Figure 10.

Underdeveloped GhVIN-RNAi seeds exhibited impaired filial tissue growth. A to D, Toluidine Blue staining of longitudinal sections of 15-d fully developed seed from wild-type (WT) cotton (A) and GhVIN-RNAi 61-9-1 (B) and underdeveloped seed from RNAi 28-4-1 (C) and RNAi 61-9-1 (D). Note that the fully developed seeds had progressed to torpedo embryo stage with cellularized endosperms (arrows in A and B), whereas the underdeveloped seeds remained in the globular embryo stage with disrupted or limited endosperm cellularization (arrowheads in C and D). E to g, Compared with the 15-d wild-type seed (E and e), line 28-4-1 (F and f) and 61-9-1 (G and g) underdeveloped seeds showed slightly bigger seed size but retarded filial tissue growth. H to j, Compared with the fully developed cotyledon embryo in the wild-type seed at 30 d, where endosperm was fully absorbed (H and h), line 28-4-1 (I and i) and 61-9-1 (J and j) underdeveloped seeds exhibited stunted embryo growth with endosperm remaining. Images labeled by lowercase letters show embryo (left) and endosperm (right) tissues isolated from the seeds presented in the images labeled with the same uppercase letters. Bars = 100 μm in A and 5 mm in E and H. The scales in B to D are the same as that in A, and the scales in e to g and h to j are same as those in E and H, respectively.