Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2008 Oct 10;49(10):1465–1477. doi: 10.1093/pcp/pcn131

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

© The Author 2008. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved.

The online version of this article has been published under an open access model. Users are entitled to use, reproduce, disseminate, or display the open access version of this article for non-commercial purposes provided that: the original authorship is properly and fully attributed; the Journal and the Japanese Society of Plant Physiologists are attributed as the original place of publication with the correct citation details given; if an article is subsequently reproduced or disseminated not in its entirety but only in part or as a derivative work this must be clearly indicated. For commercial re-use, please contact journals.permissions@oxfordjournals.org

PMC Copyright notice

Fig. 2 — Exine development in wild-type Arabidopsis. Transmission electron micrographs showing sections of developing pollen grains in wild-type Arabidopsis (Ler). Micrographs in the top row have the same magnification (A, C, E, G, I) (bars = 10 μm), and those in the bottom row have the same magnification (B, D, F, H, J) (bars = 0.5 μm). (A, B) Pollen mother cells. Each pollen mother cell is surrounded by secondary cell wall. (C, D) Tetrads. Primexine (asterisks) appears between the plasma membrane and callose wall, and the probaculae (arrowheads) are visible above the raised positions of the undulating plasma membrane. Sporopollenin is deposited more densely at the distal part of the probaculae, adjacent to the callose wall. (E, F) Microspores in the early unicellular stage. Feeble tectum, baculae and nexine I are visible. Primexine remains in the cavity of developing exine (asterisks). (G, H) Microspores in the late unicellular stage. Sexine formation is almost complete. (I, J) Tricellular mature pollen grains. Nexine II and intine have formed. Ba, bacula; CW, callose wall; In, intine; Lo, locule; M, microspore; Ne I, nexine I; Ne II, nexine II; PC, pollen coat; PM, plasma membrane; PMC, pollen mother cell; SP, sporopollenin deposited on the outer surface of tetrads; SW, secondary cell wall; T, tapetal cell; Td, tetrad; Te, tectum.