Recent Advances on Genetic and Physiological Bases of In Vitro Somatic Embryo Formation

Abstract

Somatic embryogenesis involves a broad repertoire of genes, and complex expression patterns controlled by a concerted gene regulatory network. The present work describes this regulatory network focusing on the main aspects involved, with the aim of providing a deeper insight into understanding the total reprogramming of cells into a new organism through a somatic way. To the aim, the chromatin remodeling necessary to totipotent stem cell establishment is described, as the activity of numerous transcription factors necessary to cellular totipotency reprogramming. The eliciting effects of various plant growth regulators on the induction of somatic embryogenesis is also described and put in relation with the activity of specific transcription factors. The role of programmed cell death in the process, and the related function of specific hemoglobins as anti-stress and anti-death compounds is also described. The tools for biotechnology coming from this information is highlighted in the concluding remarks.

Identification of LEC1, L1L and Polycomb Repressive Complex 2 genes and their expression during the induction phase of Medicago truncatula Gaertn. somatic embryogenesis

“…At present, only just residual data concerning the regulation of the process at the epigenetic level carried out by the Polycomb proteins are available, and all concern Arabidopsis. It is known that acquisition of embryogenic competency is related to transition from the somatic to the embryogenic state with activation of transcription factors among other from the LEC group which the prominent function is the specification of cotyledon identity (Altamura et al 2016). Since the Polycomb Repressive Complex 2 (PRC2) proteins takes part in transition from the vegetative …”

Somatic Embryogenesis. An Overview

“…It is interesting that many species require an initial shot of auxins, but thereafter the auxin must be degraded for SE to proceed (Chap. 10) (Altamura et al 2016). Clearly the onset of SE depends on a complex network of interactions among plant growth regulators, mainly auxins and cytokinins, during the early proembryogenic stages.…”

“…Unlike the initial belief that all plant cells are totipotents, it has been seen that it is necessary to create appropriate conditions for some of them to regain totipotency. Among the several factors that play a role in the induction of SE are the plant growth regulators, mainly auxins (Altamura et al 2016). It is interesting that many species require an initial shot of auxins, but thereafter the auxin must be degraded for SE to proceed (Chap.…”

Establishment of Pluripotent Cell Cultures to Explore Allelopathic Activity of Coffee Cells by Protoplast Co-Culture Bioassay Method

“…In glossaries, for example [ 7 ], stem cell developmental potency is classified into several types: unipotent, a stem cell able to develop into only one cell or tissue type; multipotent, a stem cell able to develop into more than one cell type of the plant body; pluripotent, a stem cell able to develop into most, but not all, cell types that constitute the body; and totipotent, a stem cell able to develop into all cell types. These are reflected by case studies that use various cell and tissue culture methodologies, such as callus culture, tracheary element formation, adventitious bud/root formation, and somatic embryogenesis [ 8 , 9 , 10 , 11 ]. However, to date, there are no definite and highly efficient standards for the regulation of stem cell development in in vitro plant cell and tissue cultures.…”