Do polyamines alter the sensitivity of lichens to nitrogen stress

摘要: Abstract The sensitivity of lichens measuring photosynthetic efficiency and polyamines as modulator nitrogen stress tolerance was investigated. Two lichen species with a markedly different to compounds, namely Evernia prunastri (L.) Ach. Xanthoria parietina Th.Fr., were incubated deionized water (control) solutions KNO 3 , NH 4 NO (NH ) 2 SO then exposed light conditions. F v / m parameter (maximum quantum photosystem II) used indicator. results showed that values, in the produced experimental conditions, independent from gradient. Photosynthetic E. impaired by high ammonium concentrations, while nitrate had no effect; X. hardly influenced compounds. External supply reduced polyamine inhibitors + suggesting play an important role modulating sensitivity/tolerance stress.