Ascorbate oxidation primes rice plants for enhanced defence against root-knot nematode Meloidogyne graminicola through jasmonate/ethylene-activation

Ascorbic acid (AA) is known to play a vital role in plant growth and detoxification of reactive oxygen species, however little is known about the significance of AA oxidation in plant defence against pathogens. • The role of ascorbate oxidation in rice defence against root-knot nematodes, Meloidogyne graminicola, was tested with application of AA, ascorbate oxidase (AO), dehydroascorbic acid (DHA), biosynthesis inhibitors and use of mutants. Transcriptome analysis was done on AO treated plants, and hormone measurements were executed to confirm the results. Biochemical analyses were used to study oxidative stress markers, including accumulation of H2O2, , malondialdehyde and AA/DHA. The expression profile of ascorbate oxidase treated plants is compared to untreated plants both for plants infected with Meloidigyne graminicola as for uninfected plants. Three replicates for each group. Each sample was multiplexed in four subsamples.