Physiology of heterocyst production in the blue-gree alga Anabaena doliolum. I. Nitrate and light controls.

Abstract

In the blue-green alga Anabaena doliolum heterocyst differentiation is sequential and independent of vegetative growth. Its control is photosynthetic in nature. The nature of growth curves obtained in nitrate and nitrogen-free media indicates that the heterocyst regulates vegetative growth but has no role in sporulation. The formation of the first heterocyst is determined at a certain stage during the development of a 2-celled germling into a 4-celled filament.