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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]

Due to the difficulties associated with morphological identification of insects, it became necessary to resort to other identification tools, such as DNA barcoding, where the mitochondrial cytochrome c oxidase subunit I (COI) molecular marker is commonly used. The effectiveness of DNA-based identification of species relies on the availability of sequences in public databases for comparison. Nevertheless, there is still a large number of non-sequenced species in these databases, preventing a molecular identification. In this study, we generate COI barcode sequences, with a total of 658 bp, for the six studied Chrysomelidae species. Phylogenetic and sequence divergence analyses were also performed, which allowed the discrimination of all species under study, supporting once again the suitability of this genetic marker. The obtained sequences were added to BOLD and GenBank databases, contributing to the increase of records in online databases and making the identification of some Chrysomelidae species easier. [ABSTRACT FROM AUTHOR]