TY - JOUR

T1 - Impact of heat stress on foliar biogenic volatile organic compound emission and gene expression in tomato (Solanum lycopersicum) seedlings

AU - Nagalingam, Sanjeevi

AU - Seco, Roger

AU - Musaev, Kirill

AU - Basu, Chhandak

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], including salary support for SN, RS, CB, SK, and AG. 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: © 2022 The Author(s).

PY - 2022

Y1 - 2022

N2 - We present foliar biogenic volatile organic compound (BVOC) emission data from 24-h heat-stressed tomato (Solanum lycopersicum) seedlings including speciated monoterpenes and sesquiterpenes and high time-resolution measurements of methyl salicylate and total monoterpenes. The median total monoterpene and total sesquiterpene emission rates at 30C were 18.5 and 0.172 pmol m–2 s–1, respectively, which falls within the negligible emission category of previous studies. However, initial heat exposure (39C or 42C) increased the emissions of approximately half of the targeted compounds beyond what was predicted by current BVOC emission temperature response algorithms. The enhanced emissions were not always sustained for the entire duration of the heat stress and some plants exhibited a delayed monoterpene response, where emissions peaked toward the end of the heat treatment. Methyl salicylate, a known stress marker, responded differently to the heat stress than most of the other compounds. Heat stress increased methyl salicylate emissions in some plants (at least initially), but in others, emissions declined or did not change significantly. There was no significant correlation between the magnitude of gene expression and emission induction of monoterpenes or methyl salicylate. Furthermore, the emitted monoterpenes did not exhibit any apparent light-dependent behavior, which suggests that these monoterpene stress emissions mostly originated from light-independent foliar storage pools and not from increased de novo production. In contrast, methyl salicylate emissions appear to have contributions from both de novo synthesis and stored pools, as they showed both enzyme-controlled (i.e., light-dependent) and light-independent behaviors. Analyses of the foliar essential oils demonstrate that most of the emitted BVOCs were also present in stored pools. The pool sizes were generally large enough to sustain unstressed emission levels for days to months, and even years for some compounds. However, heat-induced emission enhancement can diminish the pool sizes of some BVOCs, which could decrease subsequent emissions.

AB - We present foliar biogenic volatile organic compound (BVOC) emission data from 24-h heat-stressed tomato (Solanum lycopersicum) seedlings including speciated monoterpenes and sesquiterpenes and high time-resolution measurements of methyl salicylate and total monoterpenes. The median total monoterpene and total sesquiterpene emission rates at 30C were 18.5 and 0.172 pmol m–2 s–1, respectively, which falls within the negligible emission category of previous studies. However, initial heat exposure (39C or 42C) increased the emissions of approximately half of the targeted compounds beyond what was predicted by current BVOC emission temperature response algorithms. The enhanced emissions were not always sustained for the entire duration of the heat stress and some plants exhibited a delayed monoterpene response, where emissions peaked toward the end of the heat treatment. Methyl salicylate, a known stress marker, responded differently to the heat stress than most of the other compounds. Heat stress increased methyl salicylate emissions in some plants (at least initially), but in others, emissions declined or did not change significantly. There was no significant correlation between the magnitude of gene expression and emission induction of monoterpenes or methyl salicylate. Furthermore, the emitted monoterpenes did not exhibit any apparent light-dependent behavior, which suggests that these monoterpene stress emissions mostly originated from light-independent foliar storage pools and not from increased de novo production. In contrast, methyl salicylate emissions appear to have contributions from both de novo synthesis and stored pools, as they showed both enzyme-controlled (i.e., light-dependent) and light-independent behaviors. Analyses of the foliar essential oils demonstrate that most of the emitted BVOCs were also present in stored pools. The pool sizes were generally large enough to sustain unstressed emission levels for days to months, and even years for some compounds. However, heat-induced emission enhancement can diminish the pool sizes of some BVOCs, which could decrease subsequent emissions.

KW - BVOC emission

KW - Essential oil

KW - Gene expression

KW - Heat stress

KW - Post-illumination burst

KW - Tomato

U2 - 10.1525/elementa.2021.00096

DO - 10.1525/elementa.2021.00096

M3 - Journal article

AN - SCOPUS:85128007211

VL - 10

JO - Elementa

JF - Elementa

SN - 2325-1026

IS - 1

M1 - 96

ER -