JXB Advance Access published online on May 23, 2006
Journal of Experimental Botany, doi:10.1093/jxb/erj159
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Key Laboratory of the Ministry of Education for Plant Developmental Biology, College of Life Sciences, Wuhan University, Wuhan 430072, China
* To whom correspondence should be addressed. Arabinogalactan proteins (AGPs) have been implicated in a variety of plant development processes including sexual plant reproduction. As a crucial developmental event, plant sexual reproduction generally occurs inside an ovule embedded in an ovary. The inaccessibility of the egg cells, zygotes, and embryos has hindered our understanding of the importance of AGPs in the early events involving fertilization, zygotic division, and early embryogenesis. In this study, the well-established in vitro zygote and ovary culture systems, together with immunofluorescence and immunogold labelling techniques, were employed to investigate the role of AGPs in the early events of sexual reproduction in Nicotiana tabacum. Dramatic changes in AGP content during ovule development were evidenced by western blotting. Subcellular localization revealed that AGPs are localized in the plasma membrane, cell wall, and cytoplasm of pre- and post-fertilized egg cells, and cytoplasm and vacuoles of two-celled proembryos. Abundant AGPs were detected in unfertilized egg cells; however, the level of AGPs substantially decreased in fertilized egg cells. Polar distribution of AGPs in elongated zygotes was observed. The early two-celled proembryos just from zygote division displayed accumulation of AGPs at a low level, while in the elongated two-celled proembryos at the late stage, the AGP content clearly increased. Provision of
Received September 13, 2005
Accepted February 8, 2006
RESEARCH PAPER
Localization of arabinogalactan proteins in egg cells, zygotes, and two-celled proembryos and effects of
Yuan Qin 1
and
Jie Zhao 1 *
-D-glucosyl Yariv reagent on egg cell fertilization and zygote division in Nicotiana tabacum L
Jie Zhao, E-mail: jzhao{at}whu.edu.cn
Abstract 
GlcY, a synthetic phenylglycoside that specifically binds AGPs, to the in vitro cultures of isolated zygote and fertilized ovaries increased abnormal symmetrical division of zygotes. In the culture of pollinated but unfertilized ovaries, addition of GlcY resulted in arrest of fertilization of the egg cells, but had no effect on fertilization of the central cells. The possible roles of AGPs in fertilization, zygotic division, and proembryo development are discussed.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  X. Zhang, Y. Ren, and J. Zhao Roles of extensins in cotyledon primordium formation and shoot apical meristem activity in Nicotiana tabacum J. Exp. Bot., October 17, 2008; (2008) ern245v1. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Chen, J. Ding, Y. Ouyang, H. Du, J. Yang, K. Cheng, J. Zhao, S. Qiu, X. Zhang, J. Yao, et al. From the Cover: A triallelic system of S5 is a major regulator of the reproductive barrier and compatibility of indica-japonica hybrids in rice PNAS, August 12, 2008; 105(32): 11436 - 11441. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Coimbra, J. Almeida, V. Junqueira, M. L. Costa, and L. G. Pereira Arabinogalactan proteins as molecular markers in Arabidopsis thaliana sexual reproduction J. Exp. Bot., December 1, 2007; 58(15-16): 4027 - 4035. [Abstract] [Full Text] [PDF]
|
|