Back together: Over 1000 single-copy nuclear loci and reproductive features support the holoendoparasitic Apodanthaceae and Rafflesiaceae as sister lineages in the order Malpighiales.

The systematics of the holoendoparasitic flowering plant families Apodanthaceae and Rafflesiaceae has been discussed for over two centuries. The morphological reduction of roots, shoots and leaves in all members of both families, resulting in a cryptic mycelium-like vegetative body, has been interpreted either as a key common feature, or as a result of convergent evolution due to full dependence upon their hosts. Historically, the two families have been placed together due to similar morphological features, but recent analyses based on few mitochondrial and ribosomal gene markers placed them in the distantly related orders Cucurbitales and Malpighiales.

The gynostemium: More than the sum of its parts with emerging floral complexities.

Partial or complete floral organ fusion, which occurs in most angiosperm lineages, promotes integration of whorls leading to specialization and complexity. One of the most remarkable floral organ fusions occurs in the gynostemium, a highly specialized structure formed by the congenital fusion of the androecium and the upper portion of the gynoecium. Here we review the gynostemia evolution across flowering plants, the morphological requirements for the synorganization of the two fertile floral whorls, and the molecular basis most likely responsible for such intimate fusion process.

Spatio-temporal expression of candidate genes for nectar spur development in Tropaeolum (Tropaeolaceae: Brassicales).

Background And Aims: Tropaeolaceae (Brassicales) comprise ~100 species native to South and Central America. Tropaeolaceae flowers have a nectar spur, formed by a late expansion and evagination of the fused proximal region of the perianth (i.e.

Comparative morphoanatomy and transcriptomic analyses reveal key factors controlling floral trichome development in Aristolochia (Aristolochiaceae).

Trichomes are specialized epidermal cells in aerial plant parts. Trichome development proceeds in three stages, determination of cell fate, specification, and morphogenesis. Most genes responsible for these processes have been identified in the unicellular branched leaf trichomes from the model Arabidopsis thaliana.

Expression and Functional Studies of Leaf, Floral, and Fruit Developmental Genes in Non-model Species.

Researchers working on evolutionary developmental plant biology are inclined to choose non-model taxa to address how specific features have been acquired during ontogeny and fixed during phylogeny. In this chapter we describe methods to extract RNA, to assemble de-novo transcriptomes, to isolate orthologous genes within gene families, and to evaluate expression and function of target genes. We have successfully optimized these protocols for non-model plant species including ferns, gymnosperms, and a large assortment of angiosperms.

Complete Mitogenomes of Two Species and Phylogeny of Plantagineae (Plantaginaceae, Lamiales) Using Mitochondrial Genes and the Nuclear Ribosomal RNA Repeat.

, comprising 19 high-altitude North Andean species, is one of three genera in the Plantagineae (Plantaginaceae, Lamiales), along with and . Based primarily on plastid data and nuclear ITS, is sister to a clade of + , but Plantagineae relationships have yet to be assessed using multigene datasets from the nuclear and mitochondrial genomes. Here, complete mitogenomes were assembled for two species of ( and ).

Molecular framework underlying floral bilateral symmetry and nectar spur development in Tropaeolum, an atypical member of the Brassicales.

Premise: Floral spurs are key innovations associated with elaborate pollination mechanisms that have evolved independently several times across angiosperms. Spur formation can shift the floral symmetry from radial to bilateral, as it is the case in Tropaeolum, the only member of the Brassicales with floral nectar spurs. The genetic mechanisms underlying both spur and bilateral symmetry in the family have not yet been investigated.

Plastomes from tribe Plantagineae (Plantaginaceae) reveal infrageneric structural synapormorphies and localized hypermutation for Plantago and functional loss of ndh genes from Littorella.

Tribe Plantagineae (Plantaginaceae) comprises ~ 270 species in three currently recognized genera (Aragoa, Littorella, Plantago), of which Plantago is most speciose. Plantago plastomes exhibit several atypical features including large inversions, expansions of the inverted repeat, increased repetitiveness, intron losses, and gene-specific increases in substitution rate, but the prevalence of these plastid features among species and subgenera is unknown. To assess phylogenetic relationships and plastomic evolutionary dynamics among Plantagineae genera and Plantago subgenera, we generated 25 complete plastome sequences and compared them with existing plastome sequences from Plantaginaceae.

Evolution of the Subgroup 6 Genes and Their Contribution to Floral Color in the Perianth-Bearing Piperales.

Flavonoids, carotenoids, betalains, and chlorophylls are the plant pigments responsible for floral color. Anthocyanins, a class of flavonoids, are largely responsible for the red, purple, pink, and blue colors. genes belonging to subgroup 6 (SG6) are the upstream regulatory factors of the anthocyanin biosynthetic pathway.

Gene expression underlying floral epidermal specialization in Aristolochia fimbriata (Aristolochiaceae).

Background And Aims: The epidermis constitutes the outermost tissue of the plant body. Although it plays major structural, physiological and ecological roles in embryophytes, the molecular mechanisms controlling epidermal cell fate, differentiation and trichome development have been scarcely studied across angiosperms, and remain almost unexplored in floral organs.

Methods: In this study, we assess the spatio-temporal expression patterns of GL2, GL3, TTG1, TRY, MYB5, MYB6, HDG2, MYB106-like, WIN1 and RAV1-like homologues in the magnoliid Aristolochia fimbriata (Aristolochiaceae) by using comparative RNA-sequencing and in situ hybridization assays.

Evolution of Class II TCP genes in perianth bearing Piperales and their contribution to the bilateral calyx in Aristolochia.

Controlled spatiotemporal cell division and expansion are responsible for floral bilateral symmetry. Genetic studies have pointed to class II TCP genes as major regulators of cell division and floral patterning in model core eudicots. Here we study their evolution in perianth-bearing Piperales and their expression in Aristolochia, a rare occurrence of bilateral perianth outside eudicots and monocots.

Expression of gynoecium patterning transcription factors in (Aristolochiaceae) and their contribution to gynostemium development.

Background: In (Aristolochiaceae) flowers, the congenital fusion of the anthers and the commissural, stigmatic lobes forms a gynostemium. Although the molecular bases associated to the apical-basal gynoecium patterning have been described in eudicots, comparative expression studies of the style and stigma regulatory genes have never been performed in early divergent angiosperms possessing a gynostemium.

Results: In this study, we assess the expression of five genes typically involved in gynoecium development in .

Plastome reduction and gene content in New World Pilostyles (Apodanthaceae) unveils high similarities to African and Australian congeners.

Holoparasitism has led to extreme plastome reduction. Plastomes in the legume holoparasite Pilostyles (Apodanthaceae) are the most reduced in both size and gene content known so far in Embryophytes. Here, we found that the Pilostyles boyacensis plastome, the only American species sequenced so far, is reduced to seven functional genes, accD, rpl2, rrn16 (=16S), rrn23 (=23S), rps3, rps12 and a putative oxidoreductase (PbOx).

Evolution of RADIALIS and DIVARICATA gene lineages in flowering plants with an expanded sampling in non-core eudicots.

Premise Of The Study: Bilateral symmetry in core eudicot flowers is established by the differential expression of CYCLOIDEA (CYC), DICHOTOMA (DICH), and RADIALIS (RAD), which are restricted to the dorsal portion of the flower, and DIVARICATA (DIV), restricted to the ventral and lateral petals. Little is known regarding the evolution of these gene lineages in non-core eudicots, and there are no reports on gene expression that can be used to assess whether the network predates the diversification of core eudicots.

Methods: Homologs of the RAD and DIV lineages were isolated from available genomes and transcriptomes, including those of three selected non-core eudicot species, the magnoliid Aristolochia fimbriata and the monocots Cattleya trianae and Hypoxis decumbens.

Floral MADS-box protein interactions in the early diverging angiosperm Aristolochia fimbriata Cham. (Aristolochiaceae: Piperales).

Floral identity MADS-box A, B, C, D, E, and AGL6 class genes are predominantly single copy in Magnoliids, and predate the whole genome duplication (WGD) events in monocots and eudicots. By comparison with the model species Arabidopsis thaliana, the expression patterns of B-, C-, and D-class genes in stamen, carpel, and ovules are conserved in Aristolochia fimbriata, whereas A-, E-class, and AGL6 genes have different expression patterns. Nevertheless, the interactions of these proteins that act through multimeric complexes remain poorly known in early divergent angiosperms.

Comparative inflorescence development in selected Andean Santalales.

Premise Of The Study: Loranthaceae, Santalaceae, and Viscaceae are the most diversified hemiparasitic families of Santalales in the Andes. Their partial inflorescences (PIs) vary from solitary flowers, or dichasia in most Santalales, to congested floral groups along articles in most Viscaceae. The atypical articled inflorescences in Phoradendreae (Viscaceae), a phylogenetic novelty restricted to this tribe, have been variously described as racemes, spikes, fascicles, or as intercalary inflorescences, but no developmental studies have been performed to compare them with the construction of PIs across Santalales.

Limited mitogenomic degradation in response to a parasitic lifestyle in Orobanchaceae.

In parasitic plants, the reduction in plastid genome (plastome) size and content is driven predominantly by the loss of photosynthetic genes. The first completed mitochondrial genomes (mitogenomes) from parasitic mistletoes also exhibit significant degradation, but the generality of this observation for other parasitic plants is unclear. We sequenced the complete mitogenome and plastome of the hemiparasite Castilleja paramensis (Orobanchaceae) and compared them with additional holoparasitic, hemiparasitic and nonparasitic species from Orobanchaceae.

Deep into the Aristolochia Flower: Expression of C, D, and E-Class Genes in Aristolochia fimbriata (Aristolochiaceae).

Aristolochia fimbriata (Aristolochiaceae) is a member of an early diverging lineage of flowering plants and a promising candidate for evo-devo studies. Aristolochia flowers exhibit a unique floral synorganization that consists of a monosymmetric and petaloid calyx formed by three congenitally fused sepals, and a gynostemium formed by the congenital fusion between stamens and the stigmatic region of the carpels. This floral ground plan atypical in the magnoliids can be used to evaluate the role of floral organ identity MADS-box genes during early flower evolution.

Evolutionary Developmental Biology (Evo-Devo) Research in Latin America.

Famous for its blind cavefish and Darwin's finches, Latin America is home to some of the richest biodiversity hotspots of our planet. The Latin American fauna and flora inspired and captivated naturalists from the nineteenth and twentieth centuries, including such notable pioneers such as Fritz Müller, Florentino Ameghino, and Léon Croizat who made a significant contribution to the study of embryology and evolutionary thinking. But, what are the historical and present contributions of the Latin American scientific community to Evo-Devo? Here, we provide the first comprehensive overview of the Evo-Devo laboratories based in Latin America and describe current lines of research based on endemic species, focusing on body plans and patterning, systematics, physiology, computational modeling approaches, ecology, and domestication.

The developmental and genetic bases of apetaly in Bocconia frutescens (Chelidonieae: Papaveraceae).

Background: Bocconia and Macleaya are the only genera of the poppy family (Papaveraceae) lacking petals; however, the developmental and genetic processes underlying such evolutionary shift have not yet been studied.

Results: We studied floral development in two species of petal-less poppies Bocconia frutescens and Macleaya cordata as well as in the closely related petal-bearing Stylophorum diphyllum. We generated a floral transcriptome of B.

Flower Development and Perianth Identity Candidate Genes in the Basal Angiosperm Aristolochia fimbriata (Piperales: Aristolochiaceae).

Aristolochia fimbriata (Aristolochiaceae: Piperales) exhibits highly synorganized flowers with a single convoluted structure forming a petaloid perianth that surrounds the gynostemium, putatively formed by the congenital fusion between stamens and the upper portion of the carpels. Here we present the flower development and morphology of A. fimbriata, together with the expression of the key regulatory genes that participate in flower development, particularly those likely controlling perianth identity.

Flower and fruit characters in the early-divergent lamiid family Metteniusaceae, with particular reference to the evolution of pseudomonomery.

Evaluating the morphological relationships of angiosperm families that still remain unplaced in the current systems of classification is challenging because it requires comparative data across a broad phylogenetic range. The small neotropical family Metteniusaceae was recently placed within the lamiids, as sister to either the enigmatic Oncothecaceae or the clade (Boraginaceae + Gentianales + Lamiales + Solanales + Vahliaceae). We examined the development of two of the primary diagnostic traits of Metteniusaceae, the moniliform anthers and the unilocular gynoecium.

Generic relationships and dating of lineages in Winteraceae based on nuclear (ITS) and plastid (rpS16 and psbA-trnH) sequence data.

Phylogenetic analyses of representative species from the five genera of Winteraceae (Drimys, Pseudowintera, Takhtajania, Tasmannia, and Zygogynum s.l.) were performed using ITS nuclear sequences and a combined data-set of ITS+psbA-trnH+rpS16 sequences (sampling of 30 and 15 species, respectively).