TY - JOUR

T1 - Heat stress strongly induces monoterpene emissions in some plants with specialized terpenoid storage structures

AU - Nagalingam, Sanjeevi

AU - Seco, Roger

AU - Kim, Saewung

AU - Guenther, Alex

N1 - Funding Information: The research work presented in this paper was financially supported by the US National Science Foundation [award no: AGS-1643042 ]. RS acknowledges grants RYC2020-029216-I and CEX2018-000794-S funded by the Spanish Ministry of Science and Innovation and the State Research Agency ( MCIN/AEI/ 10.13039/501100011033 ) and by the European Social Fund “ESF Investing in your future”. Publisher Copyright: © 2023 The Author(s)

PY - 2023

Y1 - 2023

N2 - Four different plant species, sunflower (Helianthus annuus), western redcedar (Thuja plicata), American sweetgum (Liquidambar styraciflua), and red ironbark (Eucalyptus sideroxylon), were enclosed in glass or Teflon chambers, exposed to different temperatures typically ranging from 30 °C to 43 °C, and their terpenoid emission rates were quantified using gas chromatography techniques. The results show that sunflower, western redcedar, and American sweetgum were not significant constitutive monoterpene emitters at 30 °C. Monoterpene emissions from western redcedar and American sweetgum remained negligibly low up to 35 °C–37 °C, however, at higher temperatures, the emissions began to increase at a much more rapid rate than predicted by current emission models. The monoterpene emissions from sunflower, western redcedar, and American sweetgum increased by an average factor of 22, 98, and 5900 for a temperature increase (ΔT) of 13 °C, 13 °C, and 15 °C, respectively, thereby transforming them from negligible into high monoterpene emitters. The observed emission increase was substantially higher than the model-predicted increase of 3.7-fold (ΔT = 13 °C) and 4.5-fold (ΔT = 15 °C). We demonstrate that current emission algorithms cannot accurately model the emission behavior of these plant species at the high temperatures that are characteristic of severe heatwaves. Furthermore, monoterpene emissions from western redcedar and American sweetgum remained elevated for 1–7 days after the heat stress. In contrast to the other three species, red ironbark was a significant constitutive monoterpene emitter (at 30 °C) and its emission response to temperature was close to model predictions. Each of the four species investigated in this study possesses specialized foliar terpene-storing structures, for example, glandular trichomes and oil glands. The strong monoterpene emission induction observed in some of these species may be attributed to heat-induced damage to these storage structures. However, the wall permeability of these structures may vary by species and could limit the magnitude of the heat-induced emission response.

AB - Four different plant species, sunflower (Helianthus annuus), western redcedar (Thuja plicata), American sweetgum (Liquidambar styraciflua), and red ironbark (Eucalyptus sideroxylon), were enclosed in glass or Teflon chambers, exposed to different temperatures typically ranging from 30 °C to 43 °C, and their terpenoid emission rates were quantified using gas chromatography techniques. The results show that sunflower, western redcedar, and American sweetgum were not significant constitutive monoterpene emitters at 30 °C. Monoterpene emissions from western redcedar and American sweetgum remained negligibly low up to 35 °C–37 °C, however, at higher temperatures, the emissions began to increase at a much more rapid rate than predicted by current emission models. The monoterpene emissions from sunflower, western redcedar, and American sweetgum increased by an average factor of 22, 98, and 5900 for a temperature increase (ΔT) of 13 °C, 13 °C, and 15 °C, respectively, thereby transforming them from negligible into high monoterpene emitters. The observed emission increase was substantially higher than the model-predicted increase of 3.7-fold (ΔT = 13 °C) and 4.5-fold (ΔT = 15 °C). We demonstrate that current emission algorithms cannot accurately model the emission behavior of these plant species at the high temperatures that are characteristic of severe heatwaves. Furthermore, monoterpene emissions from western redcedar and American sweetgum remained elevated for 1–7 days after the heat stress. In contrast to the other three species, red ironbark was a significant constitutive monoterpene emitter (at 30 °C) and its emission response to temperature was close to model predictions. Each of the four species investigated in this study possesses specialized foliar terpene-storing structures, for example, glandular trichomes and oil glands. The strong monoterpene emission induction observed in some of these species may be attributed to heat-induced damage to these storage structures. However, the wall permeability of these structures may vary by species and could limit the magnitude of the heat-induced emission response.

KW - BVOC emission

KW - Eucalyptus

KW - Glandular trichome

KW - Heatwave

KW - Plant volatiles

KW - Sunflower

U2 - 10.1016/j.agrformet.2023.109400

DO - 10.1016/j.agrformet.2023.109400

M3 - Journal article

AN - SCOPUS:85149465713

VL - 333

JO - Agricultural and Forest Meteorology

JF - Agricultural and Forest Meteorology

SN - 0168-1923

M1 - 109400

ER -