Photosynthetic acclimation to warming in tropical forest tree seedlings.

Tropical forests have a mitigating effect on man-made climate change by acting as a carbon sink. For that effect to continue, tropical trees will have to acclimate to rising temperatures, but it is currently unknown whether they have this capacity. We grew seedlings of three tropical tree species over a range of temperature regimes (TGrowth = 25, 30, 35 °C) and measured the temperature response of photosynthetic CO2 uptake. All species showed signs of acclimation: the temperature-response curves shifted, such that the temperature at which photosynthesis peaked (TOpt) increased with increasing TGrowth. However, although TOpt shifted, it did not reach TGrowth at high temperature, and this difference between TOpt and TGrowth increased with increasing TGrowth, indicating that plants were operating at supra-optimal temperatures for photosynthesis when grown at high temperatures. The high-temperature CO2 compensation point did not increase with TGrowth. Hence, temperature-response curves narrowed with increasing TGrowth. TOpt correlated with the ratio of the RuBP regeneration capacity over the RuBP carboxylation capacity, suggesting that at high TGrowth photosynthetic electron transport rate associated with RuBP regeneration had greater control over net photosynthesis. The results show that although photosynthesis of tropical trees can acclimate to moderate warming, carbon gain decreases with more severe warming.

Micropropagation of Calophyllum brasiliense (Cambess) from nodal segments / Micropropagação de Calophyllum brasiliense (Cambess) a partir de segmentos nodais

Abstract Micropropagation of Calophyllum brasiliense Cambess. (Clusiaceae) is a way to overcome difficulties in achieving large-scale plant production, given the recalcitrant nature of the seeds, irregular fructification and absence of natural vegetative propagation of the species. Cultures were established using nodal segments 2 cm in length, obtained from 1-2 year old seedlings, maintained in a greenhouse. Mercury chloride and Plant Preservative Mixture™ were used in the surface sterilizing stage, better results being achieved with Plant Preservative Mixture™ incorporation in culture medium, at any concentration. Polyvinylpyrrolidone, activated charcoal, cysteine, ascorbic acid or citric acid were added to the culture medium to avoid oxidation. After 30 days of culture, polyvinylpirrolidone and ascorbic acid gave better results, eliminating oxidation in most explants. For shoot multiplication, benzylaminopurine was used in concentrations of 4.4 and 8.8 µM in Woody Plant Medium, resulting in an average of 4.43 and 4.68 shoots per explant, respectively, after 90 days. Indole-3-butyric acid and α-naphthalene acetic acid were used to induce root formation, reaching a maximum rooting rate of 24% with 20µM α-naphthalene acetic acid. For acclimatization. the rooted plants were transferred to Plantmax® substrate and cultured in a greenhouse, reaching 79% of survival after 30 days and 60% after one year.

Resumo A micropropagação de Calophyllum brasiliense Cambess. (Clusiaceae) é uma maneira de superar dificuldades para sua produção em larga escala, devido à natureza recalcitrante das sementes, frutificação irregular e ausência de propagação vegetativa natural da espécie. Culturas foram estabelecidas utilizando segmentos nodais com 2 cm de comprimento, obtidos de plantas com 1 a 2 anos de idade, mantidas em casa de vegetação. Cloreto de mercúrio e Plant Preservative Mixture™ foram utilizados durante a etapa de desinfestação, com melhores resultados alcançados com a incorporação de Plant Preservative Mixture™ ao meio de cultura. Polivinilpirrolidona, carvão ativado, cisteína, ácido ascórbico ou ácido cítrico foram adicionados ao meio de cultura para evitar a oxidação dos explantes. Após 30 dias de cultivo, o uso de polivinilpirrolidona ou ácido ascórbico proporcionou melhores resultados, eliminando a oxidação na maioria dos explantes. Para multiplicação das brotações, benzilaminopurina foi usada em concentrações de 4.4 e 8.8 µM em meio WPM, resultando em uma média de 4.43 e 4.68 brotações por explante, respectivamente, após 90 dias. Ácido indol-3-butírico e ácido α-naftaleno acético foram usados para a indução de raízes, alcançando um enraizamento máximo de 24% com o uso de 20µM de ácido α-naftaleno acético. As plantas enraizadas foram transferidas para substrato Plantmax® e cultivadas em casa de vegetação, alcançando 79% de sobrevivência após 30 dias e 60% após um ano.

Micropropagation of Calophyllum brasiliense (Cambess.) from nodal segments.

Micropropagation of Calophyllum brasiliense Cambess. (Clusiaceae) is a way to overcome difficulties in achieving large-scale plant production, given the recalcitrant nature of the seeds, irregular fructification and absence of natural vegetative propagation of the species. Cultures were established using nodal segments 2 cm in length, obtained from 1-2 year old seedlings, maintained in a greenhouse. Mercury chloride and Plant Preservative Mixture™ were used in the surface sterilizing stage, better results being achieved with Plant Preservative Mixture™ incorporation in culture medium, at any concentration. Polyvinylpyrrolidone, activated charcoal, cysteine, ascorbic acid or citric acid were added to the culture medium to avoid oxidation. After 30 days of culture, polyvinylpirrolidone and ascorbic acid gave better results, eliminating oxidation in most explants. For shoot multiplication, benzylaminopurine was used in concentrations of 4.4 and 8.8 µM in Woody Plant Medium, resulting in an average of 4.43 and 4.68 shoots per explant, respectively, after 90 days. Indole-3-butyric acid and α-naphthalene acetic acid were used to induce root formation, reaching a maximum rooting rate of 24% with 20µM α-naphthalene acetic acid. For acclimatization. the rooted plants were transferred to Plantmax® substrate and cultured in a greenhouse, reaching 79% of survival after 30 days and 60% after one year.

Calophyllolide content in Calophyllum inophyllum at different stages of maturity and its osteogenic activity.

Calophyllum inophyllum is a coastal plant rich in natural substances. Its ingredients have been used for the development of an anti-human immunodeficiency virus (HIV) drug. In this study, we collected C. inophyllum fruit, and the ethanol extract of the fruit was chromatographically separated using silica gel and Sephadex LH-20 columns to obtain the major compound, calophyllolide. The fruits were harvested from September to December in 2011; a quantitative analysis of the calophyllolide content was conducted using HPLC to explore the differences between the different parts of the fruit during the growing season. The results showed that in fruits of C. inophyllum, calophyllolide exists only in the nuts, and dried nuts contain approximately 2 mg·g-1 of calophyllolide. The calophyllolide levels in the nuts decreased during maturity. In addition, calophyllolide dose-dependently enhanced alkaline phosphatase (ALP) activity in murine osteoblastic MC3T3-E1 cells, without significant cytotoxicity. The expression of osteoblastic genes, ALP and osteocalcin (OCN), were increased by calophyllolide. Calophyllolide induced osteoblasts differentiation also evidenced by increasing mineralization and ALP staining.

Evaluación de los efectos antioxidante, antibacteriano y antifúngico de Calophyllum Brasilense Cambes (Lagarto Caspi) / Evaluation of antioxidant effects, antibacterial and antifungal Brasilense Calophyllum Cambes (Caspi Lizard)

Objetivo: Evaluar el efecto antibacteriano, antifúngico y antioxidante de diferentes extractos del Calophyllum brasiliense Cambess. Material y Métodos: El efecto antioxidante fue determinado por captación de radicales libres, midiendo la decoloración de una solución de 2,2-difenil-1-picril hidrazilo (DPPH); La actividad antibacteriana y antifúngica, in Vitro, se determinó mediante la prueba de dilución. El efecto antibacteriano se evaluó en cepas de E. coli ATCC25922 y Staphylococcus aureus ATCC25923, utilizando medios de cultivo: Caldo y Agar Mueller Hinton. Para evaluar el efecto antifúngico, se utilizó cepas de Cándida albicans en medio de Agar Sabouraud. Resultados: La actividad antioxidante de los extractos acuoso, metanólico y etanólico fue muy satisfactoria, siendo de 110.56 por ciento, 99.17 por ciento y 99.57 por ciento, respectivamente, a una concentración de 100 ug/mL, en comparación con la Vitamina C que presentó 86,5 por ciento. Asimismo, observamos un buen efecto antifúngico para los extractos acuoso y etanólico al 20 por ciento p/v a los volúmenes de 3, 3.5 y 4mL. y en el caso del extracto etanólico también presentó un buen efecto a una concentración del 10 por ciento a un volumen de 1.6mL. Conclusiones: Los extractos: acuoso, metanólico y etanólico, presentaron un buen efecto antioxidante y antifúngico, en las cepas estudiadas.

Objetive: To evaluate, in vitro, the antibacterial, antifungal andantioxidant effects of different extracts of Calophyllum brasiliense Cambess. Material and Methods: The antioxidant effect was tested by free radicals capture, measuring discoloration of the 2,2-diphenyl-1-pycryl hydrazyle solution (DPPH). We used a dilution to measure antibacterial and antifungal in vitro activity. Strains of E. coli ATCC25922 and Staphylococcus aureus ATCC25923 were used to evaluate antibacterial effect; using Broth and Mueller Hinton Agar as culture medium. Strains of Candida albicans and Agar Sabouraud as culture medium were usedto evaluate antifungal effect. Results: Aqueous, methanolic and ethanolic extracts, showed good antioxidant activity having 110.56 per cent, 99.17 per cent and 99.57 per cent of antioxidant activity at 100 ug/mL concentration, respectively. This is superior to the vitamin C referencepattern that showed 86,5 per cent activity. Good antifungal effect for aqueous and ethanol extracts at a 20 per cent concentration for 3, 3.5 and 4 ml of volume was determined. Ethanol extracts had the same antifungal effect at a 10 per cent concentration for 1.6mL. of volume. Conclusions: The aqueous, methanolic and ethanolic extracts showed a good antioxidant and antifungal activity on the strains studied.

Pattern of anti-HIV dipyranocoumarin expression in callus cultures of Calophyllum inophyllum Linn.

Callus cultures of Calophyllum inophyllum were established using seed, nodal/ internodal and leaf explants on WPM basal medium supplemented with indole-3-butyric acid (IBA), alpha-naphthalene acetic acid (NAA), picloram (4-amino-3,5,6-trichloropicolinic acid), and 6-benzylaminopurine (BAP) in different combinations and concentrations with the view to study the influence of hormones on callus induction and the pattern of expression of dipyranocoumarins including anti-HIV, non-nucleoside reverse transcriptase inhibitors inophyllum B and P in callus cultures. 96.01% seed explants, 87.50% nodal/internodal explants and 86.66% leaf explants were converted into calluses when inoculated on WPM supplemented with IBA 4.0 mg l(-1) along with BAP 1.0 mg l(-1), IBA 4.0 mg l(-1), and picloram 6.0 mg l(-1) along with BAP 2.0 mg l(-1), respectively. Calluses induced from seed explants were white, friable and irregular whereas nodal/internodal and leaf explants induced dark brown, nodular and compact calluses. In order to facilitate the rapid quantitative analysis of dipyranocoumarins under study, a novel HPLC method capable of separating all six dipyranocoumarins in a single isocratic run has been optimized. Quantitative HPLC analysis of callus extracts revealed that highest inophyllum B (40.59 mg 100g callus(-1)) was expressed in callus induced from seed explant on medium containing 2.0 mg l(-1) indole-3-butyric acid, while highest inophyllum P (141.35 mg 100g callus(-1)) was estimated in seed callus induced on medium containing 2.0 mg l(-1) indole-3-butyric acid along with BAP 1.0 mg l(-1).

High-light stress does not impair biomass accumulation of sun-acclimated tropical tree seedlings (Calophyllum longifolium Willd. and Tectona grandis L. f.).

Studies with seedlings of tropical rainforest trees ( Calophyllum longifolium Willd.; Tectona grandis L. f.) were designed to test whether high-light stress affects photosynthetic performance and growth. Seedlings were cultivated in pots at a field site in Central Panama (9 degrees N) and separated into two groups: (1) plants exposed to full solar radiation; (2) plants subjected to automatic neutral shading (48 %) whenever visible irradiance surpassed 1000, 1200, or 1600 micromol photons m-2 s-1. After 2-4 months, chlorophyll fluorescence (Fv/Fm ratio), photosynthetic net CO2 uptake, pigment composition, alpha-tocopherol content of leaves, and plant biomass accumulation were measured. Fully sun-exposed, compared to periodically shaded plants, experienced substantial high-light stress around midday, indicated by photoinhibition of photosystem II and depressed net CO2 uptake. Higher contents of xanthophyll cycle pigments, lutein, and alpha-tocopherol showed an enhancement of photoprotection in fully sun-exposed plants. However, in all experiments, the maximum capacity of net CO2 uptake and plant dry mass did not differ significantly between the two treatments. Thus, in these experiments, high-light stress did not impair productivity of the seedlings studied. Obviously, the continuously sun-exposed plants were capable of fully compensating for any potential costs associated with photoinhibition and repair of photosystem II, reduced CO2 assimilation, and processes of high-light acclimation.