Nuclease activities in seed secretions of Brassicaceae species.

In-gel nuclease assay demonstrating high nuclease activity in secretions from seeds of various crucifers. Seeds of Arabidopsis thaliana Ler and Col lines, Capsella bursa-pastoris, Sysimbrium irio, Moricandia nitens, Diplotaxis erucoides, Diplotaxis harra and Sinapis alba were incubated in PBS for 8 h at 4°C, the aqueous phase was collected and proteins were separated on 12% SDS/PAGE containing denatured salmon sperm DNA. Nuclease reaction was performed with or without the indicated divalent cations and activity was visualized by staining with ethidium bromide. M, protein size markers. Note that strong nuclease activity was recovered in the presence of Mg^2+/Ca²⁺.