Elicitation of peroxidase activity in genetically transformed root cultures of Beta vulgaris L.

Genetically transformed roots of red beet produce
copious levels of peroxidase (POD) - a multifunctional
*Corresponding author
enzyme with a number of commercial applications. In
an effort to elicit the POD activity, the cultures were
treated with biotic elicitors such as dry cell powders of
microbial cultures (0.1-0.5% w/v) and the respective
culture filtrates (1-5% v/v). Similarly, abiotic elicitors,
particularly metal ions (2-8 folds of that present in the
nutrient medium), the plant hormone Thidiazuron (at
0.25-1 ppm) and other bio-molecules such as
Glutathione (at 0.5-10 mM) and Methyl jasmonate (at
20-100 μM) were used. It was observed that dry cell
powder of Candida versatilis significantly elicited the
enzyme activity (3.52-fold higher than the control)
followed by glutathione (3.44-fold) and Rhizophus
oligosporus (3.09-fold). Among abiotic elicitors,
thidiazuron, Mg and Ca salts elicited 2.49, 3.03 and 2.8
fold activities respectively. While most of the biotic
elicitors were effective when added on 15th day of
culture, the abiotic elicitors were effective when added
on 20th day. Combination of highly effective elicitors
indicated that glutathione (1 mM) and dry cell powder
of R. oligosporus caused a 4-fold enhancement in
enzyme activity, accounting for 10.9 x 106 U L-1. The
present study is the first report on red beet hairy roots
where a large number of elicitors have been
systematically screened and their probable
involvements in eliciting POD activities have been
discussed.