Fading of wound-induced volatile release during Populus tremula leaf expansion

Abstract

The release of stress-driven volatiles throughout leaf development has been little studied. Therefore, we subjected poplar leaves during their developmental stage (from two days to two weeks old) to wounding by a single punch hole, and measured online the wound-induced volatile organic compound emissions. Our study shows that the emission of certain volatile compounds fades with increasing leaf age. Among these compounds we found lipoxygenase products (LOX products), acetaldehyde, methyl benzoate, methyl salicylate, and mono-and sesquiterpenes.In parallel, we studied the fading of constitutive emissions of methanol during leaf maturation, as well as the rise in isoprene constitutive emission during leaf maturation and its relationship to leaf photosynthetic capacity. We found highly significant relationships between leaf chlorophyll content, photosynthetic capacity, and leaf size during leaf ageing.As the level of constitutive defences increases with increasing leaf age, the strength of the volatile signal is expected to be gradually reduced. The higher elicitation of volatile organic compound emissions (especially LOX products) in younger leaves could be an evolutionary defence against herbivory, given that younger leaves are usually more subjected to infestation and herbivory.

Ozone‐induced foliar damage and release of stress volatiles is highly dependent on stomatal openness and priming by low‐level ozone exposure in Phaseolus vulgaris

“…To identify the signals of volatile products of the LOX pathway in the blend of parent and fragment masses detected by PTR‐TOF‐MS, pure chemicals (Sigma‐Aldrich, St. Louis, MO, USA) were individually analysed and mass signals consistent with previous studies were found (e.g. Brilli et al ; Portillo‐Estrada et al ). The total LOX product emission presented in this study is the sum of the dominant compounds with m / z of 81.070, 83.085, 85.101, 99.080, 101.096 and 143.107, representing 2‐hexenal and 3‐hexenal (C 6 H 10 O)H + , 3‐hexenol (C 6 H 12 O)H + , 1‐hexanol (C 6 H 14 O)H + , 3‐hexenol (C 6 H 12 O)H + and hexenyl acetate (C 8 H 14 O 2 )H + , respectively (Beauchamp et al ; Giacomuzzi et al ; Portillo‐Estrada et al ; Portillo‐Estrada et al ).…”

“…Methanol and methyl salicylate (MeSA) were detected as the protonated parent ions at m / z of 33.034 and 153.088, respectively (Brilli et al ; Tasin, Cappellin, & Biasioli ; Maja et al ; Brilli et al ; Giacomuzzi et al ; Portillo‐Estrada et al ; Yener et al ; Portillo‐Estrada et al ). To identify the signals of volatile products of the LOX pathway in the blend of parent and fragment masses detected by PTR‐TOF‐MS, pure chemicals (Sigma‐Aldrich, St. Louis, MO, USA) were individually analysed and mass signals consistent with previous studies were found (e.g.…”

“…Brilli et al ; Portillo‐Estrada et al ). The total LOX product emission presented in this study is the sum of the dominant compounds with m / z of 81.070, 83.085, 85.101, 99.080, 101.096 and 143.107, representing 2‐hexenal and 3‐hexenal (C 6 H 10 O)H + , 3‐hexenol (C 6 H 12 O)H + , 1‐hexanol (C 6 H 14 O)H + , 3‐hexenol (C 6 H 12 O)H + and hexenyl acetate (C 8 H 14 O 2 )H + , respectively (Beauchamp et al ; Giacomuzzi et al ; Portillo‐Estrada et al ; Portillo‐Estrada et al ). The identity of O 3 ‐induced LOX compounds and MeSA from P. vulgaris leaves was also confirmed in pilot experiments by separate GC–MS analyses carried out according to the protocol of Copolovici, Kännaste, Pazouki, and Niinemets () and Kännaste, Copolovici, & Niinemets ().…”

Contribution of volatile organic compound fluxes to the ecosystem carbon budget of a poplar short‐rotation plantation

“…The presence of methanol in the BVOC emission blend of poplar leaves is known (Hüve et al ., ). Methanol emission is related to cell elongation and division, and occurs more intensively in younger and expanding leaves (Brilli et al ., ; Portillo‐Estrada et al ., ), remarkably in early spring, even before isoprene is emitted (Ghirardo et al ., ). Therefore, a plantation of poplars, a fast‐growing species that quickly unfolds its leaves in spring, generates a burst of methanol emission due to the many young and expanding leaves during this period.…”

“…Studies have shown a temporal lag between isoprene emission and the onset of photosynthesis (Kuzma & Fall, ; Sharkey & Loreto, ; Monson et al ., ). Leaf phenology plays an important role in determining the level of isoprene emissions (Brilli et al ., ; Portillo‐Estrada et al ., ). Isoprene emission rates differ among different species of the same genus, or among genotypes of the same species, as already documented in Populus (Calfapietra et al ., ).…”