Wyniki wyszukiwania - Biblioteka Nauki

1

Simulations of Photosynthesis by a K-Subset Transforming System with Membrane

100%

Nishida T. Y.

Fundamenta Informaticae

|

2002

|

tom Vol. 49, nr 1-3

249-259

EN

By considering the inner regions of living cells' membranes, P systems with inner regions are introduced. Then, a new type of membrane computing systems are considered, called K-subset transforming systems with membranes, which can treat nonintegral multiplicities of objects. As an application, a K-subset transforming system is proposed in order to model the light reactions of the photosynthesis. The behaviour of such systems is simulated on a computer.

2

The Effects of the Growth Regulator Paclobutrazol on Physiological Characteristics of Rain Tree (Albizia saman Jacq. Merr.)

100%

Fathurrahman F. , Zahrah S. , Ernita , Heriyanto , Mahadi I.

Journal of Ecological Engineering

|

2023

|

tom Vol. 24, nr 12

346--355

EN

The increase of carbon dioxide (CO2) has been identified since the industrial revolution era. Albizia saman is a tree species which can absorb excess CO2 from the atmosphere in large quantities. This study was to identify the effect of spraying time and concentration of paclobutrazol on the growth of A. saman seedlings. This research using a completely randomized design, the first factor is spraying time which is divided into three levels: spraying at age of 25, 50 and 75 days. The second one is the concentration of paclobutrazol, consisting of four levels: control, 75, 150 and 225 mol•L-1. The further test used are DMRT at p<0.05. Paclobutrazol influences the higher rate of photosynthesis, namely 38.27 M CO2 m-2s-1. There are varied stomatal conductance values, where the highest value is 0.35 mM m-2s-1 and the lowest carbon dioxide content in treatment is 56.86 mol•L-1. The slowest transpiration rate is the combination of 50 days after treatment, and the concentration of paclobutrazol is 0.24 mM H2O m-2s-1. The shortest growth of A. saman is shown from the 50-day treatment using paclobutrazol and 150 mol•L-1 concentration. The relationship between photosynthetic rate and stomatal conductance and transpiration concludes that the trend is similar to that of the curve, whereas the trend is not the same as the internal CO2.

3

Resistance of mosses to drying, measured by the intensity of gas exchange and the content of malate and citrate

100%

Rzepka A. , Szarek W.

Annales Universitatis Paedagogicae Cracoviensis Studia Naturae

|

2021

|

tom 6

EN

Desiccation tolerance, the ability to lose virtually all of its free intracellular water and then restore normal function when rehydrated, is one of the most remarkable features of bryophytes. The aim of the study was to determine the resistance of two species of Plagiomnium undulatum (Hedw.) T.J.Kop. and Polytrichum commune Hedw. on drying to 50% relative water content of the air and rehydration. Changes in the intensity of photosynthesis and respiration as well as the content of malate and citrate in leafy moss stems were analysed. P. commune gametophores showed greater resistance to drought stress than P. undulatum. In both species, photosynthesis was much more sensitive to drought than respiration. Changes in the content of malate and citrate indicated a high plasticity of moss metabolism in conditions of water shortage and may be one of many important elements of the adaptation strategy to water deficit. The reactions of the tested mosses to dehydration and rehydration confirmed their adaptation to specific land conditions.

4

Upper Vistula River : response of aquatic communities to pollution and impoundment. 5, Photosynthetic and respiratory activity of seston

100%

Starzecka A. , Bednarz T.

Polish Journal of Ecology

|

2002

|

tom Vol. 50, nr 2

157-166

EN

From March 1997 to March 1998 the photosynthesis (PhS) and respiration of seston (Rs) and bacteria fraction (Rb) in the water of the Upper Vistula River on the section from 10.9 to 336.7 km of the river course were investigated. Methods applied: PhS - light and dark bottles, Rs - dark bottles, Rb - respiration of bacterial fraction, which was isolated by water filtration. The smallest mean yearly value of PhS (2.1-8.6 J dm^-3 24 h^-1) was found at 10.9 - 36.6 km of the river course and the greatest ones (40.4-42.7 J dm^-3 24 h^-1) at 248.2-336.7 km, in accordance with the size of the river. Rs was the smallest (23.9-28.7 J dm^-3 24 h^-1) between 10.9-45.7 km of the river course (on the rather clean sector) and decisively greater 51.6 J dm^-3 24 h^-1) at 115.6 km, at the most polluted sites. Along longitudinal profile of the Upper Vistula River Rb was equalized and ranged from 20.7 24.1 J dm^-3 24 h^-1, with the exception at 10.9 (spring clean part of the river, poor in seston) and 336.7 km of the river course, where it was 10-20% smaller. The last value might indicated the presence of organic matter easily avaiable to bacteria at this site. Rb constituted from 45 to 78% of seston Rs with the minimal value at 115.6 km of the river course (the most polluted) and its maximal participation at 10.9 km - clean part of the river, rather poor in seston.

5

Unique spectroscopic properties of synthetic 15-cis beta-carotene important in photosynthesis and medicine for photoprotective function

100%

Bialek-Bylka G. E. , Hala J. , Jazurek B. , Skrzypczak A.

Cellular and Molecular Biology Letters

|

2002

|

tom 07

|

nr Suppl.

6

CO2 balance in tomato production in a plastic tunnel of the Skierniewicki type

100%

Mydlarz J.

Folia Horticulturae

|

1997

|

tom 09

|

nr 1

7

What do plants do in winter?

88%

Wojtyla Ł. , Adamiec M. , Sobieszczuk-Nowicka E.

Edukacja Biologiczna i Środowiskowa

|

2014

|

nr 1

3-11

EN

Plants can be divided according to susceptibility to cold or frost resistance owing to their tolerance. In the temperate climate, most plants are tolerant of low temperatures and have evolved mechanisms which enable them to survive the winter and limit the negative effects. Gradual temperature drops and the gradual shortening of days in the autumn are extremely important in preparing the plant for the winter. Reduction of cell membrane fluidity and a decrease in efficiency of photosynthesis are the main mechanisms for plant perception of weather conditions. This perception stimulates the induction of processes to acquire tolerance to unfavourable conditions by modulating gene expression, the accumulation of specific proteins with cryo-protective properties and the synthesis of osmotically active and antioxidant compounds. Some species overwinter as dormant, whereas others called evergreens, maintain metabolic activity adjusted to the winter conditions.

8

Co rośliny robią nocą?

88%

Wojtyla Ł. , Adamiec M.

Edukacja Biologiczna i Środowiskowa

|

2013

|

nr 3

10-16

EN

Life on Earth is dependent on several factors. One of them is the light and the reactions taking place with his participation. With the reactions of photosynthesis solar energy is converted into energy of chemical bonds and in this form is transmitted from autotrophic organisms (the producers) to all organisms. The reactions of photosynthesis also produce oxygen, which is necessary for most of the organisms and used in the reactions of cellular respiration. Since plants produce energy and oxygen during the day, whether in this case the night is needed at all. And if so, what are plants doing at night? This paper describes the major physiological and biochemical processes that occur in plants under no access to light, both natural conditions (night) and in the case of artificial darkness. The answer to the question posed in the title is in the description of such processes as photosynthesis, cellular respiration, tropisms, control of the stomata opening/closing and regulation of flowering.

PL

Życie na Ziemi jest zależne od kilku czynników. Jednym z nich jest światło i reakcje zachodzące przy jego udziale. To dzięki reakcjom fotosyntezy energia promieniowania słonecznego zamieniana jest w energię wiązań chemicznych i w tej postaci przekazywana jest od organizmów autotroficznych, czyli producentów do wszystkich orga nizmów. W reakcjach fotosyntezy powstaje również tlen, który jest niezbędny dla większości organizmów i wykorzystywany w reakcjach oddychania komórkowego. Skoro rośliny produkują energię i tlen w dzień, to czy w takim razie noc jest im w ogóle potrzebna. A jeśli nawet tak, to co one robią w nocy? Praca ta opisuje najważniejsze procesy fizjologiczne i biochemiczne zachodzące w organizmach roślinnych przy braku dostępu do światła, zarówno w warunkach naturalnych (noc), jak i w sytuacji sztucznego zaciemnienia roślin. Odpowiedź na pytanie postawione w tytule pracy znajduje się w omówieniu m.in. takich procesów jak: fotosynteza, oddychanie komórkowe, ruchy roślin, regulacja otwierania/zamykania aparatów szparkowych i regulacja kwitnienia.

9

Impact of a Longwave UV-B Radiation on Soybean Plants Grown at Increased Nickel Concentration in Soil

88%

Skórska E. , Matuszak-Slamani R. , Romanowski H. , Szwarc W.

Journal of Ecological Engineering

|

2019

|

tom Vol. 20, nr 5

135--141

EN

Plants of soybean (Glycine max L.) cv. Augusta grew in the soil with addition of Ni in the concentration of 80 (C-80) or 120 mg∙kg-1 dry mass (C-120) or without Ni (C-0), and they were subjected to UV-B (300 nm – 315 nm) dose of 1.8 kJ m-2 d-1 for 28 days. The addition of nickel into soil in the concentration of 120 mg kg-1 (C-120) caused a decrease of the plant height by 35% compared to the control (C-0), and in the presence of UV-B (U-120) – by 43%. The shoot fresh and dry mass in the C-80 and C-120 plants were lower by 33% and 52% than in the C-0. In the presence of Ni, the intensity of net photosynthesis decreased by 55%. UV-B caused an increase of flavonoid content by 25% compared to the control (C-0), and Ni induced a reduction in the content of these compounds from 20% to 40%.

10

Detection of multi-nutrients deficiency in cereal plants by the use of chlorophyll fluorescence

88%

Jaszczuk Z. M. , Bąba W.

Journal of Water and Land Development

|

2023

|

tom no. 59

224--233

EN

Nutrient deficiency (ND) stands as a prominent environmental factor that significantly impacts global plant growth and productivity. While numerous methods have been employed for detecting nutrient deficiencies in plants, many of them are invasive, time-consuming, and costly. In contrast, chlorophyll fluorescence (ChlF) signals have emerged as a non-destructive tool for the identification of specific nutrient deficiencies, such as nitrogen (N), phosphorus (P), and potassium (K), across various plant species. In this pioneering study, ChlF measurements were employed for the first time to detect a combination of nutrient deficiencies, including deficiencies in nitrogen and phosphorus (-NP), nitrogen and potassium (-NK), potassium and phosphorus (-KP), and a complete NPK deficiency (-NPK). The experiment was conducted using wheat (Triticum aestivum) and maize (Zea mays) plants, which were grown under controlled laboratory conditions. An optimal hydroponic system was established to facilitate eight experimental conditions, namely: control, -N, -P, -K, -NP, -NK, -KP, and -NPK. Measurements were systematically collected at two-day intervals over a span of 24 days. Our findings demonstrate that chlorophyll fluorescence signals can enable the differentiation of various nutrient deficiencies even prior to the onset of observable symptoms. Furthermore, the examination of chlorophyll fluorescence parameters enables us not only to identify a singular macronutrient deficiency but also to detect multiple macronutrient deficiencies concurrently in a plant.

11

Hourly and daily variability in nitrogen and phosphorus in a lake restored by the hypolimnetic with drawal method

88%

Sieńska J. , Dunalska J. A. , Szymański D.

Oceanological and Hydrobiological Studies

|

2015

|

tom Vol. 44, No. 3

381--392

EN

An excess of nitrogen and phosphorus causes an increase in productivity, leading to degradation of a water reservoir. In order to reduce the eutrophication, protective and restoration methods are used. The objective of the paper was to determine the hourly and daily variability in nitrogen and phosphorus compounds in a lake restored by the hypolimnetic withdrawal method. In the epilimnion, the organic form dominates: 97% of Ptot and 75% of Ntot. Hourly variations in the concentration of the investigated compounds indicate that the highest values occurred at night and in the morning, whereas lower measurements were recorded at noon and in the evening. Such a distribution of the concentrations of nutrients during a day is strongly associated with photosynthesis. Along with depth, the proportion of this form decreased in favor of mineral forms. A high content of mineral phosphorus (70%) and ammonium ions (75%) in the hypolimnion results from their release from bottom sediments under anaerobic conditions. As a result of the generated thermocline, they are blocked and accumulated. At the experimental station, the concentration of mineral compounds was at a lower level than at the reference station since their amount was systematically reduced by the outflow of over-fertilized waters from the hypolimnion.

12

Formation of Yield and Grain Quality of Spring Barley Depending on Fertiliser Optimisation

88%

Mazur O. , Tkachuk O. , Mazur O. , Voloshyna O. , Tunko V. , Yakovets L.

Ecological Engineering & Environmental Technology

|

2024

|

tom Vol. 25, iss. 4

282--291

EN

In the current conditions of intensification of grain production, it is important to develop resource-saving cultivation technologies that ensure the maximum realisation of the genetic potential of crop varieties through the use of foliar fertilisation and mineral fertilisers. The article presents the results of research on the optimisation of fertilisation of spring barley plants. During the period of research, the influence of fertilisation and foliar feeding on the germination and preservation of spring barley plants, net photosynthetic productivity, elements of the yield structure, yield and grain quality was assessed. The research was conducted in the experimental field of Vinnytsia National Agrarian University during 2018–2020 on grey forest medium loamy soils. The hydrothermal conditions were quite contrasting and differed from the average perennial conditions both in terms of heat intensity and moisture level, which allowed to study the influence of the studied factors and their interaction on the formation of spring barley yield and grain quality. The maximum indicators of plant preservation, net productivity of photosynthesis, elements of crop structure, yield and grain quality were obtained in the experiment variant with the combined application of mineral fertiliser at a dose of N30P30K30 and foliar feeding of plants with Vuksal microfertiliser (BBCH 33-51) and (BBCH 51-54) in Aizhan and Aristey varieties. With the application of mineral fertiliser at a dose of N30P30K30, the grain yield of spring barley varieties Aizhan and Aristey increased by 0.99; 0.85 Mg·ha-1, and the protein content by 1.9; 2.0% compared to the control variant. With the combined application of mineral fertiliser at a dose of N30P30K30 and foliar feeding of plants with Vuksal microfertiliser, grain yield increased by 1.54; 1.23 Mg·ha-1 for one-time foliar feeding; by 1.77; 1.42 Mg·ha-1 for two-time foliar feeding, and protein content by 2.8; 2.7 and 3.4; 3.3% in Aizhan and Aristey varieties compared to the control variant, respectively.

13

Waterlogging tolerance: A review on regulative morpho-physiological homeostasis of crop plants

88%

Sharma S. , Sharma J. , Soni V. , Kalaji H. M. , Elsheery N. I.

Journal of Water and Land Development

|

2021

|

tom no. 49

16--28

EN

The natural environment is being drastically affected by climate change. Under these severe environmental conditions, the growth and productivity of agricultural crops have reduced. Due to unpredictable rainfall, crops growing in the field are often exposed to waterlogging. This leads to significant crop damage and production losses. In this review paper, the morphological and physiological adaptations such as development of aerenchyma, adventitious roots, radial root oxygen loss barrier, and changes in chlorophyll fluorescence parameters of crops under waterlogging are discussed. This will help to understand the effects of waterlogging on various crops and their adaptation that promotes crop growth and productivity. To meet the food requirements of a growing population, the development of waterlogging tolerant crops by screening and plant breeding methods is necessary for plant breeders. Better knowledge of physiological mechanisms in response to waterlogging will facilitate the development of techniques and methods to improve tolerance in crops.

14

Changes in dynamics of 14C incorporation and releaseby Antarctic marine diatoms in the presence of Lindane during subsequent light/dark periods

88%

Bystrzejewska G. , Łukowski A. , Ligowski R. , Bystrzejewska G. , Łukowski A. , Ligowski R.

|

15

Impact of water stress on physiological processes of moss Polytrichum piliferum Hedw.

88%

Romańska M.

Annales Universitatis Paedagogicae Cracoviensis Studia Naturae

|

2020

129-141

PL

Mchy są organizmami dogodnymi do badania reakcji na stres wodny, ponieważ nie posiadają epidermy, przez co odznaczają się większą wrażliwością na zmiany wilgotności niż większość innych roślin. Celem pracy było określenie wpływu stresu wodnego na przebieg procesów fizjologicznych mchów na przykładzie Polytrichum piliferum Hedw. Przeprowadzone badania pokazały, że działanie abiotycznego stresora, jakim jest woda, wpływa niekorzystnie na przebieg procesów fotosyntezy i oddychania, poprzez zmniejszenie ich natężenia. Jednak warto zaznaczyć, że proces oddychania jest w mniejszym stopniu uzależniony od uwodnienia tkanek niż proces fotosyntezy, co wyraźnie widać w przeprowadzonych tu badaniach. Za odporność mszaków na czynniki stresowe odpowiada zdolność rośliny do utrzymania homeostazy w czasie działania stresora. Również ważną rolę odgrywa zdolność zmiany homeostazy przez adaptację, przetrwanie albo pokonanie niekorzystnych warunków życiowych.

EN

Mosses are convenient organisms for studying the reaction to water stress because they do not have an epidermis, which makes them more sensitive to changes in humidity than most other plants. The aim of the study was to determine the effect of water stress on the course of physiological processes of mosses using Polytrichum piliferum Hedw. The present study showed that the action of the abiotic stressor, which is water, adversely affects the photosynthesis and dark respiration processes by reducing their intensity. However, it is worth noting that the respiration process is less dependent on tissue hydration than the photosynthesis, which is clearly demonstrated by the study results. The bryophytes’ resistance to stress factors is responsible for the plant’s ability to maintain homeostasis under stress conditions. The ability to change homeostasis by adapting, surviving or overcoming adverse living conditions also plays an important role.

16

Foliar application of pyraclostrobin alleviates oxidative stress and improves carbon assimilation in soybean

88%

Joshi-Paneri J. , Sharma S. , Guruprasad K. N.

Acta Agrobotanica

|

2023

|

tom 76

17

The influence of heavy metal ions on light-dependent proton uptake by thylakoids

88%

Polishchuk , Podorvanov V. V. , Zolotareva E. K.

Acta Physiologiae Plantarum

|

2007

|

tom 29

|

nr 1 Suppl.

18

Does melatonin improve the yield attributes of field-droughted banana under Egyptian semi-arid conditions?

88%

Hassan I. F. , Gaballah M. S. , Ogbaga C. C. , Murad S. A. , Brysiewicz A. , Bakr B. M. M. , Mira A. , Alam-Eldein S. M.

Journal of Water and Land Development

|

2022

|

tom no. 52

221--231

EN

Drought is regarded as one of the environmental constraints threatening agriculture worldwide. Melatonin is a pleiotropic molecule prevalent in plants capable of promoting plant endogenous resilience to many environmental challenges including drought. Banana is an important staple food consumed in developing countries especially in Africa. In this research, we studied the role of melatonin in the growth of bananas subjected to drought under the Egyptian semi-arid conditions. To achieve this objective, a field experiment on banana (Musa spp., cv. Williams) mother plants and first ratoon was conducted on a private farm for two seasons - 2019 and 2020. Three irrigation treatments, 100, 90 and 80% irrigation water requirements (IWR) were used in conjunction with four concentrations of melatonin as a foliar spray (0 μmol, 40 μmol, 60 μmol, and 80 μmol) to determine the effect of both treatments on banana plant performance under drought. The results showed that there was a substantial difference between treatments, with the foliar application of melatonin at 80 μmol concentration improving most of the yield attributes, relative water content, total chlorophyll and proline with water deficit. However, the foliar application of the molecule lowered the biochemical characteristics mostly at 80% IWR under the Egyptian semi-arid conditions. Overall, there was a concentration-dependent response with regards to IWR for the two seasons 2019 and 2020.

19

Effects of antitranspirants on water relations and photosynthetic rate of cultivated tropical plant (Polianthes tuberosa L.)

88%

Moftah A. , Al-Humaid A.

Polish Journal of Ecology

|

2005

|

tom Vol. 53, nr 2

165-175

EN

The effects of pinolene-base Vapor Gard (VG) emulsion type film and Kaolin, Surround (WP) particle type film antitranspirants on stomatal behavior, water status, carbon assimilation and transpiration rate of tuberose (Polianthes tuberosa L.) were stubied. The plants grown under the irrigation regimes of 100, 80 and 60% of total evapotranspiration (ET) values were investigated to select the most suitable antitranspirant for conserving irrigation water, used in cultivation of tuberose plants in arid regions. Severe water stress, decreased the stomatal frequency and conductance (gs), the leaf water potential (Ψw), the osmotic potential (Ψπ) and the turgor potential (Ψp), the relative water content (RWC), the chlorophyll content (chl), the carbon assimilation rate (A) and the transpiration rate (E). Both types of antitranspirants effectively enhanced the performance and physiological activities of water-stressed plants particularly at the 80% ET, but they did not compensate for the negative effects caused by the 60% ET treatment. However, the particle type, Kaolin, was more effective than the emulsion type, VG, due to its ability to reduce leaf temperature. The increased gs caused by VG and Kaolin sprays were accompanied by increased A suggesting that gs might have a limiting effect on A in water-stressed plants. Water use efficiency (WUE) of Kaolin-sprayed leaves was significantly higher than that of VG sprayed leaves. However, no significant differences between both antitranspirants on E were recorded. Increased WUE, therefore, could be attributed to a higher A by using Kaolin as compared with VG sprays. Thus, particle type antitranspirants are more effective in regulating water status, WUE and the photosynthetic activity of tuberose plants in arid regions.

20

Lamellar spacing of photosystem II membrane fragments upon dehydration studied by neutron membrane diffraction

88%

Pieper J. , Rusevich L. , Hauß T. , Renger G.

Optofluidics, Microfluidics and Nanofluidics

|

2015

|

tom 2

|

nr 1

EN

The effect of dehydration on the lamellar spacing of photosystem II (PS II) membrane fragments from spinach has been investigated using neutron membrane diffraction at room temperature. The diffraction data reveal a major peak at a scattering vector Q of 0.049 Å−1 at a relative humidity (r.h.) of 90% corresponding to a repeat distance D of about 129 Å. Upon dehydration to 44% r.h., this peak shifts to about 0.060 Å−1 corresponding to a distance of 104.7±2.5 Å. Within experimental error, the latter repeat distance remains almost the same at hydration levels below 44% r.h. indicating that most of the hydration water is removed. This result is consistent with the earlier finding that hydration-induced conformational protein motions in PS II membrane fragments are observed above 44% r.h. and correlated with the onset electron transfer in PS II (Pieper et al. 2008, Eur. Biophys. J. 37: 657–663).