ISSN 10214437, Russian Journal of Plant Physiology, 2015, Vol. 62, No. 1, pp. 1–13. © Pleiades Publishing, Ltd., 2015.
Original Russian Text © G.N. Smolikova, S.S. Medvedev, 2015, published in Fiziologiya Rastenii, 2015, Vol. 62, No. 1, pp. 3–16.
Carotenoids are yellow, orange, or red plant pig
ments. In green leaves carotenoids are usually invisible
because of the presence of chlorophylls. When chloro
phylls are destructed in the end of growth season, car
otenoids provide the characteristic yellow–orange
color to autumnal leaves. The term
suggested in 1831 by the German chemist Wacken
roder  who gave this name to the pigment isolated
and crystallized from carrot roots. Berzelius in 1837 
isolated yellow pigments from autumnal leaves; later he
found these pigments also in green leaves and termed
, meaning yel
, meaning leaf) by analogy with chloro
, green and
Tswett  invented a principally novel method for
separation of photosynthetic pigments (adsorption
chromatography), which allowed him not only to iso
but also to obtain three frac
tions of yellow pigments. Assuming the basic similarity
in the chemical nature of carotene and xanthophylls,
Tswett introduced the term
in order to
unify these pigments into one group (from the Latin
(carrot) and a Greek word
“form, type, or species”).
Carotenoids are indispensable components of
pigment systems in all photosynthesizing organisms.
Mutant plants devoid of carotenoids perish rapidly.
Four main functions of carotenoids in photosynthe
sis are distinguished: the lightharvesting (antenna),
antioxidant, photoprotective, and structural func
tions [4, 5].
antenna (light harvesting)
function is deter
mined by the lightinduced transition of carotenoids
from the ground state to the singlet excited state.
Then, the excitation energy of carotenoids is trans
ferred by the resonance to the nearby chlorophyll mol
ecule. However, chlorophyll molecules can also pro
duce the triplet excited state and, thereby, sensitize the
formation of singlet oxygen.
function of carotenoids is that they
are capable of preventing the damage caused by forma
tion of chlorophyll triplets and singlet oxygen [6, 7].
The mechanism of protective action of carotenoids is
based on their ability to scavenge the excitation energy
of chlorophyll triplets, thus dissipating it as heat, or to
quench singlet oxygen molecules.
In addition, carotenoids perform the function of
, i.e., they protect the photosynthetic
apparatus from photooxidation under excess light.
Switching of the carotenoid functions from lighthar
vesting to dissipation of light energy occurs in the
laxanthin (xanthophyll) cycle
. Under highintensity
light violaxanthin is first converted to antheraxanthin
and then to zeaxanthin, capable of dissipating the
excess light energy as heat. At low light zeaxanthin is
reconverted to violaxanthin.
Carotenoids can be located in various parts of chlo
roplasts and, accordingly, perform different functions.
The carotenoids present in thylakoid membranes are
involved in light reactions of photosynthesis and con
stability to lightharvesting pigment–
Seed Carotenoids: Synthesis, Diversity, and Functions
G. N. Smolikova and S. S. Medvedev
Department of Plant Physiology and Biochemistry, Faculty of Biology, St. Petersburg State University,
Universitetskaya nab. 7/9, St. Petersburg, 199034 Russia;
Received June 23, 2014
—Data on synthesis, physicochemical properties, and functions of carotenoids in developing and
dormant seeds are reviewed. During seed ripening carotenoids are involved in photosynthesis by performing
lightharvesting and protective functions specific for photosynthesizing tissues; they also serve as ABA pre
cursors. In dormant seeds carotenoids are located in the plastids where they improve the structural integrity
of membranes and protect nutrient substances against destruction. The role of carotenoids as lipophilic anti
oxidants is considered, and the mechanisms of carotenoid protective action against free radicals produced
during seed aging are discussed.
: angiosperms, seeds, chloroembryophytes, carotenoids, photosynthesis, ABA, apocarotenoids,
: Car—carotenoids; CCD—carotenoid cleavage
dioxygenases; Chl—chlorophyll(s); IPP—isopentenyl pyrophos
phate; ROS—reactive oxygen species.