Synthetic conversion of leaf chloroplasts into carotenoid-rich plastids reveals mechanistic basis of natural chromoplast development
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 i…
Conserved and newly acquired roles of PIF1 homologs in tomato (Solanum lycopersicum)
ABSTRACTPHYTOCHROME INTERACTING FACTORS (PIFs) are transcription factors that interact with the photoreceptors phytochromes and integrate multiple signaling pathways related to light, temperature, defense and hormone responses. PIFs have been extensively studied inArabidopsis thaliana, but less is known about their roles in other species. Here, we investigate the role of the two homologs of PIF1 found in tomato (Solanum lycopersicum), namely PIF1a and PIF1b. Analysis of gene expression showed very different patterns, indicating a potential evolutionary divergence in their roles. At the protein level, light regulated the stability of PIF1a, but not PIF1b, further supporting a functional dive…