The effect of red and far-red light on carotenoid synthesis by etiolated maize seedlings

Abstract

Maize ( Zea mays var. South African Horse Tooth) seedlings were germinated in darkness for 4–7 days; they were then exposed either to red light (10 min), far-red light (10 min), or to red light (10 min) followed by far-red light (10 min), and returned to darkness for a further period of either 24 or 48 hr. Red light stimulated carotenoid synthesis and growth during this period; far-red light had little effect on either; whilst illumination with far-red light following red light nullified the effect of the latter. The stimulation is most marked in young seedlings. It is concluded that the effects observed are mediated by a phytochrome system, but that the stimulation of carotenoid synthesis is not a primary site of action of the phytochrome system.