ORAL PRESENTATIONS
December 4–6, 2019, Kraków, Poland
Vol. 61, suppl. 1, 2019 17
Cyathea delgadii as a model in the study of symplasmic communication
during somatic embryogenesis
Małgorzata Grzyb1, Justyna Wróbel-Marek2, Ewa Kurczyńska2, Anna Mikuła1
1 Polish Academy of Sciences Botanical Garden–Center for Biological Diversity Conservation in Powsin,
Prawdziwka 2, 02-973 Warsaw, Poland, e-mail: m. grzyb@ obpan. pl
2 Department of Cell Biology, University of Silesia, Jagiellońska 28, 40-032 Katowice, Poland
Somatic embryogenesis (SE) is one of the most
widely analyzed methods of plants in vitro
propagation. Although, until 2015 this regeneration
path was not available to any Monilophyta
representative. Using the tree fern Cyathea
delgadii Sternb., we established an effective system
of SE in which embryos can be induced directly
from explants cultured on hormone-free medium
(Mikuła et al., 2015). Depending on the type of
initial explant used, the base of somatic embryo
formation are the divisions of single epidermal cell
or a group of neighboring cells including epidermis
and cortex. Moreover, the path of embryo formation
can be reversed from multi-to unicellular origin, by
stress treatment with high sucrose solution (Grzyb
and Mikuła, 2019). The unique course of somatic
embryo formation in
C. delgadii allows for investigating these
aspects of SE that were not available so far. Among
them, the role of symplasmic communication,
which is still poorly understood during
embryogenic transition and explored only in the
group of seed plants. Thus, the aim of the study
was to analyze the correlation between changes in
symplasmic communication and cell differentiation
during SE of C. delgadii.
The research was carried out using etiolated
sporophytes of C. delgadii as a source of initial
explants (stipe and internode), that giving embryos
of single-and multicellular origin, respectively.
To show the dynamics of changes in symplasmic
communication the low-molecular weight fuoro-
chromes of symplasmic transport, such as
8-hydroxypyrene-1, 3, 6-trisulfonic acid, trisodium
salt (HPTS) and fluorescein diacetate (FDA), were
used. The confocal microscopy analyzes were
performed on initial explants, and explants before
and after embryogenic divisions.
Our studies showed that cell differentiation
at different stages of SE in C. delgadii depend on
the symplasmic continuity within explants. Both,
the embryogenic transition and somatic embryo
formation were preceded by the changes in the
fluorochromes flow within the explant and the
cells of embryo. The differences in symplasmic
connection between SE induced by uni-and
multicellular path will be discussed.
ACKNOWLEDGEMENTS
This research was supported by the Polish National
Center for Science, no. 2017/27/N/NZ3/00434.
REFERENCES
GRZYB M, and MIKUŁA A. 2019. Explant type and stress treat-
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