Volatile-mediated between-plant communication in Scots pine and the effects of elevated ozone

Abstract

Conifers are dominant tree species in boreal forests, but are susceptible to attack by bark beetles. Upon bark beetle attack, conifers release substantial quantities of volatile organic compounds known as herbivore-induced plant volatiles (HIPVs). Earlier studies of broadleaved plants have shown that HIPVs provide information to neighbouring plants, which may enhance their defences. However, the defence responses of HIPV-receiver plants have not been described for conifers. Here we advance knowledge of plant–plant communication in conifers by documenting a suite of receiver-plant responses to bark-feeding-induced volatiles. Scots pine seedlings exposed to HIPVs were more resistant to subsequent weevil feeding and received less damage. Receiver plants had both induced and primed volatile emissions and their resin ducts had an increased epithelial cell (EC) mean area and an increased number of cells located in the second EC layer. Importantly, HIPV exposure increased stomatal conductance and net photosynthesis rate of receiver plants. Receiver-plant responses were also examined under elevated ozone conditions and found to be significantly altered. However, the final defence outcome was not affected. These findings demonstrate that HIPVs modulate conifer metabolism through responses spanning photosynthesis and chemical defence. The responses are adjusted under ozone stress, but the defence benefits remain intact.

Airborne cues accelerate flowering and promote photosynthesis in Brassica rapa

“…In the current study, we found that net photosynthesis did not differ between herbivore‐damaged plants and plants exposed to herbivore‐induced volatiles straight after exposure to the treatments. Earlier studies reported increases in photosynthesis rate upon insect feeding, which supports our observations (Gutsche et al, 2009), but to our knowledge no previous work reported increase in net photosynthesis rate upon exposure to volatile cues, except for a recent study on conifers by Yu et al (2022).…”

Light induces an increasing release of benzyl nitrile against diurnal herbivore Ectropis grisescens Warren attack in tea (Camellia sinensis) plants

“…Under complex natural environmental conditions, the quantity and composition of HIPVs as well as the timing of their emission are affected by biotic factors (e.g., herbivore density, species and age) and abiotic factors (e.g., light, temperature, water availability, fertilisation, wind and ozone) (Becker et al, 2015; Gouinguené & Turlings, 2002; Holopainen & Gershenzon, 2010; Vosteen et al, 2020; Yu et al, 2022). Light is an important environmental factor affecting accumulation of secondary metabolites in plants.…”

Plant communication across different environmental contexts suggests a role for stomata in volatile perception

“…Microorganisms, including plant pathogens, can also take advantage of similar strategies to manipulate stomatal aperture for their benefit by opening stomata for entry into plant tissues (Melotto et al, 2006;Turner & Graniti, 1969;Underwood et al, 2007). Emerging evidence also suggests that HIPVs can increase stomatal aperture of conifers, resulting in increases in net photosynthesis of receiver plants (Yu et al, 2022).…”