A carrot somatic embryo mutant is rescued by chitinase.
At the nonpermissive temperature, somatic embryogenesis of the temperature-sensitive (ts) carrot cell mutant ts11 does not proceed beyond the globular stage. This developmental arrest can be lifted by the addition of proteins secreted by wild-type cells to the culture medium. From this mixture of secreted proteins, a 32-kD glycoprotein, designated extracellular protein 3 (EP3), that allows completion of somatic embryo development in ts11 at the nonpermissive temperature was purified. On the basis of peptide sequences and biochemical characterization, EP3 was identified as a glycosylated acidic endochitinase. The addition of the 32-kD endochitinase to ts11 embryo cultures at the nonpermissive temperature appeared to promote the formation of a correctly formed embryo protoderm. These results imply that a glycosylated acidic endochitinase has an important function in early plant somatic embryo development.
De Jong
A J
AJ
Department of Molecular Biology, Agricultural University of Wageningen, The Netherlands.
Cordewener
J
J
Lo Schiavo
F
F
Terzi
M
M
Vandekerckhove
J
J
Van Kammen
A
A
De Vries
S C
SC
D000595:Amino Acid Sequence; D002688:Chitinases / Q000302:isolation & purification / Q000378:metabolism / Q000502:physiology*; D046508:Culture Techniques; D004591:Electrophoresis, Polyacrylamide Gel; D008969:Molecular Sequence Data; D009154:Mutation; D010944:Plants / Q000196:embryology / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid; D013696:Temperature
D002688:Chitinases