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The quantitative anatomical characteristics of Quercus variabilis virgin cork grown in Korea were observed by scanning electron microscopy and compared with Quercus suber reproduction cork from Portugal to obtain basic data for further utilization of domestic cork resources in Korean cork industries. Q. variabilis virgin cork showed a smaller growth ring width and higher latecork percentage than Q. suber reproduction cork. Q. variabilis showed a smaller proportion of cork cells and a higher proportion of lenticular channels than Q. suber, whereas sclereid and dark-brown zones were found only in Q. variabilis. The frequency of pentagonal cork cells in the transverse and radial sections was higher in the cork of Q. suber than in Q. variabilis. In the tangential section, Q. variabilis displayed a lower frequency of heptagonal cells and a higher frequency of pentagonal cells than Q. suber.Q. variabilis cork had a smaller cell width, lumen diameter, cell wall thickness, prism base edge and area, total cell volume, and solid volume of the cell wall than Q. suber cork. The fractional solid volume and number of cells per cm3 were higher in Q. variabilis than Q. suber.

The periderm acts as armor protecting the plant's inner tissues from biotic and abiotic stress. It forms during the radial thickening of plant organs such as stems and roots and replaces the function of primary protective tissues such as the epidermis and the endodermis. A wound periderm also forms to heal and protect injured tissues. The periderm comprises a meristematic tissue called the phellogen, or cork cambium, and its derivatives: the lignosuberized phellem and the phelloderm. Research on the periderm hasmainly focused on the chemical composition of the phellem due to its relevance as a raw material for industrial processes. Today, there is increasing interest in the regulatory network underlying periderm development as a novel breeding trait to improve plant resilience and to sequester CO2. Here, we discuss our current understanding of periderm formation, focusing on aspects of periderm evolution, mechanisms of periderm ontogenesis, regulatory networks underlying phellogen initiation and cork differentiation, and future challenges of periderm research.

This study aimed to assess the lipophilic and phenolic extractives composition of cork of Quercus suber L. grown in Algeria by gas chromatography-mass spectrometry (GC-MS) and ultra-high-performance liquid chromatograhy-mass spectrometry (UHPLC-MS), respectively. The phenolic cork oak extract was also evaluated for its scavenging activity towards DPPH radical, ABTS radical scavenging, reducing power and antibacterial activity against Staphylococcus aureus ATCC, Listeria innocua, Escherichia coil and Pseudomonas aeruginosa. The lipophilic fraction is mainly composed of thirty three compounds, with cerine, friedeline and betulinic acid as the major components. Furthermore, eighteen phenolic compouds were detected in the phenolic extract, with protocatechuic, ellagic and gallic acids as the major compounds. The methanol:water cork extract showed high DPPH scavenging ability with an ICso value of 5.69 mu g mL(-1) and an ABTS enhanced scavenging capacity when compared to BHT and trolox. A reducing power higher than BHA was also found. In addition, the phenolic fraction of cork was shown to inhibit the growth of Staphelococcus aureus (12.1 mm) and Pseudomonas aeroginisa (10.07 mm). These results indicate that algerian cork oak constitutes a good source of natutal bioactive compounds. Morever, this study is a relevant contribution to the valorization of algerian cork industrial residues, for which novel applications could be considered, namely the use of these extracts in food or nutraceutical industry. (C) 2015 Elsevier B.V. All rights reserved.

Cork forest systems are responsible for making an important economic contribution to the Mediterranean region, especially Portugal where the cork oak woodlands or montados contain about 32% of the world's area. The environmental profile derived from reproduction cork production and extraction in two Portuguese regions (Tagus valley and Alentejo) representative of the Portuguese sector were assessed in detail using the Life-Cycle Assessment (LCA) methodology from a cradle-to-gate perspective. The production line was divided into four stages considering all the processes involved: stand establishment, stand management, cork stripping and field recovery. According to the environmental results, there were remarkable differences between the two production scenarios mainly due to the intensity and repetition of forest activities even though the cork yield was reported to be the same. The management system in the Alentejo region presented the worse environmental profile in almost all the impact categories under assessment, mainly due to the shorter cycle duration of the mechanical cleaning and pruning processes. Cork stripping was identified in both scenarios as the production stage with the highest contribution to the environmental profile due to the cleaning and pruning processes. A sensitivity assessment concerning the cork yield was performed since the average production yields in the Portuguese montados are lower than the ones used in this study. Thus, if the cork yield is reduced, the environmental profile in both scenarios gets worse since almost all the forest activities involved are the same. Dr. S. González-García would like to express her gratitude to the Spanish Ministry of Education for financial support (Grant reference: EX2009-0740) for a Postdoctoral Research Fellowship taken at CESAM. Dr. A.C. Dias would like to thank FCT (Science and Technology Foundation — Portugal) for the Postdoctoral Fellowship (SFRH/BPD/20363/2004). Thanks are also due to the project ECOTECH SUDOE — International Network on LCA and Ecodesign for Eco-innovation (SOE2/P2/E377) funded by the EU Interreg IV B Sudoe Programme. published