Investigations into the mechanisms of somatic embryogenesis (SE) have largely focused on the hormonal regulation of the process
and a repertoire of strategies has been developed to regenerate many species via SE. However, the genes that regulate the
induction and development of somatic embryos have not been defined. In the recent times, regeneration via overexpression of
genes, such as
WUSCHEL or
LEAFY COTYLEDON, in
Arabidopsis has started to provide a basis for understanding the genes involved in SE. This has gone hand in hand with the availability
of genome sequence information and the availability of mutants in model plants such as
Arabidopsis and
Medicago. An improved understanding of zygotic embryogenesis and the maintenance and differentiation of stem cells in the shoot meristem
also helps to provide novel insights into the mechanisms of SE. This review examines the current understanding of the genetic
regulation of SE in the context of current molecular understanding of plant development.
Key words
Arabidopsis
-
Medicago truncatula
- plant development - plant hormones - plant stress - receptors - somatic embryogenesis - transcription regulation