Clone selection of in vitro horseradish hairy root cultures

Hungary is one of the largest horseradish (Armoracia rusticana Gaertn. Mey. et Scherb) harvesting countries. Its lacrimatory odor, taste and medicinal effects are due to isothiocyanates (ITC), which make up the essential oil of the horseradish (HREO). ITCs are hydrolytic products from glucosinolates. These compounds are intensively studied because of their strong anticarcinogen and antimicrobial effect [1].

Antifungal activity of HREO was previously analysed [2]. The two main compounds, allyl and phenylethyl ITC had the strongest antifungal effect. In our recent work we are studying these compounds produced by in vitro cultures.

Our aim was to set up in vitro genetically transformed hairy root cultures, and to select clones synthesizing antifungally active components in large amount, besides high biomass production.

Genetically different hairy root clones were created with Agrobacterium rhizogenes A4. Semiquantitative glucosinolate content was studied by LC-MS, while the ITC profile was analysed by GC-MS. The biomass growth was weighed.

From 35 hairy root clones 9 were selected. These possess the highest biomass production, considering the percentage scale results of the two main glucosinolates. Clone Ar9 contained the highest amount of sinigrin (20%), while DK34 had the highest content of gluconasturtiin (22%). Ar1 and ArL-101 had the antifungally best ratio of the two compounds. The antifungally active ITC content was supported by GC-MS analysis. Our further aim is to increase the ITC content in clones, through changing the cultivation conditions.

References:

[1] Nguyen N, Gonda S, Vasas G. A Review on the phytochemical composition and potential medicinal uses of Horseradish (Armoracia rusticana) Root. Food Rev Int 2012; 29: 261 – 275

[2] Bertóti R, Emri T, Pócsi I, Héthelyi É, Böszörményi A, Szőke É, Vasas G. A torma illóolaj antifungális aktivitásának vizsgálata. Congressus Pharmaceuticus Hungaricus XV. Gyógyszerészet Suppl 2014; 58: 82