oi’ formation.

<p><b>(A-B)</b> Longitudinal sections of wild type ovules at stage 2-III (A) and 3-VI (B) imaged using the mPS-PI technique. Ecotype Col. ii primordium, oi primordium and chalaza are highlighted in green, blue, and red, respectively. Highlighting of the chalazal tissue in red is inferred by the position of the integument primordia. <b>(C-D)</b> Longitudinal sections of wild type mature ovules imaged using the mPS-PI technique. Ecotype Col. oi’ is highlighted in red. <b>(E-F)</b> Longitudinal sections of wild type seeds at 6 DAF imaged using the mPS-PI technique. Ecotype Col. oi’ is highlighted in red. <b>(G-H)</b> Three-dimensional longitudinal (G) and transverse (H) sections of a wild type seed at 6 DAF imaged using the mPS-PI technique. Ecotype Ws. oi’ is highlighted in red. Scale bars, 10 μm (A) and 50 μm (B-H).