Morphological Description of Transgenic Soybean Chimeras Created by the Delivery, Integration and Expression of Foreign DNA Using Electric Discharge Particle Acceleration

Transgenic soybean (Glycine max L.) plants derived from electricdischarge particle acceleration experiments exhibited varyingdegrees of chimerism which was followed by the expression ofthe introduced ß-glucuronidase (gus) gene. Degreesof chimerism in transgenic plants were established by determiningexpression of the gus gene observed as blue spots, streaks orsectors in stem and leaf tissues in in vitro grown plantletsand greenhouse plants. Clonal plants were also obtained. Presenceof the gene was confirmed by Southern blot analysis. These studiespermitted the reconstruction of a partial picture for the developmentof the soybean plant. Glycine max L. cv. Williams 82, soybean, transformation, ß-glucuronidase, chimeric plant phenotypes, development     

Developmental Aspects of Soybean (Glycine max) Somatic Embryogenesis

A detailed study of the developmental aspects for soybean somaticembryogenesis was undertaken with emphasis on biochemical andhistological markers. The various stages of somatic embryo developmentin callus cultures have been identified and characterized. Germinatingembryos could be converted to fertile plants at a high frequency(90%). Dicamba (3, 6-dichloro-o-anisic acid) was found to bethe auxin of choice for the clear distinction of the variousdevelopmental phases of soybean somatic embryos. Differencesin their protein patterns were determined using polyacrylamidegel electrophoresis. This analysis revealed distinguishabledifferences in protein profiles amongst the various developmentalstages, especially in heart stage embryos. Histological studieson somatic embryos revealed specific tissue types which closelyresemble those reported for zygotic embryos. Further evidenceis provided that there is a close similarity in tissue differentiation,between somatic and zygotic embryogenesis although there aresome unique features in the development of somatic embryos. Glycine max, callus cultures, developmental stage, liquid cultures, neomorphs, plant regeneration, stage specific proteins, histology     

Transgenic Central American, West African and Asian Elite Rice Varieties Resulting from Particle Bombardment of Foreign DNA into Mature Seed-derived Explants Utilizing Three Different Bombardment Devices

We developed a novel system based on particle bombardment forthe transfer of foreign genes into eight important rice varietiesgrown in Central America, West Africa and Asia. Novel featuresof this improved protocol, which we believe will replace alternativesystems currently utilizing immature embryos, embryogenic celllines or suspension cultures include: (a) bombardment of targettissue 5 d after seed germination; (b) no requirement to selectfor embryogenic callus prior to bombardment; (c) high transformationfrequencies (up to 14%); (d) ability to recover transgenic materialat similar frequencies irrespective of bombardment devices used.Southern blot analysis and enzymatic assays in primary transformantsand progeny confirmed the stable integration and expressionof introduced transgenes in all engineered cultivars.Copyright1998 Annals of Botany Company. Oryza sativa, transgenic rice, particle bombardment, transformation.