Abstract

This study is directed to engineering the high production of salicylic acid from both genetically transformed hairy roots and callus cultures of Marigold, Calendula officinalis L., by pRi-DNA plasmid of the wild type Agrobacterium rhizogenes ATCC 13332, via "Direct injection" and "Co-cultivation" techniques. High frequency of transformed hairy roots was recorded as leaves were inoculated by mixture of pRi-DNA and PEG. Also, incubation of Marigold leaves with pRi-DNA plasmid in the presence of PEG, enhanced hairy roots formation up to 60%. Genomic DNA was isolated from these hairy roots and the derived callus. Amplification of rol C gene was done by polymerase chain reaction (sPCR) carried on T-DNA of Ri plasmid. These genes were expected to be inserted in Marigold DNA. Electrophoresis results were a decisive proof that point out from the transfer of rol C genes. The latter separated from agarose coincide with molecular weights of the specific primers. Subsequently, HPLC data confirmed the availability of salicylic acid in both transformed hairy roots and callus that recorded 45 and 42-fold, respectively more than SA content in the natural field plants. This finding indicates that this increase was due to the incidence of transgenesis of these tissues.

Key words: Transgenic plant, Agrobacterium rhizogenes, Calendula officinalis L., salicylic acid.