A protocol for axenic liquid cell cultures of a woody leguminous mangrove, Caesalpinia crista, and their amino acids profiling.

Callus induction, maintenance and protoplast cultures were achieved from immature seeds of a woody leguminous mangrove, Caesalpinia crista. Axenic cultures were possible during 1.5 months of pod storage in 0.1% benzalkonium chloride solution. Callus induction was achieved using 1 mL liquid medium in a 10 mL flat-bottomed culture tube. Protoplasts were isolated using Cellulase R10, Hemicellulase, and Driselase 20 in 0.6 M mannitol solution and sub-culturable calluses were obtained in 50 μL liquid medium using a 96-microplate method. The optimal hormonal concentration was 10 μM each of 2,4-dichlorophenoxyacetic acid and benzyladenine in liquid Murashige and Skoog's basal medium for both callus induction and maintenance, and protoplast cultures. Similarities and differences in amino acid profiles and culture conditions are discussed among woody mangrove species and non-mangrove leguminous species. Caesalpinia crista cultures were unique as they secreted a large amount of amino acids, including proline, into the liquid culture medium.