Monika MAHAJAN 
Punjab Agricultural University-Regional Research Station, Bathinda,
Punjab – India
https://10.47743/jpd.2022.29.1.909
Keywords: ploidy, endoreduplication, petal, florescent
activated cell sorter, Arabidopsis.
Abstract: Endoreduplication is alternative form
of cell cycle that involves the replication of DNA without mitosis.
It commonly occurs in various tissues of plants like pavement
cells of leaf, trichomes and sepals of flower and led to increase
in size of the cell. Shoot apical meristem (SAM) is a region from
where the aboveground organs of the plant arise. The cells in
the meristem remain in meristematic state (mitotic) and get displaced
from there to form the differentiated tissues. But how the nuclear
DNA synthesis vary from the meristematic cells to the differentiated
tissues is not very well studied. It has been observed through
the present study that the cells in shoot tip of Arabidopsis
are diploid in nature and starts to endoreduplicate at 1cm away
from the shoot, down the stem which was justified by the flow
cytometer-based DNA analysis of different Arabidopsis
tissues. Petal is known to be the most variable part of the flower
with different color, shape, size and fragrance but little is
known about its characterization. The cell identities in petal
are diverse with different cell types. One is small sized distal
cells and the other is large sized proximal cells. The present
study has addressed that the large size of proximal cells of petal
is not merely a cell expansion but is something related to endoreduplication.
This was evidenced by the DNA estimation of FACS (Florescent activated
cell sorter) sorted petal cells of Arabidopsis. This
is the first study in which SAM, stem, leaf and petal cells are
taken into account for ploidy analysis by flow cytometry. In shoot
apex we did not see endoreduplication however as the cells descend
towards the stem or leaf they enter into differentiation pathways
and undergo endoreduplication. On the other hand, different ploidies
in petal cells shows the signs of endoreduplication which can
be a way towards differentiation.
How to cite this article:
MAHAJAN M. 2022. Investigating early signs of endoreduplication
in Arabidopsis shoot: an unknown fact. J. Plant Develop.
29: 45-53.
https://doi.org/10.47743/jpd.2022.29.1.909
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