scholarly journals The Combination of Increased Temperatures and High Irradiation Causes Changes in Photosynthetic Efficiency

Plants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2076
Author(s):  
Antonela Markulj Kulundžić ◽  
Marija Viljevac Vuletić ◽  
Maja Matoša Kočar ◽  
Anto Mijić ◽  
Ivana Varga ◽  
...  
Keyword(s):  
Water Availability ◽  
Photosynthetic Efficiency ◽  
Abiotic Factors ◽  
Photosynthetic Apparatus ◽  
Principal Component ◽  
Maximum Quantum Yield ◽  
Flowering Stage ◽  
Different Temperatures ◽  
Survival And Reproduction ◽  
High Irradiation

Global warming and the associated climate change are imposing abiotic stress on plants. Abiotic factors are crucial for plant productivity, survival, and reproduction. Eight sunflower hybrids were tested in conditions of different water availability and with combinations of different temperatures and irradiation. The changes in the photosynthetic efficiency were measured in the morning (control conditions: 2013, 25.8 °C and 349.1 W m−2; 2014, 21.8 °C and 296.4 W m−2) and afternoon (the combination of increased temperatures and high irradiation: 2013, 34 °C and 837.9 W m−2; 2014, 29.4 °C and 888.9 W m−2) at a flowering stage in rainfed or irrigated conditions. The measurement time (morning and afternoon conditions) had a statistically significant effect on all the tested parameters. The performance index (PIABS) in 2013 and the maximum quantum yield of photosystem II (TR0/ABS) in 2014 are the only parameters significantly affected by the irrigation. As a result of the combined effect of increased temperatures and high irradiation, PIABS values decreased by 73–92% in rainfed conditions and by 63–87% in irrigated conditions in 2013, depending on the hybrid, while in 2014, the decrease varied between 70 and 86%. The TR0/ABS decrease was 7–17% in 2013, depending on the hybrid, and 6–12% in 2014, both in rainfed and irrigated conditions. The principal component analysis confirmed the effect of the combination of increased temperatures and high irradiation on hybrids, sorting them exclusively according to the time of measurement. All investigated parameters highly fluctuated between hybrids but without observable trends for the morning and afternoon conditions, as well as for irrigation. Plants’ reaction to the combination of increased temperatures and high irradiation manifested as a change in their photosynthetic efficiency, i.e., the photosynthetic apparatus’ functioning was impaired.

scholarly journals Thermodynamic studies of substrate binding and spin transitions in human cytochrome P-450 3A4 expressed in yeast microsomes

1996 ◽  
Vol 319 (3) ◽  
pp. 675-681 ◽  
Author(s):  
Jean-Paul RENAUD ◽  
Dmitri R. DAVYDOV ◽  
Karel P. M. HEIRWEGH ◽  
Daniel MANSUY ◽  
Gaston HUI BON HOA
Keyword(s):  
Thermodynamic Parameters ◽  
Protein Interactions ◽  
Substrate Binding ◽  
Principal Component ◽  
Yeast Saccharomyces Cerevisiae ◽  
Human Cytochrome ◽  
Different Temperatures ◽  
Haem Protein ◽  
Cytochrome P 450 ◽  
Spin Transitions

An approach to the quantitative spectral analysis of substrate binding and inactivation of cytochrome P-450 in microsomes is described. The method is based on the application of the principal component analysis technique on the Soret-region spectra measured at different temperatures at various concentrations of substrate. This approach allowed us to study the thermodynamic parameters of substrate binding and spin transitions in human cytochrome P-450 3A4 expressed in yeast (Saccharomyces cerevisiae) microsomes. These parameters are discussed in comparison with the values reported earlier by Ristau et al. [(1979) Acta Biol. Med. Ger. 38, 177–185] for rabbit liver cytochrome P-450 2B4 in solution with benzphetamine as a substrate. Our analysis shows the substrate-free states of 2B4 and 3A4 to be very similar. However, substrate binding seems to perturb haem-protein interactions in 3A4 in contrast with 2B4, where the effect of substrate binding on the thermodynamic parameters of spin transitions was insignificant. The implication of the results for the mechanism of substrate-induced spin shift is discussed.

Temperature dependence of dipalmitoyl phosphatidylcholine monolayer stability

1981 ◽  
Vol 51 (5) ◽  
pp. 1108-1114 ◽  
Author(s):  
J. Goerke ◽  
J. Gonzales
Keyword(s):  
Phase Transition ◽  
Lung Surfactant ◽  
Principal Component ◽  
Water Interface ◽  
Dipalmitoyl Phosphatidylcholine ◽  
Phase Transition Temperatures ◽  
Air Water Interface ◽  
Different Temperatures ◽  
Monolayer Stability ◽  
Isolated Rat

Dipalmitoyl phosphatidylcholine is the principal component of lung surfactant, and knowledge of its behavior as a film spread at the air-water interface is essential for understanding how lung surfactant itself works. We therefore studied the collapse rates of very low surface tension air-water monolayers of dipalmitoyl, dimyristoyl, and palmitoyl-myristoyl phosphatidylcholines at different temperatures. In each case we found that the monolayers abruptly became unstable at temperature 3–4 degree C above their bulk lipid-water phase transition temperatures (Tc). This accords with a comparable increase in Tc occurring in bulk systems subjected to high pressure. These findings are also consistent with the behavior of isolated rat lungs, which have been found to require higher transmural pressures to maintain a given volume on deflation when kept at temperature above the Tc of dipalmitoyl phosphatidylcholine.

scholarly journals Leaf geometric morphometrics among populations of Dalbergia ecastaphyllum (L.) Taub.

2019 ◽  
Vol 35 (6) ◽  
Author(s):  
Daniel Vieira de Morais ◽  
Lorena Andrade Nunes ◽  
Vandira Pereira da Mata ◽  
Maria Angélica Pereira de Carvalho Costa ◽  
Geni da Silva Sodré ◽  
...  
Keyword(s):  
Principal Component Analysis ◽  
Geometric Morphometrics ◽  
Cross Validation ◽  
Abiotic Factors ◽  
Principal Component ◽  
Canonical Variate ◽  
Validation Test ◽  
Significant Difference ◽  
Variate Analysis ◽  
Geographical Distances

Leaves are plant structures that express important traits of the environment where they live. Leaf description has allowed identification of plant species as well as investigation of abiotic factors effects on their development, such as gases, light, temperature, and herbivory. This study described populations of Dalbergia ecastaphyllum through leaf geometric morphometrics in Brazil. We evaluated 200 leaves from four populations. The principal component analysis (PCA) showed that the first four principal components were responsible for 97.81% of variation. The non-parametric multivariate analysis of variance (NPMANOVA) indicated significant difference between samples (p = 0.0001). The Mentel test showed no correlation between geographical distances and shape. The canonical variate analysis (CVA) indicated that the first two variables were responsible for 96.77 % of total variation, while the cross-validation test showed an average of 83.33%. D. ecastaphyllum leaves are elliptical and ovate.

scholarly journals ROOT SYSTEM IN MAIZE PLANTS CULTIVATED UNDER WATER DEFICIT AND APPLICATION OF CHITOSAN

2020 ◽  
Vol 19 ◽  
pp. 11
Author(s):  
LORENA GABRIELA ALMEIDA ◽  
EDER MARCOS DA SILVA ◽  
PAULO CÉSAR MAGALHÃES ◽  
DÉCIO KARAM ◽  
CAROLINE OLIVEIRA DOS REIS ◽  
...  
Keyword(s):  
Plant Growth ◽  
Root System ◽  
Water Deficit ◽  
Water Availability ◽  
Agricultural Production ◽  
Negative Effects ◽  
Flowering Stage ◽  
Specific Behavior ◽  
Maize Plants ◽  
Corn Plants

Low water availability is characterized as an abiotic stressthat limits the agricultural production. Due to the physical and chemicalcharacteristics of the chitosan (CHT), this substance might stimulatephysiological responses on plants to tolerate the water deficit. In this sense,we submitted corn plants to water deficit and application of chitosan on theleaves (140 mg/L) during pre flowering stage. It were analyzed two cornhybrids genotypes contrasting for water deficit tolerance: DKB 390 (tolerant)and BRS1010 (sensitive). Then, we performed evaluations on the rootsystem and production components. Corn plants submitted to the applicationof chitosan presented a specific behavior: when compared the hybrids,the tolerant one presented a root system that was more developed and anexpressive agronomical yield. These results highlight the fact that the chitosanstimulates plant growth, enhancing their root system and contributing toincrease the availability and absorption of water and nutrients. The chitosanpresents a potential to reduce the negative effects of water deficit on the rootsystems, without compromising the agronomical yield.

scholarly journals Diversity and spatial distribution of black flies (Diptera: Simuliidae) in the Ijuí river drainage basin, Rio Grande do Sul, Brazil

2019 ◽  
Vol 12 (2) ◽  
pp. 47-56
Author(s):  
Tieli Cláudia Menzel ◽  
Sirlei Maria Hentges ◽  
David Augusto Reynalte Tataje ◽  
Milton Norberto Strieder
Keyword(s):  
River Basin ◽  
Indicator Species ◽  
Drainage Basin ◽  
Abiotic Factors ◽  
Principal Component ◽  
Rio Grande ◽  
Anthropogenic Pressure ◽  
Black Flies ◽  
Rio Grande Do Sul ◽  
Significant Difference

Abstract. In southern Brazil there are several problems regarding the hematophageal activity of black flies, and the information on the distribution of species are still insufficient. In this study, our main goals were to recognize Simuliidae species and to analyze abiotic factors regarding the distribution of immature stages (larva and pupa) in streams from the Ijuí River basin, Northwest of Rio Grande do Sul, Brazil. We sampled simulids specimens in 27 study sites, covering three regions (high, intermediate and low altitude). Concomitantly, we recorded abiotic factors in the studied sites, such as: temperature, electrical conductivity, dissolved oxygen, atmospheric pressure, pH, altitude and stream width. For data analysis, we performed Kruskal-Wallis, ANOVA, Principal Component Analysis (PCA), Analysis of Indicator Species and Canonical Correspondence (CCA). A total of 10 species of black Flies was recorded. Simulium pertinax Kollar, Simulium incrustatum Lutz and Simulium orbitale Lutz were the most frequent. There was no significant difference in richness and density of the species between the different regions studied, except for Simulium jujuyense Paterson & Shannon. The sampled environments were segregated according to the location within the basin, and only S. jujuyense was considered an indicator species of the upper region. These results can be explained by the homogeneous conditions of the Ijuí River basin, which have suffered anthropogenic pressure mainly due to agricultural activities, resulting in losses in local aquatic biodiversity. Also, it may indicate that the control must be conducted considering the basin as a whole, and not only as isolated stretches of the streams.Diversidade e distribuição espacial de borrachudos (Diptera: Simuliidae) na bacia hidrográfica do rio Ijuí, Rio Grande do Sul, BrasilResumo. No sul do Brasil existem problemas com atividade hematofágica de borrachudos e as informações referentes à distribuição das espécies ainda são insuficientes. O presente estudo visa reconhecer as espécies de Simuliidae e analisar fatores abióticos quanto a distribuição dos estágios imaturos (larva e pupa) em riachos da Bacia do Rio Ijuí, no Noroeste do Rio Grande do Sul, Brasil. Foram coletados simulídeos em 27 pontos de estudo, cobrindo três regiões da bacia (alta, intermediária e baixa altitude). Concomitantemente, foi feito o registro de fatores abióticos nos trechos estudados, tais como: temperatura, condutividade elétrica, oxigênio dissolvido, pressão atmosférica, pH, altitude e largura do riacho. Foram realizadas análises de Kruskal-Wallis ou ANOVA, Análise de Componentes Principais (PCA), Análise de Espécie Indicadora e de Correspondência Canônica (CCA). Foi registrado um total de 10 espécies de Simuliidae. Simulium pertinax Kollar, Simulium incrustatum Lutz e Simulium orbitale Lutz foram as mais frequentes. Não ocorreu diferença na riqueza e na densidade das espécies entre as diferentes regiões estudadas, exceto para Simulium jujuyense Paterson & Shannon. Os ambientes nos pontos de amostragem foram segregados de acordo com a sua localização na bacia, e apenas S. jujuyense foi considerada uma espécie indicadora da região alta. Tais resultados podem ser explicados pelas condições homogêneas da Bacia do Rio Ijuí, que vêm sofrendo pressão antropogênica principalmente devido às atividades agrícolas, resultando em perdas na biodiversidade aquática local. Também, indicam que o controle deve ser realizado considerando a bacia como um todo e não apenas em trechos isolados dos riachos.

Thermal influence on the embryonic development and hatching rate of the flameback pygmy angelfish Centropyge aurantonotus eggs

Zygote ◽  
2019 ◽  
Vol 28 (1) ◽  
pp. 80-82
Author(s):  
Raoani Cruz Mendonça ◽  
Sarah Pittigliani Ikebata ◽  
Sérgio Leandro Araújo-Silva ◽  
João Vitor Azevedo Manhães ◽  
Mônica Yumi Tsuzuki
Keyword(s):  
Embryonic Development ◽  
Incubation Temperature ◽  
Abiotic Factors ◽  
Environmental Parameters ◽  
Hatching Rate ◽  
Influence Of Temperature ◽  
Different Temperatures ◽  
Influence Of Temperature On ◽  
Thermal Influence ◽  
Hatching Rates

SummaryThe flameback pygmy angelfish Centropyge aurantonotus, highly appreciated and valued by the aquarium market, is heavily harvested and traded. Temperature is one of the abiotic factors that has the most influence on fish development, especially in the early stages of life. For captive production, it is essential to know the appropriate environmental parameters for each species. In this sense, this study aimed to evaluate the influence of temperature on the embryonic development and hatching rates of C. aurantonotus incubated at six different temperatures (20, 22, 24, 26, 28, 30°C). Embryonic development events were very similar in terms of morphological and chronological characteristics compared with other species of the genus Centropyge. Incubation time was inversely proportional to temperature. The treatment at 22°C required twice the time of that required by 30°C treatment for hatching to occur. The best incubation temperature range was 24–28°C. Values below 22°C and at 30°C showed lower hatching rates compared with other treatments. Based on these results, the recommended temperature at which to incubate C. aurantonotus eggs is between 24–28°C.

scholarly journals Performance of Three Isolates of Metarhizium Anisopliae and Their Virulence against Zeugodacus Cucurbitae under Different Temperature Regimes, with Global Extrapolation of Their Efficiency

Insects ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 270 ◽  
Author(s):  
Susan K. Onsongo ◽  
Bernard M. Gichimu ◽  
Komivi S. Akutse ◽  
Thomas Dubois ◽  
Samira A. Mohamed
Keyword(s):  
Metarhizium Anisopliae ◽  
Abiotic Factors ◽  
Quadratic Model ◽  
Percentage Mortality ◽  
Melon Fly ◽  
Temperature Regimes ◽  
Global Mapping ◽  
Different Temperatures ◽  
Data Layer ◽  
The Tropics

The performance of entomopathogenic fungi in pest control is usually affected by both biotic and abiotic factors. This study aimed to determine the effects of various temperatures (15, 20, 25 and 30 °C) on conidial germination, mycelial growth and conidial density and virulence to the melon fly Zeugodacus cucurbitae of three selected isolates of Metarhizium anisopliae. The three isolates, ICIPE 18, ICIPE 30 and ICIPE 69, had previously been selected in laboratory bioassays. Percentage mortality by the three isolates ranged between 16.25% and 100.0% across the different temperatures. The isolates ICIPE 69 and ICIPE 18 recorded the highest percentage mortality of 96.25% and 100% and the shortest LT50 values of 2.61 and 2.63 days, respectively, at 30 °C. However, at 30 °C, ICIPE 69 produced the highest number of conidia of 90.5 × 107 /mL and was therefore selected for global mapping to predict its efficacy against Z. cucurbitae using the geospatial temperature data layer and the best fitted quadratic model. The map showed that the isolate would be more effective in the tropics than in temperate climates.

Paracetamol mediated changes modifies the photosynthetic efficiency of Vigna radiata

2018 ◽  
Author(s):  
Mohammed Abdul Rahman Al-Muwayhi
Keyword(s):  
Vigna Radiata ◽  
Photosynthetic Efficiency ◽  
Leaf Gas Exchange ◽  
Germination Rate ◽  
Carbon Dioxide Concentration ◽  
Maximum Quantum Yield ◽  
Ps Ii ◽  
Vigna Radiate ◽  
Dual Response ◽  
Use Efficiency

In our previous study, we observed that paracetamol (panadol) influences the germination rate and growth biomarker of the Vigna radiate plants. To dissect out the paracetamol mediated changes in this study was undertaken. For this study, 10 days old seedling of Vigna radiata exposed to range of pandol concentration (.005, .01, .1, or 1.0 mg/L) through foliage of plants and harvested at 31st day. Obtained data revealed the dual response of panadol concentration: 0.1 mg/L of panadol significantly increased chlorophyll and leaf gas exchange traits (net photosynthetic rate, stomatal conductance, internal carbon dioxide concentration, water use efficiency and maximum quantum yield of PS II), whereas, 1.0 mg/L of panadol significantly reduced the above parameters. It is therefore concluded that low level of panadol enhanced photosynthetic efficiency of Vigna radiata plants; however, the response is concentration dependent and could be used as growth regulators for Vigna radiata plants.

Reflectance indices as nondestructive indicators of the physiological status of Ceratonia siliqua seedlings under varying moisture and temperature regimes

2012 ◽  
Vol 39 (7) ◽  
pp. 588 ◽  
Author(s):  
Júlio Osório ◽  
Maria Leonor Osório ◽  
Anabela Romano
Keyword(s):  
Water Availability ◽  
Spectral Reflectance ◽  
Water Status ◽  
Chlorophyll Concentration ◽  
Photochemical Efficiency ◽  
Principal Component ◽  
Physiological Status ◽  
Total Chlorophyll ◽  
Ceratonia Siliqua ◽  
Reflectance Indices

We investigated the use of spectral reflectance techniques to monitor the physiological responses of Ceratonia siliqua L. seedlings exposed to different levels of water availability under normal (25 : 18°C, day : night) and elevated (32 : 21°C, day : night) temperatures. Three spectral reflectance indices (photochemical reflectance index, PRI; water index, WI; red edge position, REP) were measured along with water status, chlorophyll fluorescence and chlorophyll concentration variables in the leaves of well watered, moderately stressed, severely stressed and rehydrated plants under each temperature regime. The PSII effective photochemical efficiency (φ2) and the intrinsic efficiency of open PSII centres (F′v/F′m) correlated significantly with PRI, and these three variables loaded heavily onto the same principal component of a three-factor principal component analysis solution. Water concentration (WC) and the succulence index (SI) were more strongly correlated with WI than either water potential (ΨPD) or relative water content (RWC). Accordingly, WI, WC and SI were combined in the second principal component, and ΨPD and RWC in the third. Our results provide clear evidence for interaction between water availability and temperature in the WI and the PRI response segments of the reflectance curves. Elevated temperature inhibited the recovery of WI spectral segments more than that of the PRI segments in SS plants. REP showed a strongly positive linear relationship with leaf total chlorophyll concentration across all water and temperature treatment combinations. PRI, WI and REP are therefore reliable markers that can be used to monitor φ2, WC and total chlorophyll concentration, respectively, in C. siliqua seedlings under drought and temperature stress.

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