Fig. 2.

The pyrenoids of the saga1 mutant have aberrant starch sheaths. (A) Representative TEMs showing pyrenoids of wild-type, saga1, and saga1;SAGA1-Venus cells grown at low CO₂, illustrating defects in the starch sheath. (B) Quantification of the number of starch granules per pyrenoid in wild-type, saga1, and saga1;SAGA1-Venus cells grown at low CO₂ (n = 20 pyrenoids; Mann–Whitney U test). (C) Length of starch granules in wild-type, saga1, and saga1;SAGA1-Venus cells grown at low CO₂ (n = 162, 114, 126 starch granules; Mann–Whitney U test). (D) The cross-sectional area of pyrenoid starch in wild-type, saga1, and saga1;SAGA1-Venus cells grown at low CO₂ (n = 20 cells; Mann–Whitney U test). Error bars: SEM; **P < 0.001. (E) Example TEMs showing pyrenoids of saga1 cells with starch granules either “stacking” on top of each other or appearing to “pinch” away portions of the matrix. (Scale bars, 500 nm.)