A reference map of the Arabidopsis thaliana mature pollen proteome

Abstract

The male gametophyte (or pollen) plays an obligatory role during sexual reproduction of higher plants. The extremely reduced complexity of this organ renders pollen a valuable experimental system for studying fundamental aspects of plant biology such as cell fate determination, cell-cell interactions, cell polarity, and tip-growth. Here, we present the first reference map of the mature pollen proteome of the dicotyledonous model plant species, Arabidopsis thaliana. Based on two-dimensional gel electrophoresis, matrix-assisted laser desorption/ionization time-of-flight, and electrospray quadrupole time-of-flight mass spectrometry, we reproducibly identified 121 different proteins in 145 individual spots. The presence, subcellular localization, and functional classification of the identified proteins are discussed in relation to the pollen transcriptome and the full protein complement encoded by the nuclear Arabidopsis genome. Ó 2005 Elsevier Inc. All rights reserved.Keywords: Arabidopsis thaliana; Male gametophyte; Mass spectrometry; Mature pollen; Proteome; Two-dimensional gel electrophoresis In higher plants, development of the male gametophyte is a well-programmed and elaborate process. Male sporogenesis begins with the division of a diploid sporophytic cell giving rise to the anther wall of the stamen and the sporogenic cells. The latter cells then undergo several mitoses to differentiate into pollen mother cells. Subsequently, each diploid pollen mother cell forms a tetrad of haploid microspores via a round of DNA replication followed by two consecutive meiotic divisions. Each uninucleate microspore then undergoes an asymmetric mitotic division forming a large vegetative cell and a smaller generative cell (i.e., the bicellular pollen stage). In Arabidopsis, the generative cell undergoes another mitotic division giving rise to two sperm cells (i.e., the tricellular pollen stage). Following pollination, the vegetative cell controls the further development of the mature pollen grain and growth of the pollen tube into the style until both sperm cell nuclei are delivered to the embryo sac in the ovule, where they participate in double fertilization [1,2].The last two decades have been marked by increasing efforts to decipher the genetic and molecular basis of pollen development and functions [reviewed in 1,3,4]. In the model plant Arabidopsis thaliana, the extremely reduced, tricellular male gametophyte constitutes an ideal experimental system for analyses of important biological processes in higher plant reproduction. In addition, it represents a very useful model for studying fundamental aspects of plant biology such as cell fate determination, cell-cell interactions, cell polarity, and tip-growth [5][6][7].The availability of the full genome sequence of Arabidopsis [8] has made genome-wide, microarray-based analyses of the male gametophyte transcriptome of this model plant possible [9][10][11][12]. 13,977 male gametophyte-expressed mRNAs were recently identified using the ATH1 Genome Array, which cover...

Proteomics Identification of Differentially Expressed Proteins Associated with Pollen Germination and Tube Growth Reveals Characteristics of Germinated Oryza sativa Pollen

“…Relatively identical protein patterns were also observed in mature pollen and pollen tubes of Gymnospermae pine (15). Together with the proteomic data of mature pollen of Arabidopsis and rice (12)(13)(14), our data further indicate that pollen germination and early tube growth depend mainly on these presynthesized proteins in mature pollen. f Change in abundance of the protein spots on 2DE gel after germination.…”

“…9B). A similar proportion was found in the identified proteins from mature Arabidopsis pollen (13), implying the functional importance of isoforms.…”

“…Therefore, isoforms are generally considered to diversify the function of a protein. Recent proteomics studies have revealed that isoforms are common in analyzed seeds (60), anthers (61), and mature pollen (12)(13)(14). In our identified Unipros from mature rice pollen, 23% have isoforms (14) with wide distribution in different functional categories (Fig.…”

“…Recent proteomics studies from Arabidopsis (12,13) and rice (14) have revealed that mature pollen presynthesizes a complement of proteins required for pollen function, including those implicated in protein synthesis and carbohydrate/energy metabolism. Dai et al (14) showed that these functional categories related to carbohydrate/energy metabolism, wall metabolism, protein synthesis and degradation, and signaling are overrepresented in the proteome.…”

Combined Proteomic and Cytological Analysis of Ca2+-Calmodulin Regulation inPicea meyeriPollen Tube Growth

“…Studies focusing solely on the proteome of the male gametophyte have been performed in Arabidopsis and Pinus strobus (Fernando, 2005;Holmes-Davis et al, 2005). Recent proteomic investigations of pollens from Arabidopsis, rice, and gymnosperms have provided opportunities to complement the information derived from transcriptomic analysis and offered new insights into the mechanisms underlying pollen functional specification (Noir et al, 2005;Dai et al, 2006Dai et al, , 2007Sheoran et al, 2006). However, pollen tube development in conifers (gymnosperm) differs in several ways from that in angiosperms, such as in the extended growth period, relatively slow growth rate, and extremely delayed gametogenesis, which represent a major evolutionary divergence in male gametophyte development in the flowering plants (Fernando, 2005Williams, 2008).…”