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Effect of seed pre-sowing gamma-irradiation treatment in bread wheat lines differing by anthocyanin pigmentation

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Anthocyanins are natural antioxidants able to scavenge free radicals, which appear in plant cells under various environmental stresses. In wheat, anthocyanin pigments can be synthesized in vegetative and reproductive organs. The objective of the current study was to estimate the significance of these substances for wheat seedlings protection under irradiation stress (after treatment of dry seeds with moderate doses of gamma-irradiation, 50, 100 and 200 Gy). For this goal a set of near-isogenic lines (8 NILs) carrying different combinations of the Pp (purple pericarp) and Rc (red coleoptile) alleles were used. The effect of gammairradiation on the growth parameters and anthocyanin content in coleoptiles was studied at the 4th day after germination. The germination rate was not affected, while roots' and shoots' lengths and fresh weights as well as root number decreased significantly under irradiation treatment. The effect was deeper under higher doses. Irradiation treatment also induced change of root morphology ('hairy roots'). The effect of treatment on coleoptile anthocyanin content depended on allelic combination at the Rc loci. At the presence of 'weak' Rc-A1 allele anthocyanin content decreased, while it did not change in lines with Rc-A1 + Rc-D1 combination (NILs with intensively colored coleoptiles). Factors 'pericarp color' and 'coleoptile color' influenced vigor of the seedlings under 50 Gy, whereas under higher doses (100 and 200 Gy) these factors did not contribute to growth parameters changes. Statistically significant positive effect of anthocyanins synthesized in coleoptile (in the presence of Rc-A1 + Rc-D1 dominant alleles) on root growth of seedling germinated from 50 Gy-treated seeds was observed.
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Cereal Research Communications
DOI: 10.1556/0806.45.2017.059
© 2017 Akadémiai Kiadó, Budapest
Effect of Seed Pre-sowing Gamma-irradiation Treatment
in Bread Wheat Lines Differing by Anthocyanin Pigmentation
E.I. GordEEva1**, o.Yu. ShoEva1**, r.S. YudIna1, T.v. KuKoEva1 and E.K. KhlESTKIna1,2*
1Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences,
Lavrentjeva Ave. 10, Novosibirsk, 630090 Russia
2 Novosibirsk State University, Pirogova St. 2, Novosibirsk, 630090 Russia
(Received 6 December 2016; Accepted 4 July 2017;
Communicated by A. Börner and A. Goyal)
Anthocyanins are natural antioxidants able to scavenge free radicals, which appear in
plant cells under various environmental stresses. In wheat, anthocyanin pigments can be
synthesized in vegetative and reproductive organs. The objective of the current study was to
estimate the signicance of these substances for wheat seedlings protection under irradiation
stress (after treatment of dry seeds with moderate doses of gamma-irradiation, 50, 100 and
200 Gy). For this goal a set of near-isogenic lines (8 NILs) carrying different combinations
of the Pp (purple pericarp) and Rc (red coleoptile) alleles were used. The effect of gamma-
irradiation on the growth parameters and anthocyanin content in coleoptiles was studied at
the 4th day after germination. The germination rate was not affected, while roots’ and shoots’
lengths and fresh weights as well as root number decreased signicantly under irradiation
treatment. The effect was deeper under higher doses. Irradiation treatment also induced
change of root morphology (‘hairy roots’). The effect of treatment on coleoptile anthocy-
anin content depended on allelic combination at the Rc loci. At the presence of ‘weak’ Rc-A1
allele anthocyanin content decreased, while it did not change in lines with Rc-A1 + Rc-D1
combination (NILs with intensively colored coleoptiles). Factors ‘pericarp color’ and ‘cole-
optile color’ inuenced vigor of the seedlings under 50 Gy, whereas under higher doses (100
and 200 Gy) these factors did not contribute to growth parameters changes. Statistically
signicant positive effect of anthocyanins synthesized in coleoptile (in the presence of
Rc-A1 + Rc-D1 dominant alleles) on root growth of seedling germinated from 50 Gy-treated
seeds was observed.
Keywords: anthocyanins, coleoptile color, gamma-irradiation, pericarp color, plant vig-
or, protective effect, Pp genes, Rc genes, seed germination, seedlings growth, Triticum aes-
tivum L.
Introduction
The effects of gamma-irradiation include changes in the plant cellular structure and me-
tabolism, e.g., dilation of thylakoid membranes, distortion and swelling of mitochondria
and endoplasmic reticulum, alteration in photosynthesis, decrease of the relative water
*Corresponding author; E-mail: khlest@bionet.nsc.ru; Phone: +7(383)363-49-63; Fax: +7(383)333-12-78
**Authors contributed equally to this work
Gordeeva et al.: γ-irradiation Treatment and Anthocyanins in Wheat
Cereal Research Communications
content and the membrane integrity, modulation of the antioxidant systems, and accumu-
lation of phenolic compounds and carotenoids (Kovács and Keresztes 2002; Kim et al.
2004; Wi et al. 2007; Abou-Zeid and Abdel-Latif 2014; Ramabulana et al. 2016). Gener-
ally, ionizing radiation may have different effects on plant metabolism, growth and repro-
duction depending on the dose: positive effects at very low doses (radiostimulation or
radiation hormesis), detrimental consequences at intermediate levels and pronounced
damage at high doses. Besides the dose, the severity of the effects is dependent on other
factors such as species, cultivars, plant developmental stage (Arena et al. 2014).
The deleterious effects of ionizing radiation in biological systems arise directly via the
interaction between radiation and target macromolecules or indirectly via the generation
of free radicals, which able to produce serious cell damage (Esnault et al. 2010). For
scavenging free radicals plants have protective antioxidant system including antioxidant
defense enzymes such as superoxide dismutase, catalase, and peroxidase and non-enzy-
matic antioxidants (Caverzan et al. 2016). Among non-enzymatic antioxidants pigmented
avonoid compounds anthocyanins can be considered. Their antioxidant capacity is al-
most four times higher than that one of ascorbic acid and α-tocopherol (Bors et al. 1994;
Wang et al. 1997). Accumulation of anthocyanins is positively related to plant adaptation
under environment stresses such as salinity, drought, low temperature, heavy metals or
UV radiation (Chalker-Scott 1999; Landi et al. 2015).
In bread wheat (Triticum aestivum L., BBAADD, 2n = 6x = 42), anthocyanin pig-
ments can be synthesized in vegetative and reproductive organs such as coleoptiles (con-
trolled by the Rc genes), culms (Pc), leaf blades (Plb), leaf sheaths (Pls), glumes (Pg),
auricles (Ra), grain pericarp (complementary genes Pp-1 and Pp3), and anthers (Pan)
(Khlestkina 2012), but the signicance of these substances for wheat plant protection has
not been sufciently estimated yet.
The objective of the current study was to investigate a protective role of the anthocya-
nin pigments accumulated in wheat pericarp and coleoptile against oxidative damages
imposed by gamma-radiation. For this purpose a set of near-isogenic lines carrying differ-
ent combinations of dominant and recessive alleles of the Pp and Rc genes were used.
Materials and Methods
Plant material
A set of near-isogenic lines (NILs) differing in color of grain pericarp and coleoptile was
used (Table 1). The lines have been developed previously in the Institute of Cytology and
Genetics SB RAS (Novosibirsk, Russia) by Arbuzova et al. (1998) and Gordeeva et al.
(2015) as a convenient model for studying anthocyanin regulatory network and for as-
sessment of wheat anthocyanins’ protective role and health benets. The lines have been
developed in the genetic background of spring bread wheat ‘Saratovskaya 29’ (‘S29’)
having non-colored pericarp and light red coleoptile. Among the ‘S29’ NILs there are
lines with trait combinations “non-colored pericarp + non-colored coleoptile”, “light pur-
ple pericarp + light red coleoptile”, “non-colored pericarp + dark red coleoptile”, “dark
Gordeeva et al.: γ-irradiation Treatment and Anthocyanins in Wheat
Cereal Research Communications
purple pericarp + dark red coleoptile”. The sets of dominant alleles determining pheno-
type of each line are described in Table 1.
Irradiation treatment and measurements
Dry seeds of the lines were irradiated with 50, 100 and 200 Gray (Gy), using Cesium-137
(137Cs) gamma-irradiation source (IGUR-1”, Institute Cytology and Genetic SB RAS,
Novosibirsk, Russia). The treated and control seeds were placed in Petri dishes with lter
paper moistened with distilled water and kept for 48 hours at +4 °C in the darkness in a
growth chamber «Rubarth Apparate» (RUMED GmbH) for synchronization of germina-
tion. Thereafter the temperature in the chamber was increased to 20 °C and a daily cycle
with 12 h light/12 h darkness was set up.
At the fourth day after germination the length of the main root and that of the rst leaf
as well as fresh root and shoot weights, roots number and germination rate were meas-
ured. The experiment was performed in ve replicates for each genotype and treatment,
with twenty seedlings per replicate. Changes in root length were calculated as follows:
root length undertreatment
root lengthwithout treatment
1**%100
Changes in other root parameters and shoot lengths and weights, as well as OD530 values
of anthocyanin extracts were calculated in the same way.
All experiments were carried out using seeds produced at the same time and in the
same conditions.
Table 1. The set of the NILs carrying various combinations of Pp alleles used in the current study
No. Line full name Line short name Pericarp color
(dominant gene(s))
Coleoptile color
(dominant gene(s))
1 i:S29pp-A1pp-D1pp3 iJP7A Non-colored Non-colored
2 i:S29Pp-A1pp-D1pp3 S29 Non-colored Light red (Rc-A1)
3 i:S29Pp-A1pp-D1Pp3P iP2A Light purple
(Pp3+Pp-A1)Light red (Rc-A1)
4 i:S29Pp-A1pp-D1Pp3PF iPF2A Light purple
(Pp3+Pp-A1)Light red (Rc-A1)
5 i:S29Pp-A1Pp-D1pp3P iP7D Non-colored Dark red
(Rc-A1+Rc-D1)
6 i:S29Pp-A1Pp-D1pp3PF iPF7D Non-colored Dark red
(Rc-A1+Rc-D1)
7 i:S29Pp-A1Pp-D1Pp3P iP Dark purple
(Pp3+ Pp-A1+Pp-D1)
Dark red
(Rc-A1+Rc-D1)
8 i:S29Pp-A1Pp-D1Pp3PF iPF Dark purple
(Pp3+ Pp-A1+Pp-D1)
Dark red
(Rc-A1+Rc-D1)
Note: The lines development and their allelic combinations at the Rc and Pp loci were described in Gordeeva et al. 2015.
Gordeeva et al.: γ-irradiation Treatment and Anthocyanins in Wheat
Cereal Research Communications
Anthocyanin extraction
For anthocyanin extraction, 20 frozen coleoptiles from each replicate were homogenized
and incubated in 1% HCl/methanol (5 ml for 1 g of plant material) at 4 °C for 24 hours,
then centrifuged at 12,000 g for 30 min at 4 °C. After that supernatant was used for meas-
urement of the relative anthocyanin content at 530 nm wavelength with a spectrophotom-
eter «SmartSpecTMPlus» (BioRad).
Statistical analysis
The signicance of differences between genetic stocks of control and stressed plants were
assessed using nonparametric Mann-Whitney U-tests (Mann and Whitney 1947). The non-
parametric Kruskal–Wallis one-way analysis of variance H-test (Kruskal and Wallis 1952)
was used for determining the inuence of gamma-irradiation on growth parameters of
seedlings and factors ‘pericarp color’, ‘coleoptile colour’, and ‘pericarp and coleoptile
color’ on growth parameters changes of wheat seedlings after seeds exposure to 50, 100
and 200 Gy. The NILs were differently combined to test the effect of the coloration on
growth parameters changes. In respect to pericarp color three groups were distinguished:
‘non-colored’ (‘iJP7A’, ‘S29’, ‘iPF7D’, ‘iP7D’), ‘light purple’ (‘iPF2A’, ‘iP2A’) and ‘dark
purple’ (‘iPF’, ‘iP’). According to coleoptile color also three groups were distinguished:
‘non-colored’ (‘iJP7A’), ‘light red’ (‘S29’, ‘iPF2A’, ‘iP2A’) and ‘dark red’ (‘iPF’, ‘iP’,
‘iPF7D’, ‘iP7D’). Five groups of samples were distinguished with respect to pericarp and
coleoptile color: ‘non-colored pericarp + non-colored coleoptile’ (‘iJP7A’), ‘non-colored
pericarp + light red coleoptile’ (‘S29’), ‘light purple pericarp + light red coleoptile’ (‘iP-
F2A’, ‘iP2A’), ‘non-colored pericarp + dark red coleoptile’ (‘iPF7D’, ‘iP7D’), and ‘dark
purple pericarp + dark red coleoptile’ (‘iPF’, ‘iP’). Differences between the groups were
tested by the Dunnett’s post hoc test, taking p ≤ 0.05 as the signicance threshold. Spear-
man’s rank correlation coefcients between the parameters were calculated. Statistical hy-
potheses were tested with the program Statistica 6.0 (StatSoft Inc., 2001).
Results
Germination rate
In control conditions, germination was 95–100% (Table S1*). Gamma-irradiation seed
treatment at different doses did not affect the germination rate (Table S2, Fig. 1) with the
exception of ‘iP2A’ line under dose 200 Gy inducing 7% decrease (Fig. 1).
Shoot length and weight changes
Irradiation treatment caused changes in shoot length (Fig. 2A, Tables S2 – S3). The shoot
length decrease varied after 50 Gy from 29.7 (in the line ‘iPF’) to 44.1% (‘iP2A’), after
*Further details about the Electronic Supplementary Material (ESM) can be found at the end of the article.
Gordeeva et al.: γ-irradiation Treatment and Anthocyanins in Wheat
Cereal Research Communications
100 Gy from 50.2 (‘iPF’) to 58.2% (‘iP7D’), and from 55.4 (‘iPF’) to 61.2% (‘iP7D’)
(Fig. 2A).
The shoot weight was also inuenced by gamma-irradiation (Fig. 2B, Tables S2, S4).
The shoot weight decrease was within 30.5 (‘iPF’) – 46.3% (‘iJP7A’), 59.7 (‘iP2A’) –
64.6% (‘iPF7D’), 64.6 (‘iPF2A’) – 68.6% (‘iP7D’), after 50, 100 and 200 Gy, respec-
tively (Fig. 2B).
The level of shoot length and weight decrease varied notably between the lines after 50
Gy treatment, whereas after higher doses the changes of the parameters were similar in all
lines (Fig. 2A, 2B).
There was low positive correlation between shoot length of control plants and extent
of the shoot length decrease after seed exposure (rs= 0.18, p≤0.05), whereas there was no
correlation between shoot weight of control plants and extent of the shoot weight de-
crease.
Root system changes
Irradiation treatment caused signicant changes in root systems e.g. the length and weight
of the main root, the number of roots and the percent of seedlings with hairy roots (Tables
S2, S5–S8).
The root length decrease after seed irradiation by 50, 100, and 200 Gy ranged from
46.1 (‘iPF’) to 67.6% (‘iJP7A’), from 65.2 (‘iPF’) to 72.8 (‘iJP7A’), and from 69.1
(‘iP2A’) to 76.3 (‘iJP7A’), respectively (Fig. 2C).
Figure 1. Effect of gamma radiation on germination rate of wheat seeds exposed to 0, 50, 100 and 200 Gy.
* differences between treated (50, 100 and 200 Gy) and control (0 Gy) samples were signicant at p ≤ 0.05
Gordeeva et al.: γ-irradiation Treatment and Anthocyanins in Wheat
Cereal Research Communications
Figure 2. Effect of different doses of gamma radiation on morphological parameters changes: (A) shoot length, (B) shoot weight, (C) root length, (D) root weight;
*,** differences between treated (50, 100 and 200 Gy) and control (0 Gy) samples were signicant at p ≤ 0.05, p 0.01, respectively
Gordeeva et al.: γ-irradiation Treatment and Anthocyanins in Wheat
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Decreasing of the root weight was from 44.5 (‘iPF’) to 71.1% (‘iJP7A’), from 66.8
(‘iP2A’) to 77.4% (‘iJP7A’) and from 68.7 (‘iP2A’) to 80.8% (‘iJP7A’) after 50, 100 and
200 Gy, respectively (Fig. 2D).
Figure 3. Effect of different doses of gamma radiation on (A) changes of roots number and (B) percent of
seedlings with hairy roots. The data are present as mean of ve replicates ± SD. *,** differences between
treated (50, 100 and 200 Gy) and control (0 Gy) were samples signicant at p 0.05, p ≤ 0.01, respectively
Gordeeva et al.: γ-irradiation Treatment and Anthocyanins in Wheat
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There were low positive correlations between root length and weight of control plants
and extent of the root length and weight reduction under treatment (for root length
rs = 0.29, p ≤ 0.05; for root weight rs = 0.37, p ≤ 0.05).
The control plants root number varied from 4.67 ± 0.21 (‘iPF7D’) to 4.93 ± 0.12
(‘iJP7A’) (Table S7). Root number decreased after treatment. Decreasing of the root num-
ber varied within 9.6 (‘iP7D’) –28.6% (‘iPF2A’), 30.2 (‘iP2A’) –37.1% (‘iPF2A’), 31.4
(‘iP2A’) – 37.7% (‘iPF2A’). There was no correlation between root number in control and
changes of root number under treatment.
In control plants, only several seedlings with hairy roots were noted in ‘S29’, ‘iPF7D’,
and ‘iP’, whereas root hairs appeared in all lines under the inuence of gamma-irradiation
(Table S8). The most noticeable percent of seedlings with hairy roots was observed in
‘iPF2A’ (+59%), in ‘iP2A (+75%), and in ‘iP7D’ (+81%), while the lowest one was in
‘S29’ (+29%), in ‘iPF’ (+43%), in ‘iJP7A’ (+56%), under 50, 100, and 200 Gy, respec-
tively (Fig. 3B). The differences between lines were not statistically signicant, except
for ‘iP2Avs ‘iPF’ and ‘iPF’ vs ‘iP’ under 100 Gy (Table S8).
Changes of relative anthocyanin content
Gamma-irradiation changed anthocyanin content in coleoptiles (Tables S2, S9). The gen-
otypes with light red coleoptile pigmentation (‘S29’, ‘iPF2A’, ‘iP2A’), predetermined by
the ‘weak’ Rc-A1 allele, demonstrated signicant dose-dependent decrease in the relative
content of anthocyanins. The most pronounced decrease of level of anthocyanins was
observed in ‘iP2A’ (–33.1%) after 50 Gy, in ‘iPF2A’ (–41.4%) after 100 Gy, and in ‘S29’
(–45.6%) after 200 Gy. In the lines with dark red coleoptile color (‘iPF7D’, ‘iP7D’, ‘iPF’,
‘iP’) conferred by the combination of Rc-A1 with ‘strong’ Rc-D1 allele, the changes be-
tween control and treated samples were not statistically signicant (Fig. 4).
Strong negative correlations were observed between anthocyanin content in coleoptile
and gamma-irradiation doses in group of genotypes with lightly colored coleoptiles
(rs = –0.78, p ≤ 0.05), whereas no correlation was found between those parameters in
group of genotypes with intensively colored coleoptiles (rs = –0.15, p > 0.05).
Overall, it can be concluded that anthocyanin biosynthesis in different genotypes re-
spond differently on irradiation in dependence on alleles of the Rc-1 genes predetermin-
ing the intensity of anthocyanin pigmentation.
Effect of coleoptile color, pericarp color, and their combinations on changing growth
parameters of wheat seedlings under irradiation treatment
The one-way ANOVA on ranks was run to evaluate the effect of coleoptile and pericarp
color, and combination of these factors on growth parameters changes of wheat seedlings
after dry grain treatment with moderate doses of gamma-irradiation. As summarized in
Tables S10-S22 these factors affect morphological parameters changes only under 50 Gy,
whereas under higher doses the factors have no effect on growth parameters changes.
Gordeeva et al.: γ-irradiation Treatment and Anthocyanins in Wheat
Cereal Research Communications
The notable positive effect of anthocyanin coloration on vigor of seedling germinated
from 50 Gy- treated seeds was observed in the group of samples having dark red coleop-
tile (Fig. S1A–C). This group was characterized with the lowest reduction of root length
(Fig. S1B). The similar tendency was with changes in shoot length (Fig. S1A) and root
weight (Fig. S1C).
The root length decrease did not vary among the groups of the genotypes with dark-
colored or non-colored pericarp, whereas the group of the samples with light-colored
pericarp had the highest reduction of shoot length (Fig. S1D).
In respect to combination of pericarp and coleoptile color, the highest reduction of
shoot and root length under 50 Gy treatment was in non-colored ‘iJP7A’, however, in case
of root length the difference was not statistically signicant (Fig. S1E-F).
The obtained results demonstrated protective effect of coleoptile pigmentation on
growth parameters of wheat seedlings germinated from 50 Gy-treated seeds, whereas
under higher doses (100 and 200 Gy) anthocyanins did not contribute to growth parame-
ters changes.
Discussion
Response of avonoid metabolism to irradiation treatment
Ionizing radiation generally affects avonoid biosynthesis and related genes (Nagata et
al. 2003; Hong et al. 2014; Ramabulana et al. 2016). Studying the effect of irradiation on
anthocyanin metabolism in leaves, Sparrow et al. (1968) revealed an increase of the an-
Figure 4. Changes in relative anthocyanin content (OD530) in coleoptiles of seedlings germinated from 50, 100
and 200 Gy exposed seeds relative to that in control experiment (0 Gy). *,** differences between treated and
control samples were signicant at p ≤ 0.05, p ≤ 0.01, respectively
Gordeeva et al.: γ-irradiation Treatment and Anthocyanins in Wheat
Cereal Research Communications
thocyanin content in 35 different plant species and concluded that increase of anthocyanin
biosynthesis is a general reaction of plants on ionizing radiation. The authors noted that
irradiation doses, which induce anthocyanin content increase, are species-specic. They
varied from 30 Gy in Acer saccharum to 3420 Gy in Luzula acuminata.
This stimulating effect of ionizing radiation on anthocyanin metabolism was detected
after exposure of seedlings and adult plants. Opposite tendency was observed when seeds
were treated. In these cases, the post-irradiation suppression of avonoid synthesis has
been observed (Karabanov and Veremeitschik 1972; Zhu et al. 2010; Mohajer et al. 2014).
Response of avonoid metabolism to irradiation has also tissue-specic features (Margna
and Vainjӓrv 1976).
In the current study, the dry wheat seeds irradiation treatment also caused a reduction
of anthocyanin content in coleoptiles germinated from treated seeds compared to un-
treated control (Fig. 4). However the response was genotype-dependent: in NILs having
Rc-A1 (‘S29’, ‘iPF2A’, ‘iP2A’), predetermining light red coleoptile color a signicant
decrease of anthocyanin content was observed, whereas in NILs with additional ‘strong’
Rc-D1 allele (‘iPF7D’, ‘iP7D’, ‘iPF’, ‘iP’) conferring dark red color, there was just a
tendency of reduced anthocyanin synthesis, which was statistically insignicant (Fig. 4).
So, in the current study, it was for the rst time shown that in addition to previously
demonstrated dose-, species- and tissues-specicity of avonoid biosynthesis response on
irradiation treatment, there are genotype-dependent effects of gamma-irradiation treat-
ment on the changes of anthocyanin content.
Protective role of anthocyanin biosynthesis genes under irradiation treatment
In spite of many studies showing response of anthocyanin synthesis on gamma-irradia-
tion treatment, information demonstrating protective effect of these substances under
such type of stress was absent. Here, comparison of precise genetic stocks such as near-
isogenic lines differing by combinations of anthocyanin biosynthesis regulatory alleles
allowed investigating a role of these genes in protection of seedlings germinated from
seeds treated with moderate doses (50, 100 and 200 Gy). Under higher doses (100 and
200 Gy) there was none protective effect, while under 50 Gy the positive effect of the
coleoptiles’ pigmentation on growth parameters was detected (Fig. S1A–C). At the same
time anthocyanins accumulated in pericarp before treatment appeared to be useful for
seedling protection neither under higher doses (100 and 200 Gy; Table S10) nor under
lowest dose 50 Gy (Fig. S1D–F; Table S10). Different effect of coleoptile and pericarp
coloration may have two explanations. The rst hypothesis is related to importance of
tissue location of protective substances anthocyanins. The second hypothesis considers
importance of some processes taking place during anthocyanin synthesis (or signicance
of other non-colored substances produced along with anthocyanins). In coleoptiles, these
processes are ongoing during seedling growth after dry seed treatment, while in pericarp
just previously synthesized anthocyanins present.
In the current study, a protective role of anthocyanins accumulated in wheat coleoptile
(but not in grain) against gamma-radiation was demonstrated by using the precise genetic
Gordeeva et al.: γ-irradiation Treatment and Anthocyanins in Wheat
Cereal Research Communications
model (a set of near-isogenic lines differing by allelic state of the genes conferring pig-
mentation). Although the anthocyanin content in seedlings germinated from the treated
seeds was not changed or even decreased, the lines with intensively colored coleoptile
were more tolerant to irradiation stress in comparison with their non-colored sister line.
This protective effect was observed only under low dose of irradiation (50 Gy) whereas
under higher doses (100 and 200 Gy) anthocyanins seemed to be not enough effective as
protective compounds. The observation of a positive role of anthocyanin accumulated in
coleoptiles on vigor of seedlings germinated from 50 Gy-treated wheat grains can be re-
lated with anthocyanins’ free radicals scavenging capacity.
Acknowledgements
This work was supported by the Russian Science Foundation (project 16-14-00086).
Growing of wheat plants in ICG Plant Growth Core Facility was supported by ICG pro-
ject 324-2015-0005. We thank Ms Galina Generalova and Mrs Olga Zakharova for tech-
nical assistance and Dr Elena Antonova for fruitful discussion.
References
Abou-Zeid, H.M., Abdel-Latif, S.A. 2014. Effects of gamma irradiation on biochemical and antioxidant
defense system in wheat (Triticum aestivum L.) seedlings. Int. J. Adv. Res. 2:287–300.
Arbuzova, V.S., Maystrenko, O.I., Popova, O.M. 1998. Development of near-isogenic lines of the common
wheat cultivar ‘Saratovskaya 29’. Cereal Res. Commun. 26:39–46.
Arena, C., De Micco, V., Macaeva, E., Quintens, R. 2014. Space radiation effects on plant and mammalian
cells, and mammalian cells. Acta Astronautica 104:419–431. http://dx.doi.org/10.1016/j.actaas-
tro.2014.05.005
Bors, W., Mochel, C., Saran, M. 1994. Flavonoid antioxidants: Rate constants for reactions with oxygen radi-
cals. Met. Enzymol. 234:420–429.
Caverzan, A., Casassola, A., Patussi Brammer, S.P. 2016. Reactive oxygen species and antioxidant enzymes
involved in plant tolerance to stress. In: Shanker, A. (ed.), Abiotic and biotic stress in plants – recent
advances and future perspectives. InTech. Rijeka, Croatia. pp. 463–480.
Chalker-Scott, L. 1999. Environmental signicance of anthocyanins in plant stress responses. Photochem.
Photobiol. 70:1–9.
Esnault, A.M., Legue, F., Chenal, C. 2010. Ionizing radiation: advances in plant response. Environ. Exp. Bot.
68:231–237.
Gordeeva, E.I., Shoeva, O.Y., Khlestkina, E.K. 2015. Marker-assisted development of bread wheat near-isogen-
ic lines carrying various combinations of purple pericarp (Pp) alleles. Euphytica 203:469–476.
Hong, M.J., Kim, J.B., Yoon, Y.H., Kim, S.H., Ahn, J.W., Jeong, I.Y., Kang, S.Y., Seo, Y.W., Kim, D.S. 2014.
The effects of chronic gamma irradiation on oxidative stress response and the expression of anthocyanin
biosynthesis-related genes in wheat (Triticum aestivum). Int. J. Radiat. Biol. 17:1–31.
Khlestkina, E.K. 2012. Genes determining coloration of different organs in wheat. Vavilovskii Zhurnal Genetiki
i Selektsii (Vavilov J. of Genetics and Breeding) 16:202–216.
Karabanov, I.A., Veremeitschik, V.Ye. 1972. The inuence of irradiation on the productivity and the content of
polyphenols in buckwheat. Dokl. AN SSSR. 203:488–490. (in Russian)
Kim, J. H., Baek, M.H., Chung, B.Y., Wi, S.G., Kim, J.S. 2004. Alterations in the photosynthetic pigments and
antioxidant machineries of red pepper (Capsicum annuum L.) seedlings from gamma-irradiated seeds.
J. Plant Biol. 47:314– 321.
Kovács, E., Keresztes, Á. 2002. Effect of gamma and UV-B/C radiation on plant cells. Micron. 3:199–210.
Gordeeva et al.: γ-irradiation Treatment and Anthocyanins in Wheat
Cereal Research Communications
Kruskal, W.H., Wallis W.A. 1952. Use of ranks in one-criterion variance analysis. J. Am. Stat. Assoc. 47:583–
621.
Landi, M., Tattini, M., Gould, K.S. 2015. Multiple functional roles of anthocyanins in plant-environment inter-
actions. Environ. Exp. Bot. 119:4–17.
Mann, H.B., Whitney, D.R. 1947. On a test of whether one of two random variables is stochastically larger than
the other. Ann. Math. Statist. 18:50–60.
Mohajer, S., Taha, R.M., Lay, M.M., Esmaeili, A.K., Khalili. M. 2014. Stimulatory effects of gamma irradiation
on phytochemical properties, mitotic behaviour, and nutritional composition of sainfoin (Onobrychis vicii-
folia Scop.). Sci. World. J. Article ID 854093:1–9. http://dx.doi.org/10.1155/2014/854093.
Margna, U., Vainjӓrv, T. 1976. Irradiation effects upon avonoid accumulation in buckwheat seedlings.
Environ. Exp. Bot. 16:201–208.
Nagata, T., Todoriki, S., Masumizu, T., Suda, I., Furuta, S., Du, Z., Kikuchi, S. 2003. Levels of active oxygen
species are controlled by ascorbic acid and anthocyanin in Arabidopsis. J. Agric. Food. Chem. 51:2992–
2999.
Ramabulana, T., Mavunda, R.D., Steenkamp, P.A., Piater, L.A., Dubery, I.A., Madala, N.E. 2016. Perturbation
of pharmacologically relevant polyphenolic compounds in Moringa oleifera against photo-oxidative dam-
ages imposed by gamma radiation. J. Photochem. Photobiol. B. 156:79–86.
Sparrow, A.H., Furuya, M., Schwemmer, S.S. 1968. Effects of X- and gamma radiation on anthocyanin content
in leaves of Rumex and other plant genera. Rad. Bot. 8:7–16.
Wang, H., Cao, G., Prior, R.L. 1997. Oxygen radical absorbing capacity of anthocyanins. J. Agric. Food Chem.
45:304–309.
Wi, S.G., Chung, B.Y., Kim, J.S., Kim, J.H., Baek, M.H., Lee, J.W., Kim, Y.S. 2007. Effects of gamma irra-
diation on morphological changes and biological responses in plants. Micron. 38:553–564.
Zhu, F., Cai, Y.Z., Bao, J., Corke, H. 2010. Effect of γ-irradiation on phenolic compounds in rice grain. Food
Chem. 120:74–77.
Electronic Supplementary Material (ESM)
Electronic Supplementary Material (ESM) associated with this article can be found at the
website of CRC at http://www.akademiai.com/content/120427/
Electronic Supplementary Table S1. The percent of germinated seeds on day 4 (mean of 5 replicates ± SD, %)
Electronic Supplementary Table S2. Kruskal–Wallis H-test: effect of gamma irradiation on morphological
parameters of wheat seedlings
Electronic Supplementary Table S3. Shoot length (mean of 5 replicates ± SD, mm)
Electronic Supplementary Table S4. Shoot weight (mean of 5 replicates ± SD, mg)
Electronic Supplementary Table S5. Root length (mean of 5 replicates ± SD, mm)
Electronic Supplementary Table S6. Root weight (mean of 5 replicates ± SD, mg)
Electronic Supplementary Table S7. Root number (mean of 5 replicates ± SD)
Electronic Supplementary Table S8. The percentage of seedlings with hairy roots (mean of 5 replicates ± SD)
Electronic Supplementary Table S9. The relative anthocyanin content (OD530) in coleoptiles of lines with
dominant Rc genes (mean of 5 replicates ± SD)
Gordeeva et al.: γ-irradiation Treatment and Anthocyanins in Wheat
Cereal Research Communications
Electronic Supplementary Table S10. The summary of the Kruskal–Wallis H-test analysis, evaluating effect of
the factors ‘grain color’, ‘coleoptile color’, and both of the factors on morphological parameters of wheat
seedlings grown from irradiated seeds. The preliminary data on Kruskal–Wallis H-test analysis are presented
in Tables S11 – S22
Electronic Supplementary Table S11. Kruskal–Wallis H-test analysis: effect of pericarp color on growth param-
eters of wheat seedlings in control samples (0 Gy)
Electronic Supplementary Table S12. Kruskal–Wallis H-test analysis: effect of pericarp color on growth param-
eters of wheat seedlings under 50 Gy
Electronic Supplementary Table S13. Kruskal–Wallis H-test analysis: effect of pericarp color on growth param-
eters of wheat seedlings under 100 Gy
Electronic Supplementary Table S14. Kruskal–Wallis H-test analysis: effect of pericarp color on growth param-
eters of wheat seedlings under 200 Gy
Electronic Supplementary Table S15. Kruskal–Wallis H-test analysis: effect of coleoptile color on growth
parameters of wheat seedlings in control samples
Electronic Supplementary Table S16. Kruskal–Wallis H-test analysis: effect of coleoptile colour on growth
parameters of wheat seedlings under 50 Gy
Electronic Supplementary Table S17. Kruskal–Wallis H-test analysis: effect of coleoptile colour on growth
parameters of wheat seedlings under 100 Gy
Electronic Supplementary Table S18. Kruskal–Wallis H-test analysis: effect of coleoptile colour on growth
parameters of wheat seedlings under 200 Gy
Electronic Supplementary Table S19. Kruskal–Wallis H-test analysis: effect of pericarp and coleoptile color on
growth parameters of wheat seedlings in control samples
Electronic Supplementary Table S20. Kruskal–Wallis H-test analysis: effect of pericarp and coleoptile color on
growth parameters of wheat seedlings under 50 Gy
Electronic Supplementary Table S21. Kruskal–Wallis H-test analysis: effect of pericarp and coleoptile color on
growth parameters of wheat seedlings under 100 Gy
Electronic Supplementary Table S22. Kruskal–Wallis H-test analysis: effect of pericarp and coleoptile color on
growth parameters of wheat seedlings under 200 Gy
... Thus, the response of anthocyanin biosynthesis to cad- mium stress is dependent on the alleles of the Rc-1 genes. The genotype-dependent re- sponse of anthocyanin metabolism has been observed under different types of stresses in different cultivars and NILs of diverse plant species ( The NILs ('S29', 'iPF', 'iP') exploited in the present study have been previously tested under cold, osmotic stress and ionizing radiation ( Gordeeva et al. 2013Gordeeva et al. , 2017Shoeva et al. 2017), which allows comparing the effects of different environmental stresses on changes in anthocyanin content in the same genotypes. Under cold stress, the anthocyanin content decreased in light-red coleoptiles of 'S29' but increased in the purple coleoptiles of 'iPF ' and 'iP' (Gordeeva et al. 2013). ...
... Under cold stress, the anthocyanin content decreased in light-red coleoptiles of 'S29' but increased in the purple coleoptiles of 'iPF ' and 'iP' (Gordeeva et al. 2013). After seeds were irradiated, a decrease in antho- cyanin concentration was reported in the coleoptiles of 'S29', whereas in 'iPF' and 'iP', the anthocyanin content did not change ( Gordeeva et al. 2017). Under osmotic stress, the mode of response was similar to that under Cd treatment: a higher intensification of an- thocyanin biosynthesis was observed in 'S29' . ...
... In the present study, a protective role of anthocyanin pigments was observed under moderate (25 µM) CdCl 2 stress, whereas under heavier stress, the relationship between pigmentation and decreased root and shoot lengths was not identified (Table 2; Fig. 2, right part). The obtained results confirmed the earlier observation of the protective role of the anthocyanins of wheat coleoptiles under low doses of ionizing radiation but not under higher doses ( Gordeeva et al. 2017). It seems that anthocyanins are more effective under low or moderate stress but are not powerful enough under heavy stress. ...
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Due to anthropogenic activity, the environment is contaminated with high levels of cadmium, which is a dangerous heavy metal. At very low concentrations, cadmium is bioaccu-mulative and toxic to animals and plants, generating reactive oxygen species (ROS) that are destructive to cells of organisms. Anthocyanin pigments are natural antioxidants produced in various plant tissues and play a protective role under different environments. In the present study, the putative role of anthocyanins that accumulate in the grains and shoots of bread wheat (Triticum aestivum L.) in response to cadmium-induced toxicity (25 and 50 µM CdCl2) was studied at the seedling stage. For this purpose, a set of near-isogenic lines carrying different alleles of the Pp (purple pericarp) and Rc (red coleoptile) genes was used. The lines responded differently to Cd treatment. The observed changes in anthocyanin metabolism under stress conditions were dependent on the alleles of the Rc genes that determine coleoptile pigmentation and on CdCl2 concentration. In less-colored line carrying the Rc-A1 allele, the antioxidant system was unable to fully cope with oxidative stress and thus induced the synthesis of additional antioxidants, whereas in the most tolerant lines, which have dark-purple coleoptile pigmentation predetermined by Rc-A1+ Rc-D1, the level of anthocyanins in the coleoptiles was independent of stress. A protective role of anthocyanins presented in the coleoptiles of wheat seedlings was observed under moderate Cd stress (25 µM), whereas anthocyanins seemed to be ineffective as protective compounds under heavier stress.
... Anthocyanins (belonging to the group of flavonoids) are considered to be non-specific protectors, the synthesis of which increases under abiotic and biotic stress (Chalker-Scott 1999;Diaz-Vivancos et al. 2006;Franklin et al. 2009;Kordali et al. 2005;Treutter 2005;Gordeeva et al. 2013;Khlestkina 2013;Bandy and Bechara 2001). A series of investigations has shown that the content of flavonoids increases at low temperatures (Carrao-Panizzi et al. 1999;Gordeeva et al. 2013), under water (Shoeva et al. 2017) and salt stress (Shoeva and Khlestkina 2015), as well as after acute gamma irradiation (Gordeeva et al. 2018). When using exact genetic models such as wheat near-isogenic lines, differing in alleles of the genes that determine the accumulation of anthocyanins in the grain and coleoptile, the role of pigments has been demonstrated under the action of various types of stress of low or moderately intensity. ...
... When using exact genetic models such as wheat near-isogenic lines, differing in alleles of the genes that determine the accumulation of anthocyanins in the grain and coleoptile, the role of pigments has been demonstrated under the action of various types of stress of low or moderately intensity. However, under severe stress, anthocyanins are apparently not effective protective molecules (Gordeeva et al. 2013(Gordeeva et al. , 2018Shoeva et al. 2017;Shoeva and Khlestkina 2018). The content of low molecular weight antioxidants has been positively correlated with the parameters of growth and development of smooth brome seedlings and negatively with the proportion of seedlings that have any developmental anomalies (necrosis of various organs, changes in the shape of cotyledons, etc.) (Antonova et al. 2015). ...
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Main conclusion For the subsequent assessment of the genetic mechanisms responsible for the resistance of plants to chronic irradiation, the analysis of RAPD-cDNA with the subsequent isolation, cloning, and sequencing of expressed polymorphic sequences is a promising technique. A study was conducted on Bromopsis inermis populations that have been growing for a long time in the EURT area. Using RAPD primers, we studied the genetic spectra of plants. In analysing the UPGMA algorithm, we identified two well-distinguishable clusters with a high level of bootstrap support (> 85%): background samples hit the first, and impact samples hit the second. Our data indicate a decrease in diversity in the most polluted population, as well as the appearance of new alleles in chronically irradiated samples of the B. inermis. Smooth brome seedlings were characterised by the content of anthocyanins, comparable with other types of cereals. In the gradient of chronic irradiation, the relative content of anthocyanins was not significantly changed. For the first time, the partial nucleotide sequences of the key genes of anthocyanin biosynthesis (Chi and F3h) in the brome were determined, these sequences were found to be 191 and 356 bp in length, respectively, and were cloned and sequenced. Three copies of the Chi gene were identified in the B. inermis genome. One copy (BiChi-1) clustered with the sequences of the Aegilops tauschii gene (D genome), and the other two copies (BiChi-2 and BiChi-3) formed a separate cluster in the Pooideae subfamily adjacent to Hordeum vulgare. In the copy of BiChi-1, a complete deletion of intron 1 was detected. For the F3h gene, one copy of the B. inermis gene was obtained, which forms a separate branch in the subfamily Pooideae.
... Low doses of gamma have positive effects on cell proliferation; cell and tissue growth, germination percentage, enzyme activity, chlorophyll content, biotic and abiotic stress tolerance and crop yield [12][13][14][15]. On the other hand, high doses of gamma particles cause damage to protein synthesis, enzyme activity hormone balance, water exchange and leaf gas exchange [16]. ...
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... [143] adapted to intensive solar UV-B radiation in highland areas in Ethiopia. Studies of near-isogenic wheat lines differing in the anthocyanin content in the pericarp and coleoptile under various stress conditions showed that both pericarp and coleoptile anthocyanins protected seedlings from osmotic stress [144], while protection of seedlings under a moderate irradiation dose (pretreatment of dry seeds with 50 Gy before sowing) or moderate Cd toxicity (25 µM CdCl 2 ) was due to the coleoptile's anthocyanins only [145,146]. Flavonoid substances can prevent negative effects of excessive moisture, such as pre-harvest seed sprouting by reducing the permeability of seed coat to water [147], inhibiting α-amylase (an enzyme whose activity is directly related to seed germination of grain) [148], or inactivating dehydrogenase required for the initial phase of respiration in ripening grain and young shoots [149]. ...
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... Shoeva et al. [24] demonstrated that anthocyanins in coleoptiles protect shoots, while those in grains protect roots under drought stress (seedlings grown in 15% polyethylene glycol). In addition, anthocyanins in coleoptiles protect wheat seedlings under metal toxicity (treatment with 25 µM CdCl 2 ) [25] and moderate irradiation dose (pretreatment of dry seeds with 50 Gy before sowing) [26]. ...
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... Other studies, which show resemblance to the results obtained from other plants, also exist in this subject (Grover and Khan, 2014 ;Deshmukh et al.,2018). Studies, which show that radiation generally does not effect on germination percentage, also exist (Gordeeva et al., 2018;Kakade and Borse 2017). ...
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