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Stem succulence evolved independently in many plant lineages as an adaptation to arid environments. One of the most interesting cases is the convergence between Cactaceae and Euphorbia , which have anatomical adaptations mostly to increase photosynthetic capability and water storage. Our goal was to describe the shoot development in two succulent species of Euphorbia using light microscopy coupled with high-resolution X-ray-computed tomography. Collateral cortical bundles were observed associated with the stem ribs in both species. The analysis of vasculature demonstrated that these bundles are, in fact, leaf traces that run axially along a portion of the internode. That structural pattern is due to an ontogenetic alteration. During shoot development, the leaf-bases remain adnate to the stem near the SAM, forming an axial component. When the internode elongates, the leaf bundles stretch as cortical bundles. The meristematic activity associated with the bundles forms the stem ribs, as leaf veins near the node, and induce rib formation along the entire internode even in the portion where the leaf traces join the stele. In addition, heterochronic shifts are also involved in the evolution of the shoot system in these Euphorbia , being related to early deciduous reduced leaves and the transference of the main photosynthetic function to the stem. This study demonstrates for the first time the influence of leaf developmental shifts and stem rib formation in Euphorbia and sheds new light on the evolution of stem succulence.

The use of natural products to reduce the use of synthetic additives in meat products, reducing the oxidation and improving the shelf life is a current challenge. Meat quality from lamb patties during 10 days of display on modified atmosphere packaging (MAP) and active-edible coating were tested under six treatments: uncoated patties without coating (CON); patties with alginate coating (EC) and patties with coating and 0.1 or 0.05% of essential oils (EOs) from either thyme (TH 0.1; TH 0.05) or oregano (OR 0.1; OR 0.05). Display and treatment significantly modified ( P < 0.001) all the studied meat quality variables (pH, color, water holding capacity, weight losses, thiobarbituric acid reactive substances (TBARS), antioxidant activity). Display produced discoloration and lipid oxidation, however, the samples with essential oils presented lower ( P < 0.001) lipid oxidation than the CON or EC groups. Coated samples with or without EOs showed better color (lower lightness but higher redness and yellowness) and lower water losses ( P < 0.001) than the CON. The addition of thyme EO caused a decrease ( P < 0.001) in the consumer's overall acceptability, whereas no statistical differences appeared between CON, EC and oregano EO addition. Thus, using EOs as natural antioxidants, especially those from oregano at low dosages (0.05%), could be considered a viable strategy to enhance the shelf life and the product quality of lamb meat patties without damaging the sensory acceptability.

Background : Hedyosmum brasiliense Mart. ex Miq. (Chloranthaceae) is a dioecious shrub popularly used in Brazil to treat foot fungi and rheumatism. This work investigated the chemical composition, antifungal, and antioxidant activities of flowers and leaves of H. brasiliense essential oils; Methods : H. brasiliense male and female flowers and leaves were collected at Ilha do Cardoso (São Paulo) and the essential oils were extracted by hydrodistillation and analyzed by GC/MS and their similarity compared by Principal Component Analysis. Antifungal activity was performed by bioautography and antioxidant potential by 2,2-diphenyl-2-picrylhydrazyl hydrate (DPPH) free radical scavenging and β-carotene/linoleic acid system; Results : The major compounds for all oils were sabinene, curzerene, and carotol, but some differences in their chemical composition were discriminated by Principal Component Analysis (PCA) analysis. Bioautography showed two antifungal bands at Rf's 0.67 and 0.12 in all samples, the first one was identified as curzerene. The oils presented stronger antioxidant potential in β-carotene/linoleic acid bioassay, with IC 50 's from 80 to 180 μg/mL, than in DPPH assay, with IC 50 's from 2516.18 to 3783.49 μg/mL; Conclusions : These results suggested that curzerene might be responsible for the antifungal activity of H. brasiliense essential oils. Besides, these essential oils exhibited potential to prevent lipoperoxidation, but they have a weak radical scavenger activity., Competing Interests: The authors declare no conflict of interest.

Background: Avicennia schaueriana Stapf & Leechm. ex Moldenke (Acanthaceae) is a native species from the Brazilian mangroves presenting ecological and economic significance. This study compared the composition and the biological activities from the essential oils obtained from two A. schaueriana populations collected at Jureia-Itatins and Ilha do Cardoso., Methods: Essential oils were obtained by conventional means, and their compositions were analyzed by GC-MS. Screening assays for antimicrobial activity were carried out by the microdilution method and the antioxidant potential was assessed by the DPPH scavenging method., Results: The GC-MS analysis indicated that the Jureia oil (1) was composed mostly of the fatty acids palmitic (46.5%) and myristic (11.6%) acids, while the main components for the Ilha do Cardoso oil (2) were eugenol (19.7%), eugenol acetate (12.9%) and palmitic acid (15.1%). The oils showed an IC50 of 0.9 ± 0.011 mg/mL for 1 and 1.13 ± 0.028 mg/mL for 2 in the DPPH assay. The antimicrobial assay indicated MIC > 217 µg/mL for all tested microorganisms., Conclusions: The different essential oil composition may indicate the presence of chemotypes for A. schaueriana. The antioxidant activity of the oils was weak if compared with flavonoids. Despite the high MIC values, these oils presented some antibacterial potential against Pseudomonas aeruginosa.