Red flowers differ in shades between pollination systems and across continents.

BACKGROUND AND AIMS: Floral colour is a primary signal in plant-pollinator interactions. The association between red flowers and bird pollination is well known, explained by the 'bee avoidance' and 'bird attraction' hypotheses. Nevertheless, the relative importance of these two hypotheses has rarely been investigated on a large scale, even in terms of colour perception per se. METHODS: We collected reflectance spectra for 130 red flower species from different continents and ascertained their pollination systems. The spectra were analysed using colour vision models for bees and (three types of) birds, to estimate colour perception by these pollinators. The differences in colour conspicuousness (chromatic and achromatic contrast, purity) and in spectral properties between pollination systems and across continents were analysed. KEY RESULTS: Compared with other floral colours, red flowers are very conspicuous to birds and much less conspicuous to bees. The red flowers pollinated by bees and by birds are more conspicuous to their respective pollinators. Compared with the bird flowers in the Old World, the New World ones are less conspicuous to bees and may be more conspicuous not only to violet-sensitive but also to ultraviolet-sensitive birds. These differences can be explained by the different properties of the secondary reflectance peak (SP). SP intensity is higher in red flowers pollinated by bees than those pollinated by birds (especially New World bird flowers). A transition from high SP to low SP in red flowers can induce chromatic contrast changes, with a greater effect on reducing attraction to bees than enhancing attraction to birds. CONCLUSIONS: Shades of red flowers differ between pollination systems. Moreover, red bird flowers are more specialized in the New World than in the Old World. The evolution towards colour specialization is more likely to result in higher efficiency of bee avoidance than bird attraction.

Floral adaptations of two lilies: implications for the evolution and pollination ecology of huge trumpet-shaped flowers.

PREMISE: Evolutionary transitions among floral morphologies, many of which provide evidence for adaptation to novel pollinators, are common. Some trumpet-shaped flowers are among the largest flowers in angiosperms, occurring in different lineages. Our goal was to investigate the role of pollinators in the evolution of these flowers using Lilium. METHODS: We investigated floral traits and pollinators of L. primulinum var. ochraceum and L. brownii var. viridulum and reviewed reports of visitors to huge trumpet-shaped flowers. Using a published phylogeny of Lilium, we reconstructed ancestral floral morphological states in Lilium to elucidate the origins of trumpet-shaped lilies. RESULTS: Both lilies are largely self-incompatible and show floral syndromes indicative of hawkmoth pollination. The short trumpet-shaped lily can be pollinated by short-tongued (<40 mm) but not long-tongued hawkmoths (>65 mm), while the huge trumpet-shaped lily can be pollinated by both. A literature review including 22 species of trumpet-shaped flowers suggests that their pollinator guilds commonly include both short- and long-tongued moths. A phylogenetic reconstruction indicates that trumpet-shaped lilies possibly have multiple origins from tepal-reflexed ancestors, at least six of which have evolved huge flowers (>50 mm). CONCLUSIONS: Adaptation to short-tongued hawkmoths may have initiated the evolution of trumpet-shaped lilies. Huge trumpet-shaped lilies may have evolved as a response to selection by long-tongued hawkmoths, without excluding the short-tongued ones. This evolutionary pathway leads to a functionally more generalized pollination system instead of an increasingly specialized one and is not necessarily associated with pollinator shifts.

Pollination and seed dispersal of Aquilaria sinensis (Lour.) Gilg (Thymelaeaceae): An economic plant species with extremely small populations in China.

Pollination and seed dispersal in angiosperms have long been investigated in order to understand the coevolution of plants and animals. However, the signals from flowers and/or seeds to attract pollinators and/or seed dispersers have received comparatively little attention. In this study, the pollination biology and seed dispersal of the vulnerable agarwood plant Aquilaria sinensis (Lour.) Gilg, a traditional medicinal plant in China, was studied in its natural distribution range. The reproductive tactics of A. sinensis were studied in detail by employing various tests dealing with fruit set and also seed dispersal. Dynamic headspace extraction followed by GC-MS analysis was also performed in order to reveal the composition of floral scent. The results showed that noctuids and pyralids are the most effective pollinators of pollinator-dependent A. sinensis. The main compounds of the floral scent were (E, E)-α-Farnesene (61.9 ± 3.2%), trans-Ocimene (16.6 ± 1.2%), and Benzyl salicylate (4.6 ± 1.1%). The results obtained from seed dispersal experiments indicate that hornets are effective seed dispersers and they may play an important role in long-distance seed dispersal of A. sinensis. Based on our findings, we recommend several protection methods for this threatened agarwood plant in China.

A sexually dimorphic corolla appendage affects pollen removal and floral longevity in gynodioecious Cyananthus delavayi (Campanulaceae).

The floral traits of bisexual flowers may evolve in response to selection on both male and female functions, but the relative importance of selection associated with each of these two aspects is poorly resolved. Sexually dimorphic traits in plants with unisexual flowers may reflect gender-specific selection, providing opportunities for gaining an increased understanding of the evolution of specific floral traits. We examined sexually dimorphic patterns of floral traits in perfect and female flowers of the gynodioecious species Cyananthus delavayi. A special corolla appendage, the throat hair, was investigated experimentally to examine its influences on male and female function. We found that perfect flowers have larger corollas and much longer throat hairs than female flowers, while female ones have much exerted stigmas. The presence of throat hairs prolonged the duration of pollen presentation by restricting the amount of pollen removed by pollen-collecting bees during each visit. Floral longevity was negatively related to the rate of pollen removal. When pollen removal rate was limited in perfect flowers, the duration of the female phases diminished with the increased male phase duration. There was a weak negative correlation between throat hair length and seed number per fruit in female flowers, but this correlation was not significant in perfect flowers. These results suggest that throat hairs may enhance male function in terms of prolonged pollen presentation. However, throat hairs have no obvious effect on female function in terms of seed number per fruit. The marked sexual dimorphism of this corolla appendage in C. delavayi is likely to have evolved and been maintained by gender-specific selection.

Floral divergence, pollinator partitioning and the spatiotemporal pattern of plant-pollinator interactions in three sympatric Adenophora species.

Floral divergence among congeners may relate to differential utilization of pollinators and contribute to reducing overlap in pollination niches. To investigate whether and how floral differences are associated with differential utilization of pollinators in three sympatric Adenophora species, we analyzed floral traits and evaluated the contribution of different visitors to pollination. We compared visitation rates of different pollinator categories in different years and sites. A suite of floral traits differed among the three Adenophora species, suggesting adaptation to diurnal versus nocturnal pollination and an intermediate condition. However, many visitor species were shared among the three plant species, suggesting that floral traits did not rigorously filter visitors. Effective pollinators were large bees and moths. The importance of large bees as pollinators decreased whereas that of moths increased along the gradient from typically bee-pollinated to moth-pollinated flowers. The intermediate species (A. khasiana) differed substantially from the other two species in pollinator species but not in pollinator categories. The principal pollinator category of each species was constant across years and sites except in the intermediate species where it differed between two sites. Overall, the three sympatric species of Adenophora partition pollinators by floral divergence and the principal pollinators coincide with the predictions based on floral syndromes.

(±)Equol inhibits invasion in prostate cancer DU145 cells possibly via down-regulation of matrix metalloproteinase-9, matrix metalloproteinase-2 and urokinase-type plasminogen activator by antioxidant activity.

Exposure to soy isoflavones has been associated with low mortality of prostate cancer. In this study, we examined the effects of (±)equol and two representative isoflavones, daidzein and genistein, on migration and invasion in human prostate cancer DU145 cells. First of all, the three regents did not show significant growth inhibitive effect in DU145 cells until the treatments last for 72 h. Treatment with 5 µM, 10 µM, 50 µM (±)equol, 0.5 µM, 1 µM, 5 µM daidzein and genistein for 24 h decreased cell migration and invasion significantly. (±)equol activated phosphatase and tensin homologue deleted on chromosome ten at protein level but not mRNA level, which activated antioxidants, including superoxide dismutase and nuclear factor (erythroid-derived 2)-like 2. A reduction of malondialdehyde concentration, the product of lipid per-oxidation, was observed as well. Moreover, matrix metalloproteinase-2, matrix metalloproteinase-9, and urokinase-type plasminogen activator, the crucial members in metastasis, were down-regulated. Overall, our data indicate that (±)equol, daidzein and genistein may have significant anti-invasion effect in DU145 cells (in vitro). The effects induced by (±)equol may relate to its anti-oxidant effect mediated by phosphatase and tensin homologue deleted on chromosome ten.

Definition of life law and the situation with problems of China's life jurisprudence.

Life law is a new conception brought by the development of modern life science and biotechnology. There are many different ideas on the conception of life law in academy. The definition of life law should be footed on the domain of bioethics. Based on bioethics, life law is a group of legislations which are enacted or acknowledged by the state and implemented by the state compulsively with the goal of regulating all types of relations revolving the survival as well as terminal of human beings and some other creatures which play important roles in the maintenance of human's life and health. There are many problems in China's study on science of life law, which need paying special attention to by China's scholars.