Neste trabalho é descrito um método de regeneração de plantas, a partir de células de bananeira, em suspensão, e o efeito da biobalística no potencial regenerativo. Embriões somáticos foram obtidos de inflorescências masculinas de bananeira cv. Maçã (grupo AAB) por meio de embriogênese indireta. Parte dos calos (40%) apresentou características embriogênicas (não-friáveis, compactas e amareladas). Suspensões celulares obtidas desses calos continham pequenas massas celulares, com citoplasmas ricos em grânulos de amido, núcleos grandes e nucléolos densos. Após quatro meses, embriões somáticos começaram a se desenvolver. O número máximo de plantas regeneradas ocorreu 45-60 dias após a formação dos embriões. No primeiro experimento foram regeneradas 401 plantas. No segundo, 399 plantas foram obtidas de uma suspensão celular 6 meses mais velha do que a do primeiro experimento. Transformações celulares com uma das três construções plasmidiais utilizadas, que continham o gene uid-A, resultaram em fortes sinais de expressão cinco dias após as transformações; todavia, o número de plantas regeneradas foi muito menor do que o observado no material não bombardeado.

A plant regeneration method with cell suspension cultures of banana, and the effect of biobalistic on regeneration potential are described in this report. Somatic embryos of banana were obtained from indirect embryogenesis of male inflorescence of banana cultivar Maçã (AAB group). Part of the calluses formed (40%) showed embryogenic characteristics (nonfriable, compact and yellow color). The cell suspension, originated from embryogenic calluses, contained clusters of small tightly packed cells with dense cytoplasms, relatively large nuclei and very dense nucleoli. After four months of culture, somatic embryos started to regenerate. The maximum number of regenerated plants was observed between 45 and 60 days after embryo formation.In the first experiment, 401 plants were regenerated from approximately 10 mL of packed cells. In the second experiment, 399 plants were regenerated from a cell suspension six months older than that of the first experiment. Cell transformation using particle bombardment with three different plasmid constructions, containing the uid-A gene, resulted in a strong GUS expression five days after bombardment; however, plant regeneration from bombarded cells was much lower than nonbombarded ones.

Deciphering plant-insect interactions at the molecular level is one of the major topics of interest in contemporary plant biology research. In the last few years, various aspects of the plant response to insect damage have been investigated, including the characterization of direct and indirect responses, the regulation of gene expression resulting from insect attack and the signal transduction pathways. Such research has resulted in the proposal of new methods to enhance host resistance to insect pests, including the use of insecticidal genes that can be transferred by genetic engineering into target crops. By integrating the understanding of how plants react to insect damage with the techniques of molecular biology researchers should be able to increase the wide range of methods available for the control of insect pests. The sugarcane transcriptome project (SUCEST) has allowed the identification of several orthologues genes involved in the plant response to insect damage. In this paper we summarize several aspects of the complex interaction between plants and insects and describe the use of in silico analysis to provide information about gene expression in different sugarcane tissues in response to insect attack.

Estudou-se a indução de organogênese em segmentos internodais de maracujá amarelo (Passiflora edulis f. flavicarpa) cultivados em meio contendo 1,0 a 4,0 mg L-1 de benzilaminopurina (BAP). A formação de calo e o desenvolvimento de gemas adventícias foram acompanhados através de microscopia ótica e eletrônica de varredura, que mostrou sua ocorrência simultânea e contínua, com observação de gemas em diversos estádios de desenvolvimento em um mesmo explante. Houve proliferação de calos nas extremidades dos explantes em todos os tratamentos, inclusive no controle. A avaliação dos efeitos do BAP na indução de gemas adventícias mostrou que as concentrações de 1 ou 2 mg L-1 foram mais adequadas. Doses superiores a 2 mg L-1, apesar de eficientes para indução, foram prejudiciais ao crescimento das gemas. Crescimento e enraizamento das gemas adventícias foram obtidos em meio de cultura MS sem reguladores de crescimento e com a concentração de sais reduzida pela metade.

Organogenesis induction from internodal segments of yellow passionfruit (Passiflora edulis f. flavicarpa) was obtained in a medium supplemented with 1.0-4.0 mg L-1 benzylaminopurine (BAP). Callus proliferation and adventitious shoot development were analyzed by light and scanning electron microscopy. Callus proliferation and adventitious shoots were observed simultaneously and continuously, with asynchronous development of shoots in the explants. Proliferation of callus was observed in the explant cut ends in all treatments, including the control. The results show that concentrations of 1.0 or 2.0 mg L-1 BAP gave better rate of organogenesis. Higher concentrations were efficient for the induction of adventitious buds and, were, however, detrimental for subsequent shoot development. Growth and rooting of shoots were obtained in half strength medium without growth regulators.