Autophagy is an evolutionary conserved catabolic process deemed to maintain or restore cellular and organismal homeostasis. In plants, basal autophagy is essential for growth and development, it is required for nutrient remobilization during senescence and nutrient deficiency, for removal of organelles and macromolecules formed during plant development or damaged by environmental stresses.
Tags: somatic embryogenesis
Cytological, Biochemical and Molecular Events of the Embryogenic State in Douglas-fir (Pseudotsuga menziesii [Mirb.])
Somatic embryogenesis techniques have been developed for most coniferous species, but only using very juvenile material. To extend the techniques’ scope, better integrated understanding of the key biological, physiological and molecular characteristics of embryogenic state is required. Therefore, embryonal masses (EMs) and non-embryogenic calli (NECs) have been compared during proliferation at multiple levels.
In summary, the exposure of Norway spruce EC to UV-B radiation at different stages of maturation had the strongest effect on cell viability of embryos at early stages of development and resulted in the inhibition of somatic embryo development and/or the substantial decrease in the number of embryos. The extent of cell damage was dependent on the UV-B dose applied, as well as the embryo developmental stage, and might be related to differentiation of the outermost cell layers and formation of protoderm.
Conifer somatic embryogenesis (SE) is a process driven by exogenously supplied plant growth regulators (PGRs). Exogenous PGRs and endogenous phytohormones trigger particular ontogenetic events. Complex mechanisms involving a number of endogenous phytohormones control the differentiation of cells and tissues, as well as the establishment of structures and organs. Most of the mechanisms and hormonal functions in the SE of conifers have not yet been described.
Repetitive somatic embryogenesis induced cytological and proteomic changes in embryogenic lines of Pseudotsuga menziesii (Mirb.)
This first report of cellular and molecular changes after repetitive somatic embryogenesis in conifers shows that each cycle enhanced the structure and singularization of EMs through modulation of growth regulator pathways, thereby improving the line´s embryogenic status.
Quantification of histochemical detection of polyphenolic compounds in somatic embryos of Norway spruce
Under standard cultivation conditions, Norway spruce somatic embryos (SEs) accumulate polyphenolic compounds mostly in the root cap. In response to UV-B, the accumulation of polyphenolics increases in protodermal cells and subprotodermal cortical cells and idioblasts in hypocotyl and cotyledons where they can attenuate UV-B stress. To quantify polyphenolic compounds accumulated in somatic embryos on the histological level resin sections were prepared, stained with Toluidine Blue.
The effect of different air humidity during desiccation on the development of Norway spruce somatic embryos
The objective of the study was to follow morphological, selected biochemical and transcriptional characteristics induced by various air humidity during desiccation of Norway spruce somatic embryos. The level of free polyamines lowered, higher forms of polyamines were favoured. Expression profiles of monitored genes were variously influenced by different relative air humidity. Our data proved, that desiccation of somatic embryos is metabolically active process highly affected by relative air humidity.
Somatic embryogenesis is a developmental process where a plant somatic cell dedifferentiate to a totipotent embryonic stem cell that has the ability to give rise to an embryo under appropriate conditions. Desiccation is the final phase of normal embryonic development in most angiosperms and appears to be important in the transition from embryogeny to the ability to germinate and form normal seedlings.
The process of plant somatic embryogenesis allows the acquisition of a large number of genetically identical individuals. That fact is used in practice to obtain a rich progeny from a minimal number of seeds. At the same time, somatic embryogenesis is an ideal system for studying the early stages of plant development. Somatic embryogenesis starts by the derivation of embryogenic culture, mostly from zygotic embryos.