Cr (VI)-induced oxidative damage impairs ammonia assimilation into organic forms in Solanum lycopersicum L.

Plant Stress

Jorge Lopes¹  Fernanda Fidalgo²  Inês M. Valente³  Cristiano Soares³  Maria Martins³  Bruno Sousa³  Jorge Teixeira⁴  José A. Rodrigues⁵ 

[1] Corresponding author.;REQUIMTE, LAQV, Chemistry and Biochemistry Department, Faculty of Sciences University of Porto (FCUP), Rua do Campo Alegre 687, Porto 4169-007, Portugal;GreenUPorto - Sustainable Agrifood Production Research Center and INOV4AGRO, Biology Department, Faculty of Sciences University of Porto (FCUP), Rua Campo Alegre s/n, Porto 4169-007, Portugal;REQUIMTE, LAQV, Chemistry and Biochemistry Department, Faculty of Sciences University of Porto (FCUP), Rua do Campo Alegre 687, Porto 4169-007, Portugal;REQUIMTE, LAQV, Institute of Biomedical Sciences Abel Salazar, University of Porto, Rua Jorge Viterbo Ferreira, 228, Porto 4050-313, Portugal;

关键词: Metal pollution;    Glutamine synthetase;    Glutamate dehydrogenase;    Oxidative stress;    Tomato plant;   

DOI  :  

来源: DOAJ

【 摘 要 】

Chromium (Cr) is a dangerous metal that has been found in the environment in high amounts as the result of numerous human activities, with proven negative effects on various organisms, including plants. The exposure of some plant species to this metal resulted in reduced growth, impaired nutrient uptake, and led to an overproduction of reactive oxygen species (ROS), ultimately causing oxidative damage. Nevertheless, studies regarding the impact of Cr on nitrogen (N) metabolism, the main limiting factor for plant growth, either directly or through the occurrence of oxidative stress, are scarce. Thus, this work aimed to explore the interplay between ammonia (NH4+) assimilation, redox homeostasis and antioxidant (AOX) system of tomato plants exposed to increased concentrations of Cr (VI) (0, 5 and 10 µM). The results revealed that Cr (VI) induced biometric damages, with roots being the most affected organ. Glutamine synthetase (GS) was differentially influenced by the metal at the gene expression, protein and activity levels, whereas glutamate dehydrogenase (GDH) activity was enhanced. Moreover, in Cr (VI)-treated plants, the observed oxidative damage was dependent on metal concentration and plant organ, with a differential accumulation of ROS and a generalized increase of lipid peroxidation (LP) recorded, being paired with an overall failure of the enzymatic antioxidant (AOX) system. Still, the non-enzymatic AOX component had a relevant role in the protection of plants against Cr (VI). Overall, the obtained results suggest that Cr (VI)-mediated plant growth reduction resulted from the occurrence of oxidative stress, coupled with the lack of enzymatic AOX defense, which, consequently, affected the NH4+ assimilatory route.

【 授权许可】

Unknown