Fast and High-Efficiency Synthesis of Capsanthin in Pepper by Transient Expression of Geminivirus.

The color of the chili fruit is an important factor that determines the quality of the chili, as red chilies are more popular among consumers. The accumulation of capsanthin is the main cause of reddening of the chili fruit. Capsanthin is an important metabolite in carotenoid metabolism, and its production level is closely linked to the expression of the genes for capsanthin/capsorubin synthase ( CCS ) and carotenoid hydroxylase ( CrtZ ). We reported for the first time that the synthesis of capsanthin in chili was enhanced by using a geminivirus (Bean Yellow Dwarf Virus). By expressing heterologous β-carotenoid hydroxylase ( CrtZ ) and β-carotenoid ketolase ( CrtW ) using codon optimization, the transcription level of the CCS gene and endogenous CrtZ was directly increased. This leads to the accumulation of a huge amount of capsanthin in a very short period of time. Our results provide a platform for the rapid enhancement of endogenous CCS activity and capsanthin production using geminivirus in plants.