Table 1. Maize Plastids with and without Discrete DAPI-DNA Fluorescence
Category 1: DiscreteaCategory 2:
Diffuse Pattern and DiscreteCategory 3:
Undetectable
Cells in tissue sectionsb69NA46
Protoplastsc438
Isolated plastidsd514238
  • a Three categories of DAPI-DNA patterns in plastids were scored by visual examination of fluorescence microscopy images: (1) plastids with many nucleoids as indicated by discrete DAPI-DNA spots, (2) plastids with a diffuse DAPI-DNA signal and a few nucleoids, and (3) plastids with neither a diffuse DAPI-DNA signal nor discrete nucleoids. Examples of Categories 1 and 3 are shown in Figure 2 for tissue sections and for Categories 1 to 3 in Figure 3 for mesophyll protoplasts and Supplemental Figure 3 for isolated plastids.

  • b The number of cells with and without discrete DAPI-DNA nucleoids was determined for both fixed-then-sectioned and sectioned-then-fixed tissues from the first leaf blade of 11- and 10-d-old seedlings, respectively (see Methods and example shown in Supplemental Figure 2H). Since only two categories (discrete and undetectable) were scored, the second category is not applicable (NA) for tissue sections. For fixed-then-sectioned tissue, four fields of view were examined with 45 cells in Category 1 and 28 in Category 3; these values for sectioned-then-fixed were three fields with 24 and 18 cells, respectively.

  • c Fifteen mesophyll protoplasts from the first leaf blade of 10-d-old seedlings were examined.

  • d A total of 131 isolated plastids from the first leaf blade of 9- and 11-d-old seedlings were examined.