Coloured Components of Chloroplast Membranes as Intrinsic Membrane Probes for Monitoring the Development of Heat Injury in Intact Tissues

1979 ◽  
Vol 6 (1) ◽  
pp. 121 ◽  
Author(s):  
RM Smillie
Keyword(s):  
Chlorophyll Fluorescence ◽  
Photosystem 2 ◽  
Leaf Tissue ◽  
Proton Pumping ◽  
Cytochrome F ◽  
Heat Sensitivity ◽  
Heat Injury ◽  
Chloroplast Membrane ◽  
Photosystem 2 Activity ◽  
Membrane Probes

Assays for heat injury in intact leaves were investigated by heating leaf tissue at a rate of 1°C per minute and recording changes in chlorophyll fluorescence; chlorophyll absorbance; light-induced absorbance change at 518 nm of the bulk chloroplast pigments (chlorophylls and carotenoids); and photooxidation of chloroplast cytochrome-554 (cytochrome f ). Leaves of the golden passionfruit (Passiflora edulis forma flavicarpa were used as the experimental material. Heat injury to the chloroplast thylakoid membranes began above 35°C as evidenced by abnormal changes in chlorophyll fluorescence and absorbance and inactivation of chloroplast membrane activities. Chlorophyll fluorescence increased and chlorophyll absorbance decreased above 35°C and the increase and decrease, respectively, were greatest at 52°C. The measurements made on intact leaf tissue together with assays of photosystem 2 activity in isolated chloroplasts indicated the relative thermostabilities of several chloroplast membrane activities. Inactivation of photosystem 2 activity linked to oxygen evolution appeared to be associated with membrane changes occurring between 35 and 44°C. The 518-nm absorbance changes indicated that energy-dependent proton pumping and associated reactions were inactivated between 44 and 48°C. Photosystem-1-mediated photooxidation of cytochrome-554 became inactivated between 48 and 52°C. These studies demonstrate that chlorophylls, carotenoids and cytochrome f may be used as intrinsic membrane probes for monitoring the development of heat injury in the chloroplast membrane system. The absorbance and fluorescence changes that these compounds undergo upon heating provide a basis for reliable and rapid methods applicable to intact tissue for determining heat sensitivity in green plants.

scholarly journals The photochemical activities and electron carriers of developing barley leaves

1973 ◽  
Vol 136 (3) ◽  
pp. 803-812 ◽  
Author(s):  
Marijana Plesničar ◽  
Derek S. Bendall
Keyword(s):  
Cytochrome B ◽  
Photosystem 2 ◽  
Cytochrome F ◽  
Reaction Centre ◽  
Photosystem 1 ◽  
Photochemical Activities ◽  
Cyclic Photophosphorylation ◽  
Photosystem 2 Activity ◽  
Barley Leaves ◽  
Electron Carriers

The development of photochemical activities in isolated barley plastids during illumination of dark-grown plants has been studied and compared with the behaviour of plastocyanin, cytochromes f, b-559LP, b-563 and b-559HP and pigments P546 (C550) and P700. Electron-transport activity dependent on Photosystem 1 and cyclic photophosphorylation dependent on N-methylphenazonium methosulphate (phenazine methosulphate) were very active relative to the chlorophyll content after only a few minutes of illumination of etiolated leaves, and then rapidly declined during the first few hours of greening. By contrast, Photosystem 2 activity (measured with ferricyanide as electron acceptor) and non-cyclic photophosphorylation were not detectable during the first 2½h of greening, but then increased in total amount in parallel with chlorophyll. The behaviour of the electron carriers suggested their association with either Photosystem 1 or 2 respectively. In the first group were plastocyanin, cytochrome f and cytochrome b-563, whose concentrations in the leaf did not change during greening, and cytochrome b-559LP whose concentration fell to one-half its original value, and in the second group were cytochrome b-559HP and pigment P546, the concentrations of which closely followed the activities of Photosystem 2. Pigment P700 could not be detected during the first hour, during which time some other form of chlorophyll may take its place in the reaction centre of Photosystem 1. The plastids started to develop grana at about the time that Photosystem 2 activity became detectable.

scholarly journals Exploring Morpho-Physiological Variation for Heat Stress Tolerance in Tomato

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 347
Author(s):  
Samikshya Bhattarai ◽  
Joshua Harvey ◽  
Desire Djidonou ◽  
Daniel Leskovar
Keyword(s):  
Heat Stress ◽  
Chlorophyll Fluorescence ◽  
Open Field ◽  
Electrolyte Leakage ◽  
Leaf Gas Exchange ◽  
Total Yield ◽  
Stress Conditions ◽  
Heat Injury ◽  
Injury Index ◽  
Heat Tolerant

Texas tomato production is vulnerable to extreme heat in the spring-summer cropping period, which is exacerbated by the lack of superior genetic materials that can perform well in such environments. There is a dire need for selecting superior varieties that can adapt to warm environments and exhibit high yield stability under heat stress conditions. This research aimed at identifying heat-tolerant varieties under heat-stress conditions in controlled and open-field environments and was carried out in three stages. For the first experiment, 43 varieties were screened based on yield responses in natural open-field environment. From those, 18 varieties were chosen and exposed to control (greenhouse: 26/20 °C) and constant heat-stress (growth-chamber: 34/24 °C) conditions for three months. Measurements were done for chlorophyll fluorescence, chlorophyll content (SPAD), plant height, stem diameter and heat injury index (HII). The last experiment was conducted in an open field with a pool of varieties selected from the first and second experiments. Leaf gas exchange, leaf temperature, chlorophyll fluorescence, SPAD value, electrolyte leakage, heat injury index and yield were assessed. From the combined studies, we concluded that heat-tolerant genotypes selected by using chlorophyll fluorescence and HII in controlled heat-stress conditions also exhibited heat-tolerance in open-field environments. Electrolyte leakage and HII best distinguished tomato varieties in open-field environments as plants with low electrolyte leakage and HII had higher total yield. 'Heat Master,' 'New Girl,' 'HM-1823,' 'Rally,' 'Valley Girl,' 'Celebrity,' and 'Tribeca' were identified as high heat-tolerant varieties. Through trait correlation analysis we provide a better understanding of which traits could be useful for screening and breeding other heat-tolerant tomato varieties.

Changes in photosystem 2 activity associated with plant tolerance to lead

1981 ◽  
Vol 21 (3) ◽  
pp. 269-274 ◽  
Author(s):  
J.R. Homer ◽  
R. Cotton ◽  
E.H. Evans
Keyword(s):  
Photosystem 2 ◽  
Plant Tolerance ◽  
Photosystem 2 Activity

A biosensor for triazine herbicides based on chlorophyll fluorescence in photosystem 2

1992 ◽  
pp. 550 ◽  
Author(s):  
D.A. Moss ◽  
S. Brauer ◽  
J. Reichert ◽  
W. Mäntele ◽  
H.J. Ache
Keyword(s):  
Chlorophyll Fluorescence ◽  
Photosystem 2 ◽  
Triazine Herbicides

Contribution of Chlorophyll Fluorescence to the Reflectance of Leaves in Stressed Plants as Determined with the VIRAF-Spectrometer

1999 ◽  
Vol 54 (9-10) ◽  
pp. 849-857 ◽  
Author(s):  
Claus Buschmann ◽  
Hartmut K. Lichtenthaler
Keyword(s):  
Chlorophyll Fluorescence ◽  
Early Detection ◽  
Inflection Point ◽  
Photosynthetic Activity ◽  
Leaf Tissue ◽  
Blue Shift ◽  
Tissue Structure ◽  
Red Edge ◽  
Chl Fluorescence ◽  
Bean Leaves

Reflectance spectra allow the early detection of stressors causing differences in pigment content as well as changes of leaf tissue structure and photosynthetic activity. The reflectance decreased with increasing Chl content in greening bean leaves. In stressed leaves, in turn, the reflectance increased with decreasing Chl content. This also caused a shift of the red reflection rise (“red edge”) to shorter wavelengths (“blue shift”) associated with a blue shift of the inflection point of the red edge. The contribution of the red and far-red Chl fluorescence to the reflectance signal at the red edge of the spectrum and the shift of the wavelength position of the inflection point are demonstrated and discussed

scholarly journals Assessment of Freezing Injury in Palm Species by Chlorophyll Fluorescence

HortScience ◽  
2010 ◽  
Vol 45 (5) ◽  
pp. 845-848 ◽  
Author(s):  
María A. Equiza ◽  
David A. Francko
Keyword(s):  
Chlorophyll Fluorescence ◽  
Leaf Tissue ◽  
Freezing Injury ◽  
Strong Positive Correlation ◽  
Injury Index ◽  
Sabal Palmetto ◽  
Palm Species ◽  
Repeated Freezing ◽  
Landscape Value ◽  
Washingtonia Filifera

Freezing temperatures present major constraints for palm cultivation in temperate regions. As a result of their landscape value, there is a constant need for appropriate species and cultivars for freeze-prone areas. The objective of the present study was to evaluate the suitability of the chlorophyll fluorescence technique for quantitative assessment of freezing injury in palms. Five palm species known to differ in their freezing tolerance were selected: Copernicia alba, Washingtonia filifera, Sabal palmetto, Trachycarpus fortunei, and Rhapidophyllum hystrix. Leaf segments were frozen at –5, –10, –15, and –20 °C for 1 h. Repeated freezing–thawing cycles were additionally performed in young and older leaves of R. hystrix. Depending on the species and temperature, significant differences in the ratio of variable-to-maximal fluorescence (Fv/Fm) were detected 3 h after the freezing treatment, whereas visual symptoms appeared after 24 h. A strong positive correlation (r2 = 0.94) was found between the injury index calculated from Fv/Fm values and the index of injury based on the electrolyte leakage technique. Although both indices provided similar information, the nondestructive chlorophyll fluorescence method allows monitoring the progression of damage as well as the eventual recovery taking place in the leaf tissue after freezing.

Alteration of Atrazine Uptake and Metabolism by Tridiphane in Giant Foxtail (Setaria faberi) and Corn (Zea mays)

Weed Science ◽  
1986 ◽  
Vol 34 (6) ◽  
pp. 850-858 ◽  
Author(s):  
Rick A. Boydston ◽  
Fred W. Slife
Keyword(s):  
Zea Mays ◽  
Chlorophyll Fluorescence ◽  
Specific Activity ◽  
Reduced Glutathione ◽  
Leaf Tissue ◽  
Water Soluble ◽  
Fresh Weight ◽  
Setaria Faberi ◽  
Giant Foxtail ◽  
Uptake And Metabolism

Partially purified glutathione-s-transferase (GST) isolated from corn (Zea maysL.) seedlings was about 14-fold higher in specific activity than GST isolated from giant foxtail (Setaria faberiHerrm. # SETFA) seedlings. Greater amounts of GST activity were present in leaf tissue than in stem tissue. Four-leaf giant foxtail seedlings contained about threefold more reduced glutathione per gram fresh weight in the leaves than one- to two-leaf giant foxtail seedlings. When atrazine and reduced glutathione were used as substrates, tridiphane [2-(3,5-dichlorophenyl)-2-(2,2,2-trichloroethyl)oxirane] inhibited isolated GST from corn with an I50of about 5μM and from giant foxtail with an I50slightly lower. Tridiphane inhibited the metabolism of atrazine [6-chloro-N-ethyl-N′-(1-methylethyl)-1,3,5-triazine-2,4-diamine] to water-soluble metabolites in giant foxtail leaves but not in corn leaves. Unmetabolized atrazine levels tended to be greater in giant foxtail seedlings treated with tridiphane plus atrazine than in plants treated with atrazine alone. Tridiphane applied 12 h before atrazine increased the uptake of atrazine in both corn and five-leaf giant foxtail seedlings. The amount of atrazine metabolism to water-soluble metabolites increased in corn leaves but remained constant in giant foxtail leaves when atrazine uptake was increased. Tridiphane and atrazine combinations impaired net photosynthetic rates more than atrazine alone in giant foxtail seedlings but did not increase chlorophyll fluorescence. There was no decrease in net photosynthetic rate 12 h following applications of atrazine or tridiphane plus atrazine on corn leaves. Tridiphane did not decrease photosynthesis or increase chlorophyll fluorescence in either species when applied alone.

Chlorophyll fluorescence for rapid detection of propanil-resistant barnyardgrass (Echinochloa crus-galli)

Weed Science ◽  
1998 ◽  
Vol 46 (2) ◽  
pp. 163-169 ◽  
Author(s):  
Jason K. Norsworthy ◽  
Ronald E. Talbert ◽  
Robert E. Hoagland
Keyword(s):  
Chlorophyll Fluorescence ◽  
Incubation Temperature ◽  
Recovery Period ◽  
Screening Method ◽  
Leaf Tissue ◽  
Activity Levels ◽  
Photosynthesis Inhibition ◽  
Plastic Bags ◽  
Time Space ◽  
Aryl Acylamidase

Repeated use of propanil to control barnyardgrass (BYG) and other weeds in rice has led to the development of propanil-resistant barnyardgrass (R-BYG). R-BYG possesses elevated aryl acylamidase activity levels, which cause rapid metabolism of propanil analogous to propanil degradation in rice. The current screening method for determining propanil resistance in BYG requires about 10 mo. The present study examined the use of chlorophyll fluorescence as a more rapid method to identify propanil resistance in BYG soon after it is suspected. Chlorophyll fluorescence data from excised BYG leaf tissue (R-BYG and susceptible-BYG [S-BYG]; 13- to 41-d-old) exposed to 100 μM propanil for 2 h indicated a 95 to 100% inhibition of electron transport (photosynthesis inhibition) in both R- and S-BYG. However, when incubated in water in the dark for 22 h after the initial 2-h treatment, metabolism in R-BYG was sufficient to reduce levels of absorbed propanil and facilitate recovery. Lack of metabolism of propanil prevented recovery in S-BYG, thus allowing the two biotypes to be distinguished easily by the chlorophyll fluorescence assay. Further studies using this 2-h exposure to 100 μM propanil followed by a 22-h recovery period evaluated several assay parameters. A longer recovery time and the effects of various propanil concentrations were also evaluated. A herbicide dose-response curve showed the greatest difference in photosynthesis inhibition for both biotypes at about 100 μM propanil, but both biotypes were inhibited > 95% when treated with 400 μM propanil. Inhibition of photosynthesis in both biotypes was greatest when the recovery incubation temperature was 35 C compared to 20, 25, and 30 C. Fluorescence data from harvested tissue stored moist in plastic bags at 23 C (to simulate shipment) showed that biotypes could be differentiated even when received as late as 4 d after harvest. Thus, samples can be harvested from the field soon after propanil failure and resistance or susceptibility to propanil determined after only a few days. This technique can greatly reduce the time, space, and labor currently required to determine propanil resistance in BYG.

Sampling leaf tissue for analysis of NPQ Relaxation using Technologica Chlorophyll Fluorescence Imager Data. v1

2021 ◽  
Author(s):  
Lynn not provided Doran ◽  
gotarkar not provided
Keyword(s):  
Chlorophyll Fluorescence ◽  
Leaf Tissue

Sampling leaf tissue for analysis of NPQ Relaxation using Technologica Chlorophyll Fluorescence Imager Data.

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