Effect of irradiance and nitrogen availability on the mRNA levels of the phytoene synthase (psy), phytoene desaturase (pds), lycopene β-cyclase (lcy-b), lycopene ε-cyclase (lcy-e), carotene β-hydroxylase (chyB) and β-carotene oxygenase (bkt) genes in C. zofingiensis. Culture conditions: low irradiance (20 µmol photons m−2 s−1) and nitrate replete (black line); low irradiance and nitrate deprivation (red line); high irradiance (300 µmol photons m−2 s−1) and nitrate replete (green line); high irradiance and nitrate deprivation (blue line). Error bars indicate the standard deviations of four independent measurements.
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