scholarly journals Occurrence of neoxanthin and lutein epoxide cycle in parasitic Cuscuta species.

2008 ◽  
Vol 55 (1) ◽  
pp. 183-190 ◽  
Author(s):  
Jerzy Kruk ◽  
Renata Szymańska
Keyword(s):  
Substrate Specificity ◽  
Xanthophyll Cycle ◽  
Higher Plants ◽  
Light Stress ◽  
High Light ◽  
Light Conditions ◽  
Strong Light ◽  
Zeaxanthin Epoxidase ◽  
Typical Response ◽  
Cuscuta Species

In the present study, xanthophyll composition of eight parasitic Cuscuta species under different light conditions was investigated. Neoxanthin was not detected in four of the eight species examined, while in others it occurred at the level of several percent of total xanthophylls. In C. gronovii and C. lupuliformis it was additionally found that the neoxanthin content was considerably stimulated by strong light. In dark-adapted plants, lutein epoxide level amounted to 10-22% of total xanthophylls in only three species, the highest being for C. lupuliformis, while in others it was below 3%, indicating that the lutein epoxide cycle is limited to only certain Cuscuta species. The obtained data also indicate that the presence of the lutein epoxide cycle and of neoxanthin is independent and variable among the Cuscuta species. The xanthophyll cycle carotenoids violaxanthin, antheraxanthin and zeaxanthin were identified in all the examined species and occurred at the level found in other higher plants. The xanthophyll and lutein epoxide cycle pigments showed typical response to high light stress. The obtained results also suggest that the ability of higher plants to synthesize lutein epoxide probably does not depend on the substrate specificity of zeaxanthin epoxidase but on the availability of lutein for the enzyme.

scholarly journals Light Stress Is Not Effective to Enhanced Crassulacean Acid Metabolism

2010 ◽  
Vol 65 (1-2) ◽  
pp. 79-86 ◽  
Author(s):  
Andrzej Kornas ◽  
Zbigniew Miszalski ◽  
Ewa Surówka ◽  
Elke Fischer-Schliebs ◽  
Ulrich Lüttge
Keyword(s):  
Water Supply ◽  
Xanthophyll Cycle ◽  
Crassulacean Acid Metabolism ◽  
Acid Metabolism ◽  
Light Stress ◽  
High Light ◽  
Light Energy ◽  
Strong Light ◽  
Cam Metabolism ◽  
Single Stress

Clusia minor L., a C3-CAM intermediate, and Clusia multifl ora H. B. K., a C3 obligate, present two physiotypes of a similar morphotype occurring sympatrically in the fi eld. Both species, exposed 2 days to high light, show similar responses to this kind of stress: (i) the level of xanthophyll pigments in tested plants during the daycourse adapts to stress, (ii) the levels of antheraxanthin and zeaxanthin clearly increase during the afternoon showing increased de-epoxidation, (iii) the changes in the xanthophyll cycle are similar. Exposure to high light increases the malate levels in C. minor during the afternoon while decreases the day/night changes of the malate levels, and hence the Crassulacean Acid Metabolism (CAM) expression. It can be concluded that strong light applied as a single stress factor to well-watered plants is not effective in strengthing the CAM metabolism in a C3-CAM intermediate plant but rather suppresses the CAM activity despite exposure to high light energy. It is suggested that, when water supply is not limiting and other stresses do not prevail, C3 allows to use up the citrate pool, especially in the afternoon and enables a superior daily photon utilization.

Is the in vivo Photosystem I Function Resistant to Photoinhibition? An Answer from Photoacoustic and Far-Red Absorbance Measurements in Intact Leaves

1991 ◽  
Vol 46 (11-12) ◽  
pp. 1038-1044 ◽  
Author(s):  
Michel Havaux ◽  
Murielle Eyletters
Keyword(s):  
Light Stress ◽  
Red Light ◽  
Light Treatment ◽  
High Light ◽  
Saturation Curve ◽  
Strong Light ◽  
Ps Ii ◽  
Fluorescence Measurements ◽  
Ps I

Abstract Preillumination of intact pea leaves with a strong blue-green light of 400 W m-2 markedly inhibited both photoacoustically monitored O2-evolution activity and PS II photochemistry as estimated from chlorophyll fluorescence measurements. The aim of the present work was to examine, with the help of the photoacoustic technique, whether this high-light treatment deteriorated the in vivo PS I function too. High-frequency photoacoustic measurements indicated that photochemical conversion of far-red light energy in PS I was preserved (and even transiently stimulated) whereas photochemical energy storage monitored in light exciting both PS I and PS II was markedly diminished. Low-frequency photoacoustic measurements of the Emerson enhancement showed a spectacular change in the PS II/PS I activity balance in favor of PS I. It was also observed that the linear portion of the saturation curve of the far-red light effect in the Emerson enhancement was not changed by the light treatment. Those results lead to the conclusion that, in contrast to PS II, the in vivo PS I photofunctioning was resistant to strong light stress, thus confirming previous suggestions derived from in vitro studies. Estimation of the redox state of the PS I reaction center by leaf absorbance measurements at ca. 820 nm suggested that, under steady illumination, a considerably larger fraction of PS I centers were in the closed state in high-light pretreated leaves as compared to control leaves, presumably allowing passive adjustment of the macroscopic quantum yield of PS I photochemis­ try to the strongly reduced photochemical efficiency of photoinhibited PS II.

scholarly journals Glutathione and zeaxanthin formation during high light stress in foliose lichens

2008 ◽  
Vol 53 (No. 8) ◽  
pp. 340-344 ◽  
Author(s):  
J. Štepigová ◽  
H. Vráblíková ◽  
J. Lang ◽  
K. Večeřová ◽  
M. Barták
Keyword(s):  
Xanthophyll Cycle ◽  
Light Exposure ◽  
Light Stress ◽  
High Light ◽  
Short Term ◽  
Xanthophyll Cycle Pigments ◽  
High Light Stress ◽  
Fluorescence Label ◽  
Thiol Binding ◽  
Pure Acetone

In the presented study, we describe techniques for glutathione and pigment determination in lichens used in our laboratory. Glutathione and xanthophyll cycle pigments, especially zeaxanthin, are important antioxidants protecting plants against various stresses. In our laboratory, the high light stress in lichens has been intensively studied for several years. We extract glutathione in HCl and determine it by thiol-binding fluorescence label monobromobimane. For pigment determination, homogenized lichen thalli are extracted with pure acetone. According to our results, the total amount of glutathione decreases after a short-term high light exposure, while the amount of zeaxanthin increases.

Influence of light intensity and salt-treatment on mode of photosynthesis and enzymes of the antioxidative response system of Mesembryanthemum crystallinum

2002 ◽  
Vol 29 (1) ◽  
pp. 13 ◽  
Author(s):  
Fernando Broetto ◽  
Ulrich Lüttge ◽  
Rafael Ratajczak
Keyword(s):  
Light Stress ◽  
High Light ◽  
Mesembryanthemum Crystallinum ◽  
Stress Factors ◽  
Lag Phase ◽  
Light Conditions ◽  
Cam Plants ◽  
Salt Treatment ◽  
Sod Activity ◽  
Antioxidative Response

The metabolic switch from C3-photosynthesis to crassulacean acid metabolism (CAM),and the antioxidative response of Mesembryanthemum crystallinum L. plants cultured under severe salt stress and high light intensities, and a combination of both stress conditions, were studied. High light conditions led to a more rapid CAM induction than salinity. The induction time was still shortened when both stress factors were combined. A main pattern observed in CAM plants was a decrease in mitochondrial Mn–superoxide dismutase (SOD) activity during the day. The activities of the chloroplastic Fe–SOD and cytosolic CuZn–SOD were increased due to salt treatment after a lag phase, while catalase activity was decreased. Combination of salt and light stress did not lead to a higher SOD activity as found after application of one stress factor alone, indicating that there is a threshold level of the oxidative stress response. The fact that salt-stressed plants grown under high light conditions showed permanent photoinhibition and lost the ability for nocturnal malate storage after 9 d of treatment indicate serious malfunction of metabolism, leading to accelerated senescence. Comparison of CuZn–SOD activity with CuZn–SOD protein amount, which was determined immunologically, indicates that the activity of the enzyme is at least partially post-translationally regulated.

Cloning of the strawberry xanthophyll cycle genes VDE and ZEP and characterization of their responses to high light stress

2017 ◽  
Vol 82 (4) ◽  
pp. 211-220 ◽  
Author(s):  
Haisheng Zhu ◽  
◽  
Mindong Chen ◽  
Wang Bin ◽  
Qingfang Wen ◽  
...  
Keyword(s):  
Xanthophyll Cycle ◽  
Light Stress ◽  
High Light ◽  
High Light Stress

scholarly journals Genome-Wide Identification and Expression Analyses of the Fibrillin Family Genes Reveal Their Involvement in the Photoprotection in Cucumber

2018 ◽  
Author(s):  
Inyoung Kim ◽  
Sang-Choon Lee ◽  
Eun-Ha Kim ◽  
Kiwhan Song ◽  
Tae-Jin Yang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Dna Sequences ◽  
Light Stress ◽  
High Light ◽  
Light Conditions ◽  
Transcript Levels ◽  
Photosynthetic Organisms ◽  
Conserved Domain ◽  
Genome Wide ◽  
Cucumber Genome

Fibrillin (FBN) is a plastid lipid-associated protein found in photosynthetic organisms from cyanobacteria to plants. In this study, 10 CsaFBN genes were identified in genomic DNA sequences of cucumber (Chinese long and Gy14) through database searches using the conserved domain of FBN and the 14 FBN genes of Arabidopsis. Phylogenetic analysis of CsaFBN protein sequences showed that there was no counterpart of Arabidopsis and rice FBN5 in the cucumber genome. FBN5 is essential for growth in Arabidopsis and rice; its absence in cucumber may be because of incomplete genome sequences or that another FBN carries out its functions. Among the 10 CsaFBN genes, CsaFBN1 and CsaFBN9 were the most divergent in terms of nucleotide sequences. Most of the CsaFBN genes were expressed in the leaf, stem, and fruit. CsaFBN4 showed the highest mRNA expression levels in various tissues, followed by CsaFBN6, CsaFBN1, and CsaFBN9. High-light stress combined with low temperature decreased photosynthetic efficiency and highly induced transcript levels of CsaFBN1, CsaFBN6, and CsaFBN11, which decreased after 24 h treatment. Transcript levels of the other seven genes were changed only slightly. This result suggests that CsaFBN1, CsaFBN6, and CsaFBN11 may be involved in photoprotection under high-light conditions at low temperature.

scholarly journals Plastid terminal oxidases in Chlamydomonas: connections with astaxanthin and bio-hydrogen production

2020 ◽  
Author(s):  
Hui Li ◽  
Chao Zheng ◽  
Ming Xiao ◽  
Qin Huan ◽  
Jun Chen ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Higher Plants ◽  
Light Stress ◽  
Light Condition ◽  
Protective Role ◽  
High Light ◽  
Transcriptional Level ◽  
High Light Condition ◽  
Green Microalga ◽  
Plastid Terminal Oxidase

Abstract Background: as a plasto quinol oxidase involved in plastoquinol oxidation in higher plants and microalgae, the plastid terminal oxidase (PTOX) was first recognized in the tomato mutant GHOST (GH) and Arabidopsis mutant IMMUTANS (IM). Genome sequence analysis revealed that duplication of the PTOX gene occurs in certain eukaryotic microalgae, but not in cyanobacteria and most higher plants. PTOX may also be involved in carotenoid synthesis and play a critical protective role against stress, such as high light, heat shock and hyperosmosis. However, the connections of PTOX with astaxanthin and bio-hydrogen production and their functional relationship between two PTOX genes in the model green microalga Chlamydomonas is unknown. Results: we successfully knocked down two ptoxs through RNAi in Chlamydomonas, respectively. We demonstrated that expression levels of both PTOXs were increased under stress conditions, and interestingly when one PTOX was silenced the other’s transcriptional level was significantly raised. Conclusions: this shows a complementary relationship under high light condition. In addition, the astaxanthin accumulation level was up-regulated in silenced ptox2 strain, compared to the wide type strain. What’s more, significantly increased hydrogen production was observed in silenced ptox1 strain. In conclusion, PTOXs in Chlamydomonas are connected with not only astaxanthin accumulation but also hydrogen production, and their knock-down strains provide new insights in manipulating microalgae for high light stress tolerant strains, carotenoid production and even biofuels.

Increased heat emission and its relationship to the xanthophyll cycle in pea leaves exposed to strong light stress

1991 ◽  
Vol 8 (4) ◽  
pp. 361-370 ◽  
Author(s):  
Michel Havaux ◽  
Wieslaw I. Gruszecki ◽  
Isabelle Dupont ◽  
Roger M. Leblanc
Keyword(s):  
Xanthophyll Cycle ◽  
Light Stress ◽  
Heat Emission ◽  
Strong Light
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