Proteomic analyses of Oryza sativa mature pollen reveal proteins associated with pollen germination and tube growth

Key Laboratory of Photosynthesis & Environmental Molecular Physiology, Research Center for Molecular & Developmental Biology, Institute of Botany, Chinese Academy of Sciences, Beijing, PR China.
PROTEOMICS (Impact Factor: 3.81). 04/2006; 6(8):2504-29. DOI: 10.1002/pmic.200401351
Source: PubMed


As a highly reduced organism, pollen performs specialized functions to generate and carry sperm into the ovule by its polarily growing pollen tube. Yet the molecular genetic basis of these functions is poorly understood. Here, we identified 322 unique proteins, most of which were not reported previously to be in pollen, from mature pollen of Oryza sativa L. ssp japonica using a proteomic approach, 23% of them having more than one isoform. Functional classification reveals that an overrepresentation of the proteins was related to signal transduction (10%), wall remodeling and metabolism (11%), and protein synthesis, assembly and degradation (14%), as well as carbohydrate and energy metabolism (25%). Further, 11% of the identified proteins are functionally unknown and do not contain any conserved domain associated with known activities. These analyses also identified 5 novel proteins by de novo sequencing and revealed several important proteins, mainly involved in signal transduction (such as protein kinases, receptor kinase-interacting proteins, guanosine 5'-diphosphate dissociation inhibitors, C2 domain-containing proteins, cyclophilins), protein synthesis, assembly and degradation (such as prohibitin, mitochondrial processing peptidase, putative UFD1, AAA+ ATPase), and wall remodeling and metabolism (such as reversibly glycosylated polypeptides, cellulose synthase-like OsCsLF7). The study is the first close investigation, to our knowledge, of protein complement in mature pollen, and presents useful molecular information at the protein level to further understand the mechanisms underlying pollen germination and tube growth.

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Available from: Shaojun Dai, Oct 10, 2015
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    • "All rights reserved. (Dai et al. 2006). The variation in the amounts of these proteins upon elevated NO 2 (Table 2) indicates that NO 2 affects cytoskeleton dynamics and male gametophyte development, which also agrees with the reduced pollen viability of several plant species upon in vitro exposure of the pollen to NO 2 (Cuinica et al. 2014). "
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    ABSTRACT: Ragweed pollen is the main cause of allergenic diseases in Northern America and the weed has become a spreading neophyte in Europe. Climate change and air pollution is speculated to affect the allergenic potential of pollen. The objective of this study was to investigate the effects of NO2 , a major air pollutant, under controlled conditions, on the allergenicity of ragweed pollen. Ragweed was exposed to different levels of NO2 throughout the entire growing season, and its pollen further analysed. Spectroscopic analysis showed increased outer cell wall polymers and decreased amounts of pectin. Proteome studies using 2D-difference gel electrophoresis and liquid chromatography-tandem mass spectrometry indicated increased amounts of several Amb a 1 isoforms and of another allergen with great homology to enolase Hev b 9 from rubber tree. Analysis of protein S-nitrosylation identified nitrosylated proteins in pollen from both conditions, including Amb a 1 isoforms. However, elevated NO2 significantly enhanced the overall nitrosylation. Finally, we demonstrated increased overall pollen allergenicity by immunoblotting using ragweed antisera, showing a significantly higher allergenicity for Amb a 1. The data highlight a direct influence of elevated NO2 on the increased allergenicity of ragweed pollen and a direct correlation with an increased risk for human health. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Plant Cell and Environment 07/2015; DOI:10.1111/pce.12601 · 6.96 Impact Factor
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    • "Consequently, comprehensive analysis on spatiotemporal expression profiles in plant reproductive tissues and related processes on transcriptomic and proteomic levels were performed in different species. It provided abundant transcriptomic and proteomic data about mature pollen or even haploid male gametophyte and germinated pollen or pollen tube [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [30] [31] [32] [33] [34], matured pistil, and pollinated pistil [35] [36] [37] [38] [39] [40] [41] [42] [43]. However, these studies mainly focused on the quantitative changes of gene expression and were unable to provide any information on protein PTMs, such as phosphorylation. "
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    ABSTRACT: As the female reproductive part of a flower, pistil consists of ovary, style and stigma, and is a critical organ for the process from pollen recognition to fertilization and seed formation. Previous studies on pollen-pistil interaction mainly focused on gene expression changes with comparative transcriptomics or proteomics method. However studies on protein post-translational modifications are still lacking. Here we report a phosphoproteomic study on mature pistil of rice. Using IMAC enrichment, HILIC fraction and high-accuracy MS instrument (TripleTOF 5600), 2,347 of high confident (Ascore≥19, p≤0.01) phosphorylation sites corresponding to 1,588 phosphoproteins were identified. Among them, 1,369 phosphorylation sites within 654 phosphoproteins were newly identified; 41 Serine Phosphorylation motifs which belong to 3 groups: proline-directed, basophilic and acidic motifs were identified after analysis by motif-X; 201 genes whose phosphopeptides were identified here showed tissue-specific expression in pistil based on information mining of previous microarray data. The Mass spectra data have been deposited to the PRIDE with identifier PXD000923. This study will help us to understand the pistil development and pollination on post-translational level.This article is protected by copyright. All rights reserved
    Proteomics 10/2014; 14(20). DOI:10.1002/pmic.201400004 · 3.81 Impact Factor
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    • "In recent years, annexins from many different plants have been isolated, and their functions have been studied. As with annexins in animals, those in plants have the conserved function of the protein family and participate in many significant physiological activities, such as the cell cycle [21], pollen and seed germination [22], [23], [77], tuber development of cassava [24], cotton fiber elongation [25], petunia petal senescence [26], strawberry fruit ripening and gall ontogeny [27], primary root growth and lateral root formation [28]–[30], vascular development [31] and cork formation [32]. Most of these events are linked to Ca2+ signaling and membrane function. "
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    ABSTRACT: The regulation of pollen development and pollen tube growth is a complicated biological process that is crucial for sexual reproduction in flowering plants. Annexins are widely distributed from protists to higher eukaryotes and play multiple roles in numerous cellular events by acting as a putative "linker" between Ca2+ signaling, the actin cytoskeleton and the membrane, which are required for pollen development and pollen tube growth. Our recent report suggested that downregulation of the function of Arabidopsis annexin 5 (Ann5) in transgenic Ann5-RNAi lines caused severely sterile pollen grains. However, little is known about the underlying mechanisms of the function of Ann5 in pollen. This study demonstrated that Ann5 associates with phospholipid membrane and this association is stimulated by Ca2+ in vitro. Brefeldin A (BFA) interferes with endomembrane trafficking and inhibits pollen germination and pollen tube growth. Both pollen germination and pollen tube growth of Ann5-overexpressing plants showed increased resistance to BFA treatment, and this effect was regulated by calcium. Overexpression of Ann5 promoted Ca2+-dependent cytoplasmic streaming in pollen tubes in vivo in response to BFA. Lactrunculin (LatB) significantly prohibited pollen germination and tube growth by binding with high affinity to monomeric actin and preferentially targeting dynamic actin filament arrays and preventing actin polymerization. Overexpression of Ann5 did not affect pollen germination or pollen tube growth in response to LatB compared with wild-type, although Ann5 interacts with actin filaments in a manner similar to some animal annexins. In addition, the sterile pollen phenotype could be only partially rescued by Ann5 mutants at Ca2+-binding sites when compared to the complete recovery by wild-type Ann5. These data demonstrated that Ann5 is involved in pollen development, germination and pollen tube growth through the promotion of endomembrane trafficking modulated by calcium. Our results provide reliable molecular mechanisms that underlie the function of Ann5 in pollen.
    PLoS ONE 07/2014; 9(7):e102407. DOI:10.1371/journal.pone.0102407 · 3.23 Impact Factor
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