Measurement of nutrient content
Seedlings were grown for 7 d on half-strength MS media, after which they
were transferred to agar plates with indicated nutrients for 10 d.
Plates were kept in a growth chamber at 22°C during the day, 21°C at
night, under long day (16 h of light) conditions at 100 μmol
m−2 s−1. Mg2+-,
K+-, and Ca- content in samples (pooled plants,
~100 mg dry weight) was determined with inductively
coupled plasma optical emission spectroscopy (Spectroblue, Spectro,
Germany) analysis in the laboratory of Ekolab Žamberk, Czech Republic).