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Stunning!

Unlike in algae and other phototrophs, plant thylakoids form specialized grana stacks🥞 interconnected by single thylakoids called stromal lamellae. The 3D membrane architecture we observed is consistent with the “helical staircase model” proposed from classical TEM (💚🔬 Andrew Staehelin, RIP). 2/🧵

We made an interesting observation about plastoglobules, lipid-protein storage droplets that share one leaflet with thylakoid membranes. We saw that plastoglobules often sat within little holes in the thylakoids 🟠🕳️, perhaps increasing the area of the contact site, facilitating exchange 🔄 3/🧵

Our data enabled us to quantify native thylakoid architecture in the grana. Getting precise numbers is important for modeling photosynthetic regulation. Here’s a comparison to similar measurements made by classical TEM. We’d like to apply #CryoET to the dark-to-light💡 transition in the future. 4/🧵