Induction of Defensive Responses in <i>Eucalyptus globulus</i> (Labill) Plants, against <i>Ctenarytaina eucalypti</i> (Maskell) (Hemiptera: Psyllidae)

Abstract

This study evaluated the expression of defense compounds from the secondary metabolism of Eucalyptus globulus plants, subjected to direct and indirect stimuli by the insect Ctenarytaina eucalypti (blue gum Psyllid). Results showed that defense responses were activated in plants in all tested cases. Were detected and identified thirty-two compounds in the leaves of treated plants, of which five compounds differed with the control, and all are part of the chemical defenses from the plants, three of them were oxygenated monoterpenes (borneol, exo-2-hydroxy cineole and thymol), a aromatic carboxylic acid (benzoic acid) and a quinone (6-acethyl-flaviolin). The plants induced by volatile compounds and by indirect entomological manner, showed its capability to synthesize defensive compounds without a wound that promotes these responses. Were also found some constitutive secondary metabolites over expressed in the different inductions compared with the control.

Bionomics and feeding impact ofCtenarytaina eucalypti(Hemiptera: Psylloidea: Aphalaridae) onEucalyptus globulus(Myrtaceae) in the central tablelands of New South Wales

“…extralimital records from Eucalyptus spp. ', p. 107) Synthesis of diverse secondary metabolites in E. globulus during feeding by C. eucalypti and the perception of plant volatiles by this species have been comprehensively examined (Brennan & Weinbaum 2001a,b;Troncoso et al 2011Troncoso et al , 2012Yuvaraj et al 2013). Our study fills in the details pertaining to nymphal-and adult-feeding behaviour of C. eucalypti on E. globulus including site selection, growth rates and histological examination of feeding lesions.…”

“…The occurrence of hardened bulbous droplets of the gel saliva (forming a stylet sheath) is known in different sap-sucking Hemiptera and is implicated as an avoidance tactic to circumvent allelochemicals of the host plant, which the hemipteran stylet would encounter during feeding (Miles 1999). For instance, phenol oxidase in the gel saliva polymerises the phenolics sequestered in the plant-cell apoplast as an induced-defence mechanism and generates quinones (Sharma et al 2013a); moreover, production of quinones are known in E. globulus leaves infested by C. eucalypti (Troncoso et al 2011(Troncoso et al , 2012. Nymphal instars and adults avoid oil glands during feeding Brennan and Weinbaum (2001b), and no branching of the stylet track was evident in C. eucalypti; however, in some instances, the presence of multiple stylet tracks suggest either multiple probes by one nymph or the stylet tracks of several nymphs feeding in close proximity.…”

Structural and Chemical Profiles of Myrcia splendens (Myrtaceae) Leaves Under the Influence of the Galling Nexothrips sp. (Thysanoptera)

“…The detection of methyl salicylate (#42) in the samples of galls had also been related to acquired resistance and indirect plant defense ( Oates et al, 2016 ). Methyl salicylate is a plant semiochemical related to stress signaling ( Pickett et al, 2006 ), and it is generally described as anti-herbivoric, attractive to beneficial insects that would kill herbivores ( Bruinsma et al, 2009 ), and as a pheromone ( James and Price, 2004 ; Troncoso et al, 2012 ). In M. splendens , the production of methyl salicylate neither affected the life cycle of the inducing thrips nor attracted natural enemies, since individuals in several stages of life occurred inside the galls, and the rate of hyperparasitism was apparently low in comparison to other Neotropical systems ( Gonçalves et al, 2009 ; Carneiro et al, 2013 ).…”

Salivary gland structure of Ctenarytaina eucalypti (MASKELL, 1890) (Hemiptera) and phloem exudate in Eucalyptus globulus LABILLARDIÈRE, 1799 (Myrtaceae)

“…For instance, oxidoreductases in the gel-like saliva polymerizes the phenolics sequestered in the plantcell apoplast as an induced defence mechanism and generates quinones (SHARMA et al 2013). Production of quinones in the leaves of E. globulus leaves when infested by C. eucalypti was reported by TRONCOSO et al (2012). Cell-degrading enzymes, such as amylase, lipase and esterase, may enable C. eucalypti to pierce tissues of E. globulus (OTEN et al 2014, SHARMA et al 2013).…”