애기장대(Arabidopsis thaliana)의 엽육원형질체로부터 효율적인 식물체 재분화와 이들의 형태적 특성

Efficient Plant Regeneration from Mesophyll Protopiast of Arabidopsis thaliana and Morphological Characterization of Regenerants

Protoplasts were isolated from the leaf mesophyll tissue of in vitro 4-weeks-old Arabidopsts thallana and cultured in MS liquid medium supplemented with 2.0 mg/L NAA, 0.5 mg/L BAP and 9% mannitol in the dark at 25°C. When protoplast-derived microcolonies were dehydrated, the frequency of callus induction enhanced approximately 7-fold higher compared with non-dehydrated microcolonies in CP medium. Fifty callus lines were selected from dehydrated microcolonies. Shoots were efficiently initiated from the green spots of the selected shoot forming calli cultured on MS regeneration medium supplemented with 0.05 mg/L IAA, 7.0 mg/L 2-iP and 30 g/L sucrose under continous illumination for 4 weeks. Shoot regeneration frequencies (calli regenerating at least one shoot) were 3.5%~56%. Histological observations of shoot forming callus revealed that tracheary elements initiated from inner compact cells, and that meristemoids developed to shoot primordia and shoots. Roots were induced from these regenerating shoots on MS medium without phytohomones. These regenerants were successfully transplanted into potting soil. Morphological characterization of 50 protoplast-derived plants showed that the frequency of normal type was 78%. Key words: Protoplast-derived microcolonies, shoot forming calli, green spots, regenerants