Project description:The cultivated almond exhibits self-incompatibility of the gametophytic type regulated by the S-locus, and expressed in pistil (S-RNase) and in pollen (SFB protein). The aim of this study is to clarify the transcription pattern of these 2 S-genes and to identify additional components of the gametophytic self-incompatibility system in almond. With this aim, A2-198 (self compatible) and ITAP-1 (self incompatible) almond selections were used: RNA-seq of pistils of these two accessions both un-pollinated and pollinated with A2-198 pollen were carried out.
Project description:Plant reproduction depends on the concerted activation of many genes to assure the correct communication between pollen and pistil. Here we queried the whole transcriptome of Arabidopsis thaliana in order to identify genes with specific reproductive functions. We used the ATH1 whole genome array to profile wild-type unpollinated pistils and unfertilized ovules in comparison with the expression profile of pistils 0.5, 3.5 and 8.0 hours after pollination KEYWORDS: time course Flowers at the developmental stage 12c were emasculated 24 hours before pollination. Pistils were collected at 0, 0.5, 3.5 and 8 Hours After Pollination (HAP) and immediately frozen in liquid nitrogen. Unfertilized ovules were collected by the funiculus from dissected UP and immediately frozen in liquid nitrogen. To minimize biological variation 20 pistils were collected from a minimum of 10 plants and for ovule isolation 50 pistils were used from about 30 plants to isolate approximately 1500 ovules for each replicate experiment.
Project description:This experiment was designed to identify genes expressed preferentially in the two integuments of the Arabidopsis ovule. Pistils from wild type and two ovule mutants were compared against each aintegumenta-4 (ant-4) which lacks both integuments and inner no outer (ino-1) which lacks the outer integument. Genes that are highly expressed only in the integuments were expected to be reduced in expression in the mutants, as compared with wild type. Pistils containing ovules through all stages of ovule development prior to pollination were pooled for one experiment (FULL arrays), and for two separate experiments, a set of early differentiation stages (EARLY arrays) and a set of later differentiation stages (LATE ARRAYS) were pooled. Wild type and mutant lines are in the ecotype Landsberg erecta.
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. Pistils were collected from ms1 (Male Sterile 1) pistils that were unpollinated, or pollinated with either wild type (Col-0) pollen or myb triple mutant (myb97-1, myb101-4, myb120-3) pollen for 8 hours. We sought to examine transcriptional changes that were taking place in pollen tubes before they reached ovules in wild type pollen tubes, and what portion of this transcriptional regulation was due to MYB97, MYB101 and MYB120. Analysis of growth in the pistil allows discovery of transcriptional changes taking place during pollen tube growth in its native environment, as opposed to mature pollen or in vitro grown pollen, which are essentially naive conditions, as neither have interacted with the pistil environment and any signalling factors found therein.
Project description:Investigation of genome-wide gene expression in sepals, petals, stamens, staminodia and carpels in pre-anthesis Aquilegia flowers. One goal was to identify transcriptional signatures associated with petaloidy by comparing gene expression in petals and petaloid sepals. Other goals were to study the evolutionary origin and ecological function of staminodia by comparing a) expression patterns in stamens, staminodia and carpels, b) identifying transcriptional regulators expressed in staminodia and c) using gene set enrichment analysis to identify biological processes operating in staminodia. A 15 chip study using total RNA from the five floral tissues from three replicate natural populations with each sample representing tissue pooled from 60 flowers.
Project description:Gametophytic self-incompatibility is the primary cause of low fruit set in almond. The mechanism of recognition that determines whether the gametophyte is successfully fertilized between pollen tube SCF (F-box-SSK1-Cul1-Rbx1) protein and pistil S-RNase protein during fertilization is unclear. In this study, the pistils of two almond cultivars 'Wanfeng' and 'Nonpareil' were used as the experimental materials after selfing- and nonselfing/cross-pollination, and pistils from the stamen-removed flowers were used as controls. We used fluorescence microscopy to observe the development of pollen tubes after pollination and 4-dimensional label-free quantitation (4D-LFQ) to detect the protein expression profiles of 'Wanfeng' and 'Nonpareil' pistils and in controls. The results showed that it took 24-36 h for the development of the pollen tube to 1/3 of the pistil, and a total of 7684 differentially accumulated proteins (DAPs) were identified in the pistil after pollinating 36 h, of which 7022 were quantifiable. The up- and down-regulation of the 12 differential protein expressions identified by parallel reaction monitoring (PRM) was the same as that identified by 4D-LFQ, with an average fold-change difference of 14.34%, a maximum of 31.37% and a minimum of 3.68%. Bioinformatics analysis based on the function of the differential proteins, including classification, enrichment, and clustering, identified RNA polymerases (4 DAPs), autophagy (3 DAPs), oxidative phosphorylation (3 DAPs), and homologous recombination (2 DAPs) pathways associated with the self-incompatibility process. The interaction between the serine/threonine kinase (MARK2) protein E3 ubiquitin ligase and the microtubule protein component microtubule-associated protein tau (MAPT/ACT) was found using the STRING database, which demonstrated the involvement of the MARK2 protein in the reaction of pollen tube recognition the nonself- and the self-S-RNase protein. It provides a new way to reveal the mechanism by which almond pollen tubes recognize the self and nonself S-RNase enzyme protein.
Project description:differential expression between wild-type pistils of Arabidopsis thaliana at late 11 to late 12 floral stages, and similar stage pistils of coatlique mutant which lacks a functional embryo sac
Project description:As in animals, cell-cell communication plays pivotal role in male-female recognition during plant sexual reproduction. Prelaid peptides secreted from the female reproductive tissues guide pollen tubes towards ovules for fertilization. However, the elaborate mechanisms for this dialogue have remained elusive, particularly from the male perspective. We perform genome-wide quantitative liquid chromatography coupled tandem mass spectrometry of a pistil-stimulated pollen tube secretome and identify 801 pollen tube-secreted proteins. Interestingly, in silico analysis reveals that the pollen tube-secretome is dominated by unconventional-type secreted proteins representing 57% of the total secretome. In support, we show that unconventional-type protein, translationally controlled tumor protein, is secreted to the apoplast. Remarkably, we discover that this protein could be secreted by infiltrating through the initial phases of the conventional secretory pathway and could reach the apoplast via exosomes as demonstrated by co-localization with Oleisin1 exosome marker. We demonstrate that Arabidopsis thaliana translationally controlled tumor protein-knockdown plants have pollen tubes that poorly navigate to the target ovule, and the knocked down allele is poorly transmitted through the male. We show that regulators of the endoplasmic reticulum-trans-golgi network protein secretory pathway control secretion of pollen tube-secreted cysteine-rich proteins, including pollen tube attractants, and are essential for pollen tube growth and guidance, as well as ovule-targeting competence. This work, the first pollen tube secretome study, identifies novel genome-wide pollen tube-secreted proteins with potential function in pollen tube-ovule guidance for sexual reproduction. Functional analysis highlights a potential mechanism for pollen tube unconventional protein secretion and reveals likely regulators of pollen tube protein secretion. The association of pollen tube-secreted proteins with marker proteins shown to be secreted via exosomes in other species suggest secretion via exosomes as a possible mechanism for cell-cell communication between the pollen tube and female reproductive cells. For processed dataset with quantitative information, see Hafidh S, Potesil D, Fila J et al. Genome Bilogy 2016.
Project description:We analyzed gene expression profiles in four different floral tissues, petals, pistils, stamens, and the pith, using Agilent custum array for Symplocarpus renifolius (4 x 44k).
Project description:Genome-wide DNA sequence resources are expected to enhance our understanding of the molecular basis of plant development and lead to improvements in desirable traits in horticultural crops. In this study, we sequenced 643,366 ESTs from Eustoma grandiflorum flowers using a normalised cDNA library constructed for several different flower development stages, times of day, and pollinated stamens. The sequences were assembled into 63,401 contigs and 242,212 singletons. BlastX searches for all of the contigs in the GenBank database matched 65% of the contigs to registered sequences, while 35% presented no hits. GO mapping assigned 48% of the 63,401 contigs to GO terms. Microarray analysis showed that subsets of genes were up- or downregulated as the flower developed. The downregulated genes were enriched for GO terms related to 1) oligopeptide transport, 2) response to jasmonic acid stimulus, and 3) cell wall modification, whereas the upregulated genes were enriched for GO terms involved in 1) secondary metabolism, such as the flavonoid biosynthetic process and the terpenoid biosynthetic process, and 2) epidermal cell modification. Two-condition experiment, loop-design among 4 developmental stages. Biological replicates: 4.