Boron (B) toxicity is an important
environmental constraint that limits plant
growth and crop productivity worldwide. The
aim of the present study is mainly to
investigate the role played by silicon (Si),
calcium (Ca2+), and salicylic acid (SA) in
counteracting and ameliorating of B-induced
stress in canola plants at vegetative growth
stage. In this context, canola plants were
grown for 29 day period in soil cultures
supplied with different concentrations of
boron. Special emphasis was laid on the role
of the applied priming agents in modifying the
adverse effects of B-toxicity on the test
plants. B-treated canola plants generally
manifested a negligible change in superoxide
anion and H2O2 formation in the test plants. At
the highest B supply (100 ppm), canola leaves
exhibited significant increase in MDA and
SOD activity compared to absolute control.
Salicylic acid treatment significantly or nonsignificantly
stimulated the activity of SOD in
leaves of B or non-B-treated plants.
Furthermore Ca application induced
significantly the specific activity of
Glutathione reductase (GR) in B-treated test
plants. In addition silicon treatment
significantly enhanced the specific activity of
GR at 25 ppm B compared to absolute control
and corresponding stressed test plants.
Calcium and salicylic acid treatments partially
attenuated the activity of catalase (CAT)
compared to the reached results displayed by
B-stressed plants. The three applied priming
agents significantly or non-significantly
attenuated the activity of peroxidase (POD)
manifested by B-stressed test plants, but
generally failed to exhibit significant changes
in activity of ascorbate peroxidase (APX)
compared to absolute control. These
responses seemed to be of beneficial and
adaptive effects with awaiting more
determination.