This view shows enzymes only for those organisms listed below, in the list of taxa known to possess the pathway. If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.
|Superclasses:||Biosynthesis → Secondary Metabolites Biosynthesis → Terpenoids Biosynthesis → Sesquiterpenoids Biosynthesis|
Expected Taxonomic Range: Pinidae
Oleoresin (also simply termed 'resin' or 'pitch') is a viscous secretion common in coniferous trees, which is involved in the chemical and physical defense of conifers against predators (such as bettles and fungal pathogens). The accumulated resin is released upon tissue injury and/or produced at the site of infestation (for review, see [Trapp01]). The predator is killed, encased in resin and expelled from the bore point of entry (a process called 'pitching out'). This process has the dual function of killing and expelling the predator, but also to form a physical barrier around the wound through evaporation of the oleoresin turpentine which allows the resin acids to seal the wound [Croteau85, Gijzen93]. Oleoresin is composed in roughly equal parts of volatile turpentine (a mixture of monoterpenes and sesquiterpenes) and rosin (also known as diterpene resin acids). The exact composition of turpentine and rosin varies from one conifer species to the next, as well as depending on the resin-producing tissue analyzed [Trapp01]. The main constituents of these fractions have been regrouped in the following pathways: superpathway of oleoresin turpentine biosynthesis and superpathway of diterpene resin acids biosynthesis.
Concerning this pathway:
Compared to monoterpenes, fewer sesquiterpene synthases from conifers have been identified and studied to date. Generally, the longer chain of (2E,6E)-farnesyl diphosphate compared to that of geranyl diphosphate, and the additional double bond, allows for a greater diversity of products being formed by those enzymes. Two coniferous enzymes γ-humulene synthase and δ-selinene synthase from Grand Fir (Abies grandis) produces each in excess of 30 different sesquiterpenes olefins. In contrast, (E)-α-bisabolene synthase catalyzes only the synthesis of (E)-α-bisabolene [Bohlmann98]. Importantly, this compound has been shown to be converted by methyl-jasmonate-induced suspension cell cultures of Grand Fir into todomatuic acid, a sesquiterpene derivative structurally similar to the insect juvenile hormone III [Bohlmann98], and can disrupt insect reproduction and/or larval development [Trapp01].
Superpathways: superpathway of oleoresin turpentine biosynthesis
Bohlmann98: Bohlmann J, Crock J, Jetter R, Croteau R (1998). "Terpenoid-based defenses in conifers: cDNA cloning, characterization, and functional expression of wound-inducible (E)-alpha-bisabolene synthase from grand fir (Abies grandis)." Proc Natl Acad Sci U S A 95(12);6756-61. PMID: 9618485
Gijzen93: Gijzen M., Lewinsohn E., Croteau R. (1993). "Conifer monoterpenes: biochemistry and bark beetle chemical ecology." In Bioactive volatile compounds from plants, eds R. Teranishi, R.G. Buttery, H. Sugisawa, pp. 8-22, Washington DC: Am. Chem. Soc.
Martin04a: Martin DM, Faldt J, Bohlmann J (2004). "Functional characterization of nine Norway Spruce TPS genes and evolution of gymnosperm terpene synthases of the TPS-d subfamily." Plant Physiol 135(4);1908-27. PMID: 15310829
Steele98: Steele CL, Crock J, Bohlmann J, Croteau R (1998). "Sesquiterpene synthases from grand fir (Abies grandis). Comparison of constitutive and wound-induced activities, and cDNA isolation, characterization, and bacterial expression of delta-selinene synthase and gamma-humulene synthase." J Biol Chem 273(4);2078-89. PMID: 9442047
ByunMcKay06: Byun-McKay A, Godard KA, Toudefallah M, Martin DM, Alfaro R, King J, Bohlmann J, Plant AL (2006). "Wound-induced terpene synthase gene expression in Sitka spruce that exhibit resistance or susceptibility to attack by the white pine weevil." Plant Physiol 140(3);1009-21. PMID: 16415217
Cheng07: Cheng AX, Xiang CY, Li JX, Yang CQ, Hu WL, Wang LJ, Lou YG, Chen XY (2007). "The rice (E)-beta-caryophyllene synthase (OsTPS3) accounts for the major inducible volatile sesquiterpenes." Phytochemistry 68(12);1632-41. PMID: 17524436
Kollner08: Kollner TG, Held M, Lenk C, Hiltpold I, Turlings TC, Gershenzon J, Degenhardt J (2008). "A maize (E)-beta-caryophyllene synthase implicated in indirect defense responses against herbivores is not expressed in most American maize varieties." Plant Cell 20(2);482-94. PMID: 18296628
Kopke08: Kopke D, Schroder R, Fischer HM, Gershenzon J, Hilker M, Schmidt A (2008). "Does egg deposition by herbivorous pine sawflies affect transcription of sesquiterpene synthases in pine?." Planta 228(3);427-38. PMID: 18493792
Little02: Little DB, Croteau RB (2002). "Alteration of product formation by directed mutagenesis and truncation of the multiple-product sesquiterpene synthases delta-selinene synthase and gamma-humulene synthase." Arch Biochem Biophys 402(1);120-35. PMID: 12051690
Mercke04: Mercke P, Kappers IF, Verstappen FW, Vorst O, Dicke M, Bouwmeester HJ (2004). "Combined transcript and metabolite analysis reveals genes involved in spider mite induced volatile formation in cucumber plants." Plant Physiol 135(4);2012-24. PMID: 15310834
Schilmiller10: Schilmiller AL, Miner DP, Larson M, McDowell E, Gang DR, Wilkerson C, Last RL (2010). "Studies of a biochemical factory: tomato trichome deep expressed sequence tag sequencing and proteomics." Plant Physiol 153(3);1212-23. PMID: 20431087
Tholl05: Tholl D, Chen F, Petri J, Gershenzon J, Pichersky E (2005). "Two sesquiterpene synthases are responsible for the complex mixture of sesquiterpenes emitted from Arabidopsis flowers." Plant J 42(5);757-71. PMID: 15918888
Yu08a: Yu F, Okamto S, Nakasone K, Adachi K, Matsuda S, Harada H, Misawa N, Utsumi R (2008). "Molecular cloning and functional characterization of alpha-humulene synthase, a possible key enzyme of zerumbone biosynthesis in shampoo ginger (Zingiber zerumbet Smith)." Planta 227(6);1291-9. PMID: 18273640
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