TY - JOUR
T1 - Synthetic conversion of leaf chloroplasts into carotenoid-rich plastids reveals mechanistic basis of natural chromoplast development
AU - Llorente, Briardo
AU - Torres-Montilla, Salvador
AU - Morelli, Luca
AU - Florez-Sarasa, Igor
AU - Matus, José Tomás
AU - Ezquerro, Miguel
AU - D'Andrea, Lucio
AU - Houhou, Fakhreddine
AU - Majer, Eszter
AU - Picó, Belén
AU - Cebolla, Jaime
AU - Troncoso, Adrian
AU - Fernie, Alisdair R.
AU - Daròs, José Antonio
AU - Rodriguez-Concepcion, Manuel
PY - 2020/9/1
Y1 - 2020/9/1
N2 - Plastids, the defining organelles of plant cells, undergo physiological and morphological changes to fulfill distinct biological functions. In particular, the differentiation of chloroplasts into chromoplasts results in an enhanced storage capacity for carotenoids with industrial and nutritional value such as beta-carotene (provitamin A). Here, we show that synthetically inducing a burst in the production of phytoene, the first committed intermediate of the carotenoid pathway, elicits an artificial chloroplast-to-chromoplast differentiation in leaves. Phytoene overproduction initially interferes with photosynthesis, acting as a metabolic threshold switch mechanism that weakens chloroplast identity. In a second stage, phytoene conversion into downstream carotenoids is required for the differentiation of chromoplasts, a process that involves a concurrent reprogramming of nuclear gene expression and plastid morphology for improved carotenoid storage. We hence demonstrate that loss of photosynthetic competence and enhanced production of carotenoids are not just consequences but requirements for chloroplasts to differentiate into chromoplasts.
AB - Plastids, the defining organelles of plant cells, undergo physiological and morphological changes to fulfill distinct biological functions. In particular, the differentiation of chloroplasts into chromoplasts results in an enhanced storage capacity for carotenoids with industrial and nutritional value such as beta-carotene (provitamin A). Here, we show that synthetically inducing a burst in the production of phytoene, the first committed intermediate of the carotenoid pathway, elicits an artificial chloroplast-to-chromoplast differentiation in leaves. Phytoene overproduction initially interferes with photosynthesis, acting as a metabolic threshold switch mechanism that weakens chloroplast identity. In a second stage, phytoene conversion into downstream carotenoids is required for the differentiation of chromoplasts, a process that involves a concurrent reprogramming of nuclear gene expression and plastid morphology for improved carotenoid storage. We hence demonstrate that loss of photosynthetic competence and enhanced production of carotenoids are not just consequences but requirements for chloroplasts to differentiate into chromoplasts.
KW - Carotenoid
KW - Chromoplast
KW - Differentiation
KW - Phytoene
KW - Synthetic
UR - http://www.scopus.com/inward/record.url?scp=85090310568&partnerID=8YFLogxK
U2 - 10.1073/pnas.2004405117
DO - 10.1073/pnas.2004405117
M3 - Article
C2 - 32817419
AN - SCOPUS:85090310568
SN - 0027-8424
VL - 117
SP - 21796
EP - 21803
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 35
ER -