Methyl jasmonate and oxalic acid treatment of Norway spruce: anatomically based defense responses and increased resistance against fungal infection

Abstract

To study the effect of chemical pretreatment on conifer resistance, 13-year-old Norway spruce (Picea abies (L.) Karst.) trees were treated with methyl jasmonate (MJ) or oxalic acid (OxA) on the outer bark and inoculated with the pathogenic blue-stain fungus Ceratocystis polonica (Siem.) C. Moreau 4 weeks later. Both chemicals significantly reduced symptoms of fungal infection, but MJ was more effective than OxA (51 versus 18% reduction in length of necrotic lesions in the phloem relative to untreated control trees). Anatomical examination of treated stem tissues showed that MJ induced extensive formation of traumatic resin ducts in the xylem and extra polyphenolic parenchyma (PP) cells in the secondary phloem between the cambium and the regular annual PP cell layer. No traumatic resin ducts were formed after treatment with OxA, and the coverage of extra PP cells in OxA-treated tissues was not significantly higher than in the controls. The anatomically based defense reactions induced by MJ were similar to the reactions observed after pathogen infection, mechanical wounding and bark beetle attack. Neither MJ nor OxA had apparent phytotoxic effects on Norway spruce at the concentrations used, with needle and stem tissues of all trees appearing normal without visible symptoms of toxicity. However, trees treated with MJ had 30% less radial sapwood growth than control trees. In conclusion, MJ treatment of Norway spruce appears to have practical potential as a tool for increasing plant resistance to fungal infection, but with a modest reduction in sapwood growth.

Monoterpene responses to interacting effects of drought stress and infection by the fungus Heterobasidion parviporum in two clones of Norway spruce (Picea abies)

“…Although systemic induction of traumatic resin ducts was observed in Norway spruce (Krekling et al, 2004;Krokene et al, 2008), our data are in agreement with the study by Zhao et al (2010) showing that terpene composition did not change in the untreated tissues after treatment and distinct chemical changes were restricted to the pretreated area of the stem.…”

Accumulation of iron-binding compounds in root of Pinus sylvestris challenged by Heterobasidion annosum sensu lato

“…Conversely, our studies determined that oxalic acid correlated negatively with P. sylvestris root cell death regardless of the species challenged the plant host. In the line of agreement with our results, oxalic acid increased resistance of P. abies against necrotrophic fungus Ceratocystis polonica (Siemaszko) C. Moreau (Krokene et al 2008) or it could be connected with activation of oxalate oxidase, the enzyme release H 2 O 2 and CO 2 from oxalic acid (Zhang et al 1995). Pectolytic enzymes proved to be involved in necrotrophic process of H. annosum s. l., but their activity was not correlated with oxalic acid synthesis ).…”

Potential for the Use of Exogenous Chemical Elicitors in Disease and Insect Pest Management of Conifer Seedling Production

“…Krokene et al [31] investigated the effect of chemical pre-treatment with MeJA or oxalic acid (OxA) on pathogen resistance of 13-year-old Norway spruce trees. The outer bark of test trees was first treated with chemical and then 4 weeks later inoculated with the pathogenic blue-stain fungus Ceratocystis polonica.…”