Reaction catalyzed by phytoene desaturase (3,4-didehydrolycopene-forming) (1.3.99.30)

		+	4	acceptor	=			+	4	reduced acceptor
	all-trans-phytofluene	+		4 acceptor	=		all-trans-3,4-didehydrolycopene	+		4 reduced acceptor