Research review paper Elicitor signal transduction leading to production of plant secondary metabolites Jian Zhao a, T , Lawrence C. Davis b , Robert Verpoorte c a Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA b Department of Biochemistry, Kansas State University, Manhattan, KS 66506, USA c Division of Pharmacognosy, Section Metabolomics, Institute of Biology, Leiden University, NL-2300 RA, Leiden, The Netherlands Received 28 November 2004; received in revised form 27 January 2005; accepted 31 January 2005 Available online 13 March 2005 Abstract Plant secondary metabolites are unique sources for pharmaceuticals, food additives, flavors, and other industrial materials. Accumulation of such metabolites often occurs in plants subjected to stresses including various elicitors or signal molecules. Understanding signal transduction paths underlying elicitor-induced production of secondary metabolites is important for optimizing their commercial production. This paper summarizes progress made on several aspects of elicitor signal transduction leading to production of plant secondary metabolites, including: elicitor signal perception by various receptors of plants; avirulence determinants and corresponding plant R proteins; heterotrimeric and small GTP binding proteins; ion fluxes, especially Ca 2+ influx, and Ca 2+ signaling; medium alkalinization and cytoplasmic acidification; oxidative burst and reactive oxygen species; inositol 0734-9750/$ - see front matter D 2005 Elsevier Inc. All rights reserved. doi:10.1016/j.biotechadv.2005.01.003 Abbreviations: ACC, 1-aminocyclopropane-1-carboxylic acid; ADPR, ADP-ribose; AFLP, amplified fragment length polymorphism; AOS, allene oxide synthase; CDPK, Ca 2+ -dependent protein kinases; CHS, chalcone synthase; DAG, diacylglycerol; ERF, ethylene response factors; EST, expressed sequence tags; G- proteins, GTP-binding proteins; GSH, glutathione; HPL, hydroperoxide lyase; IP 3 , Inositol-1,4,5-trisphosphate; JA, jasmonic acid; MAPK, mitogen-activated protein kinase; lysoPC, lysophosphatidylcholine; MeJA, methyl jasmonate; OPDA, 12-oxo-PDA; PA, phosphatidic acid; PAL, phenylalanine ammonia lyase; PC, phosphati- dylcholine; PKC, protein kinase C; PLA, phospholipase A; PLC, phospholipase C; PLD, phospholipase D; PMT, pinosylvin-O-methyltransferase gene; ROS, reactive oxygen species; SA, salicylic acid; STS, stilbene synthase. T Corresponding author. Tel.: +1 713 798 7039; fax: +1 713 798 7817. E-mail addresses: jzhao1@bcm.tmc.edu (J. Zhao)8 ldavis@ksu.edu (L.C. Davis)8 verpoort@chem.leidenuniv.nl (R. Verpoorte). Biotechnology Advances 23 (2005) 283 – 333 www.elsevier.com/locate/biotechadv