Response of Spirodela oligorrhiza to Phosphorus Deficiency

The duckweed Spirodela oligorrhiza, growing in sterile defined nutrient media, was used to study some responses of plants to phosphorus deficiency. On a phosphate-deficient medium, growth of Spirodela soon slowed and eventually ceased. Older leaves became chlorotic, but newly formed leaves were dark green and contained much anthocyanin. The photosynthesis rate fell gradually, roots elongated, and chloroplasts became filled with starch.