Release of lipoxygenase products and monoterpenes by tomato plants as an indicator of Botrytis cinerea‐induced stress

Abstract

Changes in emission of volatile organic compounds (VOCs) from tomato induced by the fungus Botrytis cinerea were studied in plants inoculated by spraying with suspensions containing B. cinerea spores. VOC emissions were analysed using on-line gas chromatography-mass spectrometry, with a time resolution of about 1 h, for up to 2 days after spraying. Four phases were delimited according to the starting point and the applied day/night rhythm of the experiments. These phases were used to demonstrate changes in VOC flux caused by B. cinerea infestation. Tomato plants inoculated with B. cinerea emitted a different number and amount of VOCs after inoculation compared to control plants that had been sprayed with a suspension without B. cinerea spores. The changes in emissions were dependent on time after inoculation as well as on the severity of infection. The predominant VOCs emitted after inoculation were volatile products from the lipoxygenase pathway (LOX products). The increased emission of LOX products proved to be a strong indicator of a stress response, indicating that VOC emissions can be used to detect plant stress at an early stage. Besides emission of LOX products, there were also increases in monoterpene emissions. However, neither increased emission of LOX products nor of monoterpenes is specific for B. cinerea attack. The emission of LOX products is also induced by other stresses, and increased emission of monoterpenes seems to be the result of mechanical damage induced by secondary stress impacts on leaves.

The influence of soil salinity on volatile organic compounds emission and photosynthetic parameters of Solanum lycopersicum L. varieties

“…In our studies we found only (Z)-3-hexenol which is emitted from tomato under osmotic stress compared with the previous articles which reported four or even nine different C5 and C6 green leaf volatiles, respectively [21,16]. The emission became significant even at 100 mM NaCl in soil but was very low for control plants.…”

“…The emissions consisted of α-pinene, camphene, 2-carene, α-phellandrene, limonene, β-phellandrene, (E)-β-ocimene and terpinolene as have been previously reported by Jensen et al [21] and Copolovici et al [16]. The composition was the same for stressed and control plants and could be due to cellular damage or enhanced permeability of barriers of terpene-containing structures.…”

“…The composition was the same for stressed and control plants and could be due to cellular damage or enhanced permeability of barriers of terpene-containing structures. The same emissions have been described for B. cinerea infection of tomato which has been associated with inoculation damage [21] as well as for cold and heat stress [16]. It has been shown that the terpene emissions from storage pools scale exponentially with temperature due to the permeability changes of the glandular trichomes [16,34].…”

“…The volatile compounds emitted from tomatoes have not been studies thoroughly. The green leaf volatile emission has been reported for tomato plants inoculated with necrotrophic fungus Botrytis cinerea [21], after feeding by cotton leaf worms, Spodoptera littoralis [22] and as a result of cold and heat stress [16]. The aim of this paper is to evaluate different tomato varieties (including wild species) for their tolerance to soil salinity and to find if some volatile organic compounds can be used for rapid screening of tomato varieties for salinity stress resistance.…”

Impacts of simulated herbivory on volatile organic compound emission profiles from coniferous plants

“…Emissions of different compounds from the same plant exhibit different temporal responses to herbivory stress (Copolovici et al, 2011). Additionally, the plant stress response varies depending on the type of biotic stress and/or the type of plant; other studies have shown increases in total terpene emission rates after herbivory exposure with no change in the VOC profile (Jansen et al, 2009b;Priemé et al, 2000) or different responses of the same plant to pathogen vs. herbivory stress (Vuorinen et al, 2007). Finally, extrapolating these results to natural environments is further complicated where simultaneous exposure to multiple stressors is likely the rule rather than the exception; multiple abiotic and biotic stressors can interact to significantly alter the plant's response relative to any single stressor (Holopainen and Gershenzon, 2010;Trowbridge et al, 2014;Winter et al, 2012).…”