TITLE:
Effect of Silicon (Si) Application on Phoenix dactylifera L. Growth under Drought Stress Induced by Polyethylene Glycol (PEG) in Vitro
AUTHORS:
Ahmed Madi Waheed Al-Mayahi
KEYWORDS:
Silicon (Si), Drought Stress, Polyethylene Glycol (PEG), Tissue Culturing, Antioxidant Activity, Waxy Layer
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.7 No.13,
September
8,
2016
ABSTRACT: This study was carried out to investigate the
effects of silicon (Si) 3.6 mM (as calcium silicate) under drought stress
induced by polyethylene glycol “PEG” at 15% (MW 8000), in addition to the
control treatment on growth and some biochemical constituents of date palm cv.
Barhee cultured in vitro. Drought stress (15% PEG) depressed the growth
of shoot and decreased protein content and chlorophyll concentration. Addition
of 3.6 mM Si could improve the growth of shoot and increase the protein content
and leaf chlorophyll concentrations of stressed plants. The inclusion of Si to
the PEG containing medium significantly increased the catalase (CAT) and
superoxide dismutase (SOD) activity in regenerated shoot, compared to other
treatments. As well as drought stress 15% PEG induced significant accumulation
of shoots proline, which were decreased by added silicon. Moreover, the results
were also supported by the observation that PEG stress-induced decrease the
response percentage of root induction and root lengths was reversed by added
silicon. Addition of Si obviously significantly increased the wax content in
leaves, response percentage of root induction and root lengths of plantlets under
drought stress. The results of this study indicate that the application of
silicon improved growth attributes, effectively mitigate the adverse effect of
drought, and increase tolerance of date palm plants for drought stress during
the course of date palm tissue cultures.