Titanium dioxide nanoparticles impaired both photochemical and non-photochemical phases of photosynthesis in wheat

• Tipo: Artigo em Revista Científica Internacional
• Data: 2019

Autores

Dias, MC (Autor) Outra; Santos, C (Autor) FCUP; Pinto, G (Autor) Outra; Silva, AMS (Autor) Outra; Silva, S (Autor) Outra

Revista

Título: Protoplasma

Vol. 256

Páginas: 69-78

ISSN: 0033-183X

Editora: Springer Nature

Indexação

ISI Web of Knowledge - 30 Citações

Scopus - 44 Citações

Outras Informações

ID Authenticus: P-00P-ZE7

DOI: 10.1007/s00709-018-1281-6

Abstract (EN): Titanium dioxide nanoparticles (TiO2-NP) are increasingly being proposed for nanoagriculture but their effect on photosynthesis is limited and contradictory, mostly regarding putative chronical effects associated to the exposure to the commercial P25 formulation (anatase:rutile). This research aims at evaluating how chronical exposure to P25-NP affect photosynthetic processes in Triticum aestivum. Wheat plants were exposed (from the germination stage) to 0, 5, 50, and 150mgL(-1) P25-NP for 20days. P25-NP impaired both light-dependent and -independent phases of photosynthesis, decreased chlorophyll a content, maximal and effective efficiency of PSII, net photosynthetic rate, transpiration rate, stomatal conductance, intercellular CO2 concentration, and starch content. On the other hand, no effects were observed in photochemical and in non-photochemical quenching values, on total soluble sugar (TSS) content or in RuBisCO activity. Our results support that the induced decay in chlorophyll a content compromised the electron transport through PSII and that stomatal limitations impaired CO2 assimilation. The decline of starch content seems to be a consequence of its degradation as a mechanism to maintain the TSS levels. Consequently, we propose that photosynthetic related endpoints are sensitive and valuable biomarkers to assess TiO2-NP toxicity.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 10