Fig. 2.

Plastid morphology and photophysiological characteristics (F_v/F_m) in Mougeotia scalaris SAG 164.80 and Mougeotia sp. MZCH 240. A Light micrograph of M. scalaris SAG 164.80 in liquid medium. B Maximum PSII quantum yield (F_v/F_m) in M. scalaris SAG 164.80 solid- and liquid-medium control samples (grown for 7 days on WHM-Medium at 20°C, 120 μmol quanta m^-2 s^-1) as well as samples treated with the liquid shift—which were grown on solid medium and submerged in 10 ml liquid medium. C Light micrograph of Mougeotia sp. MZCH 240 24h after submergence. D F_v/F_m values for Mougeotia sp. MZCH 240 when grown on F/2 medium for 7days at 22°C, 120μmol quanta m^-2 s^-1 on solid and liquid medium. Liquid shift was achieved by adding 10 ml liquid medium to algal cultures grown on solid medium. F_v/F_m values were collected at 0, 1, 2, 3, 4, 6, 8, and 24 h after the shift and for the control on solid medium. Owing to the low growth rate in liquid medium values for F_v/F_m were measured only at 0, 6, and 24 h for liquid cultures of Mougeotia sp. MZCH 240. F_v/F_m for B and D was measured from the same sample at several time points (from 2h up to 24h) after liquid medium was added by using an ImagMAX/L PAM with an IMAG-K5 CCD camera (for details, see the “Material and methods” section). Solid control samples are depicted in grey, liquid control samples are shown in blue, and liquid-treated samples (shift) are depicted in pink. Statistical analysis was done using Mann-Whitney U tests with R (version 3.6.1); significant differences at p < 0.05 are depicted using letters and asterisks