soil carbon stocks are diminished. Regionally, accounting for subgrid-scale vegetation heterogeneity may lead to twofold changes in these variables. On the whole, accounting for subgrid-scale PFT heterogeneity enhances (suppresses) the carbon flux in regions where it is directed from terrestrial ecosystems to the atmosphere (from the atmosphere to terrestrial ecosystems).

Hybrid sorrel (Rumex tianschanicus × Rumex patientia) a high biomass yielding plant as an interesting object of physiological research

Hybrid sorrel (Rumex tianschanicus × Rumex patientia) a high biomass yielding plant as an interesting object of physiological research

Plant reactions as indicators of air pollution in the vicinity of a copper smelter

Several higher plant species and epiphytic lichen <em>Hypogymnia physodes</em> (L.) Nyl. were examined in the vicinity of a copper smelter. The investigations included field experiments. Ecological surveys of some biotests and bioreactions using exposure of higher plants and transplanted lichens were critically appraised. Such basic processes of plants as photosynthesis and respiration, as well as the quantitative composition of chlorophyll pigments were used as biotests. The results indicate that the photosynthesis intensity is the most useful measure for the estimation of the effect of both heavy metal and SO<sub>2</sub> pollutants. The degrees of chlorophyll degradation were in keeping with visual symptoms of injuries. For the ecological monitoring the measurement of respiration intensity, especially in lichens is not recommended. All applied biotests are presented in maps illustrating the degree of degradation of the area examined.

The pleiotropic effects of extract containing rhizobial Nod factors on pea growth and yield

AbstractRhizobial lipochitooligosacharides (Nod factors) influence the development of legume roots, including growth stimulation, nodule induction and root hair curling. However, their effect on the green parts of plants is less known, therefore we evaluated seed and foliar application of an extract containing Nod factors on pea growth and yield. Pea plants were examined from emergence to full maturity, including growth dynamics and morphological (nodule number and weight, the quantity and surface area of leaves) or physiological (photosynthesis and transpiration intensity, chlorophyll and nitrogen content) parameters. The foliar application Nod factor extract, or seed dressing followed by foliar application, resulted in the best outcomes. The number and weight of root nodules, the chlorophyll content in leaves, and the intensity of net photosynthesis were all elevated. As a consequence of Nod factor treatment, the dynamics of dry mass accumulation of pea organs were improved and the pod number was increased. A significant increase in pea yield was observed after Nod factor application. Increase of nodule and pod numbers and improved growth of roots appear to be amongst the beneficial effects of Nod factor extract on the activation of secondary plant meristems.

Effect of supplementary lighting on selected physiological parameters and yielding of tomato plants

ABSTRACT Light is one of the basic factors needed by plants for their development. The aim of this study was to measure the effect of supplementary lighting of tomato plants with HPS and LED lamps on the chosen physiological parameters and yielding of autumn-winter cultivation crops. Two tomato cultivars (‘Komeett’ F1 and ‘Starbuck’ F1 by De Ruiter Seeds) were used in this experiment. After the plants were planted, LED and HPS lamps of 100 μmol m-2 s-1 light intensity were installed. The results show that the introduction of a supplementary light source to tomato cultivation caused an increase in the intensity of photosynthesis, transpiration, stomatal conductance and chlorophyll by 57.7%, 17.1%, 39.3% and 24.4% on average, respectively. Higher values of those parameters were obtained with HPS lamps than with LED lamps. The amount of marketable crops, number of fruits and mean fruit weight were higher in both combinations in which supplementary lighting was applied, and the values of these traits were higher when the cultivation was supplementary lighted with HPS lamps than with LED lamps. Due to the overhead light configuration and continued low light output, there was no increase of efficiency when using LED lamps compared to HPS lamps despite better focusing and spectral distribution.

Wpływ równoczesnego żerowania różnych gatunków mszyc na intensywność fotosyntezy porzeczki czarnej i borówki wysokiej

The studies were conducted in the Department of Applied Entomology at Warsaw University of Life Sciences, in the field and laboratory conditions. The aim of this study was to determine the influence of aphids on the process of photosynthesis of blackcurrant cultivar Titania (attacked mainly by Aphis schneideri Börn.) and high bush blueberry cultivar Patriot (attacked by Myzus persicae Sulz and Aphis fabae Scop.). The chlorophyll content in the leaves was also estimated. The significant decrease of photosynthesis intensity was found in the leaves of blackcurrant and high bush blueberry as a result of aphid feeding, as compared to healthy ones, 32 and 27% respectively. The tendency for the increase of photosynthesis intensity in black currant leaves, not injured by aphids but originated from attacked shoots, in comparison with the leaves from healthy shoots, was observed. Chlorophyll content in the leaves of both experimental plants significantly decreased as a result of aphid feeding, especially in the case of black currant (decrease in chlorophyll a + b about 32%). Badania prowadzono w Katedrze Entomologii Stosowanej Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie, w warunkach polowych i laboratoryjnych. Celem ich było określenie szkodliwego wpływu mszyc na proces fotosyntezy porzeczki czarnej odmiany Titania (zaatakowana głównie przez Aphis schneideri Börn.) i borówki wysokiej odmiany Patriot (zaatakowanej przez Myzus persicae Sulz and Aphis fabae Scop.). Wykonano także analizę zawartości chlorofilu w liściach. Wykazano istotne ograniczenie intensywności fotosyntezy w uszkodzonych przez mszyce liściach porzeczki czarnej i borówki wysokiej w porównaniu z liśćmi zdrowymi, odpowiednio o 32 i 27%. Zaobserwowano tendencje do wzrostu intensywności fotosyntezy w liściach porzeczki nieuszkodzonych przez mszyce, lecz znajdujących się na uszkodzonym pędzie, w porównaniu do liści z pędów nieuszkodzonych. Zawartość chlorofilu w liściach obu badanych roślin istotnie zmniejszyła się w wyniku żerowania mszyc, szczególnie w przypadku porzeczki czarnej (spadek chlorofilu a + b o 32%).

Adaptive responses of photosynthesis in phytoplankton: specificity to time-scale of change in light

The relationship between photosynthesis and light intensity, as expressed by the P-I curve, is fundamental to models of primary production in the oceans. Adaptive responses of phytoplankton are man...