Abstract
Using an invitro system composed of crushed leaf tissues to simulate the wounding response in rice leaves, we established that synthesis of jasmonic acid (JA) and jasmonic acid-isoleucine (JA-Ile) can only occur in unwounded tissue and, in wounded tissue, that only the chloroplast-located section of the octadecanoid pathway is active, resulting in the accumulation of 12-oxo-phytodienoic acid (OPDA). We further showed that OPDA accumulation invitro was inhibited by 90% using the general lipase inhibitor, tetrahydrolipstatin, indicating that production of α-linolenic acid was the rate-limiting step in octadecanoid pathway activity in rice following wounding and the enzyme capacity for an active pathway was already present. We confirmed this result by showing that added α-linolenic acid stimulated OPDA synthesis invitro and stimulated OPDA, JA and JA-Ile synthesis invivo in unwounded tissue. Thus, the response to wounding can be mimicked by the provision of free α-linolenic acid. Our results draw attention to the key importance of lipase activity in initiation of JA and JA-Ile biosynthesis and our lack of knowledge of the cognate lipase(s), lipase substrate identity and mechanism(s) of activation in wounded and unwounded tissue.
| Original language | English |
|---|---|
| Pages (from-to) | 117-125 |
| Number of pages | 9 |
| Journal | Plant Physiology and Biochemistry |
| Volume | 83 |
| DOIs | |
| Publication status | Published - 2014 |
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Keywords
- 12-oxo-phytodienoic acid
- Jasmonic acid
- Octadecanoid pathway
- Oryza sativa
- α-Linolenic acid
ASJC Scopus subject areas
- Plant Science
- Genetics
- Physiology
- Medicine(all)
Cite this
α-Linolenic acid concentration and not wounding per se is the keyregulator of octadecanoid (oxylipin) pathway activity in rice (Oryza sativa L.) leaves. / Christeller, John T.; Galis, Ivan.
In: Plant Physiology and Biochemistry, Vol. 83, 2014, p. 117-125.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - α-Linolenic acid concentration and not wounding per se is the keyregulator of octadecanoid (oxylipin) pathway activity in rice (Oryza sativa L.) leaves
AU - Christeller, John T.
AU - Galis, Ivan
PY - 2014
Y1 - 2014
N2 - Using an invitro system composed of crushed leaf tissues to simulate the wounding response in rice leaves, we established that synthesis of jasmonic acid (JA) and jasmonic acid-isoleucine (JA-Ile) can only occur in unwounded tissue and, in wounded tissue, that only the chloroplast-located section of the octadecanoid pathway is active, resulting in the accumulation of 12-oxo-phytodienoic acid (OPDA). We further showed that OPDA accumulation invitro was inhibited by 90% using the general lipase inhibitor, tetrahydrolipstatin, indicating that production of α-linolenic acid was the rate-limiting step in octadecanoid pathway activity in rice following wounding and the enzyme capacity for an active pathway was already present. We confirmed this result by showing that added α-linolenic acid stimulated OPDA synthesis invitro and stimulated OPDA, JA and JA-Ile synthesis invivo in unwounded tissue. Thus, the response to wounding can be mimicked by the provision of free α-linolenic acid. Our results draw attention to the key importance of lipase activity in initiation of JA and JA-Ile biosynthesis and our lack of knowledge of the cognate lipase(s), lipase substrate identity and mechanism(s) of activation in wounded and unwounded tissue.
AB - Using an invitro system composed of crushed leaf tissues to simulate the wounding response in rice leaves, we established that synthesis of jasmonic acid (JA) and jasmonic acid-isoleucine (JA-Ile) can only occur in unwounded tissue and, in wounded tissue, that only the chloroplast-located section of the octadecanoid pathway is active, resulting in the accumulation of 12-oxo-phytodienoic acid (OPDA). We further showed that OPDA accumulation invitro was inhibited by 90% using the general lipase inhibitor, tetrahydrolipstatin, indicating that production of α-linolenic acid was the rate-limiting step in octadecanoid pathway activity in rice following wounding and the enzyme capacity for an active pathway was already present. We confirmed this result by showing that added α-linolenic acid stimulated OPDA synthesis invitro and stimulated OPDA, JA and JA-Ile synthesis invivo in unwounded tissue. Thus, the response to wounding can be mimicked by the provision of free α-linolenic acid. Our results draw attention to the key importance of lipase activity in initiation of JA and JA-Ile biosynthesis and our lack of knowledge of the cognate lipase(s), lipase substrate identity and mechanism(s) of activation in wounded and unwounded tissue.
KW - 12-oxo-phytodienoic acid
KW - Jasmonic acid
KW - Octadecanoid pathway
KW - Oryza sativa
KW - α-Linolenic acid
UR - http://www.scopus.com/inward/record.url?scp=84907371778&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84907371778&partnerID=8YFLogxK
U2 - 10.1016/j.plaphy.2014.07.013
DO - 10.1016/j.plaphy.2014.07.013
M3 - Article
C2 - 25129550
AN - SCOPUS:84907371778
VL - 83
SP - 117
EP - 125
JO - Plant Physiology and Biochemistry
JF - Plant Physiology and Biochemistry
SN - 0981-9428
ER -