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SUMMARY: The evolutionary and ecological success of spermatophytes is intrinsically linked to the seed habit, which provides a protective environment for the initial development of the new generation. This environment includes an ephemeral nourishing tissue that supports embryo growth. In gymnosperms this tissue originates from the asexual proliferation of the maternal megagametophyte, while in angiosperms it is a product of fertilization, and is called the endosperm. The emergence of these nourishing tissues is of profound evolutionary value, and they are also food staples for most of the world's population. Here, using Orthofinder to infer orthologue genes among newly generated and previously published datasets, we provide a comparative transcriptomic analysis of seed nourishing tissues from species of several angiosperm clades, including those of early diverging lineages, as well as of one gymnosperm. Our results show that, although the structure and composition of seed nourishing tissues has seen significant divergence along evolution, there are signatures that are conserved throughout the phylogeny. Conversely, we identified processes that are specific to species within the clades studied, and thus illustrate their functional divergence. With this, we aimed to provide a foundation for future studies on the evolutionary history of seed nourishing structures, as well as a resource for gene discovery in future functional studies. Significance Statement: Within seeds a specialized structure is responsible for nourishing the embryo during its development. These nourishing tissues are also important sources of staple foods and feed. Here, we provide gene expression datasets of nourishing tissues of early diverging angiosperms, and use this information for a meta‐analysis to identify pathways conserved, or divergent, throughout evolution. Thus, we aim to provide a resource for gene discovery for seed biology studies. [ABSTRACT FROM AUTHOR]

Cork cambium (or phellogen) is a secondary meristem responsible for the formation of phelloderm and phellem/cork, which together compose the periderm. In Quercus suber L. , the phellogen is active throughout the entire life of the tree, producing a continuous and renewable outer bark of cork. To identify specific candidate genes associated with cork cambium activity and phellem differentiation, we performed a comparative transcriptomic study of Q. suber secondary growth tissues (xylem and phellogen/phellem) using RNA-seq. The present work provides a high-resolution map of all the transcripts identified in the phellogen/phellem tissues. A total of 6013 differentially expressed genes were identified, with 2875 of the transcripts being specifically enriched during the cork formation process versus secondary xylem formation. Furthermore, cork samples originating from the original phellogen ('virgin' cork) and from a traumatic phellogen ('amadia' cork) were also compared. Our results point to a shortlist of potentially relevant candidate genes regulating phellogen activity and phellem differentiation, including novel genes involved in the suberization process, as well as genes associated to ethylene and jasmonate signaling and to meristem function. The future functional characterization of some of the identified candidate genes will help to elucidate the molecular mechanisms underlying cork cambium activity and phellem differentiation. [ABSTRACT FROM AUTHOR]

miRPursuit is a pipeline developed for running end-to-end analyses of high-throughput small RNA ( sRNA) sequence data in model and nonmodel plants, from raw data to identified and annotated conserved and novel sequences. It consists of a series of UNIX shell scripts, which connect open-source sRNA analysis software. The involved parameters can be combined with convenient workflow management by users without advanced computational skills. mi RPursuit presents several advantages when compared to other tools, including the possibility of processing several sRNA libraries in parallel, thus easily allowing a comparison of the differences in sRNA read accumulation among sRNA libraries. We validate mi RPursuit by using datasets from a model plant and discuss its performance with the analysis of sRNAs from non-model species. [ABSTRACT FROM AUTHOR]

miRPursuit is a pipeline developed for running end-to-end analyses of high-throughput small RNA (sRNA) sequence data in model and nonmodel plants, from raw data to identified and annotated conserved and novel sequences. It consists of a series of UNIX shell scripts, which connect open-source sRNA analysis software. The involved parameters can be combined with convenient workflow management by users without advanced computational skills. miRPursuit presents several advantages when compared to other tools, including the possibility of processing several sRNA libraries in parallel, thus easily allowing a comparison of the differences in sRNA read accumulation among sRNA libraries. We validate miRPursuit by using datasets from a model plant and discuss its performance with the analysis of sRNAs from non-model species., (© 2017 Federation of European Biochemical Societies.)