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1

Influence of ACC-ase herbicides on selected parameters of chlorophyll a fluorescence of resistant and susceptible wild oat (Avena fatua L.)

100%
Stoklosa A.
Acta Physiologiae Plantarum
|
2007
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tom 29
|
nr 1 Suppl.
2

The acceptor side of photosystem II is damaged more severely than the donor side of photosystem II in ‘Honeycrisp’ apple leaves with zonal chlorosis

84%
Chen L.-S., Cheng L.
Acta Physiologiae Plantarum
|
2010
|
tom 32
|
nr 2
To investigate the photoinhibition of photosynthesis in ‘Honeycrisp’ apple (Malus domestica Borkh. cv. Gala) leaves with zonal chlorosis, we compared pigments, CO₂ assimilation and chlorophyll (Chl) a fluorescence (OJIP) transient between chlorotic leaves and normal ones. Chl and carotenoids (Car) contents, Chl a/b ratio, and absorptance were lower in chlorotic leaves than in normal ones, whereas Car/Chl ratio was higher in the former. Although CO₂ assimilation and stomatal conductance were lower in chlorotic leaves, intercellular CO₂ concentration did not differ significantly between the two leaf types. Compared with normal leaves, chlorotic ones had increased deactivation of oxygen-evolving complexes (OEC), minimum fluorescence (Fₒ), dissipated energy, relative variable fluorescence at L-, W-, J- and I-steps, and decreased maximum fluorescence (Fm), maximum quantum yield for primary photochemistry (Fv/Fm or φRₒ/ABS), quantum yield for electron transport (ETₒ/ABS), quantum yield for the reduction of end acceptors of photosystem I (PSI) (uRo and REₒ/ABS), maximum amplitude of IP phase, amount of active photosystem II (PSII) reaction centers (RCs) per cross section (CS) and total performance index (PItot,abs). In conclusion, photoinhibition occurs at both the donor (i.e., the OEC) and the acceptor sides of PSII in chlorotic leaves. The acceptor side is damaged more severely than the donor side, which possibly is the consequence of over-reduction of PSII due to the slowdown of Calvin cycle. In addition to decreasing light absorptance by lowering Chl level, energy dissipation is enhanced to protect chlorotic leaves from photo-oxidative damage.
3
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The role of PsbS and chloroplast retrograde signaling in regulation of various Darwinian fitness traits in Arabidopsis

84%
Karpinski S. M.
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
|
2013
|
tom 94
|
nr 3
4

Preliminary assessment of antitranspirant Vapor Gard influence on Actinidia arguta growing under drought stress conditions

84%
Latocha P., Ciechocinska M., Pietkiewicz S., Kalaji M.
Annals of Warsaw University of Life Sciences - SGGW. Horticulture and Landscape Architecture
|
2009
|
tom 30
5

The effect of drought stress on chlorophyll fluorescence in Lolium-Festuca hybrids

84%
Koscielniak J., Filek W., Biesaga-Koscielniak J.
Acta Physiologiae Plantarum
|
2006
|
tom 28
|
nr 2
The effects of drought on photochemical efficiency of PSII in leaves of 22 hybrids of Festuca pratensis xLolium multiflorum and Festuca pratensis x Loliumperenne and of Festuca pratensis cv. Skra were investigated. A significant decrease of electron transport efficiency (about 25 %) in PSII (FPSII) was not found before 9 days of seedling growth in hydroponics with water potential (Yw) equal to-0.8 MPa (simulated “soil drought”). The decrease of FPSII was similarly related to that of exciialion energy capiure by open PSII reaction centre (Fv’/Fm’) and also to the decrease of the proportion of oxidized to reduced QA (photochemical fluorescence quenching, qp). According to the drought prolongation, variation of all parameters of fluorescence between genotypes significantly increased. The seedlings of some genotypes were able to recover electron transport efficiency in PSII after increasing water potential in nutrient solution (removing the “soil drought”). When plants grew in containers with soil and 4 genotypes with the highest sensitivity of electron transport to drought (S) as well as 4 genotypes with the highest tolerance (T) were compared 17 days after watering ceased, Yw in leaves considerably decreased, but the differences between S and T genotypes were often not significant in this respect. The differences between S and T genotypes, as values of Fv/Fm were concerned, also appeared small (about 5 %), similarly as that of Fv’/Fm’ (5 %), qp (12 %) and FPSII (about 15 %). Drought stress increased non-photochemical quenching of chlorophyll fluorescence (NPQ) 15to47% and this could protect the PSII reaction centres from damages because of energy excess. The increase of NPQ was not closely connected with drought resistance of plants because it was similar in some genotypes tolerant to dehydration as well as in sensitive ones. The results of the experiments suggest that resources of genetic variability in Festulolium may be sufficient for revealing differences between genoiypes on the basis of measurement of chlorophyll a fluorescence, as far as their tolerance to soil drought is concerned. As the tolerance of PSII against drought is high, the determinations of fluorescence should be peri formed rather under severe stress. Such methods seem to be useful for selection of genotypes with high drought tolerance as well as with the ability to at least partial repairing of PSII after drought.
6

Effect of inoculation with Hebeloma crustuliniforme on changes in water potential, chlorophyll content and fluorescence in leaves of poplar (Populus ssp.) cultivars differing in age

67%
Grzesiak M. T., Wojciechowska B., Hura T.
Zeszyty Problemowe Postępów Nauk Rolniczych
|
2010
|
tom 545
In this experiment a few physiological characters were measured in order to show differences in leaf water potential (Ψ), chlorophyll content (SPAD) and chlorophyll a fluorescence (F0, FM, FV, FV/FM) between leaves differing in age of 3 poplar cultivars inoculated with H. crustuliniforme. In control plants (non-inoculated) differences in water potential and chlorophyll fluorescence parameters between the examined cultivars were slight. Statistically significant differences in water potential and chlorophyll content between non-inoculated and inoculated plants were observed only for young leaves from the upper parts of the plant stem. Similarly, significant differences between treatments in initial fluorescence (F0), maximal fluorescence (FM) and in variable fluorescence (FV) were found in leaves from the middle and upper part of the plant stem. The obtained results indicated that for leaves from the upper, median and lower part of the plant stem significant differences between treatments in maximum quantum yield of PS2 (FV/FM) in leaves from different plant parts in P. petrowskayana were not observed and in P. deltoides cv. Plantierens and P. balsamifera only for leaves from the upper parts of the plant stem. Although those differences between inoculated and non-inoculated plants were relatively small, we may presume, that if they occur through a longer period they may become more distinct causing positive changes in leaves. In conclusion, it is necessary to саrrу out future studies on the mechanism by which the EMC symbiosis influences leaf physiological traits.
7
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Effect of road de-icing salts with anti corrosion agents on selected plant species

67%
Wrochna M., Malecka-Przybysz M., Gawronska H.
Acta Scientiarum Polonorum. Hortorum Cultus
|
2010
|
tom 09
|
nr 4
The effect of CaCl2 and NaCl with anti-corrosion additives (ammonium phosphate and sodium hypochlorite in amount of 3 to 5% of preparation weight), protected by Polish patent no. 198058, applied in concentrations of 4, 8 and 12 g dm-3 on germination and seedling vigour of Lolium perenne L. cv. Solen and Festuca rubra L. cv. Nimba was evaluated. Other studied parameters were: chlorophyll content, chlophyll a fluorescence and biomass accumulation in Canna × generalis, Rosa rugosa L. and Lolium perenne L. under the influence of the above mentioned substances. It was found that application of de-icing substances delayed and reduced germination of grass seedlings and declined root growth. Red fescue was less tolerant for increased salinity in soil than perennial ryegrass. Application of de-icing substances on rugosa rose, canna lilly and perennial ryegrass plants led to decrease of chlorophyll content, potential photochemical efficiency, performance index and biomass accumulation. Without anticorrosion agents the least toxic was calcium chloride and the most sodium chloride. Additives to de-icing road salts, in general, decreased NaCl toxicity and increased toxicity of CaCl2.
8
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Acclimatization of European beech (Fagus sylvatica L.) leaves first year after planting into different light conditions of young spruce stand

67%
Spulak O.
Folia Forestalia Polonica. Series A . Forestry
|
2011
|
tom 53
|
nr 2
The study presents the results of investigation on reaction of beech (Fagus sylvatica L.) leaves observed next year after planting seedlings in different positions in a young spruce stand located in upper mountain conditions. The methods of chemical analyses and assessments of chlorophyll fluorescence were applied with the aim to evaluate a course of leaf adaptation. In the young spruce stand located in the Karkonoše Mts, bare root beech seedlings after cultivation in full light were planted into three main positions to spruce trees (under the crown, within crown perimeter and in stand gaps). Next year after planting, the total biomass, leaf nutrient content and chlorophyll fluorescence parameters were evaluated. The beech trees planted under spruce (Picea sp.) crowns had significantly lower specific leaf mass and the mean leaf area was decreasing from shade to sun. Differences in nutrient contents were not significant between the treatments. We found significantly higher values of minimal (F0) and the maximum fluorescence (Fm) as well as of the maximum quantum yield of PSII photochemistry (Fv/Fm) in the leaves of beeches growing under the spruce crown. Significant differences among treatments were found also in the courses of the values of maximum fluorescence yield Y(II) and nonphotochemical quenching (NPQ). Our study indicated that bud forming processes are only partially responsible for physiological properties of beech leaves evaluated next year after planting. Photosynthetic performance is also influenced by actual growing conditions. A great part of acclimation occurs already in the first year after planting (change of the light conditions). We speculate that this phase of gradual acclimation of the assimilation apparatus can be one of the reasons of physiological weakening of the plant after planting to different light environment.
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