Lemna minor

Berek-Nagy, Peter Janos, Gergo Toth, Szilvia Bosze, Lilla Borbala Horvath, Andras Darcsi, Sandor Csikos, Daniel G. Knapp, Gabor M. Kovacs & Imre Boldizsar, 2021, The grass root endophytic fungus Flavomyces fulophazii: An abundant source of tetramic acid and chlorinated azaphilone derivatives, Phytochemistry (112851) 190, pp. 1-11 : 9

4.5.2. Lemna minor bioassay

Lemna minor L. (clone 9441) was cultured during stock cultivation in a light chamber (16 h light exposure) at 24 ◦ C on a liquid medium ( Appenroth et al., 1996). The medium was changed every 14 days. Two weeks prior to the tests, fronds were transferred into Steinberg medium to acclimate and the medium was changed after 7 days ( Naumann et al., 2007). Dilution series of the isolated compounds were made in the concentration range of 1.0–100 μM by Steinberg medium. The fronds were treated with 1.9 mL amounts of these solutions in 24-well plates for 7 days (in a light chamber, 16 h light exposure) at 24 ◦ C (the control was grown on Steinberg medium). Fronds were then counted and the total leaf area in each well was measured by the software ImageJ using the screened pictures of the plates ( Schneider et al., 2012).

Statistical analyses of the Lactuca sativa and Lemna minor bioassays were conducted by Prism v.8.0.1 (GraphPad, USA). The normality of the datasets was tested by Shapiro-Wilk test. In case of normality, one-way ANOVA was performed. When data did not exhibit normality, KruskalWallis test was carried out. To compare the treatments with the control, we used Dunett and Dunn post hoc tests, respectively at α = 0.05.