Proteome-Wide Characterization of Seed Aging in Arabidopsis: A Comparison between Artificial and Natural Aging Protocols

LoïC Rajjou,Claudette Job,Yoann Lovigny,Steven P.C Groot,Dominique Job,Maya Belghazi

doi:10.1104/pp.108.123141

Abstract

A variety of mechanisms have been proposed to account for the extension of life span in seeds (seed longevity). In this work, we used Arabidopsis (Arabidopsis thaliana) seeds as a model and carried out differential proteomics to investigate this trait, which is of both ecological and agricultural importance. In our system based on a controlled deterioration treatment (CDT), we compared seed samples treated for different periods of time up to 7 d. Germination tests showed a progressive decrease of germination vigor depending on the duration of CDT. Proteomic analyses revealed that this loss in seed vigor can be accounted for by protein changes in the dry seeds and by an inability of the low-vigor seeds to display a normal proteome during germination. Furthermore, CDT strongly increased the extent of protein oxidation (carbonylation), which might induce a loss of functional properties of seed proteins and enzymes and/or enhance their susceptibility toward proteolysis. These results revealed essential mechanisms for seed vigor, such as translational capacity, mobilization of seed storage reserves, and detoxification efficiency. Finally, this work shows that similar molecular events accompany artificial and natural seed aging.

Highlights

A variety of mechanisms have been proposed to account for the extension of life span in seeds
The controlled deterioration treatment (CDT) protocol described by Tesnier et al (2002) was used to alter seed vigor of wild-type Arabidopsis ecotype Landsberg erecta (Ler) seeds for up to 7 d
To reveal molecular mechanisms associated with the loss of seed vigor induced by CDT, a differential proteomic approach was used under two different protocols

Summary

Introduction

A variety of mechanisms have been proposed to account for the extension of life span in seeds (seed longevity). Thanks to the availability of genomic sequence information and based on the progress achieved in sensitive and rapid separation of proteins and in their high-throughput identification by electrophoresis and mass spectrometry, proteomic approaches have opened up new perspectives to analyze the complex functions of model plants and crop species (Canovas et al, 2004; Park, 2004; Agrawal et al, 2005a, 2005b, 2005c; Rossignol et al, 2006; Jorrın et al, 2007) In this way, previous proteomic studies revealed the requirements of RNA and protein synthesis for Arabidopsis seed germination (Gallardo et al, 2001, 2002a, 2002b; Rajjou et al, 2004, 2007a). These studies revealed that proteins and mRNAs stored in the dry mature seeds are sufficient for germination sensu stricto (Rajjou et al, 2004)

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Results

Conclusion