Project description:Little is known of the transcriptome of in vivo-grown pollen tubes, due to the difficulty of collection of pollen tubes elongating within the maternal gynoecium.We obtained the mRNAs undergoing translation (the translatome) of in vivo-grown pollen tubes from self-pollinated gynoecia of Arabidopsis thaliana(Col-0).
Project description:Translatome of floral buds, in vivo pollinated pollen tubes, and in vitro cultured pollen grains/tubes from LAT52-HF-RPL18 Arabidopsis
Project description:Little is known of the transcriptome of in vivo-grown pollen tubes, due to the difficulty of collection of pollen tubes elongating within the maternal gynoecium.We obtained the mRNAs undergoing translation (the translatome) of in vivo-grown pollen tubes from self-pollinated gynoecia of Arabidopsis thaliana(Col-0). Transgenic Arabidopsis plants (LAT52-HF-RPL18) harboring an epitope tagged ribosomal protein L18 driven by the pollen specific promoter (ProLAT52) were used for mRNA-ribosome complex isolation. After collection of polyribosomal (polysomal) complexes from self-pollinated (in vivo), unpollinated styles (buds), and in vitro-cultured pollen tubes, the actively translated mRNAs (the translatome) were purified, amplified to antisense RNA (aRNA). These aRNAs were hybridized to microarrays.Three independent biological replicates samples of aRNA from Bud, in vivo, and in vitro polysomal mRNA (translatomes) were hybridized to GeneChips to produce CEL files.
Project description:Pollen tubes extend through pistil tissues and are guided to ovules where they release sperm for fertilization. Although pollen tubes can germinate and elongate in a synthetic medium, their trajectory is random and their growth rates are slower compared to growth in pistil tissues. Furthermore, interaction with the pistil renders pollen tubes competent to respond to guidance cues secreted by specialized cells within the ovule. The molecular basis for this potentiation of the pollen tube by the pistil remains uncharacterized. We used a surgical procedure to obtain large quantities of uncontaminated pollen tubes that grew through the pistil and defined their transcriptome by microarray analysis. We also characterized the transcriptome of in vitro-grown pollen tubes (for 0.5hours or 4hours) and dessicated mature pollen in Arabidopsis.
Project description:Pollen tubes extend through pistil tissues and are guided to ovules where they release sperm for fertilization. Although pollen tubes can germinate and elongate in a synthetic medium, their trajectory is random and their growth rates are slower compared to growth in pistil tissues. Furthermore, interaction with the pistil renders pollen tubes competent to respond to guidance cues secreted by specialized cells within the ovule. The molecular basis for this potentiation of the pollen tube by the pistil remains uncharacterized. We used a surgical procedure to obtain large quantities of uncontaminated pollen tubes that grew through the pistil and defined their transcriptome by microarray analysis. We also characterized the transcriptome of in vitro-grown pollen tubes (for 0.5hours or 4hours) and dessicated mature pollen in Arabidopsis. Experiment Overall Design: Pollen and pollen tubes were collected as described in the protocols section for RNA extraction and hybridization on Affymetrix ATH1 Genechip microarrays.
Project description:Transcriptional profiling in open flowers of Arabidopsis wild type control plants and sdg4 mutant (SALK T-DNA line_128444). The sdg4 mutant is a Arabidopsis T-DNA mutant in which T-DNA is inserted in a SET domain protein, SDG4 (At4g30860). Expression profiling studies indicate that SDG4 might function in modulating the expression of the genes that function in the growth of pollen tubes. Keywords: epigenetic modification
Project description:Pollen germination, along with pollen tube growth, is an essential process for the reproduction of flowering plants. The germinating pollen with tip-growth characteristics provides an ideal model system for the study of cell growth and morphogenesis. As an essential step towards a detailed understanding of this important process, the objective of this study was to comprehensively analyze the transcriptome changes during pollen germination and pollen tube growth. Using Affymetrix Arabidopsis ATH1 Genome Arrays, this study is the first to show the changes in the transcriptome from desiccated mature pollen grains to hydrated pollen grains and then to pollen tubes of Arabidopsis thaliana. The number of expressed genes, either for total expressed genes or for specifically expressed genes, increased significantly from desiccated mature pollen to hydrated pollen and again to growing pollen tubes, which is consistent with the finding that pollen germination and tube growth was significantly inhibited in vitro by a transcriptional inhibitor. The results of GO analyses showed that expression of genes related to cell rescue, transcription, signal transduction and cellular transport were significantly changed, especially for up-regulation, during pollen germination and tube growth, respectively. In particular, genes of the CaM/CML, CHX and Hsp families showed the most significant changes during pollen germination and tube growth. These results demonstrate that the overall transcription of genes, both in the number of expressed genes and in the levels of transcription, was increased. Furthermore, the appearance of many novel transcripts during pollen germination as well as tube growth indicates that these newly expressed genes may function in this complex process. SUBMITTER_CITATION: Yi Wang, Wen-Zheng Zhang, Lian-Fen Song, Jun-Jie Zou, Zhen Su, and Wei-Hua Wu. Transcriptome analyses show changes in gene expression to accompany pollen germination and tube growth in Arabidopsis. Plant Physiol. September 5, 2008; 10.1104/pp.108.126375 Experiment Overall Design: Three samples are analyzed in this experiment. They are desiccated mature pollen grains (MP), hydrated pollen grains (HP) and growing pollen tubes (PT) of Arabidopsis thaliana, respectively. Each sample has two biological replicates, so that there are 6 data sets of ATH1 array in this experiment.
Project description:Pollen germination, along with pollen tube growth, is an essential process for the reproduction of flowering plants. The germinating pollen with tip-growth characteristics provides an ideal model system for the study of cell growth and morphogenesis. As an essential step towards a detailed understanding of this important process, the objective of this study was to comprehensively analyze the transcriptome changes during pollen germination and pollen tube growth. Using Affymetrix Arabidopsis ATH1 Genome Arrays, this study is the first to show the changes in the transcriptome from desiccated mature pollen grains to hydrated pollen grains and then to pollen tubes of Arabidopsis thaliana. The number of expressed genes, either for total expressed genes or for specifically expressed genes, increased significantly from desiccated mature pollen to hydrated pollen and again to growing pollen tubes, which is consistent with the finding that pollen germination and tube growth was significantly inhibited in vitro by a transcriptional inhibitor. The results of GO analyses showed that expression of genes related to cell rescue, transcription, signal transduction and cellular transport were significantly changed, especially for up-regulation, during pollen germination and tube growth, respectively. In particular, genes of the CaM/CML, CHX and Hsp families showed the most significant changes during pollen germination and tube growth. These results demonstrate that the overall transcription of genes, both in the number of expressed genes and in the levels of transcription, was increased. Furthermore, the appearance of many novel transcripts during pollen germination as well as tube growth indicates that these newly expressed genes may function in this complex process.
Project description:Polyadenylation of mRNAs is critical for their export from the nucleus, stability and efficient translation. The Arabidopsis thaliana genome encodes three isoforms of canonical nuclear poly(A) polymerase (PAPS) that redundantly polyadenylate the bulk of pre-mRNAs. However, their distinct mutant phenotypes and transcriptome studies have indicated that subsets of pre-mRNAs are preferentially polyadenylated by either PAPS1 or the two very similar PAPS2 and PAPS4 proteins. Such functional specialization raises the possibility of modulating the balance of activities between the isoforms to alter poly(A) lengths of sets of transcripts, providing an additional level of gene-expression control in plants. Here we test this notion by studying the function of PAPS1 in pollen-tube growth and guidance. Pollen tubes growing through female tissue acquire the competence to find ovules efficiently and upregulate PAPS1 expression more strongly than in vitro grown pollen tubes. Using the temperature-sensitive paps1-1 allele we show that PAPS1 activity during pollen-tube growth is required for full acquisition of competence, resulting in inefficient fertilization by paps1-1 mutant pollen tubes. While these mutant pollen tubes germinate and grow at the same rates as wild-type pollen tubes, they are compromised in locating the micropyles of ovules. Transcriptomic analyses indicate that previously identified competence-associated genes are less expressed in paps1-1 mutant than in wild-type pollen tubes. Estimating the poly(A)-tail lengths of transcripts in mutant and wild-type pollen tubes suggests that polyadenylation by PAPS1 is associated with reduced transcript abundance. Our results therefore suggest that PAPS1 upregulation during pollen-tube growth through the style plays a key role in the acquisition of competence and support the notion that plants can modulate the balance of activity between PAPS isoforms to regulate gene expression.