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Plant Signal Behav

Title:		"Calcium-dependent protein kinases, CDPK4 and CDPK5, affect early steps of jasmonic acid biosynthesis in Nicotiana attenuata"
Author(s):		Hettenhausen C; Yang DH; Baldwin IT; Wu J;
Address:		"Department of Molecular Ecology; Max Planck Institute for Chemical Ecology; Jena, Germany"
Journal Title:		Plant Signal Behav
Year:		2013
Volume:		20121206
Issue:		1
Page Number:		e22784 -
DOI:		10.4161/psb.22784
ISSN/ISBN:		1559-2324 (Electronic) 1559-2316 (Print) 1559-2316 (Linking)
Abstract:		"Calcium-dependent protein kinases (CDPKs) modulate plant development and growth and are important regulators of biotic and abiotic stress responses. Recently it was found that simultaneously silencing Nicotiana attenuata NaCDPK4 and NaCDPK5 (IRcdpk4/5 plants) results in accumulation of exceptionally high JA levels after wounding or simulated herbivory treatments, which in turn induced high levels of defense metabolites that slowed the growth of Manduca sexta, a specialist insect herbivore. To investigate the mechanism by which NaCDPK4 and NaCDPK5 regulate JA accumulation, we analyzed the transcript levels of all important enzymes involved in JA biosynthesis, but these genes showed no differences between wild-type and IRcdpk4/5 plants. Moreover, the dynamics of JA were similar between these plants, excluding the possibility of decreased degradation rates in IRcdpk4/5 plants. To gain insight into the mechanism by which NaCDPK4 and NaCDPK5 regulate JA biosynthesis, free fatty acids, including C18:3, and (9S,13S)-12-oxo-phytodienoic acid (OPDA), two important precursors of JA were quantified at different times before and after wounding and simulated herbivore feeding treatments. We show that after these treatments, IRcdpk4/5 plants have decreased levels of C18:3, but have enhanced OPDA and JA levels, suggesting that NaCDPK4 and NaCDPK5 have a role in the early steps of JA biosynthesis. The possible role of NaCDPK4 and NaCDPK5 regulating AOS and AOC enzymatic activity is discussed"
Keywords:		"Cyclopentanes/*metabolism Fatty Acids, Unsaturated/metabolism Oxylipins/*metabolism Plant Growth Regulators/*biosynthesis Plant Proteins/*metabolism Protein Kinases/*metabolism Tobacco/enzymology/*metabolism Cdpk defense herbivore insect jasmonic acid wou;"
Notes:		"MedlineHettenhausen, Christian Yang, Da-Hai Baldwin, Ian T Wu, Jianqiang eng 2012/12/12 Plant Signal Behav. 2013 Jan; 8(1):e22784. doi: 10.4161/psb.22784. Epub 2012 Dec 6"