Status Perkembangan Perbaikan Sifat Genetik Padi Menggunakan Transformasi Agrobacterium

Genetic transformation of rice becomes an important research area in recent years. Rice is staple food for almost half of world population and has been extensively used as a plant model system for monocotyledonous plant. Compare to direct DNA transfer techniques (PEG, electroporation, and DNA bombardment), Agrobacterium tumefaciens-mediated transformation was considered to be more advantageous because it is easy to handle, integration and segregation pattern are more predictable, and the likelihood to get transgenic plant with low copy number is high, thus decreasing gene silencing phenomena. Various important genes have been introduced into rice genome via Agrobacterium transformation. A number of important factors affecting the Agrobacterium transformation and the application of this technique in the next future will be discussed

Comparative Analysis of Rice Transformation Using Agrobacterium tumefaciens and Rhyzobium leguminosarum

This study was aimed to study the effectiveness of Rhizobium transformation system compared to the most widely used Agrobacterium mediated transformation system on three rice cultivars, Ciherang (Indica), Nipponbare (Japonica), and Rojolele (Javanica). Six day old calli induced from immature embryos were inoculated with Rhizobium leguminosarum bv trifolii ANU845 and Agrobacterium tumefaciens LBA288 that harbored with vector pCAMBIA 5106. This plasmid contained a minimum set of transfer machinery genes and had a gusplus and an hptII gene driven by 35S CaMV promoter in the T-DNA. The results showed that the transformation frequencies (number of PCR positive plants per number of calli inoculated) ranging from 0 to 12.05 % depend on the genotype and transfer agent used. The highest transformation frequency (12.05%) was obtained in Ciherang transformed with R. leguminosarum. Most of the transgenic rice obtainedby Rhizobium transformation were normal in morphology and fertile similar to those obtained by Agrobacterium transformation. Integration, expression and inheritance of transgenes were demonstrated by molecular and genetic analysis in T0 and T1 generations.Key words : Rhizobium leguminosarum, immature embryos, Agrobacterium tumefacien