Project description:We studied the molecular mechanisms underlying the impact of pollen nutrients on honey bee (Apis mellifera) health and how those nutrients improve resistance to parasites. Using digital gene expression, we determined the changes in gene expression induced by pollen intake in worker bees parasitized or not by the mites Varroa destructor, known for suppressing immunity and decreasing lifespan of bees. bees with or without verroa, and fed or not fed pollen
Project description:We studied the molecular mechanisms underlying the impact of pollen nutrients on honey bee (Apis mellifera) health and how those nutrients improve resistance to parasites. Using digital gene expression, we determined the changes in gene expression induced by pollen intake in worker bees parasitized or not by the mites Varroa destructor, known for suppressing immunity and decreasing lifespan of bees.
Project description:Background: Since chemical assays of soil nutrients are unreliable the UK horticultural and agricultural industries routinely apply large amounts of inorganic fertiliser to maintain crop yields and quality. Excessive fertiliser applications are both costly and can lead to unnecessary pollution. A possible solution to this problem is to use sensor (GM or non-GM) technologies that exploit the changes in plant gene expression profiles under incipient nutrient deficiency. The aim of this project is to identify genes upregulated in the early stages of nutrient depletion. Methods: Arabidopsis ecotype Col-5 (N1644) will be grown hydroponically using established techniques. In parallel experiments NP and K will be withdrawn individually after 21 d growth. RNA will be extracted from shoots of nutrient replete (control) and nutrient depleted plants 24 h after the removal of nutrients. Shoot nutrient content will be assayed by ICP-EMS as a reference. By comparing expression profiles we will be able to differentiate between genes that are upregulated by lack of specific nutrients and those upregulated by a universal stress-response system. Promoters and transcripts of these genes will underpin the development of novel sensor technologies and knowledge of the gene expression profiles will improve our understanding of the physiology of plant mineral nutrition. Experiment Overall Design: 4 samples
Project description:The number of pollen grains is a critical determinant of reproductive success in seed plants and varies among species and individuals. However, in contrast with many mutant-screening studies relevant to anther and pollen development, the natural genetic basis for variations in pollen number remains largely unexplored. To address this issue, we carried out a genome-wide association study in modern maize, ultimately revealing that a large variance of the absence or presence of sequences in the promoter region of Zea mays RPN1 (ZmRPN1) alters its expression level and thereby contributes to pollen number variation. Molecular analyses showed that ZmRPN1 interacts with ZmMSP1, an ortholog of the male germline cell number regulator in Arabidopsis and rice, and facilitates ZmMSP1 localization to the plasma membrane. Importantly, ZmRPN1 dysfunction resulted in a substantial increase in pollen number, consequently boosting seed production by increasing female-male planting ratio. Together, our findings uncover a key gene controlling pollen number, and therefore modulation of ZmRPN1 expression could be efficiently used to develop elite pollinators for modern hybrid maize breeding.
Project description:Background: Since chemical assays of soil nutrients are unreliable the UK horticultural and agricultural industries routinely apply large amounts of inorganic fertiliser to maintain crop yields and quality. Excessive fertiliser applications are both costly and can lead to unnecessary pollution. A possible solution to this problem is to use sensor (GM or non-GM) technologies that exploit the changes in plant gene expression profiles under incipient nutrient deficiency. The aim of this project is to identify genes upregulated in the early stages of nutrient depletion. Methods: Arabidopsis ecotype Col-5 (N1644) will be grown hydroponically using established techniques. In parallel experiments NP and K will be withdrawn individually after 21 d growth. RNA will be extracted from shoots of nutrient replete (control) and nutrient depleted plants 24 h after the removal of nutrients. Shoot nutrient content will be assayed by ICP-EMS as a reference. By comparing expression profiles we will be able to differentiate between genes that are upregulated by lack of specific nutrients and those upregulated by a universal stress-response system. Promoters and transcripts of these genes will underpin the development of novel sensor technologies and knowledge of the gene expression profiles will improve our understanding of the physiology of plant mineral nutrition. Keywords: growth_condition_design
Project description:We sequenced whole transcriptome from attack phase (AP) Bdellovbrio bacteriovorus HD100 after incubating it for 4 hours either in a nutrient rich meium (nutrient broth, NB) or in absence of nutrients (HEPES buffer only, H) as a control. The aim is to know how the excracellular nutrients affect the gene expression pattern of AP B. bacteriovorus. We found that the nutrients induces AP B. bacteriovorus to up-regulate its transcription and translation machinery in a way that resembles what happen during the late intraperiplasmic stage of B. bacteriovorus life cycle
Project description:We isolated tricellular pollen (TCP) and pollen mother cells (PMC) of rice using laser microdissection, and did microarray analysis with Agilent 44k rice array.
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:Global temperature increase poses a serious challenge for agricultural production worldwide, affecting yield in many crops including vegetable crops. While most crop plants can survive temperature increases during their vegetative growth periods, the reproduction phase is highly heat-stress (HS)-sensitive. Impaired pollen development and functioning under HS is implicated as the major cause for yield reduction. To better understand HS effect on pollen and identify pollen thermotolerance mechanisms, we established conditions that enable developing pollen grains to acquire thermotolerance (ATT conditions), using tomato as a model system. High-throughput sequencing at cDNA level was performed by Massive Analysis of 3’cDNA using Illumina HiSeq 2000 technology, generating a total of 6430 and 4660 transcripts differentially expressed (p ≤ 1e-05) during pollen development/maturation and following response of developing pollen to ATT, respectively. Gene Onthology functional analysis showed that transcripts related to maintenance of protein homeostasis (translation, proteolysis, protein folding) were enriched during pollen maturation and following the ATT treatment in our study, highlighting these processes as central for enabling pollen maturation and maintenance of pollen functioning under HS. The transcriptomic data was compared to available pollen proteomic data based on the same experimental setup and an overlap of 47% was detected between differentially expressed proteins and transcripts following ATT conditions, highlighting genes/proteins involved in protein folding, oxidation-reduction and translation, and validating transcriptomic results. Involvement of mitochondria and endoplasmic reticulum in pollen heat acclimation, and activation of several HSPs including sHSPs and HSP101, for protecting pollen cellular components including the translational machinery, are indicated. The results of this study can serve as a valuable resource of genes for future research on improving pollen thermotolerance.