Factors affecting genetic transformation by particle bombardment of the prickly pear cactus (O. ficus-indica)

In the present study, a novel transformation protocol for Opuntia ficus-indica was generated by means of particle bombardment. The best conditions obtained were: 900 psi rupture disk pressure, 8 cm microprojectile travel distance, and 4 h of exposition to 0.2 M mannitol. For all experiments, gold particles coated with 1.0 µg/µL of pBI426 plasmid DNA were used. With all these conditions, a 23% of transformation efficiency in terms of regeneration in selection media (100 mg/L kanamycin) was obtained. Interestingly, the presence of both transgenes: nptII and uidA, by means of PCR and RT-PCR assays was detected. The regeneration percentage achieved in terms of stable integration for both genes was 10%. In addition, we also detected adequate amounts of β-glucuronidase activity by means of the GUS fluorometric assay. The procedure described in the present investigation reveals the feasibility of using nopal for the introduction, expression, and possible production of heterologous proteins.

Stable Transformation of the Saintpaulia ionantha by Particle Bombardment

BACKGROUND

A highly efficient genetic transformation system is essential for a successful genetic manipulation of the African violet (Saintpaulia ionantha Wendl.).

OBJECTIVES

Developing a particle bombardment-based genetic transformation system for the African violet.

MATERIALS AND METHODS

A local cultivar of the African violet from Guilan province was used for transformation experiments. The pFF19G and pBin61-Ech42 vectors were used for transient and stable transformation experiments, respectively. The PCR and RT-PCR techniques were used to verify transgene presence and transcript levels in candidate transgenic lines, respectively.

RESULTS

Using leaf explants as target tissues, we transferred an endochitinase gene cDNA into African violet. Transgenic plants were regenerated on selection medium at a reasonable frequency (in average, one stable transgenic line per shot). Molecular analysis of transgenic plants by PCR and RT-PCR techniques confirmed successful integration and expression of transgene in several independent transgenic lines.

CONCLUSIONS

Our results provide an efficient stable transformation system for genetic transformation of African violet.