Blue is a favored color of many humans. While blue skies and oceans are a common visual experience, this color is less frequently observed in flowers. We first review how blue has been important in human culture, and thus how our perception of blue has likely influenced the way of scientifically evaluating signals produced in nature, including approaches as disparate as Goethe's Farbenlehre, Linneaus' plant taxonomy, and current studies of plant-pollinator networks. We discuss the fact that most animals, however, have different vision to humans; for example, bee pollinators have trichromatic vision based on UV-, Blue-, and Green-sensitive photoreceptors with innate preferences for predominantly short-wavelength reflecting colors, including what we perceive as blue. The subsequent evolution of blue flowers may be driven by increased competition for pollinators, both because of a harsher environment (as at high altitude) or from high diversity and density of flowering plants (as in nutrient-rich meadows). The adaptive value of blue flowers should also be reinforced by nutrient richness or other factors, abiotic and biotic, that may reduce extra costs of blue-pigments synthesis. We thus provide new perspectives emphasizing that, while humans view blue as a less frequently evolved color in nature, to understand signaling, it is essential to employ models of biologically relevant observers. By doing so, we conclude that short wavelength reflecting blue flowers are indeed frequent in nature when considering the color vision and preferences of bees.

Makaleyi görüntüle

Cancer is a leading cause of death around the world. Apoptosis, one of the pathways of programmed cell death, is a promising target for cancer therapy. Traditional Tibetan medicine (TTM) has been used by Tibetan people for thousands of years, and many TTMs have been proven to be effective in the treatment of cancer. This paper summarized the medicinal plants with anticancer activity in the Tibetan traditional system of medicine by searching for Tibetan medicine monographs and drug standards and reviewing modern research literatures. Forty species were found to be effective in treating cancer. More importantly, some TTMs ( e.g ., Ophiocordyceps sinensis , Phyllanthus emblica L. and Rhodiola kirilowii (Regel) Maxim.) and their active ingredients ( e.g. , cordycepin, salidroside, and gallic acid) have been reported to possess anticancer activity by targeting some apoptosis pathways in cancer, such as Bcl-2/Bax, caspases, PI3K/Akt, JAK2/STAT3, MAPK, and AMPK. These herbs and natural compounds would be potential drug candidates for the treatment of cancer.

Makaleyi görüntüle

Background The world's herbaria contain millions of specimens, collected and named by thousands of researchers, over hundreds of years. However, this treasure has remained largely inaccessible to genetic studies, because of both generally limited success of DNA extraction and the challenges associated with PCR-amplifying highly degraded DNA. In today's next-generation sequencing world, opportunities and prospects for historical DNA have changed dramatically, as most NGS methods are actually designed for taking short fragmented DNA molecules as templates. Results As a practical test of routine recovery of rDNA and plastid genome sequences from herbarium specimens, we sequenced 25 herbarium specimens up to 80 years old from 16 different Angiosperm families. Paired-end reads were generated, yielding successful plastid genome assemblies for 23 species and nuclear rDNAs for 24 species, respectively. These data showed that genome skimming can be used to generate genomic information from herbarium specimens as old as 80 years and using as little as 500 pg of degraded starting DNA. Conclusions The routine plastome sequencing from herbarium specimens is feasible and cost-effective (compare with Sanger sequencing or plastome-enrichment approaches), and can be performed with limited sample destruction.

Makaleyi görüntüle

Non-timber Forest Products (NTFPs), an important provisioning ecosystem services, are recognized for their contribution in rural livelihoods and forest conservation. Effective management through sustainable harvesting and market driven commercialization are two contrasting aspects that are bringing challenges in development of NTFPs sector. Identifying potential species having market value, conducting value chain analyses, and sustainable management of NTFPs need analysis of their use patterns by communities and trends at a regional scale. We analyzed use patterns, trends, and challenges in traditional use and management of NTFPs in the southern slope of Kangchenjunga Landscape, Eastern Himalaya and discussed potential implications for conservation and livelihoods. A total of 739 species of NTFPs used by the local people of Kangchenjunga Landscape were reported in the reviewed literature. Of these, the highest number of NTFPs was documented from India (377 species), followed by Nepal (363) and Bhutan (245). Though the reported species were used for 24 different purposes, medicinal and edible plants were the most frequently used NTFP categories in the landscape. Medicinal plants were used in 27 major ailment categories, with the highest number of species being used for gastro-intestinal disorders. Though the Kangchenjunga Landscape harbors many potential NTFPs, trade of NTFPs was found to be nominal indicating lack of commercialization due to limited market information. We found that the unsustainable harvesting and lack of marketing were the major constraints for sustainable management of NTFPs sector in the landscape despite of promising policy provisions. We suggest sustainable harvesting practices, value addition at local level, and marketing for promotion of NTFPs in the Kangchenjunga Landscape for income generation and livelihood improvement that subsequently contributes to conservation.

Makaleyi görüntüle

Background and aims Extended seed longevity in the dry state is the basis for the ex situ conservation of 'orthodox' seeds. However, even under identical storage conditions there is wide variation in seed life-span between species. Here, the effects of seed traits and environmental conditions at the site of collection on seed longevity is explored for195 wild species from 71 families from environments ranging from cold deserts to tropical forests. Methods Seeds were rapidly aged at elevated temperature and relative humidity (either 45 degrees C and 60% RH or 60 degrees C and 60% RH) and regularly sampled for germination. The time taken in storage for viability to fall to 50% (p(50)) was determined using Probit analysis and used as a measure of relative seed longevity between species. Key results Across species, p(50) at 45 degrees C and 60% RH varied from 0.1 d to 771 d. Endospermic seeds were, in general, shorter lived than non-endospermic seeds and seeds from hot, dry environments were longer lived than those from cool, wet conditions. These relationships remained significant when controlling for the effects of phylogenetic relatedness using phylogenetically independent contrasts. Seed mass and oil content were not correlated with p(50). Conclusions The data suggest that the endospermic seeds of early angiosperms which evolved in forest understorey habitats are short-lived. Extended longevity presumably evolved as a response to climatic change or the invasion of drier areas. The apparent short-lived nature of endospermic seeds from cool wet environments may have implications for re-collection and re-testing strategies in ex situ conservation.

Makaleyi görüntüle