Different molecular mechanisms may modulate sensitization and natural or induced tolerance to allergens. We have searched for differential mechanisms at humoral and cellular level in the olive pollen a~l ergi c response, checking the influence of exposure to allergens of subjects from an area with extremely high antigenic load during the pollen season. Sera and PBMCs were obtained during and outside the pollen season. Distinct Ig subtypes (total IgE and specific IgE, IgG4 and IgA), and Thl, Th2 and regulatory T cells (Treg) cytokines were analyzed in 5 groups of subjects: Group 1, non-allergic; Group 2, asymptomatic, sensitized to olive pollen; Group 3, allergic to pollen other than olive; Group 4, allergic to olive pollen (not treated); and Group 5, allergic to olive pollen, and getting specific immunotherapy. Asymptomatic subjects showed the highest total IgE levels. The major difference found between untreated and treated subjects was the high levels of non-inflammatory antibodies (lgG4) in treated patients. The main result of cytokine analyses was the statistically significant decrease in TGF-p levels in untreated olive pollen allergic subjects (pollen season) compared with treated. A slgnificnnt decrease In forkhead winged-helix transcription factor (FOXP3) mRNA expression (marker of regulatory response) and a lower presence of Treg cells in PBMCs of olive pollen allergic subjects was found. The results point to a decrease in the cellular regulatory mechanisms mediated by TGF-p and FOXP31n olive-pollen allergic patients that could be restored after specific-immunothernpy.The reason why exposure to common cnvironmcntal antigens induces allergic diseases in Some people and not in others remains undetermined.Allergen-specific CD4+ helper T-cell (Th) generation is the initial event leading to the development of allergic disease. Subtypes Th2 arc pivotal to the inflammatory cascade through production of IL-4 (essential for the development of Th2 cells), IL-S (for eosinophil recruitment), IL-13 (mediates isotype switching to IgE) and IL-9 (mucus hypersecretion). Th I cells (secreting mainly IFN-y) may contribute to the chronicity and effector phase

In this study we investigated whether the production of cleistogamous (CL) and chasmogamous (CH) floral morphs in Ruellia brevifolia is affected by water availability. To this end, the effects of two water levels were tested on plants grown in a greenhouse: soil at 100% water-holding capacity (WHC) (moist soil) and at 50% WHC (water scarcity). Additionally, we investigated fruit and seed production in plants at these two levels of water availability and evaluated whether the drought stress interferes with vegetative growth. The production of floral morphs depended on water availability: plants in moist soil produced only CH morphs and water-stressed plants produced only CL morphs. Fruit production was higher at the higher level of water availability (30.5 ± 28.20 fruits/plant at 100% WHC versus 9 ± 6.04 fruits/plant at 50% WHC; t = 4.384; P < 0.01). The mean number of seeds produced by CH and CL morphs were, respectively, 5.93 ± 2.24 and 8.17 ± 2.07 seeds/fruit (t = - 3.304; P < 0.01). Although CL morphs produced a greater number of seeds, the total seed production per plant was higher in plants at 100% WHC (180.86 seeds/plant in CH morphs versus 73.53 seeds/plant in CL morphs of plants in soil at 100% and 50% WHC, respectively; t = - 2.759; P < 0.01).  The plants in soil at 100% WHC were taller (0.48 m ± 0.07) in relation to plants in soil at 50% WHC (0.24 m ± 0.04) (t = 1.781; P < 0.01). This study provides new information about the sexual reproductive strategy of R. brevifolia, indicating that the main factor inducing cleistogamy is drought stress.

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The genus Prepusa Martius is endemic to montane regions of Brazil and comprises only six species, most of them endangered. Although studies on reproductive biology are necessary to increase knowledge of this genus and to implement conservation plans, to date, no such studies have been conducted. This study assessed the floral biology, breeding system, and pollinators of Prepusa hookeriana, an endangered species of high-altitude grasslands. We perform field observations and manual pollination experiments. Certain floral traits of this species appear to be associated with hummingbird pollination, although ornithophily is unusual in Gentianaceae. Even though cross-pollination is favoured by the presence of movement herkogamy and protandry, both prior and delayed autonomous self-pollination were observed. The only pollinator observed was the hummingbird Amazilia versicolor. Prepusa hookeriana did not show pollen limitation in the year of study. The absence of pollen limitation is related to the high reproductive success of pollination due to visits, not to autonomous selfpollination. However, we share the idea that the ability of autonomous selfing can provide a backup to cope with occasional pollination failures.

Natural environment has undergone rapid transformations, primarily attributed to human actions that threaten ecosystems' balance. Understanding the relationship between humans and nature is essential to generate effective strategies for sustainably using resources. In this study, we analyzed the environmental perception and knowledge about the biology of sea turtles through 120 informal interviews with visitors at beaches on the north-central coast of Rio de Janeiro state. Residents noticed garbage more often than tourists, as did women and younger individuals. The perception of initiatives necessary to increase the preservation of the beaches was higher for people with higher education. In general, there were no differences in biological knowledge about sea turtles between residents, tourists and people who work or study at the cities. The results point to the need for oceanic education strategies that can help raise environmental awareness through long-term conservation programs.