Changes of carotenoids contents and analysis of astaxanthin geometrical isomerization in Haematococcus pluvialis under outdoor high light conditions

2019 ◽  
Vol 51 (2) ◽  
pp. 770-778 ◽  
Author(s):  
Fengying Gong ◽  
Chunhui Zhang ◽  
Litao Zhang ◽  
Jianguo Liu
HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 541a-541
Author(s):  
Lailiang Cheng ◽  
Leslie H. Fuchigami ◽  
Patrick J. Breen

Bench-grafted Fuji/M26 apple trees were fertigated with different concentrations of nitrogen by using a modified Hoagland solution for 6 weeks, resulting in a range of leaf N from 1.0 to 4.3 g·m–2. Over this range, leaf absorptance increased curvilinearly from 75% to 92.5%. Under high light conditions (1500 (mol·m–2·s–1), the amount of absorbed light in excess of that required to saturate CO2 assimilation decreased with increasing leaf N. Chlorophyll fluorescence measurements revealed that the maximum photosystem II (PSII) efficiency of dark-adapted leaves was relatively constant over the leaf N range except for a slight drop at the lower end. As leaf N increased, non-photochemical quenching under high light declined and there was a corresponding increase in the efficiency with which the absorbed photons were delivered to open PSII centers. Photochemical quenching coefficient decreased significantly at the lower end of the leaf N range. Actual PSII efficiency increased curvilinearly with increasing leaf N, and was highly correlated with light-saturated CO2 assimilation. The fraction of absorbed light potentially used for free radical formation was estimated to be about 10% regardless of the leaf N status. It was concluded that increased thermal dissipation protected leaves from photo-oxidation as leaf N declined.


1986 ◽  
Vol 41 (5-6) ◽  
pp. 597-603 ◽  
Author(s):  
Aloysius Wild ◽  
Matthias Höpfner ◽  
Wolfgang Rühle ◽  
Michael Richter

The effect of different growth light intensities (60 W·m-2, 6 W·m-2) on the performance of the photosynthetic apparatus of mustard plants (Sinapis alba L.) was studied. A distinct decrease in photosystem II content per chlorophyll under low-light conditions compared to high-light conditions was found. For P-680 as well as for Oᴀ and Oв protein the molar ratio between high-light and low-light plants was 1.4 whereas the respective concentrations per chlorophyll showed some variations for P-680 and Oᴀ on the one and Oв protein on the other hand.In addition to the study of photosystem II components, the concentrations of PQ, Cyt f, and P-700 were measured. The light regime during growth had no effect on the amount of P-700 per chlorophyll but there were large differences with respect to PQ and Cyt f. The molar ratio for Cyt f and PQ between high- and low-light leaves was 2.2 and 1.9, respectively.Two models are proposed, showing the functional organization of the pigment system and the electron transport chain in thylakoids of high-light and low-light leaves of mustard plants.


2017 ◽  
Vol 14 (24) ◽  
pp. 5693-5704 ◽  
Author(s):  
Gabriella M. Weiss ◽  
Eva Y. Pfannerstill ◽  
Stefan Schouten ◽  
Jaap S. Sinninghe Damsté ◽  
Marcel T. J. van der Meer

Abstract. Over the last decade, hydrogen isotopes of long-chain alkenones have been shown to be a promising proxy for reconstructing paleo sea surface salinity due to a strong hydrogen isotope fractionation response to salinity across different environmental conditions. However, to date, the decoupling of the effects of alkalinity and salinity, parameters that co-vary in the surface ocean, on hydrogen isotope fractionation of alkenones has not been assessed. Furthermore, as the alkenone-producing haptophyte, Emiliania huxleyi, is known to grow in large blooms under high light intensities, the effect of salinity on hydrogen isotope fractionation under these high irradiances is important to constrain before using δDC37 to reconstruct paleosalinity. Batch cultures of the marine haptophyte E. huxleyi strain CCMP 1516 were grown to investigate the hydrogen isotope fractionation response to salinity at high light intensity and independently assess the effects of salinity and alkalinity under low-light conditions. Our results suggest that alkalinity does not significantly influence hydrogen isotope fractionation of alkenones, but salinity does have a strong effect. Additionally, no significant difference was observed between the fractionation responses to salinity recorded in alkenones grown under both high- and low-light conditions. Comparison with previous studies suggests that the fractionation response to salinity in culture is similar under different environmental conditions, strengthening the use of hydrogen isotope fractionation as a paleosalinity proxy.


2008 ◽  
Vol 55 (1) ◽  
pp. 183-190 ◽  
Author(s):  
Jerzy Kruk ◽  
Renata Szymańska

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.


2006 ◽  
Vol 33 (11) ◽  
pp. 1037 ◽  
Author(s):  
Dirk Büssis ◽  
Uritza von Groll ◽  
Joachim Fisahn ◽  
Thomas Altmann

Stomatal density of transgenic Arabidopsis thaliana plants over-expressing the SDD1 (stomatal density and distribution) gene was reduced to 40% and in the sdd1-1 mutant increased to 300% of the wild type. CO2 assimilation rate and stomatal conductance of over-expressers and the sdd1-1 mutant were unchanged compared with wild types when measured under the light conditions the plants were exposed to during growth. Lower stomatal density was compensated for by increased stomatal aperture and conversely, increased stomatal density was compensated for by reduced stomatal aperture. At high light intensities the assimilation rates and stomatal conductance of SDD1 over-expressers were reduced to 80% of those in wild type plants. Areas beneath stomata and patches lacking stomata were analysed separately. In areas without stomata, maximum fluorescence yield (Fv / Fm) and quantum yield of photosystem II (Φ PSII) were significantly lower than in areas beneath stomata. In areas beneath stomata, Fv / Fm and Φ PSII were identical to levels measured in wild type leaves. At high light intensities over-expressers showed decreased photochemical quenching (qP) compared with wild types. However, the decrease of qP was significantly stronger in areas without stomata than in mesophyll areas beneath stomata. At high CO2 partial pressures and high light intensities CO2 assimilation rates of SDD1 over-expressers did not reach wild type levels. These results indicate that photosynthesis in SDD1 over-expressers was reduced because of limiting CO2 in areas furthest from stomata at high light.


2020 ◽  
Vol 50 ◽  
pp. 101991 ◽  
Author(s):  
Xiaodan Wang ◽  
Yanan Song ◽  
Baoling Liu ◽  
Wei Hang ◽  
Renjian Li ◽  
...  

Weed Science ◽  
1971 ◽  
Vol 19 (5) ◽  
pp. 555-558 ◽  
Author(s):  
D. Hawton ◽  
E. H. Stobbe

The fate of 2,4-dichlorophenyl p-nitrophenyl ether (nitrofen) in the foliage of rape (Brassica campestris L. ‘Echo’), redroot pigweed (Amaranthus retroflexus L.), and green foxtail (Setaria viridis (L.) Beauv.) was investigated with the aid of 14C-nitrofen. Only limited amounts of the label were translocated in these species. Plants treated with 14C-nitrofen under high light conditions produced several labelled compounds of different molecular size and chromatographic properties. The time at which these compounds were first detectable depended on light intensity. At least two of these compounds are lipid-nitrofen conjugates or nitrofen polymers and others may be formed by cleavage of nitrofen at the ether linkage.


2008 ◽  
Vol 191 (5) ◽  
pp. 1581-1586 ◽  
Author(s):  
Yurie Seino ◽  
Tomoko Takahashi ◽  
Yukako Hihara

ABSTRACT The coordinated high-light response of genes encoding subunits of photosystem I (PSI) is achieved by the AT-rich region located just upstream of the core promoter in Synechocystis sp. strain PCC 6803. The upstream element enhances the basal promoter activity under low-light conditions, whereas this positive regulation is lost immediately after the shift to high-light conditions. In this study, we focused on a high-light regulatory 1 (HLR1) sequence included in the upstream element of every PSI gene examined. A gel mobility shift assay revealed that a response regulator RpaB binds to the HLR1 sequence in PSI promoters. Base substitution in the HLR1 sequence or decrease in copy number of the rpaB gene resulted in decrease in the promoter activity of PSI genes under low-light conditions. These observations suggest that RpaB acts as a transcriptional activator for PSI genes. It is likely that RpaB binds to the HLR1 sequence under low-light conditions and works for positive regulation of PSI genes and for negative regulation of high-light-inducible genes depending on the location of the HLR1 sequence within target promoters.


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