Abstract
Somatic embryogenesis is a valuable tool for investigating the totipotency of plant cells. We have established a simple culture system for inducing somatic embryogenesis from germinating embryos of Arabidopsis thaliana. One day after sowing, germinating embryos of the Nossen accession were placed on agar-solidified Gamborg's B5 medium supplemented with 4.5 μM 2,4-dichlorophenoxyacetic acid. After 14 days, light-green somatic embryos had formed in the region around the shoot apical meristems. After transfer to phytohormone-free medium, the somatic embryos grew into seedlings with cotyledon-like organs and roots, and finally into mature plants. The expression of several embryo-specific genes was detected in somatic embryos, suggesting that the somatic embryos retain embryonic features. We examined the effect of genotype on the formation of somatic embryos from germinating embryos of 352 Arabidopsis accessions. The frequency of somatic embryo formation differed markedly between the accessions and ranged from 0 to 92%. This result indicates that somatic embryogenesis from Arabidopsis germinating embryos is strongly affected by genotype.
