Figure 2.

Extra functional megaspores detection in mARF10 background

(A) pLC2:YFP FM identity marker in the wild type background.

(B–F) pLC2:YFP in the mARF10 background: (B) YFP signal detects the functional megaspore, meiosis occurred early with respect to integument development; (C) extra YFP signal detected close to the degenerated megaspores; (D and E) extra YFP signals in the L1 layer; (F) YFP signal in sporophytic tissue at ovule mature stage. The LC2 FM marker signal was counted in a fluorescent microscope and a significance of statistical analysis was performed using 95% Confidence Interval (CI): 48.98% ovules with one functional megaspore (0.3882 < p < 0.5922), 19.39% with more than one functional megaspore (0.1236 < p < 0.2887) and 31.63% without signal (0.2281 < p < 0.4191) (n = 98 ovules). In a wild type background, 97.96% (0.8776 < p < 0.9989) showed one functional megaspore and 2.04% (0.0011 < p < 0.1224) two functional megaspores (n = 49).

(G) pWOX2:CENH3_GFP in wild type background, showing a single reduced FM with five chromosomes (green dots).

(H) mature ovule with two cells at the chalaza pole expressing the GFP marker (white and yellow arrow, respectively); the cells are non-reduced, as more than five green dots are detected per cell. In the right panels, different focal planes of each one of the cells are shown: 10 chromosomes are visible in cell 1 (white arrow), while 7 in cell 2 (for more details see Video S1).

(I and J) two different focal planes of the same ovule at FG1 stage: (I) three functional megaspores are detected (white arrows). The upper one display 5 chromosomes (five green dots) (for more details see Video S2), the bottom ones present more than 5 chromosomes. (J) in a different focal plane of the same ovule, new cells expressing the FM marker are visible: the upper one (yellow arrow) display at least 8 chromosomes (magnified panels at right, full view at Video S2). Scale bars:10μm.