AtSERK1 expression precedes and coincides with early somatic embryogenesis in Arabidopsis thaliana.
The Arabidopsis thaliana primordia timing (pt) mutant was transformed with an AtSERK1::GUS construct. Liquid cultures of this line were used to study the relationship between somatic embryogenesis and the expression of SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE (AtSERK1) as a marker for cells competent to form embryos. In order to search for the expression of AtSERK1::GUS during early stages of somatic embryogenesis, histochemical as well as immunochemical approaches were used for the detection of beta-glucuronidase (GUS). Four sites of AtSERK1 expression were found in the embryogenic cultures: in embryogenic callus, where primary somatic embryos developed; in the basal parts of primary somatic embryos; in the outer layers of cotyledons of primary somatic embryos where secondary embryos were formed; and in provascular and vascular strands of developing somatic embryos. The in vitro expression of AtSERK1::GUS coincides with embryogenic development up to the heart-shaped stage. Prior to the expression in embryos, AtSERK1 was expressed in single cells and small cell clusters, indicating that AtSERK1 indeed marks embryogenic competence. Its expression in (pro)vascular strands, suggests that embryogenic cells in tissue culture retain at least in part their original identity.
Salaj
Jan
J
Laboratory of Plant Cell Biology, Wageningen University, Arboretumlaan 4, 6703 BD Wageningen, The Netherlands; Institute of Plant Genetics and Biotechnology, Slovak Academy of Sciences, Akademicka 2, P.O. Box 39A, 950 07 Nitra 1, Slovak Republic.
von Recklinghausen
Iris R
IR
Laboratory of Plant Cell Biology, Wageningen University, Arboretumlaan 4, 6703 BD Wageningen, The Netherlands.
Hecht
Valerie
V
Laboratory of Biochemistry, Department of Agrotechnology and Food Sciences, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands; School of Plant Science, University of Tasmania, Private Bag 55, Hobart, Tasmania 7001, Australia.
de Vries
Sacco C
SC
Laboratory of Biochemistry, Department of Agrotechnology and Food Sciences, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands.
Schel
Jan H N
JHN
Laboratory of Plant Cell Biology, Wageningen University, Arboretumlaan 4, 6703 BD Wageningen, The Netherlands.
van Lammeren
André A M
AAM
Laboratory of Plant Cell Biology, Wageningen University, Arboretumlaan 4, 6703 BD Wageningen, The Netherlands.
D017360:Arabidopsis / Q000196:embryology / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D008954:Models, Biological; D009154:Mutation; D030821:Plants, Genetically Modified; D011494:Protein Kinases / Q000235:genetics* / Q000378:metabolism
D029681:Arabidopsis Proteins; D011494:Protein Kinases; C440035:SERK1 protein, Arabidopsis