© 2004 Oxford University Press
Ethylene Synthesis and Auxin Augmentation in Pistil Tissues are Important for Egg Cell Differentiation after Pollination in Maize
1 Department of General Botany, Faculty of Biology, Adam Mickiewicz University, ul. Umultowska 89, 61-614 Poznan, Poland
2 Franciszek Górski Department of Plant Physiology, Polish Academy of Sciences, ul. Podluzna 3, 30-239 Kraków, Poland
3 Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Rozvojová 135, 165 02 Prague, Czech Republic
4 Reproduction et Développement des Plantes, UMR 5667, CNRS/INRA/ENS/UCBL I, Ecole Normale Superieure, 46 Allee d’Italie, 69364 Lyon, France
The role of ethylene and auxin in stigma-to-ovule signalling was investigated in maize (Zea mays L.). Maturation of the egg cells in an ear was stimulated before actual fertilization by the application of fresh pollen grains or quartz sand to fully receptive stigmas. Ethylene emission by maize ears increased in response to those treatments. Silks and ovaries were involved in ethylene synthesis after pollen or sand was shed over the silks. The content of ethylene precursor [1-aminocyclopropane-1-carboxylic acid (ACC)] increased in both pistil parts soon after pollination. ACC rise was delayed by 4 h in the ovaries, and by 8 h in the silks after mock-pollination with sand. The auxin level increased rapidly in the silks and ovaries after pollination, and it was very high in the pollinated silks due to the high indole-3-acetic acid (IAA) content of pollen grains. IAA rise also appeared in the silks and ovaries after treatment with sand but it was delayed by 8 h. Application of ACC (10 µM) or IAA (6 µM) solutions to non-pollinated silks stimulated maturation of the egg cells. Moreover, the response of the egg cells to pollination was cancelled by L-
-(2-aminoethoxyvinyl)-glycine, -aminoisobutyric acid or 2,3,5-triiodobenzoic acid applied to the silks before pollination. Thus ethylene synthesis and polar auxin transport in the silks pollinated with fresh pollen were necessary to evoke accelerated differentiation of the egg cells in maize ovules. Differences in pistil responses found between true- and mock-pollination suggest that signalling pathways are at least partially different for the reception of pollen grains and sand crystals on maize stigma.
5 Corresponding author: E-mail, ramol{at}main.amu.edu.pl; Fax, +48-61-829-56-11.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  J.-Z. Wu, Y. Lin, X.-L. Zhang, D.-W. Pang, and J. Zhao IAA stimulates pollen tube growth and mediates the modification of its wall composition and structure in Torenia fournieri J. Exp. Bot., June 1, 2008; 59(9): 2529 - 2543. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Li, W. Xu, W. Yang, Z. Kong, and Y. Xue Genome-Wide Gene Expression Profiling Reveals Conserved and Novel Molecular Functions of the Stigma in Rice Plant Physiology, August 1, 2007; 144(4): 1797 - 1812. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. F. Maraschin, W. de Priester, H. P. Spaink, and M. Wang Androgenic switch: an example of plant embryogenesis from the male gametophyte perspective J. Exp. Bot., July 1, 2005; 56(417): 1711 - 1726. [Abstract] [Full Text] [PDF]
|
|