A New Case of Ants Nesting within Branches of a Fig Tree: the Case of Ficus subpisocarpa in Taiwan

Ficus is one of many plant genera involved in interactions with ants. The interaction is however little documented. We show here that ants, belonging mainly to the genus Crematogaster, nest in hollow internodes of young branches of Ficus subpisocarpa, a monoecious fig species studied in Taiwan. The ants feed on the mutualistic fig-pollinating wasps as well as on parasitic non-pollinating fig wasps. Nevertheless fig-wasps may not constitute a sufficient food source to ensure permanent presence of ants on the tree as the ants were observed to be frequently associated with hemipterans such as coccids and aphids. Fig wasps seem to constitute a reliable and sufficient food source on some dioecious Ficus species. On the contrary, in monoecious Ficus species, resident ants have always been observed to tend homopteran in addition to feeding on fig wasps. Frequent fruiting, prolonged fruit ripening period, ramiflory and rapid growth could constitute traits facilitating strong association based on fig-wasps' consumption of the monoecious F. subpisocarpa with ants. Despite these traits, ants were observed to tend hemipterans, and F. subpisocarpa does not seem to have evolved specialized morphological traits to facilitate the association

An extreme case of plant-insect co-diversification: figs and fig-pollinating wasps

It is thought that speciation in phytophagous insects is often due to colonization of novel host plants, because radiations of plant and insect lineages are typically asynchronous. Recent phylogenetic comparisons have supported this model of diversification for both insect herbivores and specialized pollinators. An exceptional case where contemporaneous plant insect diversification might be expected is the obligate mutualism between fig trees (Ficus species, Moraceae) and their pollinating wasps (Agaonidae, Hymenoptera). The ubiquity and ecological significance of this mutualism in tropical and subtropical ecosystems has long intrigued biologists, but the systematic challenge posed by >750 interacting species pairs has hindered progress toward understanding its evolutionary history. In particular, taxon sampling and analytical tools have been insufficient for large-scale co-phylogenetic analyses. Here, we sampled nearly 200 interacting pairs of fig and wasp species from across the globe. Two supermatrices were assembled: on average, wasps had sequences from 77% of six genes (5.6kb), figs had sequences from 60% of five genes (5.5 kb), and overall 850 new DNA sequences were generated for this study. We also developed a new analytical tool, Jane 2, for event-based phylogenetic reconciliation analysis of very large data sets. Separate Bayesian phylogenetic analyses for figs and fig wasps under relaxed molecular clock assumptions indicate Cretaceous diversification of crown groups and contemporaneous divergence for nearly half of all fig and pollinator lineages. Event-based co-phylogenetic analyses further support the co-diversification hypothesis. Biogeographic analyses indicate that the presentday distribution of fig and pollinator lineages is consistent with an Eurasian origin and subsequent dispersal, rather than with Gondwanan vicariance. Overall, our findings indicate that the fig-pollinator mutualism represents an extreme case among plant-insect interactions of coordinated dispersal and long-term co-diversification

<i>Ficus dubia</i> Latex Extract Induces Cell Cycle Arrest and Apoptosis by Regulating the NF-κB Pathway in Inflammatory Human Colorectal Cancer Cell Lines

Colorectal cancer is one of the most diagnosed cancers that is associated with inflammation. Ficus dubia latex is recognized as a remedy with various therapeutic effects in traditional medicine, including anti-inflammatory and antioxidant activity. The present study aims to compare the anti-tumor activity of Ficus dubia latex extract (FDLE) against HCT-116 and HT-29 human colorectal cancer cell lines in normal and inflammatory condition and explore its mechanism of action. FDLE exhibited remarkable antiproliferative activity against HCT-116 and HT-29 colorectal cancer cell lines in both conditions using MTT and colony formation assays and more effective anti-proliferation was observed in inflammatory condition. Mechanistically, FDLE induced cell cycle arrest at G0/G1 phase by down-regulating NF-κB, cyclin D1, CDK4 and up-regulatingp21 in both cell in normal condition. In inflammatory condition, FDLE not only exhibited stronger induction of cell cycle arrest in both cells by down-regulating NF-κB, cyclin D1, CDK4 and down-regulating p21, but also selectively induced apoptosis in HCT-116 cells by down-regulating NF-κB and Bcl-xl and up-regulating Bid, Bak, cleaved caspase-7 and caspase-3 through stronger ability to regulate these proteins. Our results demonstrated that the phytochemical agent in the latex of Ficus dubia could potential be used for treatment and prevention of human colorectal cancer, especially in inflammation-induced hyperproliferation progression

Composition Diversity and Expression Specificity of the TPS Gene Family among 24 Ficus Species

Volatile organic compounds (VOCs) released by the receptive syconia of Ficus species play a vital role in attracting highly species-specific pollinating fig wasps. The components of VOCs vary considerably among Ficus species, but are generally dominated by a few common terpenoid compounds or specific proportions of several compounds. Terpene synthase (TPS) is the main source of specific and diverse terpenoids, but the evolution of the TPS gene family in Ficus and the potential functions of the TPS genes in species-specific pollination remain largely unelucidated. In this study, using transcriptomes of ostiole bracts of receptive male figs from 24 Ficus species collected from South China and Southeast Asia, we comprehensively scanned and investigated the composition and evolutionary characteristics of all TPS genes in all 24 species. We identified 248 TPS genes, including 33 orthologous genes and six singletons. Sequence and phylogenetic analysis showed that a majority of the 248 TPSs contained the DDXXD and DTE motifs, rather than the DXDD motif, and involved all subfamilies (TPS-a,b,c,e/f and g) known in other angiosperm genomes, suggesting a very diverse and complex composition of class I TPSs during the receptive phase. In addition, compared to TPS-a, which is generally the largest subfamily in some plants, the TPS-b subfamily contained the highest number of genes in Ficus species. Expression profile comparison showed that the distribution and expression levels of different TPSs among different Ficus species differed considerably, but a few TPS genes were common across most species. Positive selection analysis showed that the Ficus TPS genes were mainly under purifying selection, with only four genes having positive selection signals and two genes having positive selection sites, and two genes having relatively fast-evolving rates. The present study demonstrates the basic evolutionary characteristics of TPS genes in Ficus and reveals the roles of TPSs in shaping the diversity and specificity of the fig&ndash;fig wasp symbiotic relationship

Sequences of primers used in this study.

<p>Notes: The primer combinations ITS_5F plus ITS 4R and ITS17SE plus ITS26SE were used interchangingly with about equal success corresponding to standard protocols at C and CNRS. The combination of the <i>Ficus</i> specific internal primer ETS_Fig1_F plus 18S_ETS was only used for amplification of 13 accessions across the subsection, which could not be amplified with the standard primers.</p><p>Sequences of primers used in this study.</p

Total evidence MCC tree fromBayesian analysis of four DNA markers, morphology and leaf anatomy.

<p>Posterior probabilities (PP) above and bootstrap supports (BS) below the branches.</p

A New Classification of <i>Ficus</i> Subsection <i>Urostigma</i> (Moraceae) Based on Four Nuclear DNA Markers (ITS, ETS, G3pdh, and ncpGS), Morphology and Leaf Anatomy

<div><p><i>Ficus</i> subsection <i>Urostigma</i> as currently circumscribed contains 27 species, distributed in Africa, Asia, Australia and the Pacific, and is of key importance to understand the origin and evolution of <i>Ficus</i> and the fig-wasp mutualism. The species of subsection <i>Urostigma</i> are very variable in morphological characters and exhibit a wide range of often partly overlapping distributions, which makes identification often difficult. The systematic classification within and between this subsection and others is problematic, e.g., it is still unclear where to classify <i>F</i>. <i>amplissima</i> and <i>F</i>. <i>rumphii</i>. To clarify the circumscription of subsection <i>Urostigma</i>, a phylogenetic reconstruction based on four nuclear DNA markers (ITS, ETS, G3pdh, and ncpGS) combined with morphology and leaf anatomy is conducted. The phylogenetic tree based on the combined datasets shows that <i>F</i>. <i>madagascariensis</i>, a Madagascan species, is sister to the remainder of subsect. <i>Urostigma</i>. <i>Ficus amplissima</i> and <i>F</i>. <i>rumphii</i>, formerly constituting sect. <i>Leucogyne</i>, appear to be imbedded in subsect. <i>Conosycea</i>. The result of the phylogenetic analysis necessitates nomenclatural adjustments. A new classification of <i>Ficus</i> subsection <i>Urostigma</i> is presented along with the morphological and leaf anatomical apomorphies typical for the clades. Two new species are described ─ one in subsect. <i>Urostigma</i>, the other in <i>Conosycea</i>. One variety is raised to species level.</p></div

Evolution of some selected morphological and leaf anatomical characters optimized onto the phylogeny tree (Fig 2) using Mesquite v.2.7.5 with parsimony.

<p>A: Intermittent growth (character 3), B: Deciduous leaves (character 7), C: Staminate flowers (character 40), and D: Enlarged lithocysts (character 47).</p

PCR programsadjusted from [1,2,3] as used for each molecular marker.

<p>PCR programsadjusted from [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0128289#pone.0128289.ref001" target="_blank">1</a>,<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0128289#pone.0128289.ref002" target="_blank">2</a>,<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0128289#pone.0128289.ref003" target="_blank">3</a>] as used for each molecular marker.</p