The Sesquiterpenes(E)-ß-Farnesene and (E)-α-Bergamotene Quench Ozone but Fail to Protect the Wild Tobacco Nicotiana attenuata from Ozone, UVB, and Drought Stresses

Abstract

Among the terpenes, isoprene (C5) and monoterpene hydrocarbons (C10) have been shown to ameliorate abiotic stress in a number of plant species via two proposed mechanisms: membrane stabilization and direct antioxidant effects. Sesquiterpene hydrocarbons (C15) not only share the structural properties thought to lend protective qualities to isoprene and monoterpene hydrocarbons, but also react rapidly with ozone, suggesting that sesquiterpenes may similarly enhance tolerance of abiotic stresses. To test whether sesquiterpenes protect plants against ozone, UVB light, or drought, we used transgenic lines of the wild tobacco Nicotiana attenuata. The transgenic plants expressed a maize terpene synthase gene (ZmTPS10) which produced a blend of (E)-ß-farnesene and (E)-α-bergamotene, or a point mutant of the same gene (ZmTPS10M) which produced (E)-ß-farnesene alone,. (E)-ß-farnesene exerted a local, external, and transient ozone-quenching effect in ozone-fumigated chambers, but we found no evidence that enhanced sesquiterpene production by the plant inhibited oxidative damage, or maintained photosynthetic function or plant fitness under acute or chronic stress. Although the sesquiterpenes (E)-ß-farnesene and (E)-α-bergamotene might confer benefits under intermittent heat stress, which was not tested, any roles in relieving abiotic stress may be secondary to their previously demonstrated functions in biotic interactions.

Root volatiles in plant–plant interactions II: Root volatiles alter root chemistry and plant–herbivore interactions of neighbouring plants

“…Here, we tested whether (E)-β-caryophyllene, one of the major sesquiterpenes emitted by C. stoebe, is sufficient to increase the growth of M. melolontha on T. officinale in comparison with the full VOC blend of C. stoebe. (E)-β-caryophyllene is a widespread sesquiterpene in nature that can influence the physiology and behaviour of pathogen, nematodes, and insects (Fantaye, Köpke, Gershenzon, & Degenhardt, 2015;Huang et al, 2012;Rasmann et al, 2005;Robert et al, 2013) and may act as an antioxidant in plants (Palmer-Young, Veit, Gershenzon, & Schuman, 2015). We demonstrate that (E)-βcaryophyllene exposure leads to M. melolontha growth that is intermediate between non-exposed and C. stoebe exposed T. officinale plants, suggesting that it can partially account for the VOC effects of C. stoebe.…”

“…stoebe . ( E )‐ β ‐caryophyllene is a widespread sesquiterpene in nature that can influence the physiology and behaviour of pathogen, nematodes, and insects (Fantaye, Köpke, Gershenzon, & Degenhardt, ; Huang et al, ; Rasmann et al, ; Robert et al, ) and may act as an antioxidant in plants (Palmer‐Young, Veit, Gershenzon, & Schuman, ). We demonstrate that ( E )‐ β ‐caryophyllene exposure leads to M .…”

Plant surface reactions: an opportunistic ozone defence mechanism impacting atmospheric chemistry

“…Several studies were investigating the possibility to increase the ozone tolerance of plants by external application of ozone-scavenging compounds (Gilbert et al, 1977;Loreto et al, 2001;Vickers et al, 2009a;Singh and Agrawal, 2010;Agathokleous et al, 2014) or by enabling the emission of volatile terpenoids in transgenic plants (Vickers et al, 2009b;Palmer-Young et al, 2015). We show here that some of the tobacco varieties investigated in our experiments are intrinsically equipped with ozone scavenging compounds located on their leaf cuticula.…”

Understanding and improving global crop response to ozone pollution

“…() over‐expressed Pityriasis alba isoprene synthase in Nicotiana tabacum , and found that the transformed lines did not display visual symptoms of O 3 damage after exposure to 200 ppb O 3 for 6 h, resulting from less ROS accumulation and less membrane damage. However, over‐expression of two specific sesquiterpene compounds, (E)‐β‐farnesene and (E)‐α‐bergamotene, which are known to rapidly react with O 3 in the atmosphere, did not enhance O 3 tolerance in Nicotiana attenuata (Palmer‐Young et al ., ). Thus, the evidence that enhanced isoprenoid emissions could improve plant O 3 tolerance is mixed.…”