Embryogenic callus formation from maize protoplasts.
Maize (Zea mays L.) protoplasts have been obtained which divide rapidly and produce a callus that differentiates to form somatic embryos. The somatic embryos can be induced to form roots and small leaf-like structures. The genotype was the hybrid A188xBlack Mexican Sweet. Protoplasts were prepared from an embryogenic suspension culture derived from a Type II callus which had been selected from Type I callus produced by immature zygotic embryos. The basal medium for the suspension culture was N6 (C.C. Chu et al., 1975, Scientia Sinica 18, 659-668). The 2,4-dichlorophenoxyacetic acid concentration of the suspension culture was critical for subsequent protoplast growth and was optimal at 4.0 mg.l. Protoplasts had to be cultured in a low-osmoticum medium (0.3 M mannitol) for subsequent cell divisions to occur. The protoplasts have been transformed transiently with the gene chloramphenicol acetyltransferase (CAT) containing the 35S promoter obtained from cauliflower mosaic virus (CaMV-35S).
Department of Botany and Plant Pathology, Purdue University, 47907, West Lafayette, IN, USA.
K K
KK
Kamo
K L
KL
Chang
M E
ME
Lynn
T K
TK
Hodges