Proceedings
of the XLVI Italian Society of Agricultural Genetics - SIGA Annual Congress
Giardini
Naxos, Italy - 18/21 September, 2002
ISBN 88-900622-3-1
Poster
Abstract - 4.16
Comparison of polypeptide expression in anthers
from gametophytic male sterile-2 and wild type maize by 2-D electrophoresis
Wang W.*, Scali M.*, Vignani R.*, Sensi E.*, VILLA
M.**, Cresti M.*
*)
Dipartimento di Scienze Ambientali “G. Sarfatti”, University of
Siena, Via Mattioli 4, 53100 Siena, Italy
**)
Dipartimento di Genetica e di Biologia dei Microrganismi, University of Milano,
Via Celoria 26, 20133 Milano, Italy
2-D
electrophoresis, anther, maize, male sterility, proteome
Pollen
development is of great interest for fundamental research in cell biology, as
well as for plant breeding programs and genetic manipulation of haploid cell
lines. The present research has been focused on the isolation and
characterization of pollen-specific genes which mutations may lead to pollen
development defects . Gametophytic male sterile-2 (gaMS-2 ), is a
maize mutant obtained by transposon insertion mutagenesis. It is characterized
by lack of differentiation between the vegetative and the generative nuclei in
pollen grains, which leads to various nuclear abnormalities and to
approximately 50% of mature fertile pollen. Although the cytological events
characterizing sterile pollen grains are well described, little is known about
the biochemical and molecular processes at the basis of the mutant phenotype.
Here, we describe a comparative study of anther proteins of gaMS-2 and
wild type (wt) by 2-D electrophoresis, carried out in order to enlighten
proteins selectively expressed between the two pollen types.
Protein
extracts from anthers for 2-D electrophoresis were prepared by use of liquid
phenol (85%), followed by precipitation with 0.1 M ammonium acetate in
methanol. Phenol extraction can minimize protein degradation that may occur
during sample preparation. Our results revealed that in 2-D gels, approximately
300 protein spots could be resolved efficiently after Commassie blue staining.
These spots range from 10 to 116 kDa (pI 3-10) and the majority of them are
identical in the mutant and wt. The difference in anther proteins appears to be
limited to a few spots. In particular in the wt anthers, a protein having a MW
larger than 31 kDa (pI 10), is expressed at high levels and it seems to be
absent in the mutant. In addition, even some homologue proteins of the mutant
and wt exhibit differential levels of expression. Apparently, no visible
differences in the proteomic patterns were found in the anthers of either wt or
the mutant, at different developmental stages.
The herein described
anther-specific/-enriched proteins of wild type, deserve further investigation.
It will be crucial to determine if some of these proteins are involved in
eliciting the genetic mechanisms regulating pollen development. Protein
micro-sequencing is under way and subsequently the expression analysis will be
carried out.