Project description:Arabinogalactan proteins are proteoglycans known to have important roles during cell growth and development, namelly during pollen tube growth. A microarray experiment was performed on agp6 agp11 pollen tubes to search for genetic interactions in the context of pollen tube growth.
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:In this study, RNA-seq based comparative transcriptome analysis was used to study the genetic response of maize silk to pollen tube penetration and in comparison to the fungal invasion of Fusarium graminearum and Ustilago maydis. RNA-seq libraries of 8 tissues were generated from leaf, root, seed, pollen tube, silk, pollinated silk, infected silk with Fusarium and infected silk with Ustilago.
Project description:When pollen lands on a receptive stigma, it germinates and extends a tube inside the transmitting tissue of the pistil to deliver the sperm cells for double fertilization. The growth of the pollen tube triggers significant alterations in its gene expression. The extent to which these changes occur in the vegetative cell or extend to the sperm cells transported by the tube is unclear, but important to determine since sperm cells are believed to acquire a competency for fertilization during pollen-pistil interactions. To address these questions, we compared the transcriptomes of Arabidopsis thaliana sperm cells and vegetative nuclei isolated from mature pollen grains with those isolated from in vitro grown pollen tubes. Importantly, we also compared with transcriptomes of sperm cells obtained from pollen tubes grown under semi in vivo conditions where tubes passed through a pistil section. Our data shows that extensive transcriptomic changes occur in sperm cells during pollen tube growth, some of which are elicited only as sperms are carried through the pistil. Their analysis reveals a host of previously unidentified transcripts that may facilitate sperm maturation and gamete fusion. The vegetative cell undergoes even more extensive transcriptomic reprogramming during pollen tube growth, mainly through the upregulation of genes associated with pollen tube growth and vesicle-mediated transport. Interestingly, ATAC-seq data shows that the promoters of genes up-regulated in sperm during pollen tube growth are already accessible in sperm chromatin of mature pollen grains, suggesting pre-configured promoter accessibility. This study's expression data can be further explored here: https://bar.utoronto.ca/eFP-Seq_Browser/.
Project description:In this study, we sequenced four small RNA libraries derived from mature pollens, in vitro germinated pollens, mature silks and pollinated silks of maize, respectively. In total, 161 known miRNAs belonging to 27 families and 82 novel miRNAs were identified. Of them, miRNAs involved in pollen-silk (pistil) interactions were analyzed. On the male side, miRNA differentially expressed between mature and germinated pollen were identified, some of them participate in pollen germination and tube growth. On the female side, silk-expressed miRNAs respond to pollination were also responsive to stresses, especially drought and fungal invasion. Furthermore, GO analysis of target genes revealed that members related to anxin signal transduction and gene expressional regulation were overrepresented.The results indicated that during pollen-silk interactions, miRNAs-mediated auxin signal transduction plays important roles, and miRNAs took part in complex transcriptional regulating network.
Project description:In this study, we sequenced four small RNA libraries derived from mature pollens, in vitro germinated pollens, mature silks and pollinated silks of maize, respectively. In total, 161 known miRNAs belonging to 27 families and 82 novel miRNAs were identified. Of them, miRNAs involved in pollen-silk (pistil) interactions were analyzed. On the male side, miRNA differentially expressed between mature and germinated pollen were identified, some of them participate in pollen germination and tube growth. On the female side, silk-expressed miRNAs respond to pollination were also responsive to stresses, especially drought and fungal invasion. Furthermore, GO analysis of target genes revealed that members related to anxin signal transduction and gene expressional regulation were overrepresented.The results indicated that during pollen-silk interactions, miRNAs-mediated auxin signal transduction plays important roles, and miRNAs took part in complex transcriptional regulating network. Examination of 4 different tissues of maize to provide novel information for understanding the post-transcriptional regulations of pollen-pistil interactions
Project description:Flowering plants have immotile sperm that develop within pollen and must be carried to female gametes by a pollen tube. The pollen tube engages in molecular interactions with several cell types within the pistil and these interactions are essential for successful fertilization. We identified a group of three closely related pollen tube-expressed MYB transcription factors (MYB97, MYB101, MYB120), which are required for proper interaction of the pollen tube with the female gametophyte. These transcription factors are transcriptionally induced during growth in the pistil. They regulate a transcriptional network leading to proper differentiation and maturation of the pollen tube, promoting proper pollen tube-ovule interactions resulting in sperm release and double fertilization. We used microarrays to discover genes regulated by the transcription factors MYB97, MYB101 and MYB120 in pollen tubes growing through the pistil at 8 hours after pollination.
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:Arabinogalactan proteins are proteoglycans known to have important roles during cell growth and development, namelly during pollen tube growth. A microarray experiment was performed on agp6 agp11 pollen tubes to search for genetic interactions in the context of pollen tube growth. RNA from wt and mutant pollen tubes was extracted after 8h of in vitro germination and hybridized on Affimetrix microarrays.