Age-dependent variations of local and systemic defence responses in Arabidopsis leaves towards an avirulent strain of Pseudomonas syringae

摘要: Despite the identification of several key mechanisms underlying disease resistance, comparatively little is known about way developmental factors affect capability plants to defend themselves against microbial pathogens. Here, influence leaf age on inducible local and systemic defence responses in incompatible interaction between Arabidopsis thaliana Pseudomonas syringae pv. maculicola (avrRPM1) investigated. Comparison behaviour rosette leaves differing revealed that younger generally had invest more pronounced defences than older (non-senescent) achieve a similar degree resistance. For instance, exhibited distinctive oxidative burst stronger hypersensitive cell death response ones. The pathogen-induced expression related genes phenylalanine ammonia lyase (PAL) glutathione-S-transferase (GST) proved be higher faster leaves, respectively, whereas gene induction PR-1 (pathogenesis-related protein 1) was largely independent age. Similarly, upon bacterial inoculation, signal salicylic acid (SA) phytoalexin camalexin accumulated amounts leaves. these differences defences, growth as measure resistance inoculated In tissue distant from inoculation site, acquired (SAR) developed most effectively this associated with strong accumulation SA transcripts. However, still SAR certain degree, essentially without or accumulation. These results suggest signalling contribute realise SAR.