Journal of Photochemistry and Photobiology B: Biology 80 (2005) 71–78
www.elsevier.com/locate/jphotobiol
Effect of light quality on the accumulation of
photosynthetic pigments, proteins and mycosporine-like amino
acids in the red alga Porphyra leucosticta (Bangiales, Rhodophyta)
Nathalie Korbee *, Félix L. Figueroa, José Aguilera
Departamento de Ecologı́a, Facultad de Ciencias, Universidad de Málaga, Campus Universitario de Teatinos s/n, 29071-Málaga, Spain
Received 4 November 2004; received in revised form 7 March 2005; accepted 7 March 2005
Available online 21 April 2005
Abstract
The effect of different light qualities (white, blue, green, yellow and red light) on photosynthesis, measured as chlorophyll fluorescence, and the accumulation of photosynthetic pigments, proteins and the UV-absorbing mycosporine-like amino acids (MAAs)
was studied in the red alga Porphyra leucosticta. Blue light promoted the highest accumulation of nitrogen metabolism derived compounds i.e., MAAs, phycoerythrin and proteins in previously N-starved algae after seven days culture in ammonium enriched medium. Similar results were observed in the culture under white light. In contrast, the lowest photosynthetic capacity i.e., lowest
electron transport rate and lowest photosynthetic efficiency as well as the growth rate were found under blue light, while higher values were found in red and white lights. Blue light favored the accumulation of the MAAs porphyra-334, palythine and asterina-330
in P. leucosticta. However, white, green, yellow and red lights favored the accumulation of shinorine. The increase of porphyra-334,
palythine and asterina-330 occurred in blue light simultaneous to a decrease in shinorine. The accumulation of MAAs and other
nitrogenous compounds in P. leucosticta under blue light could not be attributed to photosynthesis and the action of a non-photosynthetic blue light photoreceptor is suggested. A non-photosynthetic photoreceptor could be also involved in the MAAs interconversion pathways in P. leucosticta.
2005 Elsevier B.V. All rights reserved.
Keywords: Light quality; Mycosporine-like amino acid; Photoreceptor; Photosynthesis; Porphyra
1. Introduction
Light quality affects photosynthesis, growth, development and morphogenesis in algae [1–6]. Physiological
and morphological processes are the main targets for
the acclimation of algae to the light field. In the red alga
Porphyra leucosticta, red light favored thallus expansion, cell division and carbon accumulation meanwhile
blue light favored the accumulation of N compounds
i.e., photosynthetic pigment and protein with little
apparent thallus expansion [3,6]. In red light-adapted
*
Corresponding author. Tel.: +34 952 133337; fax: +34 952 132000.
E-mail address: nkorbee@uma.es (N. Korbee).
1011-1344/$ - see front matter 2005 Elsevier B.V. All rights reserved.
doi:10.1016/j.jphotobiol.2005.03.002
thalli, most of the photosynthetic energy can be diverted
into new biomass due to high carbon investment efficiency that minimized the demand for synthesis of new
photosynthetic components [5]. The white light effect is
the combination of both red and blue light effects [5].
In macroalgae, the accumulation of N compounds
under different light qualities was produced due to the
stimulation of N metabolism i.e., nitrate incorporation
and stimulation of nitrate reductase activity, under the
control of non-photosynthetic photoreceptors [4,7,8].
Mycosporine-like amino acids (MAAs) are UV
absorbing and nitrogenous compounds with low molecular weight, high molar extinction coefficients and
absorption band in the UV with a maximum between
72
N. Korbee et al. / Journal of Photochemistry and Photobiology B: Biology 80 (2005) 71–78
310 and 360 nm [9,10]. Recently, it has been shown that
both UV radiation and high inorganic nitrogen availability stimulate the accumulation of MAAs in
P. leucosticta [11]. MAAs are passive sunscreens, preferentially absorbing UV photons followed by a dissipation
of the absorbed radiation energy in the form of harmless
heat without generating photochemical reactions and
thereby protecting, at least partially, photosynthesis
and growth of phototropic organisms [12–14]. Besides
having a role in UV screening, several MAAs also show
antioxidant properties [15,16], which could act as compatible solutes [10,17], and other function as nitrogen
reserve could be inferred to these compounds from the
accumulation in presence of ammonium [11,18], as occurred in the case of biliproteins [19].
Although the maximal absorption of MAAs is in the
UV region, other wavelengths such as blue light can
control the accumulation of MAAs in different algae
[20–27].
The aim of this work was to study the effect of different light qualities (white, blue, green, yellow and red
light) for one week exposure under high nitrogen availability on photosynthesis and the accumulation of
photosynthetic pigments, proteins and MAAs in the
N-starved red alga P. leucosticta. Since MAAs are
nitrogenous compounds, a further objective was to
investigate if the accumulation of these compounds is
photoregulated in the same way as other nitrogenous
compounds i.e., photosynthetic pigments (chlorophyll
and phycobiliproteins) as had been reported in previous
studies [7,8].
2. Materials and methods
2.1. Plant material and culture conditions
Specimens of P. leucosticta Thuret in Le Jolis were
collected in April 2002 from the intertidal zone of Lagos, Málaga, Southern Spain (3628 0 N 41 0 W). Discs
of approximately 1.2 cm in diameter were cut from thalli
of P. leucosticta and pre-acclimated in an illuminated
culture chamber at 16 ± 2 C in aerated cylinders filled
with artificial seawater (salinity of 33&, Instant Ocean
Sea Salt, Aquarium System, Sarrebourg, France) for
one week, without nitrogen (starved-conditions). During
this period algae were illuminated with fluorescent light
(Truelite, Duro-Test Corp., NJ, USA, 40 lmol m2 s1)
with a photoperiod of 12 h light:12 h dark.
For light quality treatments, again at 16 ± 2 C, 90
discs per treatment were transferred to five aerated cylinders with 300 lM NH4Cl and incubated for one week
with 45 lmol m2 s1 of white, blue, green, yellow and
red light and a photoperiod of 12:12 light:dark. Irradiation with white light was provided with two Truelite
fluorescent lamps. Blue light was supplied with four Phi-
lips (20W fluorescent lamps) covered with two Plexiglas
blue filters (Röhm PG627 and PG602, Röhm GmbH,
Darmstadt, Germany). Irradiation with green light was
provided with a General Electric 20W and two Sylvania
fluorescent lamps covered with one Plexiglas Röhm
PG700 green filter. Irradiation with yellow light was
supplied with one Philips low pressure sodium lamp
SOX 135W attenuated with three neutral filters (gray
nets). Red light was obtained from four General Electric
20W red lamps filtered through one Plexiglas red filter
Röhm PG502. Spectral irradiance was determined by
means of a Licor 1800-UW spectroradiometer (LICOR,
Lincoln, NE, USA). The spectral characteristics are reported in Fig. 1. In Table 1, effective irradiance for photosynthesis calculated according to the action spectra
reported in Porphyra umbilicalis [1] is shown.
Algal samples were taken after three and seven days
of incubation. Samples for pigment and protein analyses
were wrapped in aluminium foil, frozen in liquid nitrogen for several hours and then stored at 20 C until
analysis were conducted. And samples for MAAs, C
and N analyses were blotted dry with paper tissue, and
then dried in silica gel in sealed plastic bags.
2.2. Photosynthetic activity as in vivo chlorophyll
fluorescence
In vivo chlorophyll fluorescence of photosystem II
(PSII) was determined with a portable pulse modulation
fluorometer (PAM 2000, Waltz GmbH, Effeltrich,
Germany). Determination of the maximal quantum
yield of fluorescence (Fv/Fm) was achieved according to
Korbee et al. [18]. Five replicates were taken for each
treatment.
The electron transport rate (ETR) was determined
using a Diving-PAM fluorometer (Waltz GmbH, Effeltrich, Germany) according to Korbee et al. [18]. Five
replicates were taken for each treatment.
Fig. 1. Relative spectral irradiance of the lamps used: WL = white
light, BL = blue light, GL = green light, YL = yellow light, RL = red
light.
N. Korbee et al. / Journal of Photochemistry and Photobiology B: Biology 80 (2005) 71–78
Table 1
Irradiance and photosynthetic effective irradiance (PEI) expressed as
lmol m2 s1 in the different light qualities used
Light quality
Irradiance (lmol m2 s1)
PEI (lmol m2 s1)
White
Blue
Green
Yellow
Red
45
45
45
45
45
31
14
38
35
33
PEI was calculated according to the action spectra reported in
Porphyra umbilicalis [1].
2.3. Growth rate
The relative growth rate (R), expressed as % day1,
was computed from the following expression [28]:
R ¼ ðln at ln a0 Þ=t;
where at is the area measured at time (t) in days and
a0 is the area at the initial time. Ten replicates were
taken for each treatment. Disc area was determined
using an image analysis software (Visilog 5.2, Noesis,
France).
73
2.6. Structural protein content
Structural proteins were determined from the pellet
fraction obtained after centrifugation as above indicated. Sodium hydroxide 1 M was added to the pellet,
the extraction occurred for 24 h at 4 C in darkness,
after this time HCl 1 N was added and finally the content of StP was determined as described above for SP.
2.7. Extraction, identification and quantification of MAAs
MAAs determination was assayed according to
Korbee-Peinado et al. [11]. Triplicate samples of dried
algal samples (10–20 mg DW) were extracted for 2 h in
centrifuge vials with 1 ml 20% (v/v) aqueous methanol
in a water bath at 45 C. Dried extracts were re-dissolved in 100% methanol and samples were analyzed
with an HPLC system (Waters 600). The mobile phase
was 2.5% aqueous methanol (v/v) plus 0.1% acetic acid
(v/v) in water, run isocratically at 0.5 ml min1. Sample
volumes of 10 lL were injected into the C8 chromatographic column (5 lm pore size, 250 · 4 mm, Sphereclone, Phenomenex, Aschaffenburg, Germany).
MAAs were detected online with a Waters Photodiode
Array Detector 996 at 330 nm.
2.4. Photosynthetic pigments
2.8. Internal carbon and nitrogen
Two discs of approximately 10–20 mg fresh weight
(FW) per sample were extracted in 1.5 ml N,N-dimethylformamide for 24 h at 4 C in darkness. After centrifugation at 5000g for 10 min (Labofuge 400R, Heraeus,
Kendro Laboratory Products, Langenselbold, Germany), the supernatant was used for chlorophyll a
(Chl a) determination. Chl a concentration was calculated from the OD [29]. Triplicate samples were taken
from each treatment.
To determine phycobiliproteins (BP), phycoerythrin
(PE) and phycocyanin (PC), samples of 30–40 mg
(FW) of algal biomass were homogenized and extracted
in 2 ml of 0.1 M phosphate buffer (pH 6.5). The extracts
were centrifuged at 5000g for 10 min and the concentration of BP in the supernatant was determined from the
OD [30]. The supernatant was also used to determine
the content of soluble proteins (SP). And the pellet
was used to determine the content of structural proteins
(StP). Triplicate samples were taken from each
treatment.
2.5. Soluble protein content
Soluble proteins were determined using a commercial
Protein Assay (BioRad), based on Bradford method
[31]. Protein content was determined spectrophotometrically at 595 nm and concentrations were calculated by
means of standards made with bovine serum albumin
(SIGMA).
Total intracellular carbon and nitrogen contents were
determined in triplicate dry samples at 1050 C by an
elemental analyzer CNHS LECO-932 (LECO Corp.,
MI, USA) couple with an IR detector.
2.9. Statistics
The results were analyzed by one-way ANOVA with
a significance level of p < 0.05. Previously, ANOVA
assumptions (homogeneity of variances and normal distribution) were examined. To determine differences
among treatments post hoc comparisons were made
with the Tukey test [32]. Computations were done with
SPSS for Windows, version 11.5.
3. Results
The photosynthetic activity was estimated as the
Fv/Fm and the ETR. Under blue light, thallus of
P. leucosticta showed an increase in the Fv/Fm, meanwhile there was a decrease in red light (Table 2). However, the maximal electron transport rate (ETRmax)
increased significantly (p < 0.05) after the incubation under all light treatments, with the exception of blue light.
After the experimental period the greatest ETRmax value
was found under red light. The slope of the ETR versus
irradiance curve (a) was greater after the incubation
N. Korbee et al. / Journal of Photochemistry and Photobiology B: Biology 80 (2005) 71–78
Table 2
Optimal quantum yield (Fv/Fm), maximal ETR (ETRmax) and initial
slope (a) of the function ETR versus irradiance in Porphyra leucosticta
at initial time and after seven days of incubation
Treatment
Initial
Seven-day
cultures
Fv/Fm
0.70 ± 0.03
White
Blue
Green
Yellow
Red
ETRmax
a
0.70 ± 0.01a
0.72 ± 0.01b
0.69 ± 0.01a,d
0.68 ± 0.02d
0.65 ± 0.02c
a
a
1.50 ± 0.29
0.07 ± 0.02a,b
4.43 ± 1.19b
2.82 ± 0.67a,c
3.37 ± 0.98b,c
3.24 ± 0.21b,c
7.60 ± 1.26d
0.13 ± 0.01c
0.05 ± 0.01a
0.13 ± 0.02c
0.13 ± 0.02c
0.09 ± 0.01b
Different letters indicate significant differences between values
(p < 0.05) for each parameter. Data given as means ± SD (n = 5).
under white, green and yellow light than that in the initial time. No changes in a under blue and red light was
observed; however, a was greater under red than under
blue light (Table 2).
Although algal samples were taken and analyzed
after three and seven days, the pattern was the same
and therefore only data of day seven are presented.
Chl a content increased in all light treatments after the
incubation time. However, there were no significant differences among the treatments (Table 3). PE and PC
content also increased in all treatments, except PE in
red light and PC in blue light (Table 3). The increase
of PE was greater than that of PC. Furthermore, the
content of PE after seven days was significantly
(p < 0.05) higher in white and blue than in red light,
but there were no significant differences among treatments in PC content (Table 3). Soluble proteins also increased in all light treatments, reaching the greatest
values under white and blue light and the lowest under
red light (Table 3). As other nitrogenous compounds,
blue light stimulated the accumulation of structural protein (Table 3).
The internal C content did not show any difference
among light treatments, it was approximately
320 mg g1 DW. The internal N content increased in
all treatments after the incubation period (Table 3),
being higher under white, blue and green light than that
under red light. Due to the increase of N content and no
variation in C content, the relation C/N decreased in all
treatments (Table 3). The greatest C/N value was
reached in red light meanwhile the lowest value was observed under white light (Table 3).
The relative growth rate was significantly (p < 0.05)
lower in blue light than that in white, red and green light
(Table 3).
The content of MAAs increased after the incubation
period under white, blue and green light, the highest
concentration was reached under blue light meanwhile
the lowest level was reached under yellow and red light
(Fig. 2). The composition of MAAs at the start of the
experiments
was
12.01 ± 0.39%
of
shinorine,
80.42 ± 1.50% porphyra-334, 3.94 ± 0.12% palythine
and 4.31 ± 0.17% asterina-330 (Fig. 3). During the incubation period, the percentage of shinorine increased significantly (p < 0.05) in all light treatments except in blue
light, in which a decrease was observed (Fig. 3(a)).
14
12
MAAs (mg·g-1 DW)
74
10
8
6
4
2
0
Initial
WL
BL
GL
YL
RL
1
Fig. 2. Concentration of MAAs, expressed in mg g dry weight, in
Porphyra leucosticta at initial time and after seven days of culture
under light treatments. Data are expressed as mean value ± SD (n = 3)
(WL = white light, BL = blue light, GL = green light, YL = yellow
light, RL = red light).
Table 3
Chlorophyll a (Chl a), phycoerythrin (PE), phycocyanin (PC), soluble (SP) and structural proteins (StP) and total intracellular nitrogen content (N),
expressed in mg g1 dried weight and carbon/nitrogen ratio (C/N) in Porphyra leucosticta at initial time and after seven days of incubation
Light
treatment
Initial
Seven-day
cultures
White
Blue
Green
Yellow
Red
Chl a
PE
PC
SP
StP
2.83 ± 0.44a
6.11 ± 0.30a
3.47 ± 0.67a
40.7 ± 3.8a
b
b
b
b
6.83 ± 0.78
5.80 ± 0.78b
7.06 ± 0.38b
6.37 ± 0.65b
5.60 ± 0.60b
11.80 ± 1.87
11.83 ± 0.66b
10.26 ± 1.06b,c
9.84 ± 1.22b,c
7.82 ± 0.72a,c
6.31 ± 0.70
4.91 ± 0.20a,b
5.81 ± 0.60b
5.54 ± 0.14b
5.68 ± 0.62b
78.1 ± 6.1
77.4 ± 0.4b
75.2 ± 2.4b,c
72.4 ± 0.5b,c
65.2 ± 3.7c
N
120.0 ± 4.8a
C/N
37.0 ± 2.0a
a
112.1 ± 20.0
151.6 ± 3.3b
108.0 ± 15.5a
115.1 ± 14.1a
98.2 ± 10.7a
b
62.7 ± 1.7
56.9 ± 1.7b,c
56.1 ± 0.0b,c
54.0 ± 6.2c,d
47.3 ± 0.9d
R (% day1)
8.6 ± 0.2a
5.6 ± 0.2b
6.0 ± 0.1b,c
6.3 ± 0.0c
6.4 ± 0.5c
7.1 ± 0.3d
6.5 ± 1.4a,b
3.3 ± 0.7c
7.3 ± 1.3b
4.9 ± 1.0a,c
6.0 ± 0.4a,b
Relative growth rate (R), expressed in % day1, evaluated after seven days of incubation. Different letters indicate significant differences between
values (p < 0.05) for each parameter. Data given as means ± SD (n = 3 for Chl a, PE, PC, SP, StP, N and C/N; n = 10 for R).
N. Korbee et al. / Journal of Photochemistry and Photobiology B: Biology 80 (2005) 71–78
(a)
Porphyra-334 (%)
Shinorine (%)
30
25
20
15
10
5
100 (b)
80
60
40
20
0
(c)
Asterina-330 (%)
Palythine (%)
0
6
4
2
0
Initial WL BL GL YL RL
75
(d)
6
4
2
0
Initial WL BL GL YL RL
Fig. 3. Composition of MAAs in Porphyra leucosticta at initial time and after seven days of culture under light treatments. Percentage of (a)
shinorine with respect to the total amount (%), (b) porphyra-334 (%), (c) palythine (%), (d) asterina-330 (%). Data are expressed as mean value ± SD
(n = 3) (WL = white light, BL = blue light, GL = green light, YL = yellow light, RL = red light).
Table 4
Concentration of shinorine, porphyra-334, palythine and asterina-330, expressed in mg g1 dried weight, in Porphyra leucosticta at initial time and
after seven days of incubation
Treatment
Initial
Seven-day cultures
White
Blue
Green
Yellow
Red
Shinorine
Porphyra-334
Palythine
Asterina-330
0.80 ± 0.16a
5.34 ± 0.83a
0.29 ± 0.02a
0.31 ± 0.04a
2.67 ± 0.07b
0.57 ± 0.05a
2.39 ± 0.36b,c
1.96 ± 0.17c
1.87 ± 0.25c
7.27 ± 0.21b
8.88 ± 0.50c
6.54 ± 0.05a,b
5.75 ± 0.52a,b
5.69 ± 0.21a,b
0.22 ± 0.01a
0.60 ± 0.11b
0.19 ± 0.01a
0.14 ± 0.01a
0.16 ± 0.01a
0.24 ± 0.01a
0.64 ± 0.12b
0.21 ± 0.01a
0.15 ± 0.01a
0.18 ± 0.01a
Different letters indicate significant differences between values (p < 0.05) for each parameter. Data given as means ± SD (n = 3).
Meanwhile, the percentages of palythine and asterina330 decreased compared to the initial values in all light
treatments except under blue-light treatment. Thus,
both palythine and asterina-330 accumulation was
clearly stimulated by blue light (Fig. 3(c) and (d)). There
was a decrease in the percentage of porphyra-334 in all
treatments, with the exception of blue light (Fig. 3(b)).
The concentration of each MAA was shown in Table 4.
4. Discussion
In P. leucosticta, it has been shown that red light favored thallus expansion, cell division, carbon accumulation and a dramatic decrease of the protoplasmic area
and in the thickness of the cell walls, while blue light favored photosynthetic pigment, protein synthesis, numerous well-formed phycobilisomes with little apparent
thallus expansion [3,6]. White light, as the result of the
combination of all light qualities, favors both C and N
metabolisms [3,6]. The accumulation of Chl a in
P. leucosticta after one week of incubation was similar
in all light treatments, as occurred in the same species
cultured under blue and red light [4]. The content of
PE was greater in white and blue than in red light, however, there were no differences among treatments in PC
content. Previously, it has been shown in P. leucosticta
an increase not only in PE but also in PC content [4].
Soluble and structural proteins were mainly stimulated
by blue light as it has been previously reported [3,4].
The UV-screen substances, MAAs, were also stimulated
by blue light as other nitrogenous compounds [4,33].
Lüning and Dring [1] demonstrated reduced photosynthetic activity in blue light compared with other spectral bands in P. umbilicalis and other red algae
according to the action spectra for photosynthesis. In
P. leucosticta, lower photosynthetic rates have been
demonstrated under blue light relative to red light
76
N. Korbee et al. / Journal of Photochemistry and Photobiology B: Biology 80 (2005) 71–78
[3,5]. Our results are consistent with these studies; the
lowest ETRmax and the lowest photosynthetic efficiency
(a) had been shown in blue light. The lower values of
ETRmax and a under blue light has been interpreted by
a higher package effect [5] and higher amount of PE pool
not attached to phycobilisomes, as observed in this species previously by Tsekos et al. [6]. In contrast, Fv/Fm
was greater under blue than under red light. So, low
ETRmax in parallel to high Fv/Fm values under blue light
could be related to an imbalance between PSII and PSI,
with a simultaneous high demand for electron sinks i.e.,
Mehler reaction or the electron demand for the inorganic nitrogen assimilation, which is stimulated by blue
light [3,5].
Growth rate under blue light was significantly lower
than in white, red and green lights in P. leucosticta, as
it has been previously shown in this species [3,5]. The
lower growth rate under blue light could be related to
the lowest ETRmax and the lowest photosynthetic efficiency (a) observed under these culture conditions, as
described above. Other authors ascribed the lower
growth rate in blue light to two different processes in
P. leucosticta; first, to a low efficiency in photosynthetic
performance mainly produced at level of the water splitting complex of the PSII and secondly to a lower carbon
investment efficiency, leading to a deficient accumulation of photosynthetic and osmotic-related products [5].
Previous studies showed that in the Bangiales the
accumulation of MAAs was not affected by light quality
[34,35]. These results have been explained by the fact
that these species contain very high constitutive level
of MAAs (8–10 mg g1 DW), close to the maximal potential concentration [18,34,36,37]. In contrast, in our
study the initial level of MAAs was reduced to
6.7 ± 1.1 mg g1 DW, due to the previous incubation
under N-starvation conditions. When algae were transferred to a medium with high ammonium concentration,
the synthesis of MAAs was stimulated by blue or white
light. Similar stimulation, by blue light after the addition
of inorganic nitrogen, has been reported for phycobiliproteins and chlorophylls [7,8]. The accumulation of
nitrogenous compounds under blue light was related
to the stimulation of nitrate incorporation, and the stimulation of nitrate reductase and glutamine synthetase
activities [8].
This is the second report regarding the variation of
MAAs in Porphyra sp. due to light quality [11]. It has
been well established that algae respond to nutrient limitation by increasing uptake capacity and/or efficiency
for the specific nutrient [38]. The response of MAAs to
light quality and nitrogen enrichment (after starvation)
is according to the fast incorporation of nitrogen into
organic compounds i.e., PE and protein, as it has been
previously reported [3]. Wavelength dependence for
MAA synthesis in algae has been published [15,25,39].
The total UV absorbance of the microalgae Alexand-
rium excavatum increased when cells where grown in
blue light, but not to the same degree as white light
[20]. The intracellular concentration of MAAs in the
microalgae Gloeocapsa sp. achieved were directly related
to the intensity of the UV radiation (maximum at
320 nm) received by the cells; however, a small but significant increase was attained with UV radiation at
365 nm, and neither blue, green nor red light increased
MAAs concentration in this species [21]. Antarctic diatoms synthesized MAAs preferentially between 370
and 460 nm [22].
Our results indicate that blue light favored the accumulation of palythine and asterina-330 in P. leucosticta.
However, white, green, yellow and red lights favored the
accumulation of shinorine. The induction of MAAs by
red, green, blue and white light was examined in Chondrus crispus collected from Helgoland [25]. Palythine
was the most abundant MAA in this species [24]. Similar
results as in P. leucosticta were obtained, palythine was
synthesized in thalli under blue light to the same extent
observed in control samples in white light, in contrast,
no MAAs were accumulated under green and red light
[25]. The differences observed under different light qualities in the accumulation of MAAs in P. leucosticta seem
to be mediated by a non-photosynthetic photoreceptor.
Some authors suggest the presence of photoreceptors in
the synthesis of MAAs; a reduced pterin (UV-B photoreceptor) was suggested in Chlorogloeopsis PCC 6912
[40]. On the other hand, flavins have been discussed in
the induction of MAAs in C. crispus, they demonstrated
that blue light and UV radiation interact to boost the
synthesis of shinorine [25], which is in line with the photoregulation of flavin synthesis [41,42]. In addition, recently a monochromatic action spectrum for shinorine
in C. crispus indicated that the photoreceptors mediating
shinorine photoinduction might be an unidentified
UVA-type photoreceptor with absorption peaks at
320, 340 and 400 nm [27]. The fact that the increase of
palythine and asterina-330 occurred in blue light simultaneous to a decrease in shinorine in P. leucosticta suggests that blue light photoreceptor could be involved in
the MAA conversion pathway. Carreto et al. [43] illustrated the structural relationship among several MAAs
commonly detected in the marine environment. We propose the conversion from shinorine to palythine and
asterina-330 in P. leucosticta under blue light.
In summary, the greatest accumulation of MAAs,
PE and proteins in blue light cannot be attributed
to photosynthesis i.e., photosynthetic rate is low under
blue light. But rather, the accumulation of nitrogenous
compounds seems to be controlled by a non-photosynthetic blue light photoreceptor, as it has been shown
for the control of photosynthetic pigment synthesis
in red macroalgae [7]. The identification of this photoreceptor and the transduction pathway must be still
elucidated.
N. Korbee et al. / Journal of Photochemistry and Photobiology B: Biology 80 (2005) 71–78
5. Abbreviations
a
photosynthetic efficiency
a
area
BP
phycobiliprotein
Chl
chlorophyll
DW
dried weight
ETR
electron transport rate
ETRmax maximal electron transport rate
FW
fresh weight
Fv/Fm maximal quantum yield
MAAs mycosporine-like amino acids
OD
optical density
PAM pulse amplitude modulated fluorescence
PC
phycocyanin
PE
phycoerythrin
R
relative growth rate
SP
soluble protein
StP
structural protein
UV
ultraviolet radiation
Acknowledgements
This study was supported by a grant from de Ministry of Education and Science (Spain) to N.K.P. The CICYT project AGL 2001-1888-C03-02 (MCYT) and the
Research group RNM-295 (Junta de Andalucı́a). We
thank Dr. A. Cabello for improving the English grammar, and two anonymous reviewers who provided helpful comments and suggestions on the manuscript.
References
[1] K. Lüning, M.J. Dring, Action spectra and spectral quantum
yield of photosynthesis in marine macroalgae with thin and thick
thalli, Mar. Biol. 87 (1985) 119–129.
[2] M.J. Dring, Photocontrol of development in algae, Ann. Rev.
Plant Physiol. Mol. Biol. 39 (1988) 157–174.
[3] F.L. Figueroa, J. Aguilera, F.X. Niell, Red and blue light
regulation of growth and photosynthetic metabolism in Porphyra
umbilicalis (Bangiales, Rhodophyta), Eur. J. Phycol. 30 (1995)
11–18.
[4] F.L. Figueroa, J. Aguilera, C. Jiménez, J.J. Vergara, M.D.
Robles, F.X. Niell, Growth, pigment synthesis and nitrogen
assimilation in the red alga Porphyra sp. (Bangiales, Rhodophyta)
under blue and red light, Sci. Mar. 59 (1995) 9–20.
[5] J. Aguilera, F.J.L. Gordillo, U. Karsten, F.L. Figueroa, F.X.
Niell, Light quality effect on photosynthesis and efficiency of
carbon assimilation in the red alga Porphyra leucosticta, J. Plant
Physiol. 157 (2000) 86–92.
[6] I. Tsekos, F.X. Niell, J. Aguilera, F.L. Figueroa, S.G. Delivopoulos, Ultrastructure of the vegetative gametophytic cells of
Porphyra leucosticta (Rhodophyta) grown in red, blue and green
light, Phycol. Res. 50 (2002) 251–264.
[7] W. Rüdiger, F. López-Figueroa, Photoreceptors in algae, Photochem. Photobiol. 55 (1992) 949–954.
77
[8] F.L. Figueroa, Effects of light quality on nitrate reductase and
glutamine synthetase activities in the red alga Porphyra leucosticta Thur. in Le Jol. and other macroalgae, Sci. Mar. 60 (1996)
163–170.
[9] C.S. Cockell, J. Knowland, Ultraviolet radiation screening compounds, Biol. Rev. 74 (1999) 311–345.
[10] J.M. Shick, W.C. Dunlap, Mycosporine-like amino acids and
related gadusols: biosynthesis, accumulation and UV-protective
functions in aquatic organisms, Ann. Rev. Physiol. 64 (2002)
223–262.
[11] N. Korbee-Peinado, R.T. Abdala-Dı́az, F.L. Figueroa, E.W.
Helbling, Ammonium and UV radiation stimulate the accumulation of mycosporine-like amino acids in Porphyra columbina
(Rhodophyta) from Patagonia, Argentina, J. Phycol. 40 (2004)
248–259.
[12] F.R. Conde, M.S. Churio, C.M. Previtali, The photoprotector
mechanism of mycosporine-like amino acids. Excited-state properties and photostability of porphyra-334 in aqueous solution, J.
Photochem. Photobiol. B: Biol. 56 (2000) 139–144.
[13] F.R. Conde, M.O. Carignan, M.S. Churio, J.I. Carreto, In vitro
cis–trans photoisomerization of palythene and usujirene. Implications on the in vivo transformation of mycosporine-like amino
acids, Photochem. Photobiol. 77 (2003) 146–150.
[14] J.M. Shick, W.C. Dunlap, G.R. Buettner, in: S. Yoshikawa, S.
Toyokuni, Y. Yamamoto, Y. Naito (Eds.), Free Radicals in
Chemistry, Biology and Medicine, OICA Int, London, 2000, pp.
215–228.
[15] W.C. Dunlap, J.M. Shick, UV radiation absorbing mycosporinelike amino acids in coral reef organisms: a biochemical and
environmental perspective, J. Phycol. 34 (1998) 418–430.
[16] H.J. Suh, H.W. Lee, J. Jung, Mycosporine-glycine protects
biological systems against photodynamic damage by quenching
singlet oxygen with a high efficiency, Photochem. Photobiol. 78
(2003) 109–113.
[17] A. Oren, Mycosporine-like amino acids as osmotic solutes in a
community of halophilic cyanobacteria, Geomicrobiol. J. 14
(1997) 231–240.
[18] N. Korbee, P. Huovinen, F.L. Figueroa, J. Aguilera, U. Karsten,
Availability of ammonium influences photosynthesis and the
accumulation of mycosporine-like amino acids in two Porphyra
species (Bangiales, Rhodophyta), Mar. Biol. 146 (2005) 645–654.
[19] L. Talarico, G. Maranzana, Light and adaptative responses in red
macroalgae: an overview, J. Photochem. Photobiol. B: Biol. 56
(2000) 1–11.
[20] J.I. Carreto, V.A. Lutz, S.G. De Marco, M.O. Carignan, in: E.
Graneli, L. Edler, B. Sundstrom, D.M. Anderson (Eds.), Toxic
Marine Phytoplankton, Elsevier, Amsterdam, 1990, pp. 275–279.
[21] F. Garcı́a-Pichel, C.E. Wingard, R.W. Castenholz, Evidence
regarding the UV sunscreen role of a mycosporine-like compound
in the cyanobacterium Gloecapsa sp., Appl. Environ. Microbiol.
59 (1993) 170–176.
[22] L. Riegger, D. Robinson, Photoinduction of UV-absorbing
compounds in Antarctic diatoms and Phaeocystis antarctica,
Mar. Ecol. Prog. Ser. 160 (1997) 13–25.
[23] U. Karsten, T. Sawall, D. Hanelt, K. Bischof, F.L. Figueroa, A.
Flores-Moya, C. Wiencke, An inventory of UV-absorbing
mycosporine-like amino acids in macroalgae from polar to
warm-temperate regions, Bot. Mar. 41 (1998) 443–453.
[24] L.A. Franklin, I. Yakovleva, U. Karsten, K. Lüning, Synthesis of
mycosporine-like amino acids in Chondrus crispus (Florideophyceae) and the consequences for sensitivity to ultraviolet B
radiation, J. Phycol. 35 (1999) 682–693.
[25] L.A. Franklin, G. Kräbs, R. Kuhlenkamp, Blue light and UVA
radiation control the synthesis of mycosporine-like amino acids in
Chondrus crispus (Florideophyceae), J. Phycol. 37 (2001) 257–270.
[26] K. Hoyer, U. Karsten, T. Sawall, C. Wiencke, Photoprotective
substances in Antarctic macroalgae and their variation with
78
[27]
[28]
[29]
[30]
[31]
[32]
[33]
[34]
[35]
N. Korbee et al. / Journal of Photochemistry and Photobiology B: Biology 80 (2005) 71–78
respect to depth distribution, different tissues and developmental
stages, Mar. Ecol. Prog. Ser. 211 (2001) 117–129.
G. Kräbs, M. Watanabe, C. Wiencke, A monochromatic action
spectrum for the photoinduction of the UV-absorbing mycosporine-like amino acid shinorine in the red alga Chondrus crispus,
Photochem. Photobiol. 79 (2004) 515–519.
J.M. Kain, Seasonal growth and photoinhibition in Plocamium
cartilagineum (Rhodophyta) of the Isle of Man, Phycologia 26
(1987) 88–99.
W. Inskeep, P.R. Bloom, Extinction coefficients of chlorophyll a
and b in N,N-dimethylformamide and 80% acetone, Plant Physiol.
77 (1985) 483–485.
S. Beer, A. Eshel, Determining phycoerythrin and phycocyanin
concentrations in aqueous crude extracts of red algae, Aust. J.
Mar. Freshw. Res. 36 (1985) 785–792.
M.M. Bradford, A rapid and sensitive method for the quantification of micrograms quantities of protein utilizing the principle
of protein-dye binding, Anal. Biochem. 72 (1976) 248–254.
R.R. Sokal, F.J. Rohlf, Biometry, third ed., W.H. Freeman and
Company, New York, 1995.
F.L. Figueroa, Photoregulation of nitrogen metabolism ad protein
accumulation in the accumulation in the red alga Corallina
elongata Ellis et Soland, Z. Naturforsch. 48 (1993) 788–794.
A. Gröniger, C. Hallier, D.P. Häder, Influence of UV radiation
and visible light on Porphyra umbilicalis: photoinhibition and
MAA concentration, J. Appl. Phycol. 11 (1999) 437–445.
U. Karsten, J.A. West, Living in the intertidal zone-seasonal
effects on heterosides and sun-screen compounds in the red alga
[36]
[37]
[38]
[39]
[40]
[41]
[42]
[43]
Bangia atropurpurea (Bangiales), J. Exp. Mar. Biol. Ecol. 254
(2000) 221–234.
A. Gröniger, R.P. Sinha, M. Klisch, D.P. Häder, Photoprotective
compounds in cyanobacteria, phytoplankton and macroalgae-a
database, J. Photochem. Photobiol. B: Biol. 58 (2000) 115–122.
K. Hoyer, U. Karsten, C. Wiencke, Induction of sunscreen
compounds in Antarctic macroalgae by different radiation conditions, Mar. Biol. 141 (2002) 619–627.
J. Beardall, E. Young, S. Roberts, Approaches for determining
phytoplankton nutrient limitation, Aquat. Sci. 63 (2001) 44–69.
R.P. Sinha, M. Klisch, A. Gröniger, D.P. Häder, Ultravioletabsorbing/screening substances in cyanobacteria, phytoplankton
and macroalgae, J. Photochem. Photobiol. B: Biol. 47 (1998) 83–
94.
A. Portwich, F. Garcı́a-Pichel, A novel prokaryotic UVB photoreceptor in the cyanobacterium Chlorogloeopsis PCC 6912,
Photochem. Photobiol. 71 (2000) 493–499.
J.M. Christie, G.J. Jenkins, Distinct UV-B and UV-A/blue light
transduction pathways induce chalcone synthase gene expression
in Arabidopsis cells, Plant Cell 8 (1996) 1555–1567.
G. Fuglevand, J.A. Jackson, G.J. Jenkins, UV-B, UV-A and blue
light signal transduction pathways interact synergistically to
regulate chalcone synthase gene expression in Arabidopsis, Plant
Cell 8 (1996) 2347–2357.
J.I. Carreto, M.O. Carignan, N.G. Montoya, A high-resolution
reverse-phase liquid chromatography method for the analysis of
mycosporine-like amino acids (MAAs) in marine organisms, Mar.
Biol. 146 (2005) 237–252.