Ajmalicine production in methyl jasmonate-induced Catharanthus roseus cell cultures depends on Ca2+ level
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Cytosolic Ca2+ and jasmonate mediate signals that induce defense responses in plants. In this study, the interaction between Ca2+ and methyl jasmonate (MJ) in modulating defense responses was investigated by monitoring ajmalicine production in Catharanthus roseus suspension cultures. C. roseus suspensions were treated with nine combinations of CaCl2 (3, 23, and 43 mM) and MJ (0, 10, and 100 μM) on day 6 of growth. Increased Ca2+ influx through the addition of extracellular CaCl2 suppressed ajmalicine production in MJ-induced cultures. The highest ajmalicine production (4.75 mg/l) was observed when cells were treated with a low level of calcium (3 mM) combined with a high level of MJ (100 μM). In the presence of 3 mM CaCl2 in the medium, the addition of Ca2+ chelator EGTA (1, 2.5, and 5 mM) or Ca2+ channel blocker verapamil (1, 10, and 50 μM) to MJ-induced (100 μM) cultures on day 6 also inhibited ajmalicine production at higher levels of the Ca2+ inhibitors. Hence, ajmalicine production in MJ-induced C. roseus cultures depended on the intracellular Ca2+ concentration and a low extracellular Ca2+ concentration (3 mM) enhanced MJ-induced ajmalicine production.
KeywordsAjmalicine Calcium Catharanthus roseus Methyl jasmonate Signal transduction
This work was supported by the National Science Foundation (NSF-CAREER, Grant No. BES-0134511). We would like to thank Dr. Robert Verpoorte (University of Leiden, The Netherlands) for the C. roseus cultures and Pik Leng Wong for her insightful review of this manuscript.
- Cheng SH, Willmann MR, Chen HC, Sheen J (2002) Calcium signaling through protein kinases. The Arabidopsis calcium-dependent protein kinase gene family. Plant Physiol 129:469–485Google Scholar
- Gantet P, Imbault N, Thiersault M, Doireau P (1998) Necessity of a functional octadecanoid pathway for indole alkaloid synthesis by Catharanthus roseus cell suspensions cultured in an auxin-starved medium. Plant Cell Physiol 39:220–225Google Scholar
- Menke FLH, Champion A, Kijne JW, Memelink J (1999b) A novel jasmonate- and elicitor-responsive element in the periwinkle secondary metabolite biosynthetic gene Str interacts with a jasmonate- and elicitor-inducible AP2-domain transcription factor, ORCA2. EMBO J 18:4455–4463CrossRefPubMedGoogle Scholar
- Merillon J-M, Liu D, Huguet F, Chenieux J-C, Rideau M (1991) Effects of calcium entry blockers and calmodulin inhibitors on cytokinin-enhanced alkaloid accumulation in Catharanthus roseus cell cultures. Plant Physiol Biochem 29(3):289–296Google Scholar
- Moreno-Valenzuela OA, Minero-Garcia Y, Chan W, Mayer-Geraldo E, Carbajal E, Loyola-Vargas VM (2003) Increase in the indole alkaloid production and its excretion into the culture medium by calcium antagonists in Catharanthus roseus hairy roots. Biotechnol Lett 25:1345–1349CrossRefPubMedGoogle Scholar
- Odjakova M, Hadjiivanova C (2001) The complexity of pathogen defense in plants. Bulg J Plant Physiol 27:101–109Google Scholar
- Van der Fits L, Zhang H, Menke FLH, Deneka M, Memelink J (2000b) A Catharanthus roseus BPF-1 homologue interacts with an elicitor-responsive region of the secondary metabolite biosynthetic gene Str and is induced by elicitor via a JA-independent signal transduction pathway. Plant Mol Biol 44:675–685CrossRefPubMedGoogle Scholar