In:
Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, Vol. 98, No. 8 ( 2001-04-10), p. 4788-4793
Abstract:
Methyl jasmonate is a plant volatile that acts as an important
cellular regulator mediating diverse developmental processes and defense responses. We have cloned the novel gene JMT encoding an S -adenosyl- l -methionine:jasmonic
acid carboxyl methyltransferase (JMT) from Arabidopsis
thaliana . Recombinant JMT protein expressed in Escherichia coli catalyzed the formation of methyl
jasmonate from jasmonic acid with K m value
of 38.5 μM. JMT RNA was not detected in young
seedlings but was detected in rosettes, cauline leaves, and developing flowers. In addition, expression of the gene was induced both locally
and systemically by wounding or methyl jasmonate treatment. This result suggests that JMT can perceive and respond to local and
systemic signals generated by external stimuli, and that the signals may include methyl jasmonate itself. Transgenic Arabidopsis overexpressing JMT had a
3-fold elevated level of endogenous methyl jasmonate without altering jasmonic acid content. The transgenic plants exhibited
constitutive expression of jasmonate-responsive genes, including VSP and PDF1.2 . Furthermore, the
transgenic plants showed enhanced level of resistance against the virulent fungus Botrytis cinerea . Thus, our data suggest
that the jasmonic acid carboxyl methyltransferase is a key enzyme for jasmonate-regulated plant responses. Activation of JMT expression leads to production of methyl jasmonate that could act as an
intracellular regulator, a diffusible intercellular signal transducer, and an airborne signal mediating intra- and interplant communications.
Type of Medium:
Online Resource
ISSN:
0027-8424
,
1091-6490
DOI:
10.1073/pnas.081557298
Language:
English
Publisher:
Proceedings of the National Academy of Sciences
Publication Date:
2001
detail.hit.zdb_id:
209104-5
detail.hit.zdb_id:
1461794-8
SSG:
11
SSG:
12
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