Optimization of callus and cell suspension cultures of Barringtonia racemosa (Lecythidaceae family) for lycopene production

Lycopene is present in a range of fresh fruits and vegetables, especially in the leaves of Barringtonia racemosa. The traditional lycopene extraction from the plant is being employed instead of an easy propagation technique like cell culture process from the leaf explants. We intend to assess how lycopene could be extracted via tissue culture under light (illuminance: 8,200 lux under white fluorescent lamps, photoperiod 16 h per day at 25ºC) and dark. Leaf explants of Barringtonia racemosa were cultured on modified Murashige and Skoog (MS), Woody Plant Medium (WPM) and B5 media, supplemented with different concentrations of 2,4-Dichlorophenoxyacetic acid (2,4-D). Optimal conditions for callus induction and maintenance under both dark and light were investigated, and growth and lycopene accumulation were evaluated. Among media with different concentrations of 2,4-D, fast growing, friable callus initiated within three weeks after culturing on WPM basal medium supplemented with 2.0 mg L-1 (weight per volume) of 2,4-D, whereas callus induction in explants cultured on all other media started only after five weeks. Calli were subcultured once every fortnight. Pale yellow and green calli developed under conditions of dark and light respectively were then selected for evaluation of their lycopene contents. An improved reversed phase of high performance liquid chromatography (HPLC) method was used for a selective chemical determination of the lycopene content. Light induced lycopene production; and likewise maximum lycopene level incubated in light was higher than those incubated in darkness. The best growth rates of callus and cell suspension were achieved in WPM and B5 media respectively. The production of lycopene was growth-dependent through analysis of growth and lycopene content of both callus and cell suspension cultures.O licopeno está presente numa série de frutas frescas e hortaliças principalmente na folhas de Barringtonia racemosa. A extração tradicional do licopeno tem sido empregada no lugar da fácil técnica de propagação como o processo de cultura de células de explantes de folhas. É nossa intenção demonstrar como o licopeno pode ser extraído através de cultura de tecido sob luz (iluminação com lâmpadas fluorescentes brancas de 8.200 lux, 16 h por dia a 25º C) e escuro. Explantes de folhas de Barringtonia racemosa foram cultivados em meio modificado de Murashige e Skoog (MS) para plantas lenhosas e meio B5, suplementado com diferentes concentrações de ácido 2,4-Diclorofenoxiacético (2,4-D). Condições ótimas para indução e manutenção de calos sob luz e escuro foram investigadas e avaliados o crescimento e acumulo de licopeno. Entre meios com diferentes concentrações de 2,4 -D, calos friáveis de crescimento rápido tiveram início em três semanas após serem cultivados em meio basal WPM suplementado com 2.0 mg L-1 (peso por volume) de 2,4-D enquanto indução de calos em explantes cultivados em todos os outros meios começaram somente após cinco semanas. Calos foram subrepicados a cada 15 dias. Calos amarelo-pálido e verdes desenvolvidos respectivamente sob condições escura e de luz foram então selecionados para avaliação do teor de licopeno. Um método aperfeiçoado de cromatografia líquida de alto desempenho foi usado para a determinação química seletiva do teor de licopeno. A produção de licopeno induzida sob luz e também o nível máximo de licopeno incubado em luz foi mais alto do que aqueles incubados no escuro. As melhores taxas de crescimento de calo e suspensões de células foram obtidas respectivamente em meio WPM e B5. A produção de licopeno dependeu do crescimento como demonstrado pela análise do crescimento e teor de licopeno de ambos calos e cultura de células em suspensão

Tissue culture of ornamental cacti

Cacti species are plants that are well adapted to growing in arid and semiarid regions where the main problem is water availability. Cacti have developed a series of adaptations to cope with water scarcity, such as reduced leaf surface via morphological modifications including spines, cereous cuticles, extended root systems and stem tissue modifications to increase water storage, and crassulacean acid metabolism to reduce transpiration and water loss. Furthermore, seeds of these plants very often exhibit dormancy, a phenomenon that helps to prevent germination when the availability of water is reduced. In general, cactus species exhibit a low growth rate that makes their rapid propagation difficult. Cacti are much appreciated as ornamental plants due to their great variety and diversity of forms and their beautiful short-life flowers; however, due to difficulties in propagating them rapidly to meet market demand, they are very often over-collected in their natural habitats, which leads to numerous species being threatened, endangered or becoming extinct. Therefore, plant tissue culture techniques may facilitate their propagation over a shorter time period than conventional techniques used for commercial purposes; or may help to recover populations of endangered or threatened species for their re-introduction in the wild; or may also be of value to the preservation and conservation of the genetic resources of this important family. Herein we present the state-of-the-art of tissue culture techniques used for ornamental cacti and selected suggestions for solving a number of the problems faced by members of the Cactaceae family

In vitro techniques in the control of cassava mosaic disease

In IDL-69