Project description:The cultivar Desirée and the breeding line SW93-1015 were challenged with potato cyst nematodes and transcriptomes analysed after 8h and 48 h.
Project description:To effectively manage resources, regulatory cross-talk between biological processes within an organism is essential. An emerging area in plant research focuses on antagonism between regulatory systems controlling growth/development and those governing immunity. Such crosstalk represents a point of vulnerability for pathogens to exploit. Here we show that the notorious potato blight pathogen Phytophthora infestans promotes a growth and development pathway in order to antagonise plant immunity. AVR2, an effector protein secreted by P. infestans, has been shown to interact with potato BSL1, a putative phosphatase implicated in brassinosteroid hormone signalling. Plants expressing AVR2 exhibit transcriptional and phenotypic overlaps with an over-active brassinosteroid signalling pathway, and have compromised immunity. The activity of AVR2 leads to up-regulation of a functional orthologue of AtHBI1, known to facilitate cross-talk between the brassinosteroid pathway and immune signalling in Arabidopsis. Transient expression of potato HBI1-like compromises immunity and enhances leaf colonisation by P. infestans. Knowledge of how pathogens manipulate regulatory cross-talk governing resource allocation in plants will inform crop breeding efforts of the future; helping to maximise both yield and resistance to ensure food security as pressure on our agricultural systems increases.
Project description:Oryza longistaminata is an African wild rice species that possesses special traits for breeding applications. Self-incompatibility is the main cause of sterility in O. longistaminata, but here we demonstrated that its pollen fertility and vitality are normal. Lipid and carbohydrate metabolism were active throughout pollen development. In this study, transcriptomics quantitative analysis was used to investigate the profiles of genes related to lipid and carbohydrate metabolism in 4-, 6- and 8.5-mm O. longistaminata spikelets before flowering. We documented cytological changes throughout important stages of anther development, including changes in reproductive cells as they formed mature pollen grains through meiosis and mitosis. RNA-seq and proteome association analysis indicated that fatty acids were converted to sucrose after the 6-mm spikelet stage, based on the abundance of most key enzymes of the glyoxylate cycle and gluconeogenesis. In conclusion, our study provides novel insights into the pollen viability of O. longistaminata at the transcriptome level, which can be used to improve the efficiency of male parent pollination in hybrid rice breeding applications.
Project description:Pollen development in angiosperms is one of the most important processes controlling plant reproduction and therefore productivity. At the same time pollen development is highly sensitive to environmental fluctuations including temperature, drought and nutrition. Therefore pollen biology is a major focus in applied studies and breeding approaches for improving plant productivity in a globally changing climate. The most accessible developmental stages of pollen are the mature pollen and the pollen tubes and are, thus, most frequently analyzed. To reveal a complete quantitative proteome map we additionally addressed the very early stages analyzing 8 stages of tobacco pollen development from diploid microsporocytes, meioses, tetrads, microspores, polarized microspores, bipolar pollen and desiccated pollen to pollen tubes. A protocol for the isolation of the early stages was established. Proteins were extracted and analyzed by a new Gel-LC-MS fractionation protocol. In total, 3817 protein groups were identified. Quantitative analysis was performed based on peptide count. Exceedingly stage-specific differential protein regulation was observed during the conversion from the sporophytic to the gametophytic proteome. A map of highly specialized functionality for the different stages could be revealed from metabolic activity, pronounced differentiation of proteasomal and ribosomal protein complex composition up to protective mechanisms such as high levels of heat shock proteins in the very early stages of development.
Project description:The major virulence factor of Plasmodium falciparum parasites, PfEMP1 is expressed by a multigene family, termed var genes. Here selection linked integration (SLI) was utilized to modify var genes in P. falciparum parasites to select for parasite populations expressing a single var gene. Bulk RNA was isolated from ring stage parasites of these SLI parasite populations and analyzed with next generation sequencing. The proportion of exon 2 transcripts of var genes normalized to transcripts per million was determined per cell line to confirm the predominant expression of the desired var gene.
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:Pollen development in angiosperms is one of the most important processes controlling plant reproduction and thus productivity. At the same time, pollen development is highly sensitive to environmental fluctuations, including temperature, drought, and nutrition. Therefore, pollen biology is a major focus in applied studies and breeding approaches for improving plant productivity in a globally changing climate. The most accessible developmental stages of pollen are the mature pollen and the pollen tubes, and these are thus most frequently analyzed. To reveal a complete quantitative proteome map, we additionally addressed the very early stages, analyzing eight stages of tobacco pollen development: diploid microsporocytes, meiosis, tetrads, microspores, polarized microspores, bipolar pollen, desiccated pollen, and pollen tubes. A protocol for the isolation of the early stages was established. Proteins were extracted and analyzed by means of a new gel LC-MS fractionation protocol. In total, 3817 protein groups were identified. Quantitative analysis was performed based on peptide count. Exceedingly stage-specific differential protein regulation was observed during the conversion from the sporophytic to the gametophytic proteome. A map of highly specialized functionality for the different stages could be revealed from the metabolic activity and pronounced differentiation of proteasomal and ribosomal protein complex composition up to protective mechanisms such as high levels of heat shock proteins in the very early stages of development.
Project description:Recent advances have defined some of the components of photoperiodic signalling that lead to tuberisation in potato including orthologues of FLOWERING LOCUS T (StSP6A) and CYCLING DOF FACTOR (StCDF1). The aim of the current study is to investigate the molecular basis of permissive tuber initiation under long days in Solanum tuberosum Neo-Tuberosum by comparative analysis with an obligate short day Solanum tuberosum ssp. Andigena accession. We show that the Neo-Tuberosum accession, but not the Andigena, contains alleles that encode StCDF1 proteins modified in the C-terminal region, likely to evade long day inhibition of StSP6A expression. We also identify an allele of StSP6A from the Neo-Tuberosum accession, absent in the Andigena, which is expressed under long days. Other leaf transcripts and metabolites that show different abundances in tuberising and non-tuberising samples were identified adding detail to tuberisation-associated processes. Overall, the data presented in this study highlight the subtle interplay between components of the clock-CONSTANS-StSP6A axis which collectively may interact to fine-tune the timing of tuberisation.