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The genus Adenia provides a natural experiment to investigate the evolution of growth form. Within the group, trees, shrubs, herbs, vines, and lianas are present. Using ITS1 + 5.8S + ITS2 sequence data, a phylogeny of 67 of ~100 species of Adenia is inferred using parsimony and Bayesian analyses. Specific hypotheses of monophyly are also tested to couch the analyses of growth form evolution within a phylogenetic framework. Within the context of this phylogeny, synapomorphies for major clades are discussed, as are patterns of growth form evolution. Absolute divergence times of nodes are estimated using penalized likelihood, and speciation rate based on these times is inferred to be fast relative to some other lineages of life. By reconstructing evolutionary history on a sample of trees from the posterior distribution of the Bayesian analysis, it is estimated that succulent stems evolved ca. four times, and tubers ca. eight. Transitions between markedly different growth forms occur on the scale of a few hundred thousand to a few million years, and close relatives frequently have different forms with no intermediates. The rapid diversification rates, fast morphological transitions, and multiple origins of water storage tissue in roots and shoots are hypothesized to result from a shared developmental program for water storage tissue that is flexibly turned on and off during evolution in stems and roots.

• Background and Aims Early ontogenetic stages of myrmecophytic plants are infrequently associated with ants, probably due to constraints on the production of rewards. This study reports for the first time the anatomical and histological limitations constraining the production of extrafloral nectar in young plants, and the implications that the absence of protective ants imposes for plants early during their ontogeny are discussed. • Methods Juvenile, pre-reproductive and reproductive plants of Turnera velutina were selected in a natural population and their extrafloral nectaries (EFNs) per leaf were quantified. The anatomical and morphological changes in EFNs during plant ontogeny were studied using scanning electron and light microscopy. Extrafloral nectar volume and sugar concentration were determined as well as the number of patrolling ants. • Key Results Juvenile plants were unable to secrete or contain nectar. Pre-reproductive plants secreted and contained nectar drops, but the highest production was achieved at the reproductive stage when the gland is fully cup-shaped and the secretory epidermis duplicates. No ants were observed in juvenile plants, and reproductive individuals received greater ant patrolling than pre-reproductive individuals. The issue of the mechanism of extrafloral nectar release in T. velutina was solved given that we found an anatomical, transcuticular pore that forms a channel-like structure and allows nectar to flow outward from the gland. • Conclusions Juvenile stages had no ant protection against herbivores probably due to resource limitation but also due to anatomical constraints. The results are consistent with the growth-differentiation balance hypothesis. As plants age, they increase in size and have larger nutrient-acquiring, photosynthetic and storage capacity, so they are able to invest in defence via specialized organs, such as EFNs. Hence, the more vulnerable juvenile stage should rely on other defensive strategies to reduce the negative impacts of herbivory.

The angiosperm order Malpighiales includes ∼16,000 species and constitutes up to 40% of the understory tree diversity in tropical rain forests. Despite remarkable progress in angiosperm systematics during the last 20 y, relationships within Malpighiales remain poorly resolved, possibly owing to its rapid rise during the mid-Cretaceous. Using phylogenomic approaches, including analyses of 82 plastid genes from 58 species, we identified 12 additional clades in Malpighiales and substantially increased resolution along the backbone. This greatly improved phylogeny revealed a dynamic history of shifts in net diversification rates across Malpighiales, with bursts of diversification noted in the Barbados cherries (Malpighiaceae), cocas (Erythroxylaceae), and passion flowers (Passifloraceae). We found that commonly used a priori approaches for partitioning concatenated data in maximum likelihood analyses, by gene or by codon position, performed poorly relative to the use of partitions identified a posteriori using a Bayesian mixture model. We also found better branch support in trees inferred from a taxon-rich, data-sparse matrix, which deeply sampled only the phylogenetically critical placeholders, than in trees inferred from a taxon-sparse matrix with little missing data. Although this matrix has more missing data, our a posteriori partitioning strategy reduced the possibility of producing multiple distinct but equally optimal topologies and increased phylogenetic decisiveness, compared with the strategy of partitioning by gene. These approaches are likely to help improve phylogenetic resolution in other poorly resolved major clades of angiosperms and to be more broadly useful in studies across the Tree of Life.

Ant-plants produce hollow structures called domatia to host protecting ants. Although size variation in domatia is well documented between related species, intraspecific variation is little explored. The central African ant-plant Barteria dewevrei exibits strong variation in domatium size, giving the opportunity to explore the mechanism underlying variation in a mutualistic trait. We showed that domatium size in Barteria dewevrei varies between sites. We transplanted individual plants between two sites in Gabon where plants have different domatium sizes. Domatium size of transplanted plants changed, revealing that variation in this mutualistic trait is driven by phenotypic plasticity. The two sites differed in their environmental conditions: highland open savanna on sandy soil vs lowland closed tropical rain forest on sandy-loam soil. However, as stomatal density and δ 13 C of leaves did not differ between sites or between branches produced before and after transplantation, we have no cue on the role of abiotic stress (such as light intensity and water availability) in domatium size variation. As the obligate Tetraponera ant symbionts are too large to fit in the small domatia, variation of the mutualistic trait in response to environmental change through phenotypic plasticity may impact this specialized mutualism.

Gene transfers from mitochondria and plastids to the nucleus are an important process in the evolution of the eukaryotic cell. Plastid (pt) gene losses have been documented in multiple angiosperm lineages and are often associated with functional transfers to the nucleus or substitutions by duplicated nuclear genes targeted to both the plastid and mitochondrion. The plastid genome sequence of Euphorbia schimperi was assembled and three major genomic changes were detected, the complete loss of rpl32 and pseudogenization of rps16 and infA . The nuclear transcriptome of E. schimperi was sequenced to investigate the transfer/substitution of the rpl32 and rps16 genes to the nucleus. Transfer of plastid-encoded rpl32 to the nucleus was identified previously in three families of Malpighiales, Rhizophoraceae, Salicaceae and Passifloraceae. An E. schimperi transcript of pt SOD-1-RPL32 confirmed that the transfer in Euphorbiaceae is similar to other Malpighiales indicating that it occurred early in the divergence of the order. Ribosomal protein S16 ( rps16 ) is encoded in the plastome in most angiosperms but not in Salicaceae and Passifloraceae. Substitution of the E. schimperi pt rps16 was likely due to a duplication of nuclear-encoded mitochondrial-targeted rps16 resulting in copies dually targeted to the mitochondrion and plastid. Sequences of RPS16-1 and RPS16-2 in the three families of Malpighiales (Salicaceae, Passifloraceae and Euphorbiaceae) have high sequence identity suggesting that the substitution event dates to the early divergence within Malpighiales.

Leaves are often described in language that evokes a single shape. However, embedded in that descriptor is a multitude of latent shapes arising from evolutionary, developmental, environmental, and other effects. These confounded effects manifest at distinct developmental time points and evolve at different tempos. Here, revisiting datasets comprised of thousands of leaves of vining grapevine (Vitaceae) and maracuyá (Passifloraceae) species, we apply a technique from the mathematical field of topological data analysis to comparatively visualize the structure of heteroblastic and ontogenetic effects on leaf shape in each group. Consistent with a morphologically closer relationship, members of the grapevine dataset possess strong core heteroblasty and ontogenetic programs with little deviation between species. Remarkably, we found that most members of the maracuyá family also share core heteroblasty and ontogenetic programs despite dramatic species-to-species leaf shape differences. This conservation was not initially detected using traditional analyses such as principal component analysis or linear discriminant analysis. We also identify two morphotypes of maracuyá that deviate from the core structure, suggesting the evolution of new developmental properties in this phylogenetically distinct sub-group. Our findings illustrate how topological data analysis can be used to disentangle previously confounded developmental and evolutionary effects to visualize latent shapes and hidden relationships, even ones embedded in complex, high-dimensional datasets.

Passiflora tripartita var. mollissima, known locally as poro-poro, is an important native fruit used in traditional Peruvian medicine with relevant agro-industrial and pharmaceutical potential for its antioxidant capacity for human health. However, to date, only a few genetic data are available, which limits exploring its genetic diversity and developing new genetic studies for its improvement. We report the poro-poro plastid genome to expand the knowledge of its molecular markers, evolutionary studies, molecular pathways, and conservation genetics. The complete chloroplast (cp) genome is 163,451 bp in length with a typical quadripartite structure, containing a large single-copy region of 85,525 bp and a small single-copy region of 13,518 bp, separated by a pair of inverted repeat regions (IR) of 32,204 bp, and the overall GC content was 36.87%. This cp genome contains 128 genes (110 genes were unique and 18 genes were found duplicated in each IR region), including 84 protein-coding genes, 36 transfer RNA-coding genes, eight ribosomal RNA-coding genes, and 13 genes with introns (11 genes with one intron and two genes with two introns). The inverted repeat region boundaries among species were similar in organization, gene order, and content, with a few revisions. The phylogenetic tree reconstructed based on single-copy orthologous genes and maximum likelihood analysis demonstrates poro-poro is most closely related to Passiflora menispermifolia and Passiflora oerstedii. In summary, our study constitutes a valuable resource for studying molecular evolution, phylogenetics, and domestication. It also provides a powerful foundation for conservation genetics research and plant breeding programs. To our knowledge, this is the first report on the plastid genome of Passiflora tripartita var. mollissima from Peru.

In subgenus Decaloba (DC.) Rchb. of Passiflora L., the section Xerogona (Raf.) Killip (Passifloraceae) is a group of herbaceous vines found in subtropical and tropical regions of the Americas. Primarily distributed in Central America, with a few also found in the West Indies and South America, the species of Passiflora sect. Xerogona are recognized by their unusual dehiscent capsular fruit, the absence of bracts and laminar nectaries, and their transversely grooved seeds. Passiflora tenella Killip is the only species included in Passiflora sect. Xerogona with a fruit that does not appear to be a capsule, but the shape of the leaves and the absence of floral bracts and laminar nectaries suggest affiliation with this section. Fifteen species, including two subspecies, are recognized within Passiflora sect. Xerogona. Passiflora cobanensis Killip is distinguished as two subspecies, P. cobanensis subsp. cobanensis and P. cobanensis subsp. brevipes (Killip) T. Boza, with the latter subspecies transferred from P. brevipes Killip. From previous species circumscriptions, this section contains two problematic species complexes for P. capsularis L. and P. rubra L. The morphological variation between and within these two species complexes was examined in this study, using Principal Component Analysis and correlation matrices of morphological characters, and this variation was studied throughout their distributional ranges. Passiflora capsularis is recognized as a single variable species. Two species are recognized within the P. rubra complex, based primarily on floral characters, as P. cisnana Harms and P. rubra. Passiflora cisnana is lectotypified. En el subgénero Decaloba (DC.) Rchb. de Passiflora L., la sección Xerogona (Raf). Killip (Passifloraceae) es un grupo de lianas herbáceas encontradas en regiones subtropicales y tropicales de las Américas. Principalmente distribuido en Centroamérica, también se puede encontrar algunas en las Antillas y Sudamérica, las especies de Passiflora secc. Xerogona son reconocidas por su inusual fruto capsular dehiscente, la ausencia de brácteas y nectarios laminares y sus semillas transversalmente acanaladas. Passiflora tenella Killip es la única especie incluida en Passiflora secc. Xerogona con una fruta que no parece ser una cápsula, pero la forma de las hojas y la ausencia de brácteas florales y nectarios laminares sugieren la afiliación con esta sección. Quince especies, incluyendo dos subespecies, se reconocen dentro de Passiflora secc. Xerogona. Passiflora cobanensis Killip se distingue como dos subespecies, P. cobanensis subsp. cobanensis y P. cobanensis subsp. brevipes (Killip) T. Boza, con la última subespecie transferida de P. brevipes Killip. De circunscripciones anteriores de especies, esta sección contiene dos complejos problemáticos de especies para P. capsularis L. y P. rubra L. La variación morfológica entre y dentro de estas dos especies complejas se examinó en este estudio, usando el Análisis de Componentes Principales y basado en la correlación de matrices de caracteres morfológicos, y esta variación se estudió a lo largo de todos sus rangos distribucionales. Passiflora capsularis se reconoce como una sola especie variable. Dos especies se reconocen dentro del complejo P. rubra, basado principalmente en caracteres florales, como P. cisnana Harms y P. rubra Passiflora cisnana es lectotipificada.

Within the very uniform series , (treated as a synonym of in the ), , and appear particularly similar. A review of their descriptions and the associated specimens confirms their lack of morphological differentiation and leads us to formally resurrect and place the three other taxa under its synonymy. This taxonomic move is also supported by a revision of 72 additional geolocalized specimens (for a grand total of 78) and an analysis of their distribution and habitats. In fact, the bioclimatic space corresponding to the specimens previously assigned to encompasses that of all specimens previously assigned to the three other taxa under study. The species range covers a wide region, comprising the lower Amazon and the north of its basin, mostly below 200 m, and, to the west, in the upper Amazon, the Orinoco basin, and along the Andean foothills and valleys, from Venezuela to Peru, at elevations between 100 and 2200 m. In the lowlands, the species appears associated with white sand savannas and water courses. A more complete description is proposed for the species, including its unusual fusiform and slightly ribbed fruit. Another rare trait in the series is that the outer corona filaments tend to be longer than the corolla.

Kirkiin is a new type 2 ribosome-inactivating protein (RIP) purified from the caudex of Adenia kirkii with a cytotoxicity compared to that of stenodactylin. The high toxicity of RIPs from Adenia genus plants makes them interesting tools for biotechnology and therapeutic applications, particularly in cancer therapy. The complete amino acid sequence and 3D structure prediction of kirkiin are here reported. Gene sequence analysis revealed that kirkiin is encoded by a 1572 bp open reading frame, corresponding to 524 amino acid residues, without introns. The amino acid sequence analysis showed a high degree of identity with other Adenia RIPs. The 3D structure of kirkiin preserves the overall folding of type 2 RIPs. The key amino acids of the active site, described for ricin and other RIPs, are also conserved in the kirkiin A chain. Sugar affinity studies and docking experiments revealed that both the 1α and 2γ sites of the kirkiin B chain exhibit binding activity toward lactose and D-galactose, being lower than ricin. The replacement of His246 in the kirkiin 2γ site instead of Tyr248 in ricin causes a different structure arrangement that could explain the lower sugar affinity of kirkiin with respect to ricin.