Inhibition of NOS- like activity in maize alters the expression of genes involved in H2O2 scavenging and glycine betaine biosynthesis
Date
2018Author
Phillips, Kyle
Majola, Anelisa
Gokul, Arun
Keyster, Marshall
Ludidi, Ndiko
Egbichi, Ifeanyi
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Show full item recordAbstract
Nitric oxide synthase-like activity contributes to the production of nitric oxide in plants, which controls
plant responses to stress. This study investigates if changes in ascorbate peroxidase enzymatic
activity and glycine betaine content in response to inhibition of nitric oxide synthase-like activity are
associated with transcriptional regulation by analyzing transcript levels of genes (betaine aldehyde
dehydrogenase) involved in glycine betaine biosynthesis and those encoding antioxidant enzymes
(ascorbate peroxidase and catalase) in leaves of maize seedlings treated with an inhibitor of nitric
oxide synthase-like activity. In seedlings treated with a nitric oxide synthase inhibitor, transcript levels
of betaine aldehyde dehydrogenase were decreased. In plants treated with the nitric oxide synthase
inhibitor, the transcript levels of ascorbate peroxidase-encoding genes were down-regulated. We thus
conclude that inhibition of nitric oxide synthase-like activity suppresses the expression of ascorbate
peroxidase and betaine aldehyde dehydrogenase genes in maize leaves. Furthermore, catalase activity
was suppressed in leaves of plants treated with nitric oxide synthase inhibitor; and this corresponded
with the suppression of the expression of catalase genes. We further conclude that inhibition of nitric
oxide synthase-like activity, which suppresses ascorbate peroxidase and catalase enzymatic activities,
results in increased H2O2 content.