Developmental biology of the pollen wall in Arabidopsis
Loading...
Citations
Altmetric:
Altmetric::
Download
Associated Records
Authors
File Licence
Editors
Date
1998
Source Title
Journal Title
Journal ISSN
Volume Title
Publisher
University of Melbourne
Melbourne Authors
Affiliation
Science Collected Works
Document Type
PhD thesis
Subject Code
Citation
Access Status
Only available to University of Melbourne staff and students, login required
DOI
Access URL
Open Access URL
Open Access at PMC
Linked Resource URL
NHMRC Grant Code
ARC Grant Code
Description
Thesis (PhD) -- University of Melbourne, Faculty of Science, 1999
Includes bibliographical references.
Includes bibliographical references.
Abstract
By selectively removing individual genes in mutant plants, the processes involved in pollen development can be dissected and characterised. Arabidopsis thaliana seeds were mutagenised by various EMS (ethylmethane sulfonate) concentrations and various exposure times. The Ml Arabidopsis plants were grown and M2 seeds of each line were collected and stored. Some M2 seeds were sown for M2 screening. About 10,000 M2 plants were screened for ms (male sterile) mutants and about a hundred ms mutants were found. Some of them were selected for light and electron microscopical analysis of pollen wall development. Several ms mutants, ms5, ms9 and ms12, have already been partially characterised by colleagues and this work reinvestigated these with a focus on exine development.
From ultrastructural analysis, all the mutants characterised in this study were classified according to aberrations in exine development: 1. Thin exine mutants, which have very thin exines compared to those of wild type; 2. Primexine mutants that have defects in exine development and produce no mature pollen or rarely a few exceptionally large pollen grains; 3. Other exine mutants that develop exines with incomplete or abnormal sculpture. These mutants have been ordered according to their aberration time in Chapter 8.
A male sterile mutant, ms5, was found to be a pollen wall mutant. The promoter of the mutant gene has previously been fused with a GUS reporter gene and transformed into wild type plants. Here, expression of the gene was determined with a GUS enzyme assay. This study further explained the important roles of both tapetum and pollen cytoplasm in exine development. The new mutants developed here did not develop pollen with a complete exine structure because either the cytoplasm or tapetum had defects in it.
Characterising genes involved in exine development may enable future biosynthesis of sporopollenin which is remarkable for its resistance to both physical and enzymic degradation. The characterisation of pollen wall mutants produced in this study gave a clearer understanding of the processes involved in the formation of the wall in wild type pollen. A proposed model detailing the ultrastructural changes in pollen wall development is also presented here.
Notes
Terms of Use
Keywords
Arabidopsis thaliana -- Pollen -- Morphology.