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Orchids are some of the most popular ornamental plants worldwide. Orchid floral morphology has increasingly attracted horticultural and commercial attention. Although multiple genes have been shown to be involved in the formation of the orchid flower, the underlying multi-level regulatory networks are largely unknown. In this study, we analyzed the ontogeny of flower development in Cymbidium ensifolium , a traditional orchid in the tropical and subtropical regions of Asia, by performing deep sequencing of the transcriptome of individual flower organs to discover organ-specific genes potentially involved in their growth. We identified 3,017 differentially-expressed genes (DEGs) during the development of various flower organs, and observed over-representation of GROWTH-REGULATING FACTORS (GRFs) specific to flower column (gynostemium). Eleven C. ensifolium GRFs (CeGRFs) from our transcriptome data clustered into five phylogenetic subgroups. Ten of these GRFs shared a region complementary to C. ensifolium microRNA396 (Ce -miR396), and degradome sequencing confirmed the cleavage of transcripts derived from seven CeGRFs. We cloned Ce- miR396 and used a protoplast-based transient expression system to overexpress it in Cymbidium protoplasts. We observed a significant decrease in the transcripts of several CeGRFs in flowers and leaves, indicating a potential role for miR396–GRF module in organ development through the cleavage of distinct CeGRFs. Temporal and spatial expression analysis indicated that most CeGRF transcripts accumulated in flower buds and column tissues, where Ce -miR396 expression was the lowest. Expression dynamics in wild type and floral-defective mutants further confirmed a strong correlation between Ce -miR396, CeGRFs , and flower organ development and column specification. Moreover, overexpression of Ce -miR396 in Nicotiana tabacum resulted in curved pistils and reduced fertility, implying that the conserved role of Ce -miR396 in floral development. These results provide tools to better understand the biological roles of GRFs in orchid development, and open new avenues for the diversification of orchid floral patterns. [ABSTRACT FROM AUTHOR]

Bulbophyllum orchid is used as a folk medicine in Asia. However, the concentrations of bioactive constituents in the plant may vary in different tissues. Thus, this study determined the most cytotoxic tissue extract in Bulbophyllum blepharistes Rchb.f. and identified its cytotoxic bioactive compounds. The ethanol extract from rhizomes of B. blepharistes exhibits more cytotoxicity than extracts from the leaf and pseudobulb. Ten compounds isolated from the rhizome are phenanthrenes (1, 2), bibenzyls (3, 4, 5), phenylpropanoids (6), methyl benzoate (7), along with a mixture of three alkyl acrylates (8, 9, 10). Compound 2, lusianthridin (9,10-dihydro-7-methoxy-2,5-phenanthrenediol), which was reported here for the first time in Bulbophyllum , showed cytotoxicity to H69AR, HeLa, HL-60, HepG2, and MOLT-3 cells. Compound 1 and 5 (tristin) significantly inhibited the growth of MOLT-3. The rhizome of B. blepharistes appears to be a good source for the potential anticancer agents (i.e. lusianthridin). [Display omitted] • Among18 genera of Orchidaceae, the extract of Bulbophyllum showed the most cytotoxic effect. • The ethanolic extract from rhizome of Bulbophyllum orchid rich in bioactive compounds. • The cytotoxic of Bulbophyllum dihydrophenanthrene and bibenzyl effect to various cell lines. [ABSTRACT FROM AUTHOR]

Background and Aims: The Platanthera clade dominates the North American orchid flora and is well represented in eastern Asia. It has also generated some classic studies of speciation in Platanthera sections Platanthera and Limnorchis. However, it has proved rich in taxonomic controversy and near-monotypic genera. The clade is reviewed via a new molecular phylogenetic analysis and those results are combined with brief reconsideration of morphology in the group, aiming to rationalize the species into a smaller number of larger monophyletic genera and sections. [ABSTRACT FROM PUBLISHER]

Goodyera foliosa is a terrestrial orchid in Asia and has been listed as an endangered species in the Red List. In this study, we assembled the complete chloroplast genome of G. foliosa using Illumina sequencing data. Its full-length of 154,008 bp including a pair of invert repeats (IR) regions of 25,045 bp, large single-copy (LSC) region of 83,248 bp, and small single-copy (SSC) region of 20,670 bp. The chloroplast genome contains 127 genes, including 80 protein-coding genes, 39 tRNA genes, and 8 rRNA genes. In addition, the phylogenetic analysis base on 12 chloroplast genomes of Orchidaceae indicates that G. schlechtendaliana is closely related to G. foliosa. Our study would be helpful for the formulation of conservation strategies and further research of G. foliosa. [ABSTRACT FROM AUTHOR]

Background and Aims: Lizard orchids of the genus Himantoglossum include many of Eurasia's most spectacular orchids, producing substantial spikes of showy flowers. However, until recently the genus had received only limited, and entirely traditional, systematic study. The aim of the current work was to provide a more robust molecular phylogeny in order to better understand the evolutionary relationships among species of particular conservation concern., Methods: All putative species of Himantoglossum s.l. were sampled across its geographical range. A large subsample of the 153 populations studied contributed to an initial survey of nuclear ribosomal internal transcribed spacer (nrITS) ribotypes. Smaller subsets were then sequenced for four plastid regions and the first intron of the low-copy-number nuclear gene LEAFY. Rooted using Steveniella as outgroup, phylogenetic trees were generated using parsimony and Bayesian methods from each of the three datasets, supplemented with a ribotype network., Key Results: The resulting trees collectively determined the order of branching of the early divergent taxa as Himantoglossum comperianum > H. robertianum group > H. formosum, events that also involved significant morphological divergence. Relaxed molecular clock dating suggested that these divergences preceded the Pleistocene glaciations (the origin of the H. robertianum group may have coincided with the Messinian salinity crisis) and occurred in Asia Minor and/or the Caucasus. Among more controversial taxa of the H. hircinum-jankae clade, which are only subtly morphologically divergent, topological resolution was poorer and topological incongruence between datasets was consequently greater., Conclusions: Plastid sequence divergence is broadly consistent with prior, morphologically circumscribed taxa and indicates a division between H. hircinum-adriaticum to the west of the Carpathians and H. jankae-caprinum (plus local endemics) to the east, a distinction also suggested by nrITS ribotypes. LEAFY phylogenies are less congruent with prior taxonomic arrangements and include one likely example of paralogy. Himantoglossum metlesicsianum fully merits its IUCN Endangered status. Potentially significant genetic variation was detected within Steveniella satyrioides, H. robertianum and H. hircinum. However, confident circumscription of the more derived species of Himantoglossum s.s., including local endemics of hybrid origin, must await future morphometric and population-genetic analyses., (© The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)