A new species of Iochroma Benth. (Solanaceae) from the eastern Andes of Colombia.

Iochromaorozcoae A.Orejuela & S.D.Sm., sp. nov. (Solanaceae) is described from the Andean forests of Cundinamarca in the eastern cordillera of Colombia. Iochromaorozcoae was first collected by the eminent Spanish priest and botanist José Celestino Mutis in the late part of the 18th century, but the specimens have lain unrecognised in herbaria for over 200 years. The species shares many features with its closest relative, Iochromabaumii S.D.Sm. & S.Leiva, but it differs from it in having small flowers with five corolla lobes and few inflorescences per branch, located near the shoot apex with 1 to 4 (-8) flowers, fruits that are greenish-yellow when ripe and its restricted geographic distribution. A description of I.orozcoae is provided, along with a detailed illustration, photographs of live plants, a comparison with closely-related species and a key to all Colombian species of Iochroma Benth. In closing, we emphasise the value of historical collections for the knowledge of biodiversity.

ResumenIochromaorozcoae A.Orejuela & S.D.Sm., sp. nov. (Solanaceae) se describe a partir de los bosques andinos de Cundinamarca, en la cordillera oriental de Colombia. Iochromaorozcoae fue recolectada por primera vez por el eminente sacerdote y botánico español José Celestino Mutis a finales del siglo XVIII, pero los especímenes han permanecido sin ser reconocidos en herbarios durante más de 200 años. La especie comparte muchas características con su pariente más cercano, Iochromabaumii S.D.Sm. & S.Leiva, pero difiere de esta en sus flores más pequeñas con cinco lóbulos de la corola y pocas inflorescencias por rama ubicadas cerca del ápice de la rama, con 1 a 4 (­8) flores por inflorescencia, frutos verde-amarillentos al madurar, y su distribución geográfica restringida. Se presenta una descripción de I.orozcoae, junto con una ilustración detallada, fotografías en vivo, una comparación con las especies cercanamente relacionadas y una clave para las especies colombianas de Iochroma Benth. Finalmente, enfatizamos el valor de las colecciones históricas para el conocimiento de la biodiversidad.

Fossil berries reveal global radiation of the nightshade family by the early Cenozoic.

Fossil discoveries can transform our understanding of plant diversification over time and space. Recently described fossils in many plant families have pushed their known records farther back in time, pointing to alternative scenarios for their origin and spread. Here, we describe two new Eocene fossil berries of the nightshade family (Solanaceae) from the Esmeraldas Formation in Colombia and the Green River Formation in Colorado (USA). The placement of the fossils was assessed using clustering and parsimony analyses based on 10 discrete and five continuous characters, which were also scored in 291 extant taxa. The Colombian fossil grouped with members of the tomatillo subtribe, and the Coloradan fossil aligned with the chili pepper tribe. Along with two previously reported early Eocene fossils from the tomatillo genus, these findings indicate that Solanaceae were distributed at least from southern South America to northwestern North America by the early Eocene. Together with two other recently discovered Eocene berries, these fossils demonstrate that the diverse berry clade and, in turn, the entire nightshade family, is much older and was much more widespread in the past than previously thought.

How to approach the study of syndromes in macroevolution and ecology.

Syndromes, wherein multiple traits evolve convergently in response to a shared selective driver, form a central concept in ecology and evolution. Recent work has questioned the existence of some classic syndromes, such as pollination and seed dispersal syndromes. Here, we discuss some of the major issues that have afflicted research into syndromes in macroevolution and ecology. First, correlated evolution of traits and hypothesized selective drivers is often relied on as the only evidence for adaptation of those traits to those hypothesized drivers, without supporting evidence. Second, the selective driver is often inferred from a combination of traits without explicit testing. Third, researchers often measure traits that are easy for humans to observe rather than measuring traits that are suited to testing the hypothesis of adaptation. Finally, species are often chosen for study because of their striking phenotypes, which leads to the illusion of syndromes and divergence. We argue that these issues can be avoided by combining studies of trait variation across entire clades or communities with explicit tests of adaptive hypotheses and that taking this approach will lead to a better understanding of syndrome-like evolution and its drivers.

Transcription Factors Evolve Faster Than Their Structural Gene Targets in the Flavonoid Pigment Pathway.

Dissecting the relationship between gene function and substitution rates is key to understanding genome-wide patterns of molecular evolution. Biochemical pathways provide powerful systems for investigating this relationship because the functional role of each gene is often well characterized. Here, we investigate the evolution of the flavonoid pigment pathway in the colorful Petunieae clade of the tomato family (Solanaceae). This pathway is broadly conserved in plants, both in terms of its structural elements and its MYB, basic helix-loop-helix, and WD40 transcriptional regulators, and its function has been extensively studied, particularly in model species of petunia. We built a phylotranscriptomic data set for 69 species of Petunieae to infer patterns of molecular evolution across pathway genes and across lineages. We found that transcription factors exhibit faster rates of molecular evolution (dN/dS) than their targets, with the highly specialized MYB genes evolving fastest. Using the largest comparative data set to date, we recovered little support for the hypothesis that upstream enzymes evolve slower than those occupying more downstream positions, although expression levels do predict molecular evolutionary rates. Although shifts in floral pigmentation were only weakly related to changes affecting coding regions, we found a strong relationship with the presence/absence patterns of MYB transcripts. Intensely pigmented species express all three main MYB anthocyanin activators in petals, whereas pale or white species express few or none. Our findings reinforce the notion that pathway regulators have a dynamic history, involving higher rates of molecular evolution than structural components, along with frequent changes in expression during color transitions.

Chromosome Evolution in the Family Solanaceae.

This review summarizes and discusses the knowledge of cytogenetics in Solanaceae, the tomato family, its current applications, and prospects for making progress in fundamental systematic botany and plant evolution. We compile information on basic chromosome features (number, size, morphology) and molecular cytogenetics (chromosome banding and rDNA patterns). These data were mapped onto the Solanaceae family tree to better visualize the changes in chromosome features and evaluate them in a phylogenetic context. We conclude that chromosomal features are important in understanding the evolution of the family, especially in delimiting clades, and therefore it is necessary to continue producing this type of data. The potential for future applications in plant biology is outlined. Finally, we provide insights into understanding the mechanisms underlying Solanaceae's diversification that could substantially contribute to developing new approaches for future research.

New physaloid fruit-fossil species from early Eocene South America.

PREMISE: Solanaceae is a scientifically and economically important angiosperm family with a minimal fossil record and an intriguing early evolutionary history. Here, we report a newly discovered fossil lantern fruit with a suite of features characteristic of Physalideae within Solanaceae. The fossil comes from the early Eocene Laguna del Hunco site (ca. 52 Ma) in Chubut, Argentina, which previously yielded the only other physaloid fruit fossil, Physalis infinemundi. METHODS: The fruit morphology and calyx venation pattern of the new fossil were compared with P. infinemundi and extant species of Solanaceae. RESULTS: Physalis hunickenii sp. nov. is clearly distinct from P. infinemundi in its fruiting calyx with wider primary veins, longer and thinner lobes, and especially in its venation pattern with high density, transverse tertiary veins; these features support its placement in a new species. In comparison with extant physaloid genera, the calyx venation pattern and other diagnostic traits reinforce placement of the new fossil, like P. infinemundi, within the tribe Physalideae of Solanaceae. CONCLUSIONS: Both species of fossil nightshades from Laguna del Hunco represent crown-group Solanaceae but are older than all prior age estimates of the family. Although at least 20 transoceanic dispersals have been proposed as the driver of range expansion of Solanaceae, the Patagonian fossils push back the diversification of the family to Gondwanan times. Thus, overland dispersal across Gondwana is now a likely scenario for at least some biogeographic patterns, in light of the ancient trans-Antarctic land connections between South America and Australia.

Historical biogeography of the fern genus Polystichum (Dryopteridaceae) in Austral South America.

A group of seven endemic Polystichum species inhabit Patagonia, the southern region of South America. To date, evolutionary relationships of these Austral South American Polystichum remain unknown. The biota of the Southern Andes appears to be more closely related to the temperate Australasian species than to northern South American ones. Differences in morphological characters suggested that Austral South American Polystichum follows that biogeographical pattern, not being closely related to their congeners in the Northern and Central Andes. We sought to reveal the evolutionary relationships, estimate the divergence times and reconstruct both ancestral areas and ancestral ploidy levels of Austral South America Polystichum. Phylogenetic relationships were estimated using maximum likelihood and Bayesian approaches. The seven Austral South American species plus 31 Polystichum species spanning all other major biogeographic regions were sampled for three DNA markers. Divergence times were estimated in BEAST and Bayesian binary Markov chain Monte Carlo reconstruction was applied in order to infer ancestral areas. The evolution of ploidy was reconstructed on the maximum clade credibility tree, using stochastic character mapping. Austral South American Polystichum was recovered as monophyletic. The earliest divergence reconstructed within the Austral South American Clade was that of Polystichum andinum; subsequently two other lineages diverged comprising the remaining Austral South American species. The Austral South American lineage is not closely allied to North and Central Andes congeners. Long-distance dispersal of an ancestral tetraploid from Australasia during the late Miocene is the most likely explanation for the origin of Patagonian Polystichum. Then, Pliocene and Pleistocene orogenic and climatic changes may have shaped its diversification in Patagonia.

Redox Systemic Signaling and Induced Tolerance Responses During Soybean-Bradyrhizobium japonicum Interaction: Involvement of Nod Factor Receptor and Autoregulation of Nodulation.

The symbiotic relationship between legumes and nitrogen-fixing rhizobia induces local and systemic responses, which ultimately lead to nodule formation. The autoregulation of nodulation (AON) is a systemic mechanism related to innate immunity that controls nodule development and involves different components ranging from hormones, peptides, receptors to small RNAs. Here, we characterized a rapid systemic redox changes induced during soybean-Bradyrhizobium japonicum symbiotic interaction. A transient peak of reactive oxygen species (ROS) generation was found in soybean leaves after 30 min of root inoculation with B. japonicum. The ROS response was accompanied by changes in the redox state of glutathione and by activation of antioxidant enzymes. Moreover, the ROS peak and antioxidant enzyme activation were abolished in leaves by the addition, in either root or leaf, of DPI, an NADPH oxidase inhibitor. Likewise, these systemic redox changes primed the plant increasing its tolerance to photooxidative stress. With the use of non-nodulating nfr5-mutant and hyper-nodulating nark-mutant soybean plants, we subsequently studied the systemic redox changes. The nfr5-mutant lacked the systemic redox changes after inoculation, whereas the nark-mutant showed a similar redox systemic signaling than the wild type plants. However, neither nfr5- nor nark-mutant exhibited tolerance to photooxidative stress condition. Altogether, these results demonstrated that (i) the early redox systemic signaling during symbiotic interaction depends on a Nod factor receptor, and that (ii) the induced tolerance response depends on the AON mechanisms.

Repeated evolution of a morphological novelty: a phylogenetic analysis of the inflated fruiting calyx in the Physalideae tribe (Solanaceae).

PREMISE OF THE STUDY: The evolution of novel fruit morphologies has been integral to the success of angiosperms. The inflated fruiting calyx, in which the balloon-like calyx swells to completely surround the fruit, has evolved repeatedly across angiosperms and is postulated to aid in protection and dispersal. We investigated the evolution of this trait in the tomatillos and their allies (Physalideae, Solanaceae). METHODS: The Physalideae phylogeny was estimated using four regions (ITS, LEAFY, trnL-F, waxy) with maximum likelihood (ML) and Bayesian inference. Under the best-fitting ML model of trait evolution, we estimated ancestral states along with the numbers of gains and losses of fruiting calyx accrescence and inflation with Bayesian stochastic mapping. Also, phylogenetic signal in calyx morphology was examined with two metrics (parsimony score and Fritz and Purvis's D). KEY RESULTS: Based on our well-resolved and densely sampled phylogeny, we infer that calyx evolution has proceeded in a stepwise and directional fashion, from non-accrescent to accrescent to inflated. In total, we inferred 24 gains of accrescence, 24 subsequent transitions to a fully inflated calyx, and only two reversals. Despite this lability, fruiting calyx accrescence and inflation showed strong phylogenetic signal. CONCLUSIONS: Our phylogeny greatly improves the resolution of Physalideae and highlights the need for taxonomic work. The comparative analyses reveal that the inflated fruiting calyx has evolved many times and that the trajectory toward this phenotype is generally stepwise and irreversible. These results provide a strong foundation for studying the genetic and developmental mechanisms responsible for the repeated origins of this charismatic fruit trait.

Phylogenetic relationships of Deprea: New insights into the evolutionary history of physaloid groups.

Deprea is the genus with the second highest species richness in tribe Physalideae (Solanaceae) and comprises 50 species that are mainly distributed in the Andes of South America. The taxonomy of Deprea has been unstable after controversial hypotheses about its position and circumscription. Additionally, biogeographical inferences are only based on observations of the restricted area of distribution of some species and no ancestral area estimation have been performed. Here, we present a phylogenetic analysis and an ancestral area reconstruction of Deprea in order to establish its circumscription, resolve its position within Physalideae, and reconstruct its biogeographical history. Phylogenetic analyses were conducted using Maximum Likelihood and Bayesian approaches. Forty-three Deprea species and 26 related taxa were sampled for three DNA markers (psbA-trnH, ITS, and waxy). A Bayesian binary MCMC model was applied in order to infer ancestral areas. Deprea is resolved as a strongly supported monophyletic group according to its current circumscription and is placed within subtribe Withaninae of Physalideae. The phylogenetic relationships enabled us to solve taxonomic problems including the rejection and acceptance of previous synonyms. The most probable ancestral area for Deprea is the Northern Andes of South America and the Amotape-Huancabamba zone. Our phylogeny provides increased resolution and support for the current position and circumscription of Deprea. Better resolution of interspecific relationships was also obtained, although some affinities remain unclear. The phylogenetic and ancestral area reconstructions provide a framework for addressing taxonomic problems and investigating new evolutionary questions.

Changes in the circumscription of Deprea (Physalideae, Solanaceae): thirty two new combinations.

According to the latest phylogenetic and cytogenetic results, Larnax and Deprea should be merged in order to form a natural group. Consequently, we propose 32 combinations of Larnax species names under Deprea: Depreaabra-patriciae (S.Leiva & Barboza) S.Leiva & Deanna, comb. nov., Depreaaltomayoensis (S.Leiva & Quip.) Barboza & Deanna, comb. nov., Depreaandersonii (N.W.Sawyer) Deanna & S.Leiva, comb. nov., Depreabongaraensis (S.Leiva) Deanna & Barboza, comb. nov., Depreachotanae (S.Leiva, Pereyra & Barboza) S.Leiva, comb. nov., Depreadarcyana (N.W.Sawyer) Barboza & S.Leiva, comb. nov., Depreadilloniana (S.Leiva, Quip. & N.W.Sawyer) Barboza, comb. nov., Depreagrandiflora (N.W.Sawyer & S.Leiva) Deanna & Barboza, comb. nov., Depreaharlingiana (Hunz. & Barboza) S.Leiva & Deanna, comb nov., Depreahawkesii (Hunz.) Deanna, comb. nov., Depreakann-rasmussenii (S.Leiva & Quip.) S.Leiva & Barboza, comb. nov., Deprealongipedunculata (S.Leiva, E.Rodr. & J.Campos) Barboza, comb. nov., Deprealutea (S.Leiva) Deanna, comb. nov., Depreamacasiana (Deanna, S.Leiva & Barboza) Barboza, comb. nov., Depreamaculatifolia (E.Rodr. & S.Leiva) S. Leiva, comb. nov., Depreanieva (S.Leiva & N.W.Sawyer) Barboza & Deanna, comb. nov., Depreaparviflora (N.W.Sawyer & S.Leiva) S.Leiva, comb. nov., Depreapedrazae (S.Leiva & Barboza) Deanna & S.Leiva, comb. nov., Depreaperuviana (Zahlbr.) S.Leiva & Barboza, comb. nov., Depreapilosa (S.Leiva, E.Rodr. & J.Campos) Deanna, comb. nov., Depreapomacochaensis (S.Leiva) Barboza, comb. nov., Depreapsilophyta (N.W.Sawyer) S.Leiva & Deanna, comb. nov., Depreapumila (S.Leiva, Barboza & Deanna) S.Leiva, comb. nov., Depreapurpurea (S.Leiva) Barboza & S.Leiva, comb. nov., Depreapurpureocarpa (S.Leiva, Deanna & Barboza) Deanna, comb. nov., Depreasachapapa (Hunz.) S.Leiva & Deanna, comb. nov., Depreasagasteguii (S.Leiva, Quip. & N. W.Sawyer) Barboza, comb. nov., Depreasawyeriana (S.Leiva, E.Rodr. & J.Campos) S.Leiva, comb. nov., Depreaschjellerupiae (S.Leiva & Quip.) Barboza & Deanna, comb. nov., Depreasteyermarkii (Hunz.) S.Leiva & Barboza, comb. nov., Depreatoledoana (Barboza & S.Leiva) Barboza, comb. nov., and Depreavasquezii (S.Leiva, E.Rodr. & J.Campos) Deanna, comb. nov.