Universit?? de Strasbourg researchers reported in/The Plant Journal/that
suppressing jasmonate signaling reduction in Arabidopsis JASMONIC ACID
OXIDASE mutants led to broad-spectrum stress tolerance.

Jasmonate signaling for adaptive and developmental responses is
controlled by the boost of the hormone called jasmonoyl-isoleucine
(JA-Ile), which is triggered by internal or external cues. In a previous
study by the same team, it was shown that JAO2, an isoform of four
Arabidopsis JASMONIC ACID OXIDASES, diverts the precursor jasmonic acid
to its hydroxylated form HO-JA to reduce JA-Ile formation and signaling.
This led to/JAO2/-deficient lines with improved defenses and better
tolerance to biotic stress. In a follow up study, the researchers
further studied the organization and regulatory functions of the JAO
pathway.

Results showed that the suppression of the JAO2 improved the expression
of about 400 JA-regulated genes in unstimulated leaves, which are mostly
linked to biotic and abiotic stress responses. Furthermore,/jao2/alleles
and a triple/jao/mutant showed enhanced survival capacity under severe
drought stress.

Broad�spectrum stress tolerance conferred by suppressing jasmonate
signaling attenuation in Arabidopsis JASMONIC ACID OXIDASE mutants -
Marquis - - The Plant Journal - Wiley Online Library
[onlinelibrary.wiley.com]