The accumulation of terpenoid oils does not incur a growth cost in Eucalyptus polybractea seedlings.

The deployment of secondary metabolites, such as terpenes, as anti-herbivore defences is thought to be costly for plants in terms of primary metabolism. Moreover, it is assumed that the cost of this deployment is modified by resource availability. In this study we examined the impact of terpenoid oil accumulation on the growth of Eucalyptus polybractea R.T.Baker seedlings from four maternal half-sib families, under conditions of sufficient and limiting nitrogen. The foliar oil concentration measured was extremely variable, varying almost 20-fold to a maximum of 13% (w / DW). Oil concentration was higher in plants grown under high nitrogen than in low-nitrogen plants, and it was positively correlated with foliar nitrogen concentration. Oil concentration was related to maternal concentration, although this relationship was weak because of the variation encountered. The composition of oil, dominated by monoterpenes, was also extremely variable, although this variation could not be adequately explained by either nitrogen availability or the seedling parentage. Importantly, we detected no negative correlations between oil concentration and relative growth rate (RGR), net assimilation rate (NAR), or leaf nitrogen productivity (LNP). Rather, under nitrogen limiting conditions, positive correlations were detected between oil concentration and all three indices. We conclude that oil accumulation is associated with factors that promote growth and if there is a cost to oil deployment, it could not be detected using the experimental design employed here.

[1]  M. Adams,et al.  What determines interspecific variation in relative growth rate of Eucalyptus seedlings? , 2005, Oecologia.

[2]  M. Adams,et al.  What determines rates of photosynthesis per unit nitrogen in Eucalyptus seedlings? , 2004, Functional plant biology : FPB.

[3]  I. E. Woodrow,et al.  Terpene deployment in Eucalyptus polybractea; relationships with leaf structure, environmental stresses, and growth. , 2004, Functional plant biology : FPB.

[4]  I. E. Woodrow,et al.  Cyanogenesis in Eucalyptus polyanthemos seedlings: heritability, ontogeny and effect of soil nitrogen. , 2004, Tree physiology.

[5]  I. E. Woodrow,et al.  Light alters the allocation of nitrogen to cyanogenic glycosides in Eucalyptus cladocalyx , 2002, Oecologia.

[6]  I. E. Woodrow,et al.  Defense chemistry of cyanogenic Eucalyptus cladocalyx seedlings is affected by water supply. , 2002, Tree physiology.

[7]  M. Litvak,et al.  Supply and demand processes as controls over needle monoterpene synthesis and concentration in Douglas fir [Pseudotsuga menziesii (Mirb.) Franco] , 2002, Oecologia.

[8]  T. Kolb,et al.  The Role of Monoterpenes in Resistance of Douglas Fir to Western Spruce Budworm Defoliation , 2002, Journal of Chemical Ecology.

[9]  I. Southwell,et al.  Monoterpenoid accumulation in Melaleuca alternifolia seedlings. , 2002, Phytochemistry.

[10]  I. E. Woodrow,et al.  Temporal and spatial variation in cyanogenic glycosides in Eucalyptus cladocalyx. , 2000, Tree physiology.

[11]  K. Raffa,et al.  Sources of Variation in Concentration and Composition of Foliar Monoterpenes in Tamarack (Larix laricina) Seedlings: Roles of Nutrient Availability, Time of Season, and Plant Architecture , 1999, Journal of Chemical Ecology.

[12]  V. Kitunen,et al.  Responses of Pinus sylvestris branches to simulated herbivory are modified by tree sink/source dynamics and by external resources , 1999 .

[13]  J. Koricheva,et al.  Regulation of Woody Plant Secondary Metabolism by Resource Availability: Hypothesis Testing by Means of Meta-Analysis , 1998 .

[14]  B. Kimball,et al.  Effects of Thinning and Nitrogen Fertilization on Sugars and Terpenes in Douglas-Fir Vascular Tissues: Implications for Black Bear Foraging , 1998 .

[15]  I. E. Woodrow,et al.  The effects of elevated CO2 atmospheres on the nutritional quality of Eucalyptus foliage and its interaction with soil nutrient and light availability , 1997, Oecologia.

[16]  T. Holopainen,et al.  Effects of nitrogen fertilization on secondary chemistry and ectomycorrhizal state of Scots pine seedlings and on growth of grey pine aphid , 1996, Journal of Chemical Ecology.

[17]  R. Monson,et al.  Ecological Controls over Monoterpene Emissions from Douglas‐Fir (Pseudotsuga Menziesii) , 1995 .

[18]  B. Lamb,et al.  Monoterpene emission from ponderosa pine , 1994 .

[19]  J. H. Langenheim.  Higher plant terpenoids: A phytocentric overview of their ecological roles , 1994, Journal of Chemical Ecology.

[20]  A. C. Matheson,et al.  Genetic parameters and expected gains from selection for monoterpene yields in Petford Eucalyptus camaldulensis , 1994, New Forests.

[21]  J. Harborne.  Herbivores, their interactions with secondary metabolites : 2nd edn, Vol. 2, Ecological and Evolutionary Processes: edited by G. A, Rosenthal and M. R. Berenbaum, Academic Press, San Diego, 1992. 493pp. $99. ISBN 0-12-597184-2. , 1993 .

[22]  R. Muzika.  Terpenes and phenolics in response to nitrogen fertilization: A test of the carbon/nutrient balance hypothesis , 1993, CHEMOECOLOGY.

[23]  D. Herms,et al.  The Dilemma of Plants: To Grow or Defend , 1992, The Quarterly Review of Biology.

[24]  A. House,et al.  Eucalyptus Leaf Oils Use Chemistry Distillation and Marketing , 1991 .

[25]  Russell K. Monson,et al.  Isoprene and monoterpene emission rate variability: Observations with Eucalyptus and emission rate algorithm development , 1991 .

[26]  S. Larsson,et al.  Effects of nitrogen fertilization on pine needle chemistry and sawfly performance , 1991, Oecologia.

[27]  Thomas J. Givnish,et al.  On the economy of plant form and function. , 1988 .

[28]  F. Stuart Chapin,et al.  Resource Availability and Plant Antiherbivore Defense , 1985, Science.

[29]  F. Stuart Chapin,et al.  Carbon/nutrient balance of boreal plants in relation to vertebrate herbivory , 1983 .

[30]  J. W. Hanover.  Genetics of terpenes I. Gene control of monoterpene levels in Pinus monticola dougl. , 1966, Heredity.

[31]  S. Cork,et al.  Methods and pitfalls of extracting condensed tannins and other phenolics from plants: Insights from investigations onEucalyptus leaves , 2004, Journal of Chemical Ecology.

[32]  Julia Koricheva,et al.  META-ANALYSIS OF SOURCES OF VARIATION IN FITNESS COSTS OF PLANT ANTIHERBIVORE DEFENSES , 2002 .

[33]  T. Lyons,et al.  Monoterpene and isoprene emissions from 15 Eucalyptus species in Australia , 2000 .

[34]  G. Seufert,et al.  On the monoterpene emission under heat stress and on the increased thermotolerance of leaves of Quercus ilex L. fumigated with selected monoterpenes , 1998 .

[35]  É. Bauce,et al.  Influence of resource availability on growth and foliar chemistry within and among young white spruce trees , 1998 .

[36]  M. Lerdau,et al.  Allocation theory and chemical defense , 1997 .

[37]  A. Barton,et al.  Heritability of cineole yield in eucalyptus kochii , 1991 .

[38]  M. Berenbaum,et al.  The chemical participants , 1991 .

[39]  Christopher B. Field,et al.  photosynthesis--nitrogen relationship in wild plants , 1986 .

[40]  A. Fahn.  Secretory tissues in plants , 1979 .