Mediation of a Mutualistic Conflict for Pollination via Fig Phenology and Odor Recognition between Ficus and Fig Wasp.

The vegetative and reproductive growth of plants provide the basic tempo for an ecosystem, and when species are interdependent, phenology becomes crucial to regulating the quantity and quality of the interactions. In plant-insect interactions, the plants signal the beginning of their reproductive period with visual and chemical cues; however, in the case of Ficus mutualism, the cues are strictly chemical. The volatile organic compounds emitted by a fig species are a unique, specific blend that provides a signal to mutualistic wasps that the figs are receptive for pollination. In this study, we studied both the phenological pattern of Ficus septica in Central Taiwan and its emissions of volatile compounds at receptivity. This dioecious fig species displays a pattern of continuous vegetative and reproductive production all through the year with a decrease in winter. In parallel, the odor blends emitted by male and female trees are similar but with seasonal variations; these are minimal during winter and increase with the size of the wasp population during the favorable season. In addition, the pollinating females cannot distinguish between the male and female summer odor blends. The link between odor similarity, pollinators and intersexual conflict is discussed.

Glucose/Glutathione Co-triggered Tumor Hypoxia Relief and Chemodynamic Therapy to Enhance Photothermal Therapy in Bladder Cancer.

Photothermal therapy (PTT) is a potential treatment for cancer that makes use of near-infrared (NIR) laser irradiation and is expected to assist traditional anti-cancer drug therapies; however, the therapeutic efficacy of PTT is restricted by thermal resistance due to the overexpression of heat shock proteins and insufficient penetration depth of lasers. Thus, PTT needs to be combined with additional therapeutic methods to obtain the optimal therapeutic efficacy for cancer. Herein, a multifunctional therapeutic platform combining PTT with glucose-triggered chemodynamic therapy (CDT) and glutathione (GSH)-triggered hypoxia relief was developed via GOx@MBSA-PPy-MnO2 NPs (GOx for glucose oxidase, M for Fe3O4, BSA for bovine serum albumin, and PPy for polypyrrole). GOx@MBSA-PPy-MnO2 NPs have excellent photothermal efficiency and can release Mn2+, which catalyzes the transformation of H2O2 into hydroxyl radicals (·OH) and O2 via a Fenton-like reaction, effectively destroying cancer cells and relieving tumor hypoxia. Meanwhile, a high content of H2O2 was produced via GOx catalysis of glucose, further enhancing the CDT efficiency. In addition, in vitro and in vivo experiments showed that the inhibition of cancer cell proliferation and effective inhibition of tumors could be caused by the combined PTT/glucose-triggered CDT effects and hypoxia relief of the GOx@MBSA-PPy-MnO2 NPs. Overall, this work provides evidence of a synergistic therapy that remarkably improves therapeutic efficacy and significantly prolongs the lifetime of mice compared with controls.

One-Step Aminomalononitrile-Based Coatings Containing Zwitterionic Copolymers for the Reduction of Biofouling and the Foreign Body Response.

Many biomedical devices benefit from antibiofouling coatings, which can reduce biointerfacial interactions such as protein adsorption and cell attachment. In this study, we synthesized zwitterionic copolymers consisting of sulfobetaine methacrylate (SB) and 2-aminoethyl methacrylate (AE) via free radical polymerization and combined these copolymers in solution with aminomalononitrile to form zwitterionic coatings in an autopolymerization process. The successful deposition of coatings containing different SB/AE ratios was demonstrated by X-ray photoelectron spectroscopy. The one-step surface modification process was carried out on polydimethylsiloxane (PDMS), tissue culture polystyrene, and gold substrates, demonstrating that this method can be transferred to different substrate materials. The ability of optimized coatings to reduce serum protein adsorption was demonstrated by quartz crystal microbalance measurements while the ability to resist cell attachment for 24 h was demonstrated using L929 mouse fibroblasts. The stability of the coatings under physiological conditions was investigated, and resistance to cell attachment was maintained over a period of 45 days. Furthermore, the resistance of the copolymer coating to cell attachment was maintained after both ethylene oxide sterilization and autoclaving. Finally, copolymer-modified PDMS samples were investigated with regard to their ability to reduce the foreign body response in vivo. Here, a significant reduction in the capsule thickness (approximately 50%) was observed in nude mice after 2 and 4 weeks. It is expected that the one-step, facile, and versatile surface modification strategy discussed here will find applications in biomedical devices.

Topographic effect on the phenology of Ficus pedunculosa var. mearnsii (Mearns fig) in its northern boundary distribution, Taiwan.

Mearns fig grows at the edge of coastal vegetation on uplifted coral reefs, its population and mutualistic-pollinators are susceptible to the influence of extreme weather. To determine the phenology of Mearns fig and the effects of various weather events under small-scale topographic differences, phenology was conducted for 3 years and 7 months. Results showed that Mearns figs had multiple leaf and fig productions year-round. Topographic effects caused population in Frog Rock Trail and Jialeshuei, which are less than 10 km away from each other, to exhibit different phenological patterns after experiencing severe weather events. Northeast monsoons led the Jialeshuei population to show low amounts of leaves and figs in winter and the phenological production was also susceptible to disturbances by typhoons in summer. Fig reproduction in such environment was disadvantageous to maintain pollinators. Besides, topographic complex in microhabitat of Frog Rock Trail protected some individuals from these same events thus safeguard population's survival. The phenology of Mearns fig would respond to the weather events sensitively, which serve as references for estimating the mutualism system, and as indicators of climate change.

Effects of climate change on a mutualistic coastal species: Recovery from typhoon damages and risks of population erosion.

Presently, climate change has increased the frequency of extreme meteorological events such as tropical cyclones. In the western Pacific basin, these cyclones are called typhoons, and in this area, around Taiwan Island, their frequency has almost doubled since 2000. When approaching landmasses, typhoons have devastating effects on coastal vegetation. The increased frequency of these events has challenged the survival of coastal plant species and their posttyphoon recovery. In this study, a population of coastal gynodioecious Ficus pedunculosa var. mearnsii (Mearns fig) was surveyed for two years to investigate its recovery after Typhoon Morakot, which occurred in August 2009. Similar to all the Ficus species, the Mearns fig has an obligate mutualistic association with pollinating fig wasp species, which requires syconia (the closed Ficus inflorescence) to complete its life cycle. Moreover, male gynodioecious fig species produces both pollen and pollen vectors, whereas the female counterpart produces only seeds. The recovery of the Mearns fig was observed to be rapid, with the production of both leaves and syconia. The syconium:leaf ratio was greater for male trees than for female trees, indicating the importance of syconium production for the wasp survival. Pollinating wasps live for approximately 1 day; therefore, receptive syconia are crucial. Every typhoon season, few typhoons pass by the coasts where the Mearns fig grows, destroying all the leaves and syconia. In this paper, we highlight the potential diminution of the fig population that can lead to the extinction of the mutualistic pair of species. The effects of climate change on coastal species warrant wider surveys.