Fig. 7

Identification of carotenogenic mutants and functional validation of RAM5. a Colony color phenotypes of RAMs. All strains were streaked on PDA plate and incubated at 28 °C for 2 days. b Schematic diagram of CAR1 structure and its deletion and complementation strategies. CAR1 genomic sequence (Dark red line) ranging from − 662 to + 2928 was used to complement the car1 mutant. c Southern blot hybridization of candidate CAR1 null mutant (car1Δ). d Pigment colors of WT, null mutant (car1Δ) and complementation strain (car1C) in either liquid broth or agar medium. e HPLC chromatogram of carotenoids from WT, car1Δ and car1C. All strains were cultured in medium B2001 for 5 days. f Quantitative analysis of 4 different carotenoid species (microgram of carotenoid per dry cell weight, μg/g DCW) in WT, car1Δ and car1C strains. g Changes of CAR1 mRNA levels in WT, car1Δ, and car1C. All cells were cultured in carotenoid production media B2001 for 1 day before RNA extraction. Actin encoding gene (ACT1) was used as the reference