VASCULARIZATION OF ZYGOTIC AND SOMATIC EMBRYOS OF ARABIDOPSIS THALIANA

摘要

Somatic embryos were induced from immature zygotic embryos of Arabidopsis thaliana cultured oil Gamborg basal medium (135) supplemented with dichlorophenoxyacetic acid (2.4-D) at 5 mu M l(-1). The somatic embryos were of unicellular origin. The sequence of divisions and the orientation of newly formed walls resembled the Onagrad pattern of early embryogenesis. Histological studies revealed no connection between the somatic embryos and explant tissue. In contrast to zygotic embryos. in late heart-shaped somatic embryos both sieve and tracheary elements were present. The sieve elements that formed in somatic embryos were characterized by larger plates than normal sieve elements observed in seedlings. Typical features of the tracheary elements ill somatic embryos were irregular shape and thickening of the secondary walls.