Picolinic acid spray stimulates the antioxidative metabolism and minimizes impairments on photosynthesis on wheat leaves infected by Pyricularia oryzae.

摘要: Fungal pathogens produce toxins that are important for their pathogenesis and/or aggressiveness towards hosts. Picolinic acid (PA), a non-host selective toxin, causes lesions on rice leaves resembling those originated from Pyricularia oryzae infection. Considering can be useful plant diseases control, this study investigated whether the foliar spray with PA wheat (Triticum aestivum L.) plants, in non-phytotoxic concentration, could increase resistance to blast, stimulate anti-oxidative metabolism, and minimize alterations photosynthesis. The at concentrations greater than 0.1 mg ml-1 caused lesions, compromised photosynthesis was linked accumulation of hydrogen peroxide (H2 O2 ) superoxide anion radical (O2 •- ). mycelial growth, conidia production germination decreased by 0.3 . Blast severity significantly reduced 59 23%, respectively, 72 96 h after inoculation plants sprayed (0.1 24 before fungal compared non-sprayed plants. Reduction blast symptoms increases ascorbate peroxidase (EC 1.11.1.11), catalase 1.11.1.6), glutathione 1.11.1.9), reductase 1.8.1.7), glutathione-S-transferase 2.5.1.18), 1.11.1.7), dismutase 1.15.1.1) activities, lower H2 accumulation, malondialdehyde as well less impairments photosynthetic apparatus. A more efficient antioxidative metabolism rapidly scavenges reactive oxygen species generated during P. infection, without dramatically decreasing performance, remarkable effect obtained spray.