TY - JOUR
T1 - The Role of Carotenogenic Metabolic Flux in Carotenoid Accumulation and Chromoplast Differentiation
T2 - Lessons From the Melon Fruit
AU - Feder, Ari
AU - Chayut, Noam
AU - Gur, Amit
AU - Freiman, Zohar
AU - Tzuri, Galil
AU - Meir, Ayala
AU - Saar, Uzi
AU - Ohali, Shachar
AU - Baumkoler, Fabian
AU - Gal-On, Amit
AU - Shnaider, Yula
AU - Wolf, Dalia
AU - Katzir, Nurit
AU - Schaffer, Ari
AU - Burger, Joseph
AU - Li, Li
AU - Tadmor, Yaakov
N1 - Publisher Copyright:
© Copyright © 2019 Feder, Chayut, Gur, Freiman, Tzuri, Meir, Saar, Ohali, Baumkoler, Gal-On, Shnaider, Wolf, Katzir, Schaffer, Burger, Li and Tadmor.
PY - 2019/10/30
Y1 - 2019/10/30
N2 - Carotenoids have various roles in plant physiology. Plant carotenoids are synthesized in plastids and are highly abundant in the chromoplasts of ripening fleshy fruits. Considerable research efforts have been devoted to elucidating mechanisms that regulate carotenoid biosynthesis, yet, little is known about the mechanism that triggers storage capacity, mainly through chromoplast differentiation. The Orange gene (OR) product stabilizes phytoene synthase protein (PSY) and triggers chromoplast differentiation. OR underlies carotenoid accumulation in orange cauliflower and melon. The OR’s ‘golden SNP’, found in melon, alters the highly evolutionary conserved Arginine108 to Histidine and controls β-carotene accumulation in melon fruit, in a mechanism yet to be elucidated. We have recently shown that similar carotenogenic metabolic flux is active in non-orange and orange melon fruit. This flux probably leads to carotenoid turnover but known carotenoid turnover products are not detected in non-orange fruit. Arrest of this metabolic flux, using chemical inhibitors or mutations, induces carotenoid accumulation and biogenesis of chromoplasts, regardless of the allelic state of OR. We suggest that the ‘golden SNP’ induces β-carotene accumulation probably by negatively affecting the capacity to synthesize downstream compounds. The accumulation of carotenoids induces chromoplast biogenesis through a metabolite-induced mechanism. Carotenogenic turnover flux can occur in non-photosynthetic tissues, which do not accumulate carotenoids. Arrest of this flux by the ‘golden SNP’ or other flux-arrest mutations is a potential tool for the biofortification of agricultural products with carotenoids.
AB - Carotenoids have various roles in plant physiology. Plant carotenoids are synthesized in plastids and are highly abundant in the chromoplasts of ripening fleshy fruits. Considerable research efforts have been devoted to elucidating mechanisms that regulate carotenoid biosynthesis, yet, little is known about the mechanism that triggers storage capacity, mainly through chromoplast differentiation. The Orange gene (OR) product stabilizes phytoene synthase protein (PSY) and triggers chromoplast differentiation. OR underlies carotenoid accumulation in orange cauliflower and melon. The OR’s ‘golden SNP’, found in melon, alters the highly evolutionary conserved Arginine108 to Histidine and controls β-carotene accumulation in melon fruit, in a mechanism yet to be elucidated. We have recently shown that similar carotenogenic metabolic flux is active in non-orange and orange melon fruit. This flux probably leads to carotenoid turnover but known carotenoid turnover products are not detected in non-orange fruit. Arrest of this metabolic flux, using chemical inhibitors or mutations, induces carotenoid accumulation and biogenesis of chromoplasts, regardless of the allelic state of OR. We suggest that the ‘golden SNP’ induces β-carotene accumulation probably by negatively affecting the capacity to synthesize downstream compounds. The accumulation of carotenoids induces chromoplast biogenesis through a metabolite-induced mechanism. Carotenogenic turnover flux can occur in non-photosynthetic tissues, which do not accumulate carotenoids. Arrest of this flux by the ‘golden SNP’ or other flux-arrest mutations is a potential tool for the biofortification of agricultural products with carotenoids.
KW - OR genes
KW - carotenoids accumulation
KW - melon (Cucumis melo L.)
KW - metabolic flux
KW - tomato (Solanum lycopersicum)
UR - http://www.scopus.com/inward/record.url?scp=85075482743&partnerID=8YFLogxK
U2 - 10.3389/fpls.2019.01250
DO - 10.3389/fpls.2019.01250
M3 - Review article
C2 - 31736986
AN - SCOPUS:85075482743
SN - 1664-462X
VL - 10
JO - Frontiers in Plant Science
JF - Frontiers in Plant Science
M1 - 1250
ER -