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In our previous work we found considerable accumulation of early light-inducible proteins (ELIPs) in barley during adaptation
to combined high light and cold stress, an accumulation which occurred preferentially in the apical part of the leaves (M.-H.
Montané et al., 1997, Planta 202: 293–302). Here we studied, under the same conditions, the effect of adaptation on the composition
of thylakoid membrane proteins and pigments, particularly xanthophylls and chlorophyll, and their distribution within the
barley leaf. It was observed that high light fluxes appeared to favour the trimerization of the light-harvesting complex of
photosystem II (LHC II) whereas cold appeared to favour the monomers of LHC II. High light, cold or the combination of both
factors had only a small effect on the protein composition of the thylakoid membranes except for the proteins of LHC II which
were found to decrease under high light to a greater extent at 25 °C than at 5 °C. The total xanthophyll-cycle carotenoid
content increased linearly with cellular development, the highest amount being observed in the apical part of the leaf. Cold
and high light acted synergistically to induce less than a doubling in the amount of total xanthophylls, while chlorophylls
a and b remained nearly constant. The fraction consisting of antheraxanthin plus zeaxanthin was up to 4- to 5-fold higher at 5 °C
than at 25 °C. As determined previously (Montané et al. 1997), the same conditions caused a 15-fold increase in the accumulation
of ELIPs. Consequently, neither the distribution of total xanthophylls nor that of antheraxanthin plus zeaxanthin along the
leaf followed the same pattern as ELIP. Thus, the accumulation of xanthophylls cannot be stoichiometrically correlated with
that of ELIPs. Using electrophoresis in the presence of decylmaltoside, we could demonstrate for the first time that ELIPs
of 13.5 kDa are contained in high-molecular-mass complexes of >100 kDa, which are located in the unstacked stroma lamellar
region of the thylakoid membranes.
Received: 6 April 1998 / Accepted: 26 January 1999 相似文献
3.
Exposure of barley (Hordeum vulgare L.) leaves to strong white light (1500 μmol photons · m−2 · s−1) decreased the quantum yield of photosynthetic oxygen evolution in green light preferentially absorbed by carotenoids (Φ-510)
but not in red light exclusively absorbed by chlorophylls (Φ-650). This phenomenon was observed to be (i) rapidly induced
(within a few minutes), (ii) slowly reversible in darkness (within about 1 h), (iii) insensitive to dithiothreitol and (iv)
maximally induced by photon flux densities higher than about 1000 μmol · m−2 · s−1. Determination of the carotenoid composition of the major light-harvesting complex of PSII (LHCII) and analysis of the thylakoid
membrane lipid fluidity before and after strong illumination of barley leaves in the presence or the absence of dithiothreitol
showed that the light-induced decrease in the Φ-510/Φ-650 ratio did not require the physical detachment of carotenoids from
the pigment antennae. Compared to barley plants grown under moderate light and temperature conditions, plants grown in sustained
high irradiance at elevated temperature exhibited (i) a lower Φ-510/Φ-650 ratio, (ii) a reduced size of the functional PSII
pigment antenna in green light (but not in red light) and (iii) a marked increase in the amount of free carotenoids found
in non-denaturing Deriphat-containing electrophoretic gels of thylakoid membranes. Similarly, the Φ-510/Φ-650 ratio of the
LHCII-deficient chlorina-f2 barley mutant was very low compared to the wild type. Separation and quantification of the cis/trans carotenoid isomers of barley leaves revealed that strong illumination did not induce pronounced cis-trans isomerization of xanthophylls. Taken together, the data suggest that the efficiency of energy transfer from carotenoids to
chlorophylls varies with the light environment both in the short term and in the long term, with excess light energy noticeably
inhibiting the photosynthetic light-harvesting function of carotenoids. The photoprotective significance of this carotenoid
decoupling from the chlorophyll antennae is discussed.
Received: 28 July 1997 / Accepted: 25 October 1997 相似文献
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The influence of phytohormones, salicylic acid (SA) and methyl jasmonate (MJ) on the antioxidant systems in Haematococcus
pluvialis was investigated. Both SA and MJ at 500 μM concentration reduced the growth of alga with salicylic acid, having more pronounced
effect. Carotenoid and chlorophyll contents were decreased by SA and increased by MJ. Salicylic acid (100 μM) increased astaxanthin
content to 6.8-fold under low light (30 μmol m−2 s−1), while MJ (10 μM) showed marginal increase in astaxanthin. Salicylic acid (500 μM) increased superoxide dismutase activity
to 4.5- and 3.3-fold and ascorbate peroxidase (APX) activity to 15.5- and 7.1-fold under low and high light, respectively.
Methyl jasmonate increased catalase activity (1.4-fold) under high light and APX activity (5.4-fold) under low light. Different
mechanism of oxidative stress induced antioxidant production may be the plausible reason for this varied response for salicylic
acid and methyl jasmonate. Higher concentrations of SA and MJ inhibited astaxanthin accumulation by different mechanisms either
by scavenging the free radicals or by increasing primary carotenoids production. At lower concentrations, these phytohormones
could be used for elicitation of secondary carotenoid production. 相似文献
6.
Diana M. Cheng Gad G. Yousef Mary H. Grace Randy B. Rogers J. Gorelick-Feldman I. Raskin Mary Ann Lila 《Plant Cell, Tissue and Organ Culture》2008,94(1):73-83
In order to develop a sustainable source of metabolism-enhancing phytoecdysteroids, cell suspension and hairy root cultures
were established from shoot cultures of wild-harvested Ajuga turkestanica, a medicinal plant indigenous to Uzbekistan. Precursors of phytoecdysteroids (acetate, mevalonic acid cholesterol) or methyl
jasmonate (an elicitor) were added to subculture media to increase phytoecdysteroid accumulation. In cell suspension cultures,
20-hydroxyecdysone (20E) content increased 3- or 2-fold with the addition of 125 or 250 μM methyl jasmonate, respectively,
compared to unelicited cultures. Precursor addition, however, did not provoke phytoecdysteroid accumulation. In hairy root
cultures, addition of sodium acetate, mevalonic acid, and methyl jasmonate, but not cholesterol, increased phytoecdysteroid
content compared to unelicited cultures. Hairy root cultures treated with 150 mg l−1 sodium acetate, or 15 or 150 mg l−1 mevalonic acid, increased 20E content approximately 2-fold to 19.9, 20.4 or 21.7 μg mg−1, respectively, compared to control (10.5 μg mg−1). Older hairy root cultures, extracted after the seventh subculture cycle, also showed increases in 20E content (24.8 μg mg−1), turkesterone (0.9 μg mg−1) and cyasterone (8.1 μg mg−1) compared to control cultures maintained for a shorter duration of four subculture cycles. Doses of 10 or 20 μg ml−1 hairy root extract increased protein synthesis by 25.7% or 31.1%, respectively, in a C2C12 mouse skeletal cell line. These
results suggest that sustainable production of metabolically active phytoecdysteroid can be achieved through hairy root culture
systems.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
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E. J. Olguín S. Galicia R. Camacho G. Mercado T. J. Pérez 《Applied microbiology and biotechnology》1997,48(2):242-247
The use of untreated sea water supplemented with anaerobic effluents from digested pig waste and sodium bicarbonate was evaluated
as a low-cost medium for semi-continuous cultivation of a mixed culture of two Spirulina strains in outdoor raceways under temperate climatic conditions (pond temperature in the range 21–26 °C and light intensity
in the range 225–957␣μE m−2 s−1). The mixed culture had a predominant population (86.6 ± 3.9%) of an atypical Spirulina strain consisting of straight filaments, which appeared spontaneously after the strain with helicoidal trichomes had been
subcultured. Morphological studies for the identification of the type and size of trichomes of the two strains (HF and SF)
were carried out. The proportions of the two strains were observed to be stable during the monitoring period (30 days). Three
different sets of semicontinuous cultures were carried out. Sets 1 and 2 were operated under regime 1 (a single addition of
anaerobic effluents at time zero and no pH control) during the same season (June and July) of different years. Set 3 was operated
under regime 2 (semi-continuous addition of anaerobic effluents and pH control) during the autumn. A minimum productivity
of 3.6 g m−2 day−1 was obtained at one of the lowest temperatures (22.1 °C) and light intensities (245 μE m−2 s−1) and a maximum productivity of 10.9 g m−2 day−1 was observed at the highest temperature (25 °C) and highest average light intensity (618 μE m−2 s−1) registered for sets 1 and 2. The protein content in the Spirulina biomass harvested from these two sets varied from 17% to 65.6%. In set 3, a maximum productivity of 9.0 g m−2 day−1 was recorded at an average temperature of 24.4 °C and at an average light intensity of 668 μE m−2 s−1. The protein content in this set under regime 2 varied within a narrower range than in set 1 and set 2 (from 34.8% to 49.1%),
apparently because of a continuous availability of ammonia nitrogen at a level of 30–50 mg l−1. However, in terms of the removal of ammonia nitrogen and chemical oxygen demand, regime 1 was more efficient than regime␣2.
Received: 3 September 1996 / Received revision: 19 February 1997 / Accepted: 7 March 1997 相似文献
9.
CO2 exchange of the endolithic lichen Verrucaria baldensis was measured in the laboratory under different conditions of water content, temperature, light, and CO2 concentration. The species had low CO2 exchange rates (maximum net photosynthesis: c. 0.45 μmol CO2 m−2 s−1; maximum dark respiration: c. 0.3 μmol CO2 m−2 s−1) and a very low light compensation point (7 μmol photons m−2 s−1 at 8°C). The net photosynthesis/respiration quotient reached a maximum at 9–15°C. Photosynthetic activity was affected only
after very severe desiccation, when high resaturation respiratory rates were measured. Microclimatic data were recorded under
different weather conditions in an abyss of the Trieste Karst (northeast Italy), where the species was particularly abundant.
Low photosynthetically active radiation (normally below 40 μmol photons m−2 s−1), very high humidities (over 80%), and low, constant temperatures were measured. Thallus water contents sufficient for CO2 assimilation were often measured in the absence of condensation phenomena.
Received: 22 September 1996 / Accepted: 26 April 1997 相似文献
10.
L. Guglielmo G. C. Carrada G. Catalano A. Dell'Anno M. Fabiano L. Lazzara O. Mangoni A. Pusceddu V. Saggiomo 《Polar Biology》2000,23(2):137-146
Studies on the chemical and biological properties of annual pack ice at a coastal station in Terra Nova Bay (74°41.72′S,
164°11.63′E) were carried out during austral spring at 3-day intervals from 5 November to 1 December 1997. Temporal changes
of nutrient concentrations, algal biomasses, taxonomic composition, photosynthetic pigment spectra and P–E relationships were
studied. Quantity, composition and degradation rates of organic matter in the intact sea ice were also investigated. In addition,
microcosm experiments were carried out to evaluate photosynthetic and photo-acclimation processes of the sympagic flora in
relation to different light regimes. High concentrations of ammonia were measured in four ice-cores (weighted mean values
of the cores ranged from 4.3 ± 1.9 μM to 7.2 ± 3.4 μM), whereas nitrate and phosphate displayed high concentrations (up to
35.9 μM and 7.6 μM, respectively) only in the bottom layer (135–145 cm depth). Particulate carbohydrate and protein concentrations
in the intact sea ice ranged from 0.5 to 2.3 mg l−1 and 0.2 to 2.0 mg l−1, respectively, displaying a notable accumulation of organic matter in the bottom colored layer, where bacterial enzymatic
activities also reached the highest values. Aminopeptidase activity was extremely high (up to 19.7 μM l−1 h−1 ± 0.05 in the bottom layer), suggesting a rapid turnover rate of nitrogen–enriched organic compounds (e.g. proteins). By
contrast, bacterial secondary production was low, suggesting that only a very small fraction of mobilized organic matter was
converted into bacterial biomass (<0.01‰). The sympagic autotrophic biomass (in terms of chlorophaeopigments) of the bottom
layer was high, increasing during the sampling period from 680 to 2480 μg l−1. Analyses of pigments performed by HPLC, as well as microscope observations, indicated that diatoms dominated bottom communities.
The most important species were Amphiprora sp. and Nitschia cfr. stellata. Bottom sympagic communities showed an average P
B
max
of 0.12 mgC mg Chl−1 and low photoadaptation index (E
k=18 μE m−2 s−1, E
m=65 μE m−2 s−1). Results of the microcosm experiment also indicated that communities were photo-oxidized when irradiance exceeded 100 μE m−2 s−1. This result suggests that micro- autotrophs inhabiting sea ice might have a minor role in the pelagic algal blooms.
Accepted: 4 August 1999 相似文献
11.
Indole-3-butyric acid at 25 μM with methyl jasmonate (MJ) at 100 μM in Panax ginseng synergistically stimulated both root growth and ginsenoside accumulation compared with 100 μM MJ alone. Productivity of ginsenoside
was 10 mg l−1 d−1 compared to 7.3 mg l−1 d−1 with MJ elicitation alone. 相似文献
12.
Artemisinin production by hairy roots of Artemisia annua L. was increased 6-fold to 1.8 μg mg−1 dry wt over 6 days by adding 150 mg chitosan l−1. The increase was dose-dependent. Similar treatment of hairy roots with methyl jasmonate (0.2 mM) or yeast extract (2 mg ml−1) increased artemisinin production to 1.5 and 0.9 μg mg−1 dry wt, respectively. 相似文献
13.
To test the hypothesis that the contribution of phosphoribulokinase (PRK) to the control of photosynthesis changes depending
on the light environment of the plant, the response of transgenic tobacco (Nicotiana tabacum L.) transformed with antisense PRK constructs to irradiance was determined. In plants grown under low irradiance (330 μmol m−2 s−1) steady-state photosynthesis was limited in plants with decreased PRK activity upon exposure to higher irradiance, with a
control coefficient of PRK for CO2 assimilation of 0.25 at and above 800 μmol m−2 s−1. The flux control coefficient of PRK for steady-state CO2 assimilation was zero, however, at all irradiances in plant material grown at 800 μmol m−2 s−1 and in plants grown in a glasshouse during mid-summer (alternating shade and sun 300–1600 μmol m−2 s−1). To explain these differences between plants grown under low and high irradiances, Calvin cycle enzyme activities and metabolite
content were determined. Activities of PRK and other non-equilibrium Calvin cycle enzymes fructose-1,6-bisphosphatase, sedoheptulose-1,7-bisphosphatase
and ribulose-1,5-bisphosphate carboxylase-oxygenase were twofold higher in plants grown at 800 μmol m−2 s−1 or in the glasshouse than in plants grown at 330 μmol m−2 s−1. Activities of equilibrium enzymes transketolase, aldolase, ribulose-5-phosphate epimerase and isomerase were very similar
under all growth irradiances. The flux control coefficient of 0.25 in plants grown at 330 μmol m−2 s−1 can be explained because low ribulose-5-phosphate content in combination with low PRK activity limits the synthesis of ribulose-1,5-bisphosphate.
This limitation is overcome in high-light-grown plants because of the large relative increase in activities of sedoheptulose-1,7-bisphosphatase
and fructose-1,6-bisphosphatase under these conditions, which facilitates the synthesis of larger amounts of ribulose-5-phosphate.
This potential limitation will have maintained evolutionary selection pressure for high concentrations of PRK within the chloroplast.
Received: 15 November 1999 / Accepted: 27 January 2000 相似文献
14.
Lamia Trabelsi Hatem Ben Ouada Hassen Bacha Mohamed Ghoul 《Journal of applied phycology》2009,21(4):405-412
The effects of light intensity and temperature on Arthrospira platensis growth and production of extracellular polymeric substances (EPS) in batch culture were evaluated using a three-level, full-factorial
design and response surface methodology. Three levels were tested for each parameter (temperature: 30, 35, 40°C; light intensity:
50, 115, 180 μmol photons m−2 s−1). Both growth and EPS production are influenced mainly by the temperature factor but the interaction term temperature*light
intensity also had a significant effect. In addition, conditions optimising EPS production are different from those optimising
growth. The highest growth rate (0.414 ± 0.003 day−1) was found at the lowest temperature (30°C) and highest light intensity (180 μmol photons m−2 s−1) tested, no optima were detectable within the given test range. Obviously, optima for growth must be at a temperature lower
than 30°C and a light intensity higher than 180 μmol photons m−2 s−1. For EPS production, light intensity had a positive linear effect (optimum obviously higher than 180 μmol photons m−2 s−1), but for the temperature parameter a maximum effect was detectable at 35°C. 相似文献
15.
Size-fractionated chlorophyll a (Chla)-specific productivity (μgC μgChla
−1 h−1) was measured at 11 stations off the northern coast of the South Shetland Islands during summer. The Chla-specific productivity of the 2- to 10 or 10- to 330-μm fraction was highest at 100% and 23% light depths. The Chla-specific productivity of the 2- to 10-μm fraction was generally highest, and that of the <2 or 10- to 330-μm fraction was
sometimes highest at 12% and 1% light depths. Temperature was less than 3°C within the euphotic zone at all stations. The
hypothesis of Shiomoto et al., according to which Chla-specific productivity of picophytoplankton (<2 μm) is not significantly higher than that of larger phytoplankton (>2 μm)
in water colder than 10°C, was supported on condition that light is not limited for larger phytoplankton.
Received: 16 September 1997 / Accepted: 8 December 1997 相似文献
16.
Lolium temulentum L. Ba 3081 was grown hydroponically in air (350 μmol mol−1 CO2) and elevated CO2 (700 μmol mol−1 CO2) at two irradiances (150 and 500 μmol m−2 s−1) for 35 days at which point the plants were harvested. Elevated CO2 did not modify relative growth rate or biomass at either irradiance. Foliar carbon-to-nitrogen ratios were decreased at elevated
CO2 and plants had a greater number of shorter tillers, particularly at the lower growth irradiance. Both light-limited and light-saturated
rates of photosynthesis were stimulated. The amount of ribulose-1,5-bisphosphate carboxylase-oxygenase (Rubisco) protein was
increased at elevated CO2, but maximum extractable Rubisco activities were not significantly increased. A pronounced decrease in the Rubisco activation
state was found with CO2 enrichment, particularly at the higher growth irradiance. Elevated-CO2-induced changes in leaf carbohydrate composition were small in comparison to those caused by changes in irradiance. No CO2-dependent effects on fructan biosynthesis were observed. Leaf respiration rates were increased by 68% in plants grown with
CO2 enrichment and low light. We conclude that high CO2 will only result in increased biomass if total light input favourably increases the photosynthesis-to-respiration ratio.
At low irradiances, biomass is more limited by increased rates of respiration than by CO2-induced enhancement of photosynthesis.
Received: 23 February 1999 / Accepted: 15 June 1999 相似文献
17.
Romy Kandzia Rudolf Grimm Christoph Eckerskorn Peter Lindemann Martin Luckner 《Planta》1998,204(3):383-389
Lanatoside 15′-O-acetylesterase (LAE) from in-vitro-cultivated cells of Digitalis lanata Ehrh. was isolated and partially sequenced. The enzyme was extracted with citrate buffer from acetone dry powder. It was
purified in a two-step chromatographical procedure including Phenyl Sepharose hydrophobic interaction chromatography followed
by CM Sepharose cation-exchange chromatography to more than 330 μmol · s−1 · (g protein)−1. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of the purified protein showed a major band at 39 kDa.
The protein was identified by correlation of band intensity on SDS-PAGE and enzyme activity of CM Sepharose column fractions.
Size-exclusion chromatography on Sephacryl 200 revealed a single activity peak with an apparent molecular mass of about 85 kDa.
Electrophoresis under nondenaturating conditions of purified LAE showed only one band with esterase activity. The intensity
of this band was correlated with that of the 39-kDa band after SDS-PAGE. About 30% of the protein, including the N-terminus
and several fragments obtained by Lys-C protease digestion, was sequenced. A fragment obtained by Lys-C digestion showed partial
homology to other hydrolases and apoplasmic proteins. It included the probable location of an active-site histidine. The activity
of LAE was high in non-morphogenic D. lanata cell strains selected for high activities in the chemical transformation of cardenolides, but rather low in the proembryogenic
masses of the embryogenic cell strain VIII. It increased during the development of somatic embryos. The LAE activity in leaves
of D. lanata plants was in the range 4–24 nmol · s−1 · (g protein)−1.
Received: 25 March 1997 / Accepted: 3 July 1997 相似文献
18.
The role of gibberellins (GAs) in the regulation of shoot elongation is well established but the phytohormonal control of
dry-matter production is poorly understood. In the present study, shoot elongation and dry-matter production were resolved
by growing Brassica napus L. seedlings under five light intensities (photon flux densities) ranging from 25 to 500 μmol m−2 s−1. Under low light, plants were tall but produced little dry weight; as light intensity was increased, plants were progressively
shorter but had increasing dry weights. Endogenous GAs in stems of 16- and 17-d-old plants were analyzed by gas chromatography-selected
ion monitoring with [2H2] internal standards. The contents of GAs increased dramatically with decreasing light intensity: GA1, GA3, GA8 and GA20 were 62, 15, 16 and 32 times higher, respectively, under the lowest versus highest light intensities. Gibberellin A19 was not measured at 25 μmol m−2 s−1 but was 9␣times greater in the 75 compared to 500 μmol m−2 s−1 treatment. Shoot and hypocotyl lengths were closely positively correlated with (log) GA concentration (for example: r
2 = 0.93 for GA1 and hypocotyl length) but shoot dry matter was negatively correlated with GA concentration. The application of gibberellic
acid (GA3) produced elongation of plants grown under high light, indication that their low level of endogenous GA was limiting shoot
elongation. Although endogenous GA20 showed the greatest influence of light treatment, metabolism of [3H]GA20 and of [3H]GA1 was only slightly influenced by light intensity, suggesting that neither 2β- nor 3β-hydroxylation were points of metabolic
regulation. The results of this study indicate that GAs control shoot elongation but are not directly involved in the regulation
of shoot dry weight in Brassica. The study also suggests a role of GAs in photomorphogenesis, serving as an intermediate between light condition and shoot
elongation response.
Received: 18 June 1998 / Accepted: 29 July 1998 相似文献
19.
Maize glutathione-dependent formaldehyde dehydrogenase: protein sequence and catalytic properties 总被引:2,自引:0,他引:2
Glutathione-dependent formaldehyde dehydrogenase (FDH; EC 1.2.1.1) has been purified 3900-fold from maize cell-suspension
cultures to a specific activity of 4.68 μmol (mg protein)−1 min−1. The homogeneous enzyme consisted of two identical subunits with a molecular mass of 42 kDa, and an isoelectric point of
5.8. Eight tryptic peptides were sequenced and gave a perfect fit to the protein sequence derived from maize Fdh cDNA (J. Fliegmann and H. Sandermann, 1997, Plant Mol Biol 34: 843–854). There was 62% identity with the eucaryotic FDH consensus
sequence. Michaelis constants of approx. 20 μm (formaldehyde), approx. 50 μm (glutathione) and approx. 31 μm (NAD+) were determined for the maize enzyme as well as for FDH partially purified from dog lung. Besides S-hydroxymethylglutathione, pentanol-1, octanol-1, and ω-hydroxyfatty acids served as substrates for both FDH preparations.
The unusual substrate specificity indicates that FDH may be involved in the detoxification of long-chain lipid peroxidation
products.
Received: 1 April 1998 / Accepted: 18 November 1998 相似文献
20.
Kinetic models for astaxanthin production by high cell density mixotrophic culture of the microalga Haematococcus pluvialis 总被引:3,自引:0,他引:3
High cell density cultivation of Haematococcus pluvialis for astaxanthin production was carried out in batch and fed-batch modes in 3.7-L bioreactors with stepwise increased light
intensity control mode. A high cell density of 2.65 g L−1 (batch culture) or 2.74 g L−1 (fed-batch culture) was obtained, and total astaxanthin production in the fed-batch culture (64.36 mg L−1) was about 20.5% higher than in the batch culture (53.43 mg L−1). An unstructured kinetic model to describe the microalga culture system including cell growth, astaxanthin formation, as
well as sodium acetate consumption was proposed. Good agreement was found between the model predictions and experimental data.
The models demonstrated that the optimal light intensity for mixotrophic growth of H. pluvialis in batch or fed-batch cultures in a 3.7-L bioreactor was 90–360 μmol m−2 s−1, and that the stepwise increased light intensity mode could be replaced by a constant light intensity mode.
Received 24 December 1998/ Accepted in revised form 23 April 1999 相似文献