Nitro-oxidative stress contributes to selenite toxicity in pea (Pisum sativum L)

BACKGROUND AND AIMS: Selenium (Se) phytotoxicity at the cellular level disturbs the synthesis and functions of proteins, together with the generation of an oxidative stress condition. This study reveals the nitro-oxidative stress events, supplemented by a broad spectrumed characterisation of the Se-induced symptoms. METHODS: Applying several, carefully selected methods, we investigated the selenite treatment-induced changes in the Se and sulphur contents, pigment composition, hydrogen peroxide level, activity of the most important antioxidative enzymes, glutathione, nitric oxide and peroxynitrite, lipid peroxidation and protein tyrosine nitration. RESULTS: The Se content increased intensively and concentration-dependently in the organs of the treated plants, which led to altered vegetative and reproductive development. The level of the investigated reactive oxygen species and antioxidants supported the presence of the Se-induced oxidative stress, but also pointed out nitrosative changes, in parallel. CONCLUSIONS: The presented results aim to map the altered vegetative and reproductive development of Se-treated pea plants. Mild dose of Se has supportive effect, while high concentrations inhibit growth. Behind Se toxicity, we discovered both oxidative and nitrosative stress-induced modifications. Moreover, the presented data first reveals selenite-induced concentration- and organ-dependent tyrosine nitration in pea.