Abstract:
Waterlogging is one of the most devastating abiotic stresses which often results in
oxidative stress to plants. Sesame (Sesamum indicum L. cv. BARI Til-4) is extremely
susceptible to anaerobic environment induced by waterlogging and the
hypoxic/anoxic condition which results in the reduced growth and yield along with
the overproduction of various reactive oxygen species (ROS; O
1
O
2
iii
2
•
−
, OH
). The present study was designed to investigate the duration-dependent changes in
the morpho-physiological, anatomical and biochemical attributes of sesame to
waterlogging stress. The sesame plants were subjected to waterlogging for 2, 4 and 6
days at vegetative, reproductive and maturity stage of plant growth and the data were
measured after completion of the each treatment duration. A treatment with 8 days
waterlogging duration was added for the biochemical study. Present study proves that
waterlogging exerts severe damage effect on different physiological parameters and
yield attributes of sesame plant. The plants showed an increasing trend in the lipid
peroxidation, H
2
O
and methylglyoxal (MG) content with the increasing duration of
stress. Proline (Pro) content was slightly decreased along with the leaf relative water
content (RWC) with increasing duration of waterlogging. Photosynthetic pigments
like chlorophyll a, b, and total chlorophyll and carotenoid contents also decreased
with time in stressed plants. The content of glutathione (GSH) and oxidized
glutathione (GSSG) increased, while the ratio of GSH/GSSG and Ascorbate (AsA)
content decreased which indicates the the disruption of redox balance in the cell.
Activities of ascorbate peroxidase (APX), monodehydroascorbate reductase
(MDHAR) and glutathione peroxidase (GPX) increased, while the dehydroascorbate
2
reductase (DHAR), glutathione reductase (GR) and catalase (CAT) activities mostly
decreased. Waterlogging modulated the glyoxalase system mostly by enhancing
glyoxalse II (Gly II) activities with a slight increase in glyoxalse I (Gly I). So, the
present study also proves the induction of oxidative stress under waterlogging stress
in sesame plants and the enhancement of the stress level with increasing duration.
Description:
A Thesis
Submitted to the Faculty of Agriculture,
Sher-e-Bangla Agricultural University, Dhaka,
in partial fulfilment of the requirements
for the degree of
MASTER OF SCIENCE (MS)
IN
AGRONOMY
