Skip to main content
. 2019 Jun 14;14(6):e0218029. doi: 10.1371/journal.pone.0218029

Fig 5. Transmission electron microscopy observation of tapetum development in the Ogura-CMS line and its maintainer fertile (MF) line of turnip.

Fig 5

(A, F) Microspore mother cell stage. Micropores mother cells are surrounded by the tapetum, middle layer, endothecium, and epidermis from the inside out. (B, G) Tetrad stage, showing four distinctive surrounding walls and vacuolated tapetums. The tapetal cells in (G) swell to expand at the center of the locule, with larger vacuoles and a clearing cytoplasm. (C, H) Uninucleate microspore stage. Middle layer disappears and elaioplasts emerge in (C), whereas middle layer persists and tapetosomes were ubiquitous in (H). (D, I) Bicellular stage. Premature degradation of the tapetum occurs in (I), compared with integral tapetal cells with a large amount of elaioplasts in (D). (E, J) Mature pollen stage, showing the absence of the endothecium in (J). E, epidermis; En, endothecium; Ep, elaioplast; M, microspore; ML, middle layer; Nu, nuclei; T, tapetum; Ts, tapetosome; Ve, vacuole. Bars = 5 μm.