Mechanistic insights from a quantitative analysis of pollen tube guidance

BMC Plant Biology

Research Article

Matthew Jones-Rhoades¹  Shannon F Stewman²  Aaron R Dinner³  Daphne Preuss⁴  Prabhakar Bhimalapuram⁵  Martin Tchernookov⁶ 

[1] Department of Biology, Knox College, 2 E South St, 61401-4999, Galesburg, IL, USA;Department of Chemistry, The University of Chicago, 929 E 57th St, 60637, Chicago, IL, USA;James Franck Institute, The University of Chicago, 929 E 57th St, 60637, Chicago, IL, USA;Current address:Department of Physiology and Biophysics, Albert Einstein College of Medicine of Yeshiva University,Jack and Pearl Resnick Campus, 1300 Morris Park Ave, 10461, Bronx, NY, USA;Department of Chemistry, The University of Chicago, 929 E 57th St, 60637, Chicago, IL, USA;James Franck Institute, The University of Chicago, 929 E 57th St, 60637, Chicago, IL, USA;Institute for Biophysical Dynamics, The University of Chicago, 929 E 57th Street, 60637, Chicago, IL, USA;Department of Molecular Genetics and Cell Biology, CLSC 1106, 920 E 58th St, 60637, Chicago, IL, USA;Current address:Chromatin,Inc, Suite 280, 3440 S Dearborn St, 60616, Chicago, IL, USA;Institute for Biophysical Dynamics, The University of Chicago, 929 E 57th Street, 60637, Chicago, IL, USA;International Institute of Information Technology, Gachibowli, 500 032, Hyderabad, Andhra Pradesh, India;James Franck Institute, The University of Chicago, 929 E 57th St, 60637, Chicago, IL, USA;Department of Physics, The University of Chicago, 5740 S Ellis Ave, 60637, Chicago, IL, USA;

关键词: Pollen Tube;    Pollen Tube Growth;    Persistence Length;    Longe Incubation Time;    Synergid Cell;   

DOI  :  10.1186/1471-2229-10-32

 received in 2009-08-25, accepted in 2010-02-22,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundPlant biologists have long speculated about the mechanisms that guide pollen tubes to ovules. Although there is now evidence that ovules emit a diffusible attractant, little is known about how this attractant mediates interactions between the pollen tube and the ovules.ResultsWe employ a semi-in vitro assay, in which ovules dissected from Arabidopsis thaliana are arranged around a cut style on artificial medium, to elucidate how ovules release the attractant and how pollen tubes respond to it. Analysis of microscopy images of the semi-in vitro system shows that pollen tubes are more attracted to ovules that are incubated on the medium for longer times before pollen tubes emerge from the cut style. The responses of tubes are consistent with their sensing a gradient of an attractant at 100-150 μm, farther than previously reported. Our microscopy images also show that pollen tubes slow their growth near the micropyles of functional ovules with a spatial range that depends on ovule incubation time.ConclusionsWe propose a stochastic model that captures these dynamics. In the model, a pollen tube senses a difference in the fraction of receptors bound to an attractant and changes its direction of growth in response; the attractant is continuously released from ovules and spreads isotropically on the medium. The model suggests that the observed slowing greatly enhances the ability of pollen tubes to successfully target ovules. The relation of the results to guidance in vivo is discussed.

【 授权许可】

Unknown   
© Stewman et al; licensee BioMed Central Ltd. 2010. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.