Isolation of structurally intact secretory cavities from leaves of African marigold, Tagetes erecta L. (Asteraceae)

Foliar secretory cavities were isolated from Tagetes erecta L. plants. Leaf discs were vacuum infiltrated with a macerating enzyme solution (cellulysin/macerozyme in a mineral salts medium) and alternately ultrasonicated and shaken on a rotary shaker. Secretory cavities free of surrounding mesophyll and vascular tissue were obtained after 3 sonication/shaking cycles. Based on both visual inspection and retention of secretion products, the cavities were structurally intact; they also were viable according to their reaction to vital dyes, e.g., trypan blue. The described protocol should be useful in isolating other embedded secretory structures.