Proteomic Analysis and Extensive Protein Identification from Dry, Germinating Arabidopsis Seeds and Young Seedlings

Abstract

Proteins accumulated in dry, stratified Arabidopsis seeds or young seedlings, totaled 1100 to 1300 depending on the time of sampling, were analyzed by using immobilized pH gradient 2-DE gel electrophoresis. The molecular identities of 437 polypeptides, encoded by 355 independent genes, were determined by MALDI-TOF or TOF-TOF mass spectrometry. In the sum, 293 were present at all stages and 95 were accumulated during the time of radicle protrusion while another 18 appeared in later stages. Further analysis showed that 226 of the identified polypeptides could be located in different metabolic pathways. Proteins involved in carbohydrate, energy and amino acid metabolism constituted to about 1/4, and those involved in metabolism of vitamins and cofactors constituted for about 3 % of the total signal intensity in gels prepared from 72 h seedlings. Enzymes related to genetic information processing increased very quickly during early imbibition and reached highest level around 30 h of germination.

In-Depth Temporal Transcriptome Profiling Reveals a Crucial Developmental Switch with Roles for RNA Processing and Organelle Metabolism That Are Essential for Germination in Arabidopsis

“…The morphological changes observed during germination in this study ( Fig. 2A) comply with previous observations during germination (Fu et al, 2005). Furthermore, this up-regulated expression pattern can be readily observed in a previous Arabidopsis germination study that analyzed global transcriptomic changes without stratification of seeds (cluster 1; Supplemental Fig.…”

“…Over/ underrepresented functional categories were identified by z-score analysis, where statistical significance is represented by a falsecolor heat map (up, orange; down, green) where a z-score of 1.96 represents a P value of 0.05. D, Protein abundance profiles (from Fu et al, 2005) were compared with transcript abundance profiles during germination. The percentage of transcripts in each cluster that showed similar (up-regulated/down-regulated) protein abundance profiles during germination is indicated.…”

“…As the seed is often the primary product utilized by humans, it is not surprising that seed germination is an intensively studied topic. There are a plethora of excellent articles and reviews characterizing seed dormancy and germination, with loss-of-function and gain-of-function mutants analyzed, across multiple species and utilizing many "omics" technologies (Gallardo et al, 2001;Fu et al, 2005;Nakabayashi et al, 2005;Cadman et al, 2006;Holdsworth et al, 2008a;Sreenivasulu et al, 2008;Howell et al, 2009). It has been observed that seed dormancy occurs in most plant species and provides seeds with a mechanism to survive extended periods of debilitating conditions prior to germination.…”

“…To dissect the molecular mechanisms that exist downstream of the hormonal signals regulating germination, transcriptomic and metabolomic profiling studies have been carried out in a range of species including Arabidopsis (Arabidopsis thaliana; Gallardo et al, 2001;Fu et al, 2005;Nakabayashi et al, 2005;Fait et al, 2006), barley (Hordeum vulgare; Sreenivasulu et al, 2008), and rice (Oryza sativa; Howell et al, 2009). These studies have revealed some common properties of transcriptomic changes that occur across these plant species.…”

Primary metabolite mobilization during germination in rosewood (Aniba rosaeodora Ducke) seeds

“…During germination, enzymatic hydrolysis of storage proteins in the endosperm forms a reservoir of small peptides and amino acids, which are translocated to supply organic nitrogen to the growing seedling. Proteins involved in carbohydrate, energy and amino acid metabolism constituted to about ¼ of total proteins extracted in the germinating seeds (FU et al, 2005). In rosewood, protein levels were slightly modified during seed germination, being the highest content recorded in 2-5 cm radicles ( Figure 2B).…”