scholarly journals Ultrastructure of photosynthetic apparatus and pigment content of floating and submerged leaves of Nuphar lutea and Nymphaea alba

2015 ◽  
Vol 72 (5) ◽  
pp. 487-497
Author(s):  
O.M. Klymenko ◽  
2021 ◽  
Author(s):  
Vasyl Brykov ◽  
Оleksandr Polischuk ◽  
Оlena Bilous ◽  
Vladyslav Zhezherya ◽  
Ramilla Brykova ◽  
...  

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 744
Author(s):  
Petra Peharec Štefanić ◽  
Karla Košpić ◽  
Daniel Mark Lyons ◽  
Lara Jurković ◽  
Biljana Balen ◽  
...  

Silver nanoparticles (AgNPs) are the most exploited nanomaterial in agriculture and food production, and their release into the environment raises concern about their impact on plants. Since AgNPs are prone to biotransformation, various surface coatings are used to enhance their stability, which may modulate AgNP-imposed toxic effects. In this study, the impact of AgNPs stabilized with different coatings (citrate, polyvinylpyrrolidone (PVP), and cetyltrimethylammonium bromide (CTAB)) and AgNO3 on photosynthesis of tobacco plants as well as AgNP stability in exposure medium have been investigated. Obtained results revealed that AgNP-citrate induced the least effects on chlorophyll a fluorescence parameters and pigment content, which could be ascribed to their fast agglomeration in the exposure medium and consequently weak uptake. The impact of AgNP-PVP and AgNP-CTAB was more severe, inducing a deterioration of photosynthetic activity along with reduced pigment content and alterations in chloroplast ultrastructure, which could be correlated to their higher stability, elevated Ag accumulation, and surface charge. In conclusion, intrinsic properties of AgNP coatings affect their stability and bioavailability in the biological medium, thereby indirectly contributing changes in the photosynthetic apparatus. Moreover, AgNP treatments exhibited more severe inhibitory effects compared to AgNO3, which indicates that the impact on photosynthesis is dependent on the form of Ag.


2021 ◽  
Vol 12 (3) ◽  
pp. 7-16
Author(s):  
Z. Bilousova ◽  
◽  
V. Keneva ◽  
Y. Klipakova ◽  
◽  
...  

To obtain the maximum yield of winter wheat, it is necessary to further optimize the existing cultivation technologies in the direction of their adaptation to changing environmental conditions. One of the areas of adaptation of plants to adverse abiotic factors is the active functioning of the photosynthetic apparatus, which depends on the amount of nutrients introduced. The influence of fertilizer application on the condition of the pigment complex of winter wheat plants in the conditions of the Southern Steppe of Ukraine has been studied. Two varieties of winter wheat were selected for the study: Shestopalivka and Mason. The experiment scheme involved the application of fertilizers at sowing (K0; K12) and foliar treatment with various tank mixtures (urea; urea + magnesium sulfate; urea + magnesium sulfate + potassium monophosphate). The pigment content has been determined by grinding fresh leaves of winter wheat, followed by the addition of a solvent in the form of acetone. Measurements of pigments were performed using a spectrophotometer. According to the research results, it was established that before the foliar treatment the a-chlorophyll content and carotenoids was higher in the plant leaves of the Shestopalivka variety. At the same time, the b-chlorophyll content on the contrary was higher for plants of the Mason variety by 17%, which may be due to the adaptation of plants of this variety to lack of light. On the 3rd day after foliar treatment, a decrease in the pigment content in the plant leaves of all experimental variants has been observed, which was due to the active growth of the photosynthetic surface and a decrease in the total dry matter mass. There was no significant difference between the varieties of the content of photosynthetic pigments in this period. On the 10th day after foliar treatment, an increase in a- and b-chlorophyll content has been observed for both studied varieties, which may be the result of adaptation of the photosynthetic apparatus of winter wheat plants to lighting conditions. Foliar treatment of winter wheat plants with a tank mixture of urea with magnesium sulfate and potassium monophosphate contributed to a further increase in the content of a-chlorophyll by 12-23%, and b-chlorophyll by 5-37% depending on the variety compared to the control. The results of the research testify to the high efficiency of complex application of nitrogen-phosphorus-potassium fertilizers for foliar treatment of winter wheat plants in the BBCH 31 stage, both against the background of pre-sowing application of potassium fertilizers and without it.


PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3212 ◽  
Author(s):  
Peter F. Klok ◽  
Gerard van der Velde

Floating leaf blades of waterlilies fulfill several functions in wetland ecosystems by production, decomposition and turnover as well as exchange processes. Production and turnover rates of floating leaf blades of three waterlily species, Nuphar lutea (L.) Sm., Nymphaea alba L. and Nymphaea candida Presl, were studied in three freshwater bodies, differing in trophic status, pH and alkalinity. Length and percentages of leaf loss of marked leaf blades were measured weekly during the growing season. Area and biomass were calculated based on leaf length and were used to calculate the turnover rate of floating leaf blades. Seasonal changes in floating leaf production showed that values decreased in the order: Nymphaea alba, Nuphar lutea, Nymphaea candida. The highest production was reached for Nuphar lutea and Nymphaea alba in alkaline, eutrophic water bodies. The production per leaf was relatively high for both species in the acid water body. Nymphaea candida showed a very short vegetation period and low turnover rates. The ratio Total potential leaf biomass/Maximum potential leaf biomass (P/Bmax) of the three species ranged from 1.35–2.25. The ratio Vegetation period (Period with floating leaves)/Mean leaf life span ranged from 2.94–4.63, the ratio Growth period (Period with appearance of new floating leaves)/Vegetation period from 0.53–0.73. The clear differences between Nymphaea candida versus Nuphar lutea and Nymphaea alba, may be due to adaptations of Nymphaea candida to an Euro-Siberic climate with short-lasting summer conditions.


2009 ◽  
Vol 44 (7) ◽  
pp. 695-700 ◽  
Author(s):  
Antelmo Ralph Falqueto ◽  
Daniela Cassol ◽  
Ariano Martins de Magalhães Júnior ◽  
Antônio Costa de Oliveira ◽  
Marcos Antonio Bacarin

The objective of this work was to evaluate the physiological changes that occur in different leaves during the early and late grain-filling stages of two rice genotypes (Oryza sativa subsp. indica , BRS Pelota cultivar, and O. sativa subsp. japonica , BRS Firmeza cultivar), which present differences in grain yield potential. The plants were cultivated in greenhouse. Pigment content, chlorophyll fluorescence, electron transport and oxygen evolution rate were determined in the grain-filling stage, from the first to the forth leaf (top to bottom). Pigment content, photochemical efficiency of photosystem II and electron transport decreased significantly according to the position of leaves in 'BRS Pelota'. The BRS Firmeza cultivar shows higher pigment content and higher activity of the photosynthetic apparatus in comparison to 'BRS Pelota' during the grain-filling stage.


Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1469
Author(s):  
Martin A. Stefanov ◽  
Georgi D. Rashkov ◽  
Ekaterina K. Yotsova ◽  
Preslava B. Borisova ◽  
Anelia G. Dobrikova ◽  
...  

The impacts of different NaCl concentrations (0–250 mM) on the photosynthesis of new hybrid lines of maize (Zea mays L. Kerala) and sorghum (Sorghum bicolor L. Shamal) were investigated. Salt-induced changes in the functions of photosynthetic apparatus were assessed using chlorophyll a fluorescence (PAM and OJIP test) and P700 photooxidation. Greater differences between the studied species in response to salinization were observed at 150 mM and 200 mM NaCl. The data revealed the stronger influence of maize in comparison to sorghum on the amount of closed PSII centers (1-qp) and their efficiency (Φexc), as well as on the effective quantum yield of the photochemical energy conversion of PSII (ΦPSII). Changes in the effective antenna size of PSII (ABS/RC), the electron flux per active reaction center (REo/RC) and the electron transport flux further QA (ETo/RC) were also registered. These changes in primary PSII photochemistry influenced the electron transport rate (ETR) and photosynthetic rate (parameter RFd), with the impacts being stronger in maize than sorghum. Moreover, the lowering of the electron transport rate from QA to the PSI end electron acceptors (REo/RC) and the probability of their reduction (φRo) altered the PSI photochemical activity, which influenced photooxidation of P700 and its decay kinetics. The pigment content and stress markers of oxidative damage were also determined. The data revealed a better salt tolerance of sorghum than maize, associated with the structural alterations in the photosynthetic membranes and the stimulation of the cyclic electron flow around PSI at higher NaCl concentrations. The relationships between the decreased pigment content, increased levels of stress markers and different inhibition levels of the function of both photosystems are discussed.


Sign in / Sign up

Export Citation Format

Share Document