Skip Navigation


Plant and Cell Physiology Advance Access originally published online on January 30, 2009
Plant and Cell Physiology 2009 50(3):610-625; doi:10.1093/pcp/pcp019
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
50/3/610    most recent
pcp019v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Yamada, T.
Right arrow Articles by van Doorn, W. G.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Yamada, T.
Right arrow Articles by van Doorn, W. G.
Agricola
Right arrow Articles by Yamada, T.
Right arrow Articles by van Doorn, W. G.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author 2009. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oxfordjournals.org

Homologs of Genes Associated with Programmed Cell Death in Animal Cells are Differentially Expressed During Senescence of Ipomoea nil Petals

Tetsuya Yamada1,2,*, Kazuo Ichimura1, Motoki Kanekatsu2 and Wouter G. van Doorn3

1National Institute of Floricultural Science, Tsukuba, 305-8519 Japan
2Faculty of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, 183-8509 Japan
3Mann Laboratory, Department of Plant Sciences, University of California, Davis, CA 95616, USA

*Corresponding author: E-mail, teyamada{at}cc.tuat.ac.jp; Fax, +81-41-3675733.


  Abstract

In senescent petals of Ipomoea nil, we investigated the expression of genes showing homology to genes involved in animal programmed cell death (PCD). Three encoded proteins were homologous to apoptotic proteins in animals: Bax inhibitor-1 (BI-1), a vacuolar processing enzyme (VPE; homologous to caspases) and a monodehydroascorbate reductase [MDAR; homologous to apoptosis-inducing factor (AIF)]. AIFs harbor an oxidoreductase domain and an apoptotic domain. MDARs exhibit homology to the AIF oxidoreductase domain, not to the apoptotic domain. The three other genes studied relate to autophagy. They encode homologs to vacuolar protein sorting 34 (VPS34) and to the Arabidopsis autophagy-related proteins 4b and 8a (ATG4b and ATG8a). The transcript abundance of MDAR decreased continuously, whereas that of the other genes studies exhibited a transient increase, except ATG4b whose abundance stayed high after an increase. Treatment with ethylene advanced the time to visible petal senescence, and hastened the changes in expression of each of the genes studied. In order to assess the role of VPS34 in petal senescence, we studied the effect of its inhibitor 3-methyladenine (3-MA). 3-MA reduced the time to visible petal senescence, and also accelerated the time to DNA degradation. Remarkably, 3-MA increased the time to nuclear fragmentation, indicating that the time to visible petal senescence was independent of nuclear fragmentation. The data on 3-MA might suggest the idea that autophagy is not a cause of PCD, but part of the remobilization process.

Keywords: Apoptosis - Autophagy - Ethylene - Homologous genes - Petal senescence - Programmed cell death.

Abbreviations: AIF, apoptosis-inducing factor; AIFL, AIF-like; AIFM, AIF, mitochondrion-associated; AIFsh, short AIF; AMID, AIF-homologous mitochondrion-associated inducer of death; APG (ATG), autophagy; Bax, Bcl-2-associated X protein; Bcl-2, B-cell lymphoma protein 2; BI-1, Bax-inhibitor 1; CTAB, cetyltrimethylammonium bromide; DAPI, 4',6-diamino-2-phenylindole; ER, endoplasmic reticulum; EST, expressed sequence tag; 3-MA, 3-methyladenine; MDAR, monodehydroascorbate reductase; PARP, poly(ADP-ribose)-polymerase; PCD, programmed cell death; PI3K, phosphatidylinositol 3-kinase; ROS, reactive oxygen species; RT–PCR, reverse tanscription–PCR; VPE, vacuolar processing enzyme; VPS, vacuolar protein sorting

(Received November 4, 2008; Accepted January 27, 2009)
Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.