Butll. Inst. Cat. Hist. Nat., 64:125-133. 1996 SISTEMES I PROCESSOS SISTEMES I PROCESSOS plantes recorden exposicions prèvies i produei- PALABRAS CLAVE: Terpenoides; lenguaje ve- xen terpens (i compostos d’altres llenguatges getal; comunicación planta-planta, planta- químics com els dels fenols o els dels alca- loides) quan els necessiten. Per tant, les plan- animal y planta-microorganismos; memoria. tes també tenen llenguatges i el dels Terpenoids and Plant Communication terpenoids n’és un dells. MOTS CLAU: Terpenoids; llenguatge vegetal; Introduction Joan Llusià, Marc Estiarte & Josep Peñuelas* comunicació planta-planta, planta-animal, planta-microorganismes; memòria. Increasing recognition of the ecological Rebut: 3.10.95 Acceptat: 29.04.96 importance of terpenoids is reflected by the Resumen several recent reviews of the ecological chemistry and role of terpenoids (Harborne, Los terpenoides y la comunicación Abstract KEYWORDS: Terpenoids, plant language, plant- 1991; Gershenzon & Croteau, 1991; Lerdau plant, plant-animal and plant-microorganism vegetal & Peñuelas, 1993; Langenheim, 1994; Terpenoids are compounds containing an inte- communication, memory. Gershenzon, 1994). A defensive role has ger number of 5C units, the «syllables». There Los terpenoides son compuestos que contienen persistently been presented as the main role is an astonishing array of structures, the un número integral de cinco unidades de carbo- and the function of secondary compounds, «words», resulting from the sequential no, las «sílabas». Existe un sorprendente núme- combination of these basic five-carbon units Resum ro de estructuras, las «palabras», que resultan including terpenoids, since the field of in the familiar categories of C10 (mono-), C15 de la combinación secuencial de estas unidades chemical ecology developed essentially básicas de cinco carbonos en categorías de C10 (sesqui-), C20 (di-), C30 (tri-) C40 (tetra-) and Els Terpenoids i la comunicació vegetal arround the concept of coevolution (Feeny, C>40 (poly-) terpenoids. Terpenoids are induced (mono-), C15 (sesqui-), C20 (di-), C30 (tri-), C40 1992). However, the fact that higher plant and emitted in response to internal (genetic (tetra-) i C>40 (poli-) terpenoides. Los terpe- and biochemical) and external (ecological) Els terpenoids són compostos que contenen noides son inducidos y emitidos en respuesta a terpenoids result in mediation of numerous factors, both abiotic and biotic. They are un nombre integral de cinc unitats de carboni, factores internos (genéticos y bioquímicos) y kinds of ecological interactions makes them emitted in quantitatively and qualitatively les «sil·labes». Hi ha un sorpenent nombre externos (ecológicos), tanto abióticos como d’estruc-tures, les «paraules», que resulten de also act as infochemicals (Dicke & Sabelis, diverse blends, the «messages», that arrive bióticos. Son emitidos en mezclas cuantitativa 1988). There is also a lively debate on the to the environment either through la combinació seqüencial d’aquestes unitats y cualitativamente diversas, los «mensajes», volatilization (mono- and sesquiterpenes), bàsiques de cinc carbonis en categories de los cuales llegan al ambiente a través de la vo- ecological and evolutionary significance of leaching or decomposition of plant debris. C10 (mono-), C15 (sesqui-), C20 (di-), C30 (tri- latilización (mono- y sesquiterpenos), la li- plant communication (Langenheim, 1994; Their information or effect is received and res- ), C40 (tetra-) i C>40 (poli-) terpenoids. Els xiviación, o la descomposición de los restos Bruin et al., 1995). We have proposed to ponded by other parts of the plant, other terpenoids són induïts i emesos en resposta a vegetales. Su información es recibida por otras factors interns (genètics i bioquímics) i externs merge both subjects, terpenoids and plant plants, animals and microorganisms. partes de la planta, por otras plantas, por ani- (ecològics), tant abiòtics com biòtics. Són Part of such terpenoid «words» are common males y por microorganismos. communication, by approaching terpenoids emesos en barreges quantitativament i to all plants. For example, carotenoids, Alguno de estos terpenoides («palabras») son as a chemical «language» of plants (Pe- qualitativa diverses, els «missatges», els quals chlorophylls or hormones such as cytokinins, comunes a todas las plantas. Por ejemplo, los arriben a l’ambient a través de la volatilització ñuelas et al., 1995a). Here we present the gibberellins, or abscicic acid, are terpenoid carotenoides, las clorofilas, algunas hormo- derivatives. But there are also «dialects» of (mono- i sesquiterpens), la lixiviació, o la development of such approach. Terpenoids descomposició de les restes vegetals. La seva nas como las citoquininas, las giberelinas o the terpenoid «language» that are qualitatively el ácido abscísico son derivados terpénicos. are emitted in response to internal and or quantitatively characteristic of each family informació és rebuda per altres parts de la external factors, and their information or planta, per altres plantes, per animals i per Pero también existen «dialectos» del «lengua- and each species, or even each cultivar and je» de los terpenos que son cualitativamente effect is received and responded by other each organ of the plant. They even seem to be microorganismes. Algun d’aquests terpenoids («paraules») són o cuantitativamente característicos de cada parts of the plant, other plants, animals and kept in «memory». Some plants might remember familia y de cada especie y, a menudo, de previous exposures and produce terpenes (and comuns a totes les plantes. Per exemple, els microorganisms. A survey of recently carotenoids, les clorofil·les o hormones com cada cultivar y de cada órgano de la planta. compounds of other chemical languages such Incluso parece ser que algunas plantas re- recorded ecological effectivity of terpenoids as phenolics or alkaloids) when they are ara les citoquinines, les giberelines o l’àcid abscísic són derivats terpènics. Però també hi cuerdan exposiciones previas y producen shows it to be concentration or dosage needed. Thus, plants also have languages, and terpenos (y compuestos de otros lenguajes that of terpenoids is one of them. ha «dialectes» del «llenguatge» dels terpens dependent (Harborne, 1991). For example, que són qualitativament o quantitativament químicos como los de los fenoles o los de los biological reaction of insects to terpenoids característics de cada família i de cada espè- alcaloides) cuando los necesitan. Por tanto, *Centre de Recerca Ecològica i Aplicacions Forestals cie, i sovint de cada cultivar i de cada òrgan las plantas también tienen «lenguajes» y el characteristically is one of attraction or (CREAF), Facultat de Ciències, Universitat Autònoma, de los terpenoides es uno de ellos. stimulation at low concentrations, with the E-08193 Bellaterra, Barcelona. de la planta. Fins i tot sembla ser que algunes 125 126 SISTEMES I PROCESSOS response becoming increasingly of repellence considerable ecological consequences 1994). There can even be a possible role of Allelochemicals and allelopathy. or inhibition as the concentration increases (Langenheim, 1994). They play an important biotic selection pressures in determining the Reese (1979) used the term «allelochemi- (Lovett, 1989). role in plant communication. They are distribution of plant terpenoids (Lincoln & cal» to describe «non-nutritional chemicals induced in response to internal (genetic and Lagenheim, 1978). produced by one organism that affect the «Syllables, words and messages» biochemical) and external (ecological) growth, health, behavior or population Terpenoids are compounds containing an factors and to both, abiotic and biotic factors, Internal communication (an immune biology of other species». Allelopathy is integral number of 5C units. We can and they get a dosage dependent response system) identified particularly with chemical activity consider those units as the «syllables». (Langenheim, 1994). Like in any other Portions of the plants seem to be able to between plants (Kolzowski et al., 1991); There is an astonishing array of structures language, the «dialects» or particular communicate with the other parts. For however, entomologists refer to allelopathy resulting from the sequential combination terpenoid classes characterize certain plant- example, the existence of some sort of in a broader sense as the communication of basic five-carbon units in the familiar families (Takabayashi et al., 1994). They internal communication system whereby between plants and other organisms. categories of C10 (mono-), C15 (sesqui-), also vary qualitative and quantitatively damaged portions of the plant rely Allelopathic roles are often ascribed to C20 (di-), C30 (tri-) C40 (tetra-) and C>40 intraspecifically (reviewed by Langenheim, information to other undamaged portions mono- and sesquiterpene messages. (poly-) terpenoids, which we can consider 1994 and Takabayashi et al., 1994). They has been suggested in the attack of ento- Terpenoid toxicity results from several the «words». Both the number and structural even vary qualitatively and quantitatively mophagous insects (Dixon & Payne, 1980; effects such as inhibition of ATP formation, diversity of terpenoids provide enormous among organs and during organ deve- Elzen et al.,1984; Turlings et al., 1991). alkylation of nucleophiles, disruption of hor- potential for mediating significant ecological lopment (Langenheim et al., 1978; 1986). Turlings & Tumlinson (1992) propose