Background: Ascorbic acid (Asc) is one of the most abundant antioxidants and it
serves as amajor contributor to
protect plants against oxidative damage. Plants use two enzymes that participate in the metabolic recycling of
Asc. One of these two enzymes is dehydroascorbate reductase (DHAR). It directly regenerates Asc from its
oxidized state and thus prevents Asc from being irreversibly hydrolyzed to 2, 3-diketogulonic acid. This study
aimed to examine whether over-expression of DHAR leads to an enhanced oxidative stress tolerance in
tobacco plants.
Results: In this study, we functionally characterized a novel JcDHAR gene from
Jatropha curcas
and found via
quantitative RT-PCR analysis that JcDHAR can be induced with H
2O
2, salt and PEG stresses. The DHAR activities
of transgenic tobacco plants increased from 2.0 to 5.3 fold compared to wild-type plants. As a result, the
transgenic plants displayed enhanced tolerance to oxidative stress.
Conclusions: Our results indicate that JcDHAR expression can effectively enhance the tolerance to oxidative stress
in plants.