Oak gall wasp infections ofQuercus roburleaves lead to profound modifications in foliage photosynthetic and volatile emission characteristics

Abstract

Oak trees (Quercus) are hosts of diverse gall-inducing parasites, but the effects of gall formation on the physiology and biochemistry on host oak leaves is poorly understood. The influence of infection by four species from two widespread gall wasp genera, Neuroterus (N. anthracinus and N. albipes) and Cynips (C. divisa and C. quercusfolii), on foliage morphology, chemistry, photosynthetic characteristics, constitutive isoprene, and induced volatile emissions in Q. robur was investigated. Leaf dry mass per unit area (M A ), net assimilation rate per area (A A ), stomatal conductance (g s ), and constitutive isoprene emissions decreased with the severity of infection by all gall wasp species. The reduction in A A was mainly determined by reduced M A and to a lower extent by lower content of leaf nitrogen and phosphorus in gall-infected leaves. The emissions of lipoxygenase pathway volatiles increased strongly with increasing infection severity for all 4 species with the strongest emissions in major vein associated species, N. anthracinus. Monoterpene and sesquiterpene emissions were strongly elicited in N. albipes and Cynips species, but not in N. anthracinus. These results provide valuable information for diagnosing oak infections using ambient air volatile fingerprints and for predicting the impacts of infections on photosynthetic productivity and whole tree performance.

The Psyllids Triozoida Limbata Supplant the Defenses of Psidium Guajava Plants to Garentee Feeding and Protection

“…The leaf colour alterations were due to the chlorophyll degradation (yellowing-leaf chlorosis) and accumulation of anthocyanins (purplish-red leaf colour) [59]. Morpho-anatomical changes in guava leaves caused by T. limbata reduces plant productivity, possibly due to the reduction of photosynthesis and an increase of photoassimilates consumption [60,61]. The chlorosis caused the decrease of leaf area, formation of roll galls, and necrosis of the leaves observed in this work.…”

“…The chlorosis caused the decrease of leaf area, formation of roll galls, and necrosis of the leaves observed in this work. On the other hand, the feeding of sap-sucking insects like the psyllid consumes photoassimilates of the plants [60,61].…”

Impact of Gall-Forming Insects on Global BVOC Emissions and Climate: A Perspective

“…Typically, plant stressors like herbivorous insects alter the emission patterns of BVOC emitting plants and shift the share of BVOCs of different atmospheric oxidation capacity which subsequently alter the dynamics of SOA formation, abundance, and properties (Yli-Pirilä et al, 2016;Faiola et al, 2018). As example, a predominately isoprene emitting species may, under stress, emit monoterpenes as major share of compounds or increase the overall emission by induced BVOCs that are not apparent in non-stressed situations (Brilli et al, 2009;Toome et al, 2010;Copolovici et al, 2014bCopolovici et al, , 2017Jiang et al, 2016Jiang et al, , 2018Kmieć et al, 2018). While herbivorous insects have got already large attention in the literature of plant stress physiology (Holopainen and Gershenzon, 2010;Blande et al, 2014;Copolovici et al, 2014a;Loreto et al, 2014) much less is known on BVOC emissions induced by insects that do not destroy plant tissue or defoliate plants.…”

Induction, engineering, and hijacking of defensive strategies of the host by a gall‐inducing weevil

“…Indeed, gall induction results in several levels of tissue and cell modifications that may impact host‐plant metabolism, physiology, and development (Jiang et al. , Oliveira et al. ).…”

“…This galling insect may damage its host plant by redirecting and draining valuable resources to develop and maintain the large gall structure (2.11 cm long AE SE 0.11, N = 56). Indeed, gall induction results in several levels of tissue and cell modifications that may impact host-plant metabolism, physiology, and development (Jiang et al 2018, Oliveira et al 2016). In some cases, cell and tissue damage may have resulted in costly mechanisms to prevent gall induction (Fernandes 1990, Giron et al 2016, including ant bodyguarding, as described above.…”