open access

https://hdl.handle.net/2115/78577

Elevated CO2 offsets the alteration of foliar chemicals (n-icosane, geranyl acetate, and elixene) induced by elevated O-3 in three taxa of O-3-tolerant eucalypts

英語

Tropospheric ozone

2020-05-11

Northeast Forestry University

Journal of forestry research

32

789-803

Eucalypts are important forest resources in southwestern China, and may be tolerant to elevated ground-level ozone (O-3) concentrations that can negatively affect plant growth. High CO2 may offset O-3-induced effects by providing excess carbon to produce secondary metabolites or by inducing stomatal closure. Here, the effects of elevated CO2 and O-3 on leaf secondary metabolites and other defense chemicals were studied by exposing seedlings of Eucalyptus globulus, E. grandis, and E. camaldulensis x E. deglupta to a factorial combination of two levels of O-3 (< 10 nmol mol(-1) and 60 nmol mol(-1)) and CO2 (ambient: 370 mu mol mol(-1) and 600 mu mol mol(-1)) in open-top field chambers. GC-profiles of leaf extracts illustrated the effect of elevated O-3 and the countering effect of high CO2 on compounds in leaf epicuticular wax and essential oils, i.e., n-icosane, geranyl acetate and elixene, compounds known as a first-line defense against insect herbivores. n-Icosane may be involved in tolerance mechanisms of E. grandis and the hybrid, while geranyl acetate and elixene in the tolerance of E. globulus. Elevated O-3 and CO2, singly or in combination, affected only leaf physiology but not biomass of various organs. Elevated CO2 impacted several leaf traits, including stomatal conductance, leaf mass per area, carbon, lignin, n-icosane, geranyl acetate and elixene. Limited effects of elevated O-3 on leaf physiology (nitrogen, n-icosane, geranyl acetate, elixene) were commonly offset by elevated CO2. We conclude that E. globulus, E. grandis and the hybrid were tolerant to these O-3 and CO2 treatments, and n-icosane, geranyl acetate and elixene may be major players in tolerance mechanisms of the tested species.

学術雑誌論文

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Creative Commons Attribution 4.0 International

1007-662X