Recognition of the genus Thaumatophyllum Schott − formerly Philodendron subg. Meconostigma (Araceae) − based on molecular and morphological evidence

Philodendron subgenus Meconostigma has been a well-circumscribed group since 1829. Members of this group are easily distinguished by diagnostic morphological characters as well as by a distinct ecology and geographical distribution. Based on molecular, morphological and cytological evidence, we propose the recognition of P. subg. Meconostigma as a distinct genus, Thaumatophyllum Schott. We also present the necessary new combinations, an emended key and some nomenclatural and taxonomic corrections regarding 21 names of Thaumatophyllum

The Role of bZIP Transcription Factors in Green Plant Evolution: Adaptive Features Emerging from Four Founder Genes

BACKGROUND: Transcription factors of the basic leucine zipper (bZIP) family control important processes in all eukaryotes. In plants, bZIPs are regulators of many central developmental and physiological processes including photomorphogenesis, leaf and seed formation, energy homeostasis, and abiotic and biotic stress responses. Here we performed a comprehensive phylogenetic analysis of bZIP genes from algae, mosses, ferns, gymnosperms and angiosperms. METHODOLOGY/PRINCIPAL FINDINGS: We identified 13 groups of bZIP homologues in angiosperms, three more than known before, that represent 34 Possible Groups of Orthologues (PoGOs). The 34 PoGOs may correspond to the complete set of ancestral angiosperm bZIP genes that participated in the diversification of flowering plants. Homologous genes dedicated to seed-related processes and ABA-mediated stress responses originated in the common ancestor of seed plants, and three groups of homologues emerged in the angiosperm lineage, of which one group plays a role in optimizing the use of energy. CONCLUSIONS/SIGNIFICANCE: Our data suggest that the ancestor of green plants possessed four bZIP genes functionally involved in oxidative stress and unfolded protein responses that are bZIP-mediated processes in all eukaryotes, but also in light-dependent regulations. The four founder genes amplified and diverged significantly, generating traits that benefited the colonization of new environments

Evolution of Philodendron (Araceae) species in Neotropical biomes

Philodendron is the second most diverse genus of the Araceae, a tropical monocot family with significant morphological diversity along its wide geographic distribution in the Neotropics. Although evolutionary studies of Philodendron were conducted in recent years, the phylogenetic relationship among its species remains unclear. Additionally, analyses conducted to date suggested the inclusion of all American representatives of a closely-related genus, Homalomena, within the Philodendron clade. A thorough evaluation of the phylogeny and timescale of these lineages is thus necessary to elucidate the tempo and mode of evolution of this large Neotropical genus and to unveil the biogeographic history of Philodendron evolution along the Amazonian and Atlantic rainforests as well as open dry forests of South America. To this end, we have estimated the molecular phylogeny for 68 Philodendron species, which consists of the largest sampling assembled to date aiming the study of the evolutionary affinities. We have also performed ancestral reconstruction of species distribution along biomes. Finally, we contrasted these results with the inferred timescale of Philodendron and Homalomena lineage diversification. Our estimates indicate that American Homalomena is the sister clade to Philodendron. The early diversification of Philodendron took place in the Amazon forest from Early to Middle Miocene, followed by colonization of the Atlantic forest and the savanna-like landscapes, respectively. Based on the age of the last common ancestor of Philodendron, the species of this genus diversified by rapid radiations, leading to its wide extant distribution in the Neotropical region. © 2016 Loss-Oliveira et al

Floral Evolution of <i>Philodendron</i> Subgenus <i>Meconostigma</i> (Araceae)

<div><p>Elucidating the evolutionary patterns of flower and inflorescence structure is pivotal to understanding the phylogenetic relationships of Angiosperms as a whole. The inflorescence morphology and anatomy of <i>Philodendron</i> subgenus <i>Meconostigma</i>, belonging to the monocot family Araceae, has been widely studied but the evolutionary relationships of subgenus <i>Meconostigma</i> and the evolution of its flower characters have hitherto remained unclear. This study examines gynoecium evolution in subgenus <i>Meconostigma</i> in the context of an estimated molecular phylogeny for all extant species of subgenus <i>Meconostigma</i> and analysis of ancestral character reconstructions of some gynoecial structures. The phylogenetic reconstructions of all extant <i>Meconostigma</i> species were conducted under a maximum likelihood approach based on the sequences of two chloroplast (<i>trn</i>k and <i>matK</i>) and two nuclear (ETS and 18S) markers. This topology was used to reconstruct the ancestral states of seven floral characters and to elucidate their evolutionary pattern in the <i>Meconostigma</i> lineage. Our phylogeny shows that <i>Meconostigma</i> is composed of two major clades, one comprising two Amazonian species and the other all the species from the Atlantic Forest and Cerrado biomes with one Amazonian species. The common ancestor of the species of subgenus <i>Meconostigma</i> probably possessed short stylar lobes, long stylar canals, a stylar body, a vascular plexus in the gynoecium and druses in the stylar parenchyma but it is uncertain whether raphide inclusions were present in the parenchyma. The ancestral lineage also probably possessed up to 10 ovary locules. The evolution of these characters seems to have occurred independently in some lineages. We propose that the morphological and anatomical diversity observed in the gynoecial structures of subgenus <i>Meconostigma</i> is the result of an ongoing process of fusion of floral structures leading to a reduction of energy wastage and increase in stigmatic surface.</p></div

Detection of the first incidence of Akodon paranaensis naturally infected with the Jabora virus strain (Hantavirus) in Brazil

We characterised hantaviruses circulating in different Akodon rodent species collected in midwestern Santa Catarina (SC), southern Brazil, where the Jabora hantavirus (JABV) strain was first identified in Akodon montensis. Genetic and phylogenetic analyses based on a partial S segment indicated that, in SC, Akodon paranaensis and A. montensis carried the same type of hantavirus. Additionally, we conducted the first genomic characterisation of the complete S segment from the Brazilian JABV strain. This is the first report of A. paranaensis infected with the JABV

Specimens of <i>Philodendron</i> subg. Meconostigma.

<p>a. A hemiepiphytic specimen of <i>P. goeldii</i> indicated by the white arrow in the Amazon Forest (Manaus city, Amazonas state), b. <i>P. goeldii</i> leaf. c. A P. corcovadense individual growing directly on sand in the Atlantic Rainforest, Restinga vegetation (Maricá city, Rio de Janeiro state), d. A hemiepiphytic specimen of <i>P. williamsii</i> in the Atlantic Rainforest <i>s.s.</i>, (Itacaré city, Bahia state), e. A population of <i>P. leal-costae</i> pointed by the white arrow in the Caatinga inselberg (Milagres city, Bahia state), f. Bromelicolous habit of <i>P. leal-costae</i>, g. <i>P. saxicola</i> rupicolous habit in the Cerrado biome, <i>campo rupestre</i> vegetation (Lençóis city, Bahia state).</p

Maximum-likelihood phylogenies based on the isolated markers ETS and <i>matK</i>.

<p>a. Phylogeny based on ETS marker, b. Phylogeny based on <i>matK</i> marker. aLRT values ≥85% are indicated in the branch nodes.</p

Morphological characters of <i>Philodendron</i> subg. <i>Meconostigma</i>.

<p>a. <i>P. bipinnatifidum</i> inflorescence as an example of a typical <i>Philodendron</i> subg. <i>Meconostigma</i> inflorescence, b. Upper view of some of the <i>P. bipinnatifidum</i> female flowers showing stylar lobes, c. Longitudinal cut of <i>P. bipinnatidifum</i> female flowers, d. Transversal cut of a <i>P. bipinnatifidum</i> female flower, e. Longitudinal cut of a <i>P. adamantinum</i> female flower. Acronyms list: MZ = male zone; SZ = sterile male zone; FZ = female zone; SL = stylar lobes; SB = stylar body; SC = stylar canals; Ov = ovules; Lo = locules; Dr = druses; Ra = raphides.</p

Maximum-likelihood phylogeny of <i>Meconostigma</i> species based on ETS and <i>matK</i> markers.

<p>aLRT values ≥85% are indicated in the branch nodes.</p

Bayesian analysis phylogeny of <i>Meconostigma</i> species based on ETS and <i>matK</i> markers.

<p>Posterior probabilities ≥85% are indicated in the branch nodes.</p