Chapter 1
Pathways for Carotenoid Biosynthesis, Degradation,
and Storage
Tianhu Sun, Yaakov Tadmor, and Li Li
Abstract
Carotenoids are isoprenoid compounds synthesized de novo in all photosynthetic organisms as well as in
some nonphotosynthetic bacteria and fungi. In plants, carotenoids are essential for light harvesting and
photoprotection. They contribute to the vivid color found in many plant organs. The cleavage of carotenoids produces small molecules (apocarotenoids) that serve as aroma compounds, as well as phytohormones and signals to affect plant growth and development. Since carotenoids provide valuable nutrition
and health benefits for humans, understanding of carotenoid biosynthesis, catabolism and storage is
important for biofortification of crops with improved nutritional quality. This chapter primarily introduces
our current knowledge about carotenoid biosynthesis and degradation pathways as well as carotenoid
storage in plants.
Key words Carotenoids, Biosynthesis, Degradation, Sequestration/Storage, Pathways
1 Introduction
Carotenoids are a group of isoprenoids synthesized de novo in all
photosynthetic organisms of plants, algae and cyanobacteria, as well
as in some nonphotosynthetic bacteria and fungi [1–3]. Animals,
with very few exceptions (i.e., pea aphids, spider mites, and gall
midges), are unable to synthesize carotenoids but accumulate in
specific tissues or organs. Carotenoids exert multifaceted functions
for plant survival [4]. They are also important for human nutrition
and health [2].
Carotenoids are produced exclusively in plastids in plants [5].
The biochemical backbone of carotenoid biosynthesis pathway was
established around 1960s by the labeling and inhibition
studies along with mutant analysis [6]. Nearly all the major genes
that encode enzymes to catalyze the core reactions of carotenogenesis were cloned by the end of last century [7]. A nonmevalonate
pathway, that is, the plastidial 2-C-methyl-D-erythritol
Manuel Rodrı ´guez-Concepcio ´ n and Ralf Welsch (eds.), Plant and Food Carotenoids: Methods and Protocols,
Methods in Molecular Biology, vol. 2083, https://doi.org/10.1007/978-1-4939-9952-1_1,
© Springer Science+Business Media, LLC, part of Springer Nature 2020
3
Pathways for Carotenoid Biosynthesis, Degradation,
and Storage
Tianhu Sun, Yaakov Tadmor, and Li Li
Abstract
Carotenoids are isoprenoid compounds synthesized de novo in all photosynthetic organisms as well as in
some nonphotosynthetic bacteria and fungi. In plants, carotenoids are essential for light harvesting and
photoprotection. They contribute to the vivid color found in many plant organs. The cleavage of carotenoids produces small molecules (apocarotenoids) that serve as aroma compounds, as well as phytohormones and signals to affect plant growth and development. Since carotenoids provide valuable nutrition
and health benefits for humans, understanding of carotenoid biosynthesis, catabolism and storage is
important for biofortification of crops with improved nutritional quality. This chapter primarily introduces
our current knowledge about carotenoid biosynthesis and degradation pathways as well as carotenoid
storage in plants.
Key words Carotenoids, Biosynthesis, Degradation, Sequestration/Storage, Pathways
1 Introduction
Carotenoids are a group of isoprenoids synthesized de novo in all
photosynthetic organisms of plants, algae and cyanobacteria, as well
as in some nonphotosynthetic bacteria and fungi [1–3]. Animals,
with very few exceptions (i.e., pea aphids, spider mites, and gall
midges), are unable to synthesize carotenoids but accumulate in
specific tissues or organs. Carotenoids exert multifaceted functions
for plant survival [4]. They are also important for human nutrition
and health [2].
Carotenoids are produced exclusively in plastids in plants [5].
The biochemical backbone of carotenoid biosynthesis pathway was
established around 1960s by the labeling and inhibition
studies along with mutant analysis [6]. Nearly all the major genes
that encode enzymes to catalyze the core reactions of carotenogenesis were cloned by the end of last century [7]. A nonmevalonate
pathway, that is, the plastidial 2-C-methyl-D-erythritol
Manuel Rodrı ´guez-Concepcio ´ n and Ralf Welsch (eds.), Plant and Food Carotenoids: Methods and Protocols,
Methods in Molecular Biology, vol. 2083, https://doi.org/10.1007/978-1-4939-9952-1_1,
© Springer Science+Business Media, LLC, part of Springer Nature 2020
3