Epicormic bud protection traits vary along a latitudinal gradient in a neotropical savanna.

Regrowth via production of epicormic shoots is an important strategy for many woody plants after environmental disturbances such as fire, drought, and herbivory. Populations spreading across a broad latitudinal gradient offer opportunities to investigate if essential traits vary with heterogenous environmental conditions, such as in savanna ecosystems. This information can help us predict plant responses to climate change. Here, we evaluated if epicormic bud protection traits varied among populations of three focal savanna species (Miconia albicans, Solanum lycocarpum, and Zeyheria montana) that have a wide distribution and grow under variable climatic conditions. We randomly sampled 225 individuals over five spatially independent sites (7°, 10°, 15°, 18°, and 24° S) in Brazil, totaling 15 individuals per species per area. We analyzed anatomical transverse sections of five buds per species per area to assess the relative area occupied by crystal and phenolic idioblasts, the thickness of the trichome boundary layer, and to test if these traits were associated with climatic conditions. The buds were protected by cataphylls and composed of a variable number of undeveloped leaves enveloping the shoot apex. For M. albicans, we found an association between maximum temperature and both phenolic idioblasts and trichome boundary layer, but no association with crystal idioblasts. In S. lycocarpum, only the trichome boundary layer was associated with maximum temperature plus high radiation. Z. montana showed no variation. Combination of two or more traits can lead to the development of adaptative strategies to different climatic conditions. We present for the first time an analysis of epicormic bud traits in plant populations occurring in an extensive latitudinal gradient and shed light on how maximum temperature is associated with these traits, contributing to a better understanding of plant resprouting capabilities in widespread savanna plant species.

Evaluation of anatomical and physiological traits of Solanum pennellii Cor. associated with plant yield in tomato plants under water-limited conditions.

Although intensively studied, few works had looked into S. pennellii's ability to cope with water-deficit conditions from a breeding point of view. In this study, we assessed potential traits of S. pennellii, that had previously been linked to high yields in other plant species, under long-term water-limited conditions and made a parallel with plant yield. For this purpose, the drought-resistant tomato genotypes IL 3-5 and IL 10-1, and the drought-sensitive IL 2-5 and IL 7-1 at seed level, together with both parents the S. pennellii accession LA 716 and the cultivar M82 were kept at 50 and 100% ASW throughout the growing season. Our findings confirm the superiority of LA 716 under water-limited conditions compared to the other S. lycopersicum genotypes in terms of plant water status maintenance. Percentual reduction on plant yield was higher in IL 3-5 and IL 10-1 than in M82 plants, indicating no correlation between drought resistance on germination and plant productive stages. A strong positive correlation was found between fruit yield and A, gs, and Ψleaf at 50% ASW, suggesting these traits as important selection criteria. LT and gmin, LA 716's most promising traits, did not show a linear correlation with fruit yield under low water regimes. This study unravels traits behind tomato performance under water-limited conditions and should work as guidance for breeders aiming at developing drought-resistant tomato cultivars.

Functional anatomy reveals secretory activity in papillose anthers of a buzz-pollinated Solanum species (Cyphomandra clade - Solanaceae).

Pollination in Solanum (Solanaceae) species is commonly performed by female bees, which vibrate anthers to extract pollen. Another pollen removal type is by male euglossine bees, milking the anthers when searching for floral scents produced by secretory tissues (osmophorous) at the swollen connective of the anthers of species in the Cyphomandra clade. Some species of this clade, however, are buzz-pollinated and present papillate anthers that should also have secretory activity, a hypothesis here tested. The anthers of Solanum luridifuscescens were fixed at different stages of development and analysed under light microscopy, SEM and TEM. Histochemical tests for the detection of starch and lipids were done. Epidermal cells of the abaxial surface of the anthers were visibly papillose, had large nuclei and dense cytoplasm rich in organelles such as mitochondria and plastids, typical features of secretory tissues. In this site, lipid droplets were detected, concomitantly with starch consumption, compatible with the secretory process in osmophores. No exudate or accumulation of substances was seen on the surface; in agreement with a previous pollination study performed in field conditions, where no pollinators were observed collecting floral scents, only pollen. The histochemical and structural analyses have evidenced the lipidic composition of the secretion, strongly pointing to terpenes as the secreted compounds. Ours findings show that papillae of the anthers have secretory activities that produce lipophilic compounds. This does not result in resources for bees, but could be an evolutionary step to the development of more specialised anthers in the Cyphomandra clade.

The ecology, evolution, and biogeography of dioecy in the genus Solanum: with paradigms from the strong dioecy in Solanum polygamum, to the unsuspected and cryptic dioecy in Solanum conocarpum.

UNLABELLED: • PREMISE OF THE STUDY: Island plants are over-exploited and "under-explored." Understanding the reproductive biology of plants, especially rare species, is fundamental to clarifying their evolution, estimating potential for change, and for creating effective conservation plans. Clarification of sexual systems like dioecy, and unusual manifestations of it in specific studies within Solanum, helps elucidate evolutionary patterns and genetic and ecological control of sex expression.• METHODS: Studies of reproductive systems of two Caribbean endemics, S. polygamum and S. conocarpum, combined multifaceted analyses of field populations and of multiple generations of greenhouse plants.• KEY RESULTS: The dioecy in both species is, like that in other solanums, largely cryptic, although the gender of S. polygamum flowers is obvious. The rare S. conocarpum is recognized as dioecious; floral gender is not obvious. Variation in sex expression facilitated experiments and promoted hypotheses on control and significance of morphological features and sex expression.• CONCLUSIONS: Confirmed dioecy in at least 15 solanums is distributed across the genus, with perhaps 6 independent origins, and with crypticity in the form of morphologically hermaphroditic, but functionally unisexual, flowers characterizing all species. Dioecy is not more strongly associated with islands. Inaperturate pollen in pistillate flowers characterizes almost all, but not the two dioecious species studied herein. Dioecy in both species indicates leakiness (rare hermaphroditic flowers on male plants) that helps explain island colonization and radiation. Leakiness allowed confirmation-usually impossible for dioecious species-of self-compatibility for S. polygamum, and thus support for the hypothesis that dioecy evolved to promote outcrossing.

Anatomy, histochemistry and micromorphology of leaves of Solanum granuloso-leprosum dunal / Anatomia, histoquímica e micromorfologia de folhas de Solanum granuloso-leprosum dunal

In the present work the anatomical, histochemical and micromorphological features of S. granuloso-leprosum leaves were approached in order to evaluate its characteristics associated with its pioneer role. Glandular and non-glandular trichomes were observed on both epidermal surfaces, although in greater number on the ab axial surface. Stellate trichomes presented a thick lignified cell wall. Leaves were amphiestomatic with a single palisade layer and a slightly smaller spongy parenchyma. The epidermal cells of the abaxial surface were shorter than the adaxial ones, both with stomata paracytic. Vascular bundles were bicolateral and idioblasts with conspicuous crystalliferous inclusions were observed in the mesophyll. Lipid drops were evidenced in the spongy parenchyma by Sudan III, Nile Blue, Nadi reagent and Sudan Black histochemical tests. Negative results for alkaloids and phenol compounds were observed. The evaluated anatomical and hystochemical data highlights mesophytic characteristics in accordance with S. granuloso-leprosum pioneer plant role.

No presente trabalho foi abordada a anatomia, histoquímica e micromorfologia de folhas de S. granuloso-leprosum no intuito de se levantar características associadas a sua função de espécie pioneira. Tricomas glandulares e não glandulares foram observados em ambas as faces da epiderme, apesar de maior número na superfície abaxial. Tricomas estrelados apresentaram uma parede espessa e lignificada. As folhas são anfiestomáticas com uma única camada de paliçada e um parênquima lacunoso com células menores que as do paliçádico. As células da face abaxial da epiderme são menores, e ambas as faces apresentam estômatos paracíticos. Os feixes vasculares são bicolaterais e idioblastos com inclusões cristalinas conspícuas. Gotas de lipídeo foram evidenciadas no parênquima lacunoso com os testes histoquímicos de Sudan III, azul do Nilo, reagente de Nadi e Sudan Black. Foram observados resultados negativos para alcaloides e fenóis. Os dados anatômicos e histoquímicos avaliados permitiram verificar que S. granuloso-leprosum apresentam características mesófilas, os quais estão em conformidade com o seu papel fitossociológicos como pioneira.

Mating system in Mexican populations of the annual herb Solanum rostratum Dunal (Solanaceae).

Traditionally, annual colonising species are expected to have high rates of self-fertilisation, although recent theoretical and empirical studies have shown that cross-fertilisation can be selected for under heterogeneous pollination environments. Solanum rostratum is a self-compatible annual herb that colonises disturbed habitats. Despite the lack of physiological mechanisms to prevent self-fertilisation, pollen transfer between individuals is expected to be favoured because of its complex floral morphology. In previous studies of S. rostratum it has been shown that anther dimorphism within flowers results in precise pollen placement on the pollinator's body, and the presence of mirror-image floral morphs within plants promotes outcrossing in experimental arrays. However, the mating system of natural populations of S. rostratum has never been assessed, and thus whether it is predominantly selfing or outcrossing remains unknown. We hypothesise that floral and inflorescence morphology of S. rostratum should facilitate cross-fertilisation, making it a predominantly outcrossing despite its lack of a self-incompatibility system. To test this hypothesis, we estimated outcrossing rates by genotyping 700 individuals at 13 microsatellite loci, sampled from four populations across a 690-km transect in the species' native range. We found that populations had mean outcrossing rates of 0.70 ± 0.03, with multiple sires contributing to paternity of each progeny array (average effective number of sires = 8.97 ± 0.57). This indicates that natural populations S. rostratum have relatively high levels of outcrossing, probably facilitated by its floral and inflorescence morphology. We speculate that partial selfing in this species may be an unavoidable consequence of displaying multiple flowers at the same time (geitonogamy), as well as the result of self-pollen transfer by illegitimate visitors.

Striking natural diversity in glandular trichome acylsugar composition is shaped by variation at the Acyltransferase2 locus in the wild tomato Solanum habrochaites.

Acylsugars are polyesters of short- to medium-length acyl chains on sucrose or glucose backbones that are produced in secretory glandular trichomes of many solanaceous plants, including cultivated tomato (Solanum lycopersicum). Despite their roles in biotic stress adaptation and their wide taxonomic distribution, there is relatively little information about the diversity of these compounds and the genes responsible for their biosynthesis. In this study, acylsugar diversity was assessed for 80 accessions of the wild tomato species Solanum habrochaites from throughout the Andes Mountains. Trichome metabolites were analyzed by liquid chromatography-time of flight-mass spectrometry, revealing the presence of at least 34 structurally diverse acylsucroses and two acylglucoses. Distinct phenotypic classes were discovered that varied based on the presence of glucose or sucrose, the numbers and lengths of acyl chains, and the relative total amounts of acylsugars. The presence or absence of an acetyl chain on the acylsucrose hexose ring caused clustering of the accessions into two main groups. Analysis of the Acyltransferase2 gene (the apparent ortholog of Solyc01g105580) revealed differences in enzyme activity and gene expression correlated with polymorphism in S. habrochaites accessions that varied in acylsucrose acetylation. These results are consistent with the hypothesis that glandular trichome acylsugar acetylation is under selective pressure in some populations of S. habrochaites and that the gene mutates to inactivity in the absence of selection.

Changes in micro RNA expression in a wild tuber-bearing Solanum species induced by 5-Azacytidine treatment.

Phenotypic plasticity is often postulated as a principal characteristic of tuber-bearing wild Solanum species. The hypotheses to explore this observation have been developed based on the presence of genetic variation. In this context, evolutionary changes and adaptation are impossible without genetic variation. However, epigenetic effects, which include DNA methylation and microRNAs expression control, could be another source of phenotypic variation in ecologically relevant traits. To achieve a detailed mechanistic understanding of these processes, it is necessary to separate epigenetic from DNA sequence-based effects and to evaluate their relative importance on phenotypic variability. We explored the potential relevance of epigenetic effects in individuals with the same genotype. For this purpose, a clone of the wild potato Solanum ruiz-lealii, a non-model species in which natural methylation variability has been demonstrated, was selected and its DNA methylation was manipulated applying 5-Azacytidine (AzaC), a demethylating agent. The AzaC treatment induced early flowering and changes in leaf morphology. Using quantitative real-time PCR, we identified four miRNAs up-regulated in the AzaC-treated plants. One of them, miRNA172, could play a role on the early flowering phenotype. In this work, we showed that the treatment with AzaC could provide meaningful results allowing to study both the phenotypic plasticity in tuber-bearing Solanum species and the inter-relation between DNA methylation and miRNA accumulations in a wide range of species.

Estrutura de populações naturais de Solanum lycocarpum St Hil (Solanaceae) / Natural population structure of the Solanum lycocarpum St Hil (Solanaceae)

Solanum lycocarpum St. Ril é uma Solanaceae, do Gênero Solanum, ao qual pertencem várias espécies longamente conhecidas e utilizadas, sobretudo, na alimentação humana, tais como a batata (Solanum tuberosum) e a berinjela (S. melongena). A S. lycocarpum é uma espécie diplóide (2n igual 24), predominantemente alógama e estudos anteriores sugerem que os cruzamentos entre parentes não são comuns. É uma planta nativa do Cerrado (a Savana brasileira, um Bioma rico em biodiversidade e em endemismo), mas sua ocorrência se dá especificamente em áreas abertas, de vegetação baixa e com maior incidência de luminosidade. A espécie apresenta um comportamento ruderal e é considerada pioneira, podendo ser utilizada para recuperação de áreas degradadas. Conhecida por fruta-do-lobo ou lobeira, é um componente fundamental da dieta de vários animais do Cerrado, especialmente do lobo-guará (Chrysocyon brachyurus), um importante dispersor da espécie. S. lycocarpum é considerada medicinal e aos seus compostos bioativos são atribuídas ações hipoglicemiantes e antiinflamatórias, entre outras. Da mesma maneira que outras espécies do Gênero Solanum, a S. lycocarpum, contém glicoalcalóides como a solasodina, um potencial precursor para a síntese de estrógenos e solamargina, cuja atividade demonstrou-se eficiente no tratamento de linhagens de células cancerígenas resistentes a quimioterápicos, relacionando-a com a interrupção da expressão de alguns oncogenes responsáveis pelo desenvolvimento desta resistência. Devido a sua potencial importância medicinal e a comprovada importância ambiental, a estrutura genética de populações de S. lycocarpum foi investigada utilizando­ -se marcadores moleculares microssatélites desenvolvidos exclusivamente para esta espécie.

[Leaf anatomy of four species of Solanum L. section Acanthophora Dunal in Venezuela]. / Anatomia foliar de cuatro especies de Solanum L. seccion Acanthophora Dunal en Venezuela.

Anatomical characteristics of S. acerifolium Dun., S. agrarium Sendtn., S. capsicoides All. and S. mammosum L., leaves were studied in order to recognize some useful features for its interspecific delimitation. 5 to 10 healthy fully expanded leaves, taken from the middle third of the plant, were examined in at least 3 different plants for each studied species. Samples were preserved in 70% FAA. Additionally, herbarium specimens (4-5 leaves/specimen) were hydrated in lactophenol and examined. The middle third of the foliar lamina and the petiole were prepared following the classical techniques used for anatomical studies. Clearing process of the foliar lamina was also made. The results show similar histological configuration in all studied species. Among the most remarkable features are: the type of leaf regarding to stomata location, number of petiole layers, angular collenchyma, petiole cross section shape and the type of vascular bundles. Finally, it is concluded that the anatomical study of the leaves of mentioned species is useful for its delimitation.

Prospecção de marcadores morfológicos, anatômicos, micro e macromoleculares de Solanum cernuum Vell (Solanaceae)

A maioria das plantas medicinais consumidas pela população e utilizada pela indústria farmacêutica é geralmente imprecisa na sua identificação toxonômica. Isto afeta a qualidade e eficácia da droga vegeral, além do uso dos fitoterápicos em geral. Com o objetivo de contribuir para o controle de qualidade de drogas comercializadas, inteiras ou trituradas, buscamos marcadores para autenticação de vegetais, que utilizem, além das características morfológicas e anatômicas, seu perfil micromolecular e genômico. Utilizamos neste estudo a 'panacéia', um vegetal largamente utilizado pela população de Minas Gerais como hemostático, sudorífero e diurético, dentre outros usos. Uma das espécies conhecidas por este nome é a Solanum cernuum Vell., da família Solanacease, que pode ser adquirida sem receituário em várias farmácias de BH. Nesta espécie, os caracteres morfológicos podem ser empregados para a identidicação, se as plantas forem comercializadas inteiras. Porém, em plantas trituradas, a presença dos ápices dos tricomas, pode ser um indicativo da presença da espécie. Neste estudo, um perfil cromatográfico característico do extrato de folhas de S. cernuum foi obtido por CCD e por CLAE. Duas substâncias foram isoladas deste extrato, identificadas como glicosídeos flavônicos. Análise do perfil de amplificação obtido por RAPD e por amplificação de regiões espaçadoras do DNA ribossomal mostraram perfis característicos para S. cernuum. Cinco amostras de panacéia do comércio de BH foram analisadas em paralelo com o padrão de S. cernuum. Constatamos que a amostra da Catedral Farmácia Homeopática, não continha S. cernuum. A confirmação da presença ou ausência da espécie é possível utilizando apenas um dos métodos propostos. Entretanto, recomendamos que pelo menos dois métodos sejam empregados, para que tenhamos resultados mais confiáveis.

Prospecção de marcadores morfológicos, anatômicos, micro e macromoleculares de Solanum cernuum Vell (Solanaceae) / Prospecting markers of morphological, anatomical, micro and macromolecular of Solanum cernuum Vell (Solanaceae)

A maioria das plantas medicinais consumidas pela população e utilizada pela indústria farmacêutica é geralmente imprecisa na sua identificação toxonômica. Isto afeta a qualidade e eficácia da droga vegeral, além do uso dos fitoterápicos em geral. Com o objetivo de contribuir para o controle de qualidade de drogas comercializadas, inteiras ou trituradas, buscamos marcadores para autenticação de vegetais, que utilizem, além das características morfológicas e anatômicas, seu perfil micromolecular e genômico. Utilizamos neste estudo a 'panacéia', um vegetal largamente utilizado pela população de Minas Gerais como hemostático, sudorífero e diurético, dentre outros usos. Uma das espécies conhecidas por este nome é a Solanum cernuum Vell., da família Solanacease, que pode ser adquirida sem receituário em várias farmácias de BH. Nesta espécie, os caracteres morfológicos podem ser empregados para a identidicação, se as plantas forem comercializadas inteiras. Porém, em plantas trituradas, a presença dos ápices dos tricomas, pode ser um indicativo da presença da espécie. Neste estudo, um perfil cromatográfico característico do extrato de folhas de S. cernuum foi obtido por CCD e por CLAE. Duas substâncias foram isoladas deste extrato, identificadas como glicosídeos flavônicos. Análise do perfil de amplificação obtido por RAPD e por amplificação de regiões espaçadoras do DNA ribossomal mostraram perfis característicos para S. cernuum. Cinco amostras de panacéia do comércio de BH foram analisadas em paralelo com o padrão de S. cernuum. Constatamos que a amostra da Catedral Farmácia Homeopática, não continha S. cernuum. A confirmação da presença ou ausência da espécie é possível utilizando apenas um dos métodos propostos. Entretanto, recomendamos que pelo menos dois métodos sejam empregados, para que tenhamos resultados mais confiáveis.

Prospecção de marcadores morfológicos, anatômicos, micro e macromoleculares de Solanum cernuum Vell (Solanaceae) / Prospecting markers of morphological, anatomical, micro and macromolecular of Solanum cernuum Vell (Solanaceae)

A maioria das plantas medicinais consumidas pela população e utilizada pela indústria farmacêutica é geralmente imprecisa na sua identificação toxonômica. Isto afeta a qualidade e eficácia da droga vegetal, além do uso dos fitoterápicos em geral. Com o objetivo de contribuir para o controle de qualidade de drogas comercializadas, inteiras ou trituradas, buscamos marcadores para autenticação de vegetais, que utilizem, além das características morfológicas e anatômicas, seu perfil micromolecular e genômico. Utilizamos neste estudo a 'panacéia', um vegetal largamente utilizado pela população de Minas Gerais como hemostático, sudorífero e diurético, dentre outros usos. Uma das espécies conhecidas por este nome é a Solanum cernuum Vell., da família Solanacease, que pode ser adquirida sem receituário em várias farmácias de BH. Nesta espécie, os caracteres morfológicos podem ser empregados para a identidicação, se as plantas forem comercializadas inteiras. Porém, em plantas trituradas, a presença dos ápices dos tricomas, pode ser um indicativo da presença da espécie. Neste estudo, um perfil cromatográfico característico do extrato de folhas de S. cernuum foi obtido por CCD e por CLAE. Duas substâncias foram isoladas deste extrato, identificadas como glicosídeos flavônicos. Análise do perfil de amplificação obtido por RAPD e por amplificação de regiões espaçadoras do DNA ribossomal mostraram perfis característicos para S. cernuum. Cinco amostras de panacéia do comércio de BH foram analisadas em paralelo com o padrão de S. cernuum. Constatamos que a amostra da Catedral Farmácia Homeopática, não continha S. cernuum. A confirmação da presença ou ausência da espécie é possível utilizando apenas um dos métodos propostos. Entretanto, recomendamos que pelo menos dois métodos sejam empregados, para que tenhamos resultados mais confiáveis.