Abstract
We investigated the impact of
Bacillus thuringiensis
as seed treatment and application with silicon on lettuce plants exposed to salinity levels (4 dS m
−1
and 8 dS m
−1
). Results revealed that leaves number, head weight, total yield, relative water content (RWC), and chlorophyll a and b declined considerably due to two salinity levels. Oxidative stress markers, i.e., hydrogen peroxide (H
2
O
2
), superoxide (O
2
−
), and lipid peroxidation (MDA) dramatically augmented in stressed plants. On the other hand, leaves number, total yield, RWC, and chlorophyll a, b in stressed lettuce plants were considerably enhanced because of the application of Si or
B. thuringiensis.
In contrast, EL%, MDA, and H
2
O
2
were considerably reduced in treated lettuce plants with Si and
B. thuringiensis
. In addition, the treatment with Si and
B. thuringiensis
increased head weight (g) and total yield (ton hectare-1), and caused up-regulation of proline and catalase, superoxide dismutase, peroxidase, and polyphenol oxidase activity in lettuce leaves under salinity conditions.