@article {29101, title = {In vitro antifungal activity of extracts obtained from Hypericum perforatum adventitious roots cultured in a mist bioreactor against planktonic cells and biofilm of Malassezia furfur}, journal = {Natural Product Research}, year = {2015}, month = {Jan-07-2016}, pages = {1 - 7}, issn = {1478-6419}, doi = {10.1080/14786419.2015.1028059}, url = {http://www.tandfonline.com/doi/full/10.1080/14786419.2015.1028059}, author = {Simonetti, Giovanna and Tocci, Noemi and Valletta, Alessio and Brasili, Elisa and D{\textquoteright}Auria, Felicia Diodata and Idoux, Alicia and Pasqua, Gabriella} } @article {29098, title = {Hypericum robsonii spec. nova sect. Trigynobrathys (Hypericaceae) from the Misiones Province in Argentina}, journal = {Phyton}, volume = {55}, year = {2015}, pages = {17-29}, chapter = {17}, abstract = {

Plant collections conducted in connection with ethnobotanical studies carried
out with the Guaran\í peoples of Misiones Province, Argentina, resulted in the discovery
of a new species of Hypericum L. (Hypericaceae), which is characterized by
its epigeous herbaceous scions produced seasonally from subterranean stems or
roots. This species, H. robsonii H. A. Keller \& S. Crockett, is described and illustrated
for the first time. Information about its ecology, habitat and distribution,
phenology and ethnobotany is provided.

}, author = {Hector A. Keller and Sara L. Crockett} } @article {29095, title = {A new species of Hypericum (Hypericaceae) from Southern Brazil}, journal = {Phytotaxa}, volume = {192}, year = {2015}, month = {15-01-2015}, pages = {290}, abstract = {

In this article we describe and illustrate Hypericum austrobrasiliense, a new species endemic to the grasslands of the Brazilian Atlantic Forest biome and restricted to Southern Brazil. This distinctive species is classified as Endangered based on IUCN Red List criteria.

}, issn = {1179-3155}, doi = {10.11646/phytotaxa.192.410.11646/phytotaxa.192.4.6}, url = {http://biotaxa.org/Phytotaxa/issue/view/phytotaxa.192.4}, author = {Vogel Ely, Cleusa and Boldrini, Ilsi Iob and Bordignon, S{\'e}rgio Augusto de Loreto} } @article {29094, title = {The role of ABA in the freezing injury avoidance in two Hypericum species differing in frost tolerance and potential to synthesize hypericins}, journal = {Plant Cell, Tissue and Organ Culture (PCTOC)}, year = {2015}, month = {08-03-2015}, abstract = {

Cold stress is a major environmental factor that limits the distribution of plants and determines the spectrum and amount of secondary metabolites with a protective function. The most studied representative of the genus Hypericum, H. perforatum L. (St. John\’s wort), is known as a producer of the photodynamic pigment hypericin, the unique bioactive compound structurally belonging to naphtodianthrones. In relation to the cosmopolitan distribution, we hypothesised that low temperature stress could increase the content of naphtodianthrones as a part of the adaptive mechanisms. Two strategies in preventing the freezing injury in the genus Hypericum were defined. Based on a frost-killing temperature (LT50) in untreated (control) plants and more than a 10 \°C decrease in LT50 in cold-acclimated plants, we demonstrated the freezing tolerance for H. perforatum. On the contrary, the freezing avoidance was preferable in H. canariense\—the species endemic to (sub)tropical Canary Islands and Madeira. The freezing tolerance/avoidance was related to the course of ABA accumulation/depletion in H. perforatum/H. canariense under a subfreezing temperature of \−4 \°C; however, the effect of dehydration or application of 76 \μM ABA on the level of endogenous ABA was comparable. The 48-h exposure of H. perforatum control plants to \−4 \°C resulted in a 1.6-fold increase in the content of naphtodianthrones, along with the 1.5-fold increase of ABA. On the contrary, neither dehydration nor exogenous ABA stimulated the biosynthesis of these compounds. Our findings indicate possible integration of ABA signalling into naphtodianthrones biosynthesis under subfreezing conditions; this mechanism could be modified by plant tolerance to cold environments.

}, issn = {0167-6857}, doi = {10.1007/s11240-015-0748-9}, url = {http://link.springer.com/10.1007/s11240-015-0748-9}, author = {Bru{\v n}{\'a}kov{\'a}, Katar{\'\i}na and Petijov{\'a}, Linda and Z{\'a}me{\v c}n{\'\i}k, Ji{\v r}{\'\i} and Ture{\v c}kov{\'a}, Veronika and Cellarova, Eva} } @article {29093, title = {Spatial chemo-profiling of hypericin and related phytochemicals in Hypericum species using MALDI-HRMS imaging}, journal = {Analytical and Bioanalytical Chemistry}, year = {2015}, month = {08-03-2015}, abstract = {

Advanced analytical imaging techniques, including matrix-assisted laser desorption/ionization high-resolution mass spectrometry (MALDI-HRMS) imaging, can be used to visualize the distribution, localization, and dynamics of target compounds and their precursors with limited sample preparation. Herein we report an application of MALDI-HRMS imaging to map, in high spatial resolution, the accumulation of the medicinally important naphthodianthrone hypericin, its structural analogues and proposed precursors, and other crucial phytochemical constituents in the leaves of two hypericin-containing species, Hypericum perforatum and Hypericum olympicum. We also investigated Hypericum patulum, which does not contain hypericin or its protoforms. We focused on both the secretory (dark glands, translucent glands, secretory canals, laminar glands, and ventral glands) and the surrounding non-secretory tissues to clarify the site of biosynthesis and localization of hypericin, its possible precursors, and patterns of localization of other related compounds concomitant to the presence or absence of hypericin. Hypericin, pseudohypericin, and protohypericin accumulate in the dark glands. However, the precursor emodin not only accumulates in the dark glands but is also present outside the glands in both hypericin-containing species. In hypericin-lacking H. patulum, however, emodin typically accumulates only in the glands, thereby providing evidence that hypericin is possibly biosynthesized outside the dark glands and thereafter stored in them. The distribution and localization of related compounds were also evaluated and are discussed concomitant to the occurrence of hypericin. Our study provides the basis for further detailed investigation of hypericin biosynthesis by gene discovery and expression studies.

}, issn = {1618-2642}, doi = {10.1007/s00216-015-8682-6}, url = {http://link.springer.com/10.1007/s00216-015-8682-6}, author = {Kusari, Souvik and Sezgin, Selahaddin and Nigutova, Katarina and Cellarova, Eva and Spiteller, Michael} } @article {29092, title = {De novo sequencing of the Hypericum perforatum L. flower transcriptome to identify potential genes that are related to plant reproduction sensu lato}, journal = {BMC Genomics}, volume = {16}, year = {2015}, month = {31-3-2015}, abstract = {

Background St. John\’s wort (Hypericum perforatum L.) is a medicinal plant that produces important metabolites with antidepressant and anticancer activities. Recently gained biological information has shown that this species is also an attractive model system for the study of a naturally occurring form of asexual reproduction called apomixis, which allows cloning plants through seeds. In aposporic gametogenesis, one or multiple somatic cells belonging to the ovule nucellus change their fate by dividing mitotically and developing functionally unreduced embryo sacs by mimicking sexual gametogenesis. Although the introduction of apomixis into agronomically important crops could have revolutionary implications for plant breeding, the genetic control of this mechanism of seed formation is still not well understood for most of the model species investigated so far. Methods We used Roche 454 technology to sequence the entire H. perforatum flower transcriptome of whole flower buds and single flower verticils collected from obligately sexual and unrelated highly or facultatively apomictic genotypes, which enabled us to identify RNAs that are likely exclusive to flower organs (i.e., sepals, petals, stamens and carpels) or reproductive strategies (i.e., sexual vs. apomictic). Results Here we sequenced and annotated the flower transcriptome of H. perforatum with particular reference to reproductive organs and processes. In particular, in our study we characterized approximately 37,000 transcripts found expressed in male and/or female reproductive organs, including tissues or cells of sexual and apomictic flower buds. Ontological annotation was applied to identify major biological processes and molecular functions involved in flower development and plant reproduction. Starting from this dataset, we were able to recover and annotate a large number of transcripts related to meiosis, gametophyte/gamete formation, and embryogenesis, as well as genes that are exclusively or preferentially expressed in sexual or apomictic libraries. Real-Time RT-qPCR assays on pistils and anthers collected at different developmental stages from accessions showing alternative modes of reproduction were used to identify potential genes that are related to plant reproduction sensu lato in H. perforatum. Conclusions Our approach of sequencing flowers from two fully obligate sexual genotypes and two unrelated highly apomictic genotypes, in addition to different flower parts dissected from a facultatively apomictic accession, enabled us to analyze the complexity of the flower transcriptome according to its main reproductive organs as well as for alternative reproductive behaviors. Both annotation and expression data provided original results supporting the hypothesis that apomixis in H. perforatum relies upon spatial or temporal mis-expression of genes acting during female sexual reproduction. The present analyses aim to pave the way toward a better understanding of the molecular basis of flower development and plant reproduction, by identifying genes or RNAs that may differentiate or regulate the sexual and apomictic reproductive pathways in H. perforatum.

}, doi = {10.1186/s12864-015-1439-y}, url = {http://www.biomedcentral.com/1471-2164/16/254}, author = {Galla, Giulio and Vogel, Heiko and Sharbel, Timothy F and Barcaccia, Gianni} } @article {29086, title = {Oligocene niche shift, Miocene diversification - Cold tolerance and accelerated speciation rates in the St. John{\textquoteright}s Worts (Hypericum, Hypericaceae)}, journal = {BMC Evolutionary BiologyBMC Evolutionary Biology}, volume = {50}, year = {2015}, pages = {80}, abstract = {

Background: Our aim is to understand the evolution of species-rich plant groups that shifted from tropical into cold/temperate biomes. It is well known that climate affects evolutionary processes, such as how fast species diversify, species range shifts, and species distributions. Many plant lineages may have gone extinct in the Northern Hemisphere due to Late Eocene climate cooling, while some tropical lineages may have adapted to temperate conditions and radiated; the hyper-diverse and geographically widespread genus Hypericum is one of these.

Results: To investigate the effect of macroecological niche shifts on evolutionary success we combine historical biogeography with analyses of diversification dynamics and climatic niche shifts in a phylogenetic framework. Hypericum evolved cold tolerance c. 30 million years ago, and successfully colonized all ice-free continents, where today ~500 species exist. The other members of Hypericaceae stayed in their tropical habitats and evolved into ~120 species. We identified a 15\–20 million year lag between the initial change in temperature preference in Hypericum and subsequent diversification rate shifts in the Miocene.

Conclusions: Contrary to the dramatic niche shift early in the evolution of Hypericum most extant species occur in temperate climates including high elevations in the tropics. These cold/temperate niches are a distinctive characteristic of Hypericum. We conclude that the initial release from an evolutionary constraint (from tropical to temperate climates) is an important novelty in Hypericum. However, the initial shift in the adaptive landscape into colder climates appears to be a precondition, and may not be directly related to increased diversification rates. Instead, subsequent events of mountain formation and further climate cooling may better explain distribution patterns and species-richness in Hypericum. These findings exemplify important macroevolutionary patterns of plant diversification during large-scale global climate change.

}, doi = {10.1186/s12862-015-0359-4}, url = {http://www.biomedcentral.com/1471-2148/15/80}, author = {N{\"u}rk, N. M. and Uribe-Convers, S. and Gehrke, B. and Tank, D. C. and Blattner, F. R.} } @article {29084, title = {All in an afternoon: mixed breeding system in one-day lasting flowers of Hypericum elodes L. (Hypericaceae)}, journal = {Plant Biosystems - An International Journal Dealing with all Aspects of Plant Biology}, year = {2015}, pages = {1 - 9}, issn = {1126-3504}, doi = {10.1080/11263504.2014.1000421}, url = {http://www.tandfonline.com/doi/abs/10.1080/11263504.2014.1000421}, author = {Carta, A. and Savio, L. and Bedini, G. and Peruzzi, L. and Fisogni, A. and Galloni, M.} } @article {29083, title = {Local climate explains degree of seed dormancy in Hypericum elodes L. (Hypericaceae)}, journal = {Plant Biology}, year = {2015}, month = {Jan-03-2015}, pages = {n/a - n/a}, doi = {10.1111/plb.12310}, url = {http://doi.wiley.com/10.1111/plb.12310}, author = {Carta, A. and Probert, R. and Puglia, G. and Peruzzi, L. and Bedini, G.}, editor = {Bekker, R.} }