COMPARISON OF THE GROWTH-PATTERN AND ROSMARINIC ACID PRODUCTION IN ROSEMARY (ROSMARINUS-OFFICINALIS) SHOOTS AND GENETICALLY TRANSFORMED CALLUS-CULTURES

Rosmarinic acid is a natural antioxidant and is found as a secondary m etabolite in rosemary (Rosmarinus officinalis). It is of interest in f ood preservation due to its antioxidant and antimicrobial activities. Previously maintained shoot-based clonal line of rosemary designated a s R-l (based on RA content, total phenolics content, tolerance to Pseu domonas sp and RA stimulation) was used in this study to compare RA bi osynthesis in shoot vs callus cultures. Callus cultures were generated from shoot cultures of R-l line following transformation with Agrobac terium rhizogenes-containing a natural plasmid that alters plant devel opment. The shoot and transformed callus cultures Bf R-l were isolated and maintained separately on hormone free Murashige and Skoog medium (MS/HF). The effect of light and dark conditions on callus growth and RA production was investigated. RA biosynthesis in shoot cultures was also compared due to its relevance to greenhouse production and organ culture. We found that callus maintained in light grows more rapidly w hen compared to shoot grown in light and callus grown in dark. The rat io of biomass accumulated by callus (Light): callus (Dark): Shoot was 4:1:1 based on fresh weight and 4:1:2 based on dry weight. The ratio o f peak RA levels (expressed mg/g DW) was 1:1:10. RA production in call us was small compared to shoot and light had no effect on peak RA leve l in the callus system, but it effected the growth rate significantly.