Extended Data Fig. 9: saga1 mutants have multiple pyrenoids and lack matrix-traversing membranes even in the absence of starch.

a, In an earlier model¹³, we hypothesized that an increased surface area of misshapen starch leads to multiple pyrenoids which are missing matrix-traversing membranes in the saga1 mutant. In that model, abnormal starch causes the formation of multiple matrix condensates; matrix-starch linker proteins mediate the influence of starch on matrix morphology and condensate number. b, TEM images of wild-type and mutant pyrenoids, including the starchless sta6 mutant and the saga1;sta6 double mutant. Previous work^24,47 found that the starchless sta6 mutant has a functional pyrenoid in growth conditions similar to the ones used in this study. c, Fluorescence images of RBCS1-Venus expressed in the wild type compared to mutant backgrounds. All images in each row are shown at the same scale.