TRANSIENT AND STABLE TRANSFORMATION IN MANGO BY PARTICLE BOMBARDMENT

Genetic manipulation of plants requires a system for the introduction of foreign DNA into the cells. Particle Bombardment offers a rapid and efficient method for the delivery of DNA for transient and stable transformation studies. In this work we describe a system using mango proembryogenic masses of two polyembryonic cultivars (‘Carabao’ and ‘Kensington Pride’) as a target tissue for particle bombardment. The -glucuronidase (gus A) was used as reporter gene. The parameters associated with particle bombardment were optimized using transient expression assays of the -glucuronidase gene in proembryogenic masses. Osmotic treatment and particle acceleration pressure had a major effect on GUS transitory expression. Under optimal conditions, more than 1000 GUS foci were observed per microgram of bombarded DNA.

Stable transformation assays of proembryogenic tissue were initiated using the green fluorescent protein as reporter gene. The implications of the system for transformation and regeneration of embryogenic tissue are discussed.