Project description:The proteome of the gametophytes of Diplazium maximum, a temperate Himalayan Polypoidale fern was studied in response to micro-environmental changes. The study was expected to reveal the key proteins associated with a gametophyte’s response to sucrose mediated changes in osmotic potential. A major aim of the study was to identify proteins that would express differentially under micro-environmental stress and also to gain an understanding of the adaptive responses/competence of D. maximum gametophytes. The genes/proteins identified in the study have potential utility in various crop improvement programs.
Project description:How plants first invented seeds is a longstanding unresolved evolutionary question. Seed-bearing plants arose from within seedless vascular plants, with ferns as their closest relatives, but how seed development originated from ancestral reproductive development has remained unresolved by comparative morphology or the fossil record. To investigate this question at the level of gene network evolution, we identified genes associated with reproduction across sporophyte and gametophyte reproductive development of the fern Ceratopteris richardii and tested their conservation with reproductive gene networks in Arabidopsis thaliana. The flowering signal gibberellin was conserved with the fern shoot sporing transition and sporophyte sporophyll genes were conserved with floral development but not seeds. Post-fertilization gametophyte archegonium genes demonstrated significant conservation with both pre- and post-fertilization seed gene networks, together with two experimentally validated post-fertilization mechanisms. We conclude that the seed may first have arisen through the mis-expression of archegonium developmental programmes within the developing sporophyte sporangium.
Project description:The aim of this experiment was to analyse the expression of two sets of genes identified as being putatively sporophyte-specific or gametophyte-specific by a suppressive subtraction hybridisation using cDNA from immature sporophytes and immature gametophytes of the Ectocarpus strain Esil32. The expression of these genes was analysed in the sporophyte and gametophyte generations of the life cycle (again using immature algae that had not yet produces zoidangia) and in the sporophyte generation of a mutant strain, immediate upright, that exhibits gametophyte-like characteristics during the sporophyte generation.
Project description:Background and Aims: Ferns are providing insight into fundamental biological processes, and spatial transcriptomics is a potent tool in unraveling complexes of plant development. This research is targeted at leaf development in the water fern Ceratopteris richardii with the use of spatial transcriptomics. Methods: A shoot tip of sporophytes under vegetative growth was investigated using spatial transcriptomics, which conducted spot clustering, marker gene identification, and functional enrichment. Ribosomal protein genes were queried using BLAST program and categorized based on multi-alignment produced by Clustalw2 program. RNA in situ tissue hybridization was performed on three ribosomal protein genes. Key Results: Leaves were mutually different at the level of transcriptome under various developmental stages. There were unexpected complexes in tissue structure for stems. A few transcription factors were identified characteristic of leaf development. Activities associated with translation were very different between tissues, and ribosomal protein genes were heterogeneous at the level of transcription. Ribosomal protein genes were specifically expressed in the shoot apical meristem, leaf primordia, and vasculature of various organs. Conclusions: Leaves are mutually different under various developmental stages in C. richardii, with contribution of transcription factors. Stems are unexpectedly complex in tissue structure. Organs/tissues are very different in translation activity from each other, partly due to transcription heterogeneity of ribosomal protein genes. Ribosomal protein genes are specifically expressed in the shoot apical meristem, leaf primordia, and vasculature.
Project description:The fern Ceratopteris richardii has two distinct generations: the haploid gametophyte and diploid sporophyte, which resembles the difference between the major land plant clades of bryophytes and tracheophytes. We profiled the fast auxin-dependent phosphorylation response in both generations to identify the shared evolutionary targets and differences between the two generations
Project description:Brown algae (Phaeophyceae) are complex photosynthetic organisms with a very different evolutionary history to green plants, to which they are only distantly related. These seaweeds are the dominant species in rocky coastal ecosystems and they exhibit many interesting adaptations to these, often harsh, environments. The brown algae are also important because they are one of only a very small number of eukaryotic lineages that have evolved complex multicellularity. This work used whole genome tiling array approach to generate a comprehensive transcriptome map of the filamentous seaweed Ectocarpus siliculosus (Dillwyn) Lyngbye, a model organism for the brown algae. Keywords: high-resolution tiling array, brown algae, ectocarpus The slides were hybridised with two, labelled samples: 1) a mixture of labelled cDNA corresponding to RNA samples from mature sporophytes and gametophytes and from immature sporophytes stressed either in high salt medium or by addition of hydrogen peroxide and 2) genomic DNA as a control.
