Correlations between leaf toughness and phenolics among species in contrasting environments of Australia and New Caledonia

Read Jennifer, Sanson Gordon D., Caldwell Elizabeth, Clissold Fiona J., Chatain Alex, Peeters Paula, Lamont Byron B., De Garine-Wichatitsky Michel, Jaffré Tanguy, Kerr Stuart. 2009. Correlations between leaf toughness and phenolics among species in contrasting environments of Australia and New Caledonia. Annals of Botany, 103 (5) : 757-767.

Quartile : Q1, Sujet : PLANT SCIENCES

Résumé : Background and Aims: Plants are likely to invest in multiple defences, given the variety of sources of biotic and abiotic damage to which they are exposed. However, little is known about syndromes of defence across plant species and how these differ in contrasting environments. Here an investigation is made into the association between carbon-based chemical and mechanical defences, predicting that species that invest heavily in mechanical defence of leaves will invest less in chemical defence. Methods: A combination of published and unpublished data is used to test whether species with tougher leaves have lower concentrations of phenolics, using 125 species from four regions of Australia and the Pacific island of New Caledonia, in evergreen vegetation ranging from temperate shrubland and woodland to tropical shrubland and rainforest. Foliar toughness was measured as work-to-shear and specific work-to-shear (work-to-shear per unit leaf thickness). Phenolics were measured as 'total phenolics' and by protein precipitation (an estimate of tannin activity) per leaf dry mass. Key Results: Contrary to prediction, phenolic concentrations were not negatively correlated with either measure of leaf toughness when examined across all species, within regions or within any plant community. Instead, measures of toughness (particularly work-to-shear) and phenolics were often positively correlated in shrubland and rainforest (but not dry forest) in New Caledonia, with a similar trend suggested for shrubland in south-western Australia. The common feature of these sites was low concentrations of soil nutrients, with evidence of P limitation. Conclusions: Positive correlations between toughness and phenolics in vegetation on infertile soils suggest that additive investment in carbon-based mechanical and chemical defences is advantageous and cost-effective in these nutrient-deficient environments where carbohydrate may be in surplus.

Mots-clés Agrovoc : feuille, composé phénolique, propriété physicochimique, composition chimique, répulsif d'origine végétale, pâturage, forêt tropicale, savane, plante d'abroutissement, arbuste

Mots-clés géographiques Agrovoc : Australie, Nouvelle-Calédonie, France

Classification Agris : F60 - Physiologie et biochimie végétale
K01 - Foresterie - Considérations générales
L51 - Physiologie animale - Nutrition
000 - Autres thèmes

Champ stratégique Cirad : Axe 6 (2005-2013) - Agriculture, environnement, nature et sociétés

Auteurs et affiliations

• Read Jennifer, Monash University (AUS)
• Sanson Gordon D., Monash University (AUS)
• Caldwell Elizabeth, Monash University (AUS)
• Clissold Fiona J., Monash University (AUS)
• Chatain Alex, Monash University (AUS)
• Peeters Paula, Monash University (AUS)
• Lamont Byron B., Curtin University (AUS)
• De Garine-Wichatitsky Michel, CIRAD-ES-UPR AGIRs (ZWE) ORCID: 0000-0002-5438-1473
• Jaffré Tanguy, IRD (NCL)
• Kerr Stuart, Monash University (AUS)

Source : Cirad-Agritrop (https://agritrop.cirad.fr/578574/)

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