We analyzed plastid structures from a crystal-forming Arabidopsis thaliana PHYTOENE SYNTHASE -overexpressing line by transmission electron microscopy. These roots were shown to accumulate similarly high carotenoid levels like callus. Ultrastructural analysis revealed plastid-localized membrane remnants exclusively in the carotenoid-accumulating line, while these structures were absent in WT roots. Read more in:
Schaub P, Rodriguez-Franco M, Cazzonelli CI, Álvarez D, Wüst F, Welsch R (2018), Establishment of an Arabidopsis callus system to study the interrelations of biosynthesis, degradation and accumulation of carotenoids. PLoS ONE 13(2): e0192158.