Effect of regurgitant from Leptinotarsa decemlineata on wound responses in Solanum tuberosum and Phaseolus vulgaris

Abstract

The effect of regurgitant from Leptinotarsa decemlineata Say larvae on wound-induced responses was studied using two plant species, Solanum tuberosum L. and Phaseolus vulgaris L. Wounding of one leaf of intact S. tuberosum plants differentially affected ethylene production and activities of peroxidase and polyphenol oxidase. Only polyphenol oxidase activity was stimulated by wounding in both wounded and systemic leaves. Peroxidase activity was not affected by wounding. Wounding caused only a transient increase of ethylene production from wounded leaves. The application of regurgitant to wound surfaces stimulated ethylene production as well as activities of peroxidase and polyphenol oxidase in both wounded and systemic leaves. Wounding significantly enhanced ethylene production and polyphenol oxidase activity in wounded and systemic leaves of P. vulgaris. The application of regurgitant caused an amplification of ethylene production, peroxidase activity, and polyphenol oxidase activity, in both wounded and systemic leaves of bean plants. Several substances were tested for their role as possible endogenous signals in P. vulgaris. Hydrogen peroxide and methyl jasmonate appeared as potential local and systemic signals of ethylene formation in wounded bean plants. Local ethylene production in leaf discs was differentially affected by the regurgitant application in potato versus bean plants. While all tested concentrations of regurgitant caused stimulation of ethylene formation from potato leaf discs, ethylene production was completely inhibited by increasing concentrations of the regurgitant in bean leaf discs. Our data present evidence that ethylene may play an important role in the interaction between plants and herbivores at the level of recognition of a particular herbivore leading to specific induction of signalling cascades.

Effects of Insect Herbivory on Physiological and Biochemical (Oxidative Enzyme) Responses of the Halophyte Atriplex subspicata (Chenopodiaceae)

“…One speciÞc oxidative enzyme, peroxidase, has been shown to increase when plants encounter insect related stress (Felton et al 1994, Ni et al 2001, Ni and Quisenberry 2003, Heng-Moss et al 2004 and has also been linked directly to salt tolerance in other Atriplex species (Wang et al 1997). Felton et al (1994) found herbivore defoliation increased selective oxidative enzymes, and several mechanical defoliation studies since then have shown plants to respond speciÞcally with increased peroxidase activity when introduced to injury (Tscharntke et al 2001, Kruzmane et al 2002, Roitto et al 2003. Increased activity would indicate potentially harmful oxidative species created by stress are being reduced to prevent further tissue injury.…”

Larval feeding induced defensive responses in tobacco: comparison of two sibling species of Helicoverpa with different diet breadths

“…Stout et al (1998) found that in tomato leaves aphid feeding can induce POD activities, but H. zea feeding cannot induce POD activities. Leptinotarsa decemlineata regurgitant treating on wound of Solanum tuberosum L. and Phaseolus vulgaris L. can also stimulate POD production (Kruzmane et al 2002).…”

Arthropod-induced neoplastic formations on trees change photosynthetic pigment levels and oxidative enzyme activities

“…Another enzyme of defensive oxygen metabolism is peroxidase, induced by a wide variety of environmental stress factors, including wounding and herbivores (Forslund et al 2000;Kruzmane et al 2002). In addition, changes in photosynthetic pigment composition may constitute adaptive responses to stress conditions (Morales et al 2002).…”

“…Polyphenol oxidase is a well known defense enzyme (Thypiapong et al 2004) induced in response to herbivory (Constabel et al 2000;Kruzmane et al 2002).…”