Suberoylanilide hydroxamic acid induced microspore embryogenesis and promoted plantlet regeneration in ornamental kale (Brassica oleracea var. acephala).

Abstract

Isolated Microspore Culture (IMC) is an efficient method to obtain the homozygous strain; however, it is difficult to apply in ornamental kale due to its low rate of microspore embryogenesis. Histone acetylation is an important epigenetic mechanism and may affect the changes of the microspore development pathway, promoting microspore embryogenesis. Here, microspores from three cut-flower ornamental kales, namely Crane Feather Queen (CFQ), Crane Pink (CP), and Crane Bicolor (CB), were treated with the histone deacetylase (HDAC) inhibitor suberoylanilide hydroxamic acid (SAHA) to induce embryogenesis. The haploid 'CFQ' microspore plantlets were doubled with colchicine. The results for 'CFQ' revealed that, the appropriate concentration of SAHA was 0.03μM and obtained 17.27 embryos per bud. For 'CP,' the appropriate concentration of SAHA was 0.045μM and obtained 11.19 embryos per bud. For 'CB,' the appropriate concentration of SAHA was 0.045μM and obtained 6.10 embryos per bud. Haploid 'CFQ' microspore plantlets were treated with 75mg/L colchicine for 7 d and the doubling rate was 41.7%. Haploid 'CFQ' plantlets were treated with 1000mg/L colchicine by root-soaking for 4h and the doubling rate was 64.3%. SAHA could promote microspore embryogenesis, and colchicine root soaking was more effective than adding colchicine to the medium for haploid plantlet doubling in cut-flower ornamental kale.