Do s genes or deleterious recessives control late-acting self-incompatibility in Handroanthus heptaphyllus (Bignoniaceae)? A diallel study with four full-sib progeny arrays.

BACKGROUND AND AIMS: Genetically controlled self-incompatibility (SI) mechanisms constrain selfing and thus have contributed to the evolutionary diversity of flowering plants. In homomorphic gametophytic SI (GSI) and homomorphic sporophytic SI (SSI), genetic control is usually by the single multi-allelic locus S. Both GSI and SSI prevent self pollen tubes reaching the ovary and so are pre-zygotic in action. In contrast, in taxa with late-acting self-incompatibility (LSI), rejection is often post-zygotic, since self pollen tubes grow to the ovary, where fertilization may occur prior to floral abscission. Alternatively, lack of self fruit set could be due to early-acting inbreeding depression (EID). The aim of our study was to investigate mechanisms underlying the lack of selfed fruit set in Handroanthus heptaphyllus in order to assess the likelihood of LSI versus EID. METHODS: We employed four full-sib diallels to study the genetic control of LSI in H. heptaphyllus using a precociously flowering variant. We also used fluorescence microscopy to study the incidence of ovule penetration by pollen tubes in pistils that abscised following pollination or initiated fruits. KEY RESULTS: All diallels showed reciprocally cross-incompatible full sibs (RCIs), reciprocally cross-compatible full sibs (RCCs) and non-reciprocally compatible full sibs (NRCs) in almost equal proportions. There was no significant difference between the incidences of ovule penetrations in abscised pistils following self- and cross-incompatible pollinations, but those in successful cross-pollinations were around 2-fold greater. CONCLUSIONS: A genetic model postulating a single S locus with four S alleles, one of which, in the maternal parent, is dominant to the other three, will produce RCI, RCC and NRC full sib situations each at 33 %, consistent with our diallel results. We favour this simple genetic control over an EID explanation since none of our pollinations, successful or unsuccessful, resulted in partial embryo development, as would be expected under a whole-genome EID effect.

A polysaccharide fraction from "ipê-roxo" (Handroanthus heptaphyllus) leaves with gastroprotective activity.

A polysaccharide fraction from Handroanthus heptaphyllus leaves was obtained with a simple and quick purification method. Methylation analysis and NMR spectroscopy indicated the presence of a complex polysaccharide fraction mainly constituted by a type II arabinogalactan. This is the first report in literature on structural elucidation of polysaccharides of species from genus Handroanthus. Oral and intraperitoneal administration of the polysaccharide fraction from Handroanthus heptaphyllus (HHSF) protected the gastric mucosa in an acute model of gastric lesion induced by ethanol, preserving gastric mucus. Furthermore, in the indomethacin model, HHSF reduced wounded area and inhibited mucus and GSH depletion. HHSF also accelerated gastric ulcer healing, accompanied by the maintenance of GSH levels. In addition, in an oxidative stress model with human epithelial cell line (Caco-2), HHSF was able to preserve GSH levels and was not toxic to cells. Collectively, these results showed that HHSF has an interesting antiulcerogenic activity and could constitute an interesting option for the treatment of gastric ulcer.

Shoot segment and substrate composition in rooting of juvenile ipe-roxo mini-cuttings / Tipo de segmento e composição do substrato no enraizamento de miniestacas juvenis de ipê-roxo

ABSTRACT: This study aimed to evaluate the rooting capability of apical and nodal mini-cuttings of ipe-roxo ( Handroanthus heptaphyllus ) in different substrates. Shoots produced from mini-stumps were fractioned into mini-cuttings 2-cm long apical or nodal mini-cuttings and treated with 1000 mg L-1 of indolebutyric acid (IBA). Four substrate combinations were evaluated: commercial substrate composed of pine bark and vermiculite in proportions of 1:1, 2:1 and 1:2 (v /v) and commercial substrate, vermiculite and sand in the proportion of 1:1:1 (v/v). The factorial experiment utilized a completely random design, with five replicates of four mini-cuttings. Rooting, shooting and survival percentage, number and length of shoots and roots were evaluated at 60 and 90 days of growth. Commercial substrate and vermiculite are a good combination for rooting mini-cuttings of ipe-roxo. Apical and nodal mini-cuttings exhibit similar rooting behavior and both are feasible for production of ipe- roxo plantlets.

RESUMO: O objetivo deste estudo foi avaliar o enraizamento de miniestacas apicais e nodais de ipê-roxo ( Handroanthus heptaphyllus ) em diferentes substratos. Brotos coletados de minicepas foram seccionados em miniestacas de 2cm de comprimento, classificadas em apical ou nodal e tratadas com 1000mg L-1 de ácido indolbutírico (AIB). Foram também testadas as composições de substrato comercial à base de casca de pinus e vermiculita nas proporções de 1:1; 2:1 e 1:2 (v/v) e de substrato comercial, vermiculita e areia grossa (1:1:1 v/v). O experimento foi um fatorial no delineamento inteiramente casualizado, com cinco repetições de quatro miniestacas. A porcentagem de enraizamento, de brotação e de sobrevivência, o número e comprimento de brotos e raízes foram avaliados aos 60 e 90 dias. Miniestacas de ipê-roxo cultivadas em substrato comercial e vermiculita apresentam maior capacidade de enraizamento. Miniestacas apicais e nodais apresentam similar comportamento de enraizamento, podendo ambas serem utilizadas para a produção de mudas de ipê-roxo.

Compostos fenólicos da casca de Handroanthus heptaphyllus (Mart. ) Mattos e efeitos do extrato aquoso no perfil lipídico, glicêmico e na lipoperoxidação em ratos diabéticos / Phenolic compounds from Handroanthus heptaphyllus (Mart. ) Mattos bark and effects of aqueous extract on lipid profile, glucose, and lipid peroxidation in diabetic rats

RESUMO A preocupação com o tratamento do Diabetes mellitus (DM) leva a uma crescente busca por terapias alternativas, como o uso de plantas medicinais, entre as quais, destaca-se o uso de Handroanthus heptaphyllus (Mart.) Mattos (popular Ipê roxo). Neste estudo realizamos a investigação química da presença de compostos fenólicos em H. heptaphyllus e o efeito do tratamento com o extrato aquoso da casca desta planta em parâmetros bioquímicos e nos níveis de lipoperoxidação tecidual e plasmática em animais diabéticos. Metodologia: Ratos Wistar machos foram submetidos ao desenvolvimento do quadro de DM por meio da administração intraperitoneal (IP) de Aloxano monohidrato (150 mg/Kg IP). Após a confirmação de hiperglicemia (>200 mg dL-1), os animais foram distribuídos nos grupos Diabético (D; n=6) e Diabético Tratado (DT; n=6). O tratamento consistiu na administração diária do extrato aquoso da casca de H. heptaphyllus via oral (v.o.) (150mg/Kg v.o.) por quatro semanas. O extrato aquoso foi analisado qualitativamente por cromatografia de camada delgada. Resultados: A análise qualitativa do extrato aquoso da casca indicou a presença de compostos fenólicos da subclasse flavonoides. O tratamento com o extrato aquoso reduziu a glicemia de jejum a partir da 3ª semana de tratamento, melhorou a resposta glicêmica à sobrecarga de glicose, diminuiu os níveis de triglicerídeos e índice LDL (Triglicerídeos/HDL). Estes resultados sugerem o uso terapêutico do extrato aquoso das cascas de H. heptaphyllus no tratamento do DM.

ABSTRACT Alternative medicine for diabetes mellitus (DM) treatment represents a growing research area on the use of medicinal plants, of which Handroanthus heptaphyllus (mart.) Mattos (popularly known as purple ipe) is most prominent. In this study, we investigated the presence of phenolic compounds and the effects of treatment with aqueous extract of in H. heptaphyllus in biochemical profile in plasma and the levels of lipid peroxidation in tissues and plasma in diabetic animals. Male Wistar rats were induced to develop DM through intraperitoneal (IP) administration of alloxan monohydrate (150 mg/kg IP). Once hyperglycemia (>200 mg dL-1) was confirmed, the animals were divided into the Diabetic (D; n=6) and Treated Diabetic (TD; n=6) groups. The TD group received daily administration (150 mg/kg v.o.) of aqueous extract of H. heptaphyllus for four weeks. The aqueous extract was also analyzed qualitatively by layer chromatography. Qualitative analysis of the aqueous extract of the bark indicated the presence of phenolic compounds from the flavonoid subclass. The treatment with the aqueous extract reduced fasting blood glucose levels from the third week of treatment on, improved the glycemic response to the glucose tolerance test, and lowered the levels of triglycerides and the LDL index (triglycerides/HDL). These findings suggest therapeutic use of the aqueous extract of H. heptaphyllus bark in treating DM.