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


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 150 mg L−1 P25-NP for 20 days. 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.

This is a preview of subscription content, log in to check access.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5


Chl a(b):

Chlorophyll a(b)



C i :

Intercellular CO2 concentration

E :

Transpiration rate

Fm :

Maximal fluorescence yield of dark-adapted state

F m′:

Maximal fluorescence yield of light-adapted state

F v/F m :

Photosystem II (PSII) maximum efficiency

F 0 :

Minimal fluorescence yield of dark-adapted state

g s :

Stomatal conductance


Non-photochemical quenching

P N :

Net photosynthetic rate


Photochemical quenching


PSII effective photochemical efficiency


Relative water content


Total soluble sugars


  1. Alfonso SU, Bruggemann W (2012) Photosynthetic responses of a C3 and three C4 species of the genus Panicum (s.L.) with different metabolic subtypes to drought stress. Photosynth Res 112(3):175–191

    Article  CAS  PubMed  Google Scholar 

  2. Asli S, Neumann P (2009) Colloidal suspensions of clay or titanium dioxide nanoparticles can inhibit leaf growth and transpiration via physical effects on root water transport. Plant Cell Environ 32(5):577–584

    Article  CAS  PubMed  Google Scholar 

  3. Bacelar EA, Santos DL, Moutinho-Pereira JM, Lopes JI, Gonçalves BC, Ferreira TC, Correia CM (2007) Physiological behaviour, oxidative damage and antioxidative protection of olive trees grown under different irrigation regimes. Plant Soil 292(1–2):1–12

    Article  CAS  Google Scholar 

  4. Bhatt I, Tripathi BN (2011) Interaction of engineered nanoparticles with various components of the environment and possible strategies for their risk assessment. Chemosphere 82(3):308–317

    Article  CAS  PubMed  Google Scholar 

  5. Boxall A, Tiede K, Chaudhry Q (2007) Engineered nanomaterials in soils and water: how do they behave and could they pose a risk to human health? Nanomedicine 2(6):919–927

    Article  CAS  PubMed  Google Scholar 

  6. Calabrese EJ (2015) Hormesis: principles and applications. Homeopathy 104(2):69–82

    Article  PubMed  Google Scholar 

  7. Conway JR, Beaulieu AL, Beaulieu NL, Mazer SJ, Keller AA (2015) Environmental stresses increase photosynthetic disruption by metal oxide nanomaterials in a soil-grown plant. ACS Nano 9(12):11737–11749

    Article  CAS  PubMed  Google Scholar 

  8. Fenoglio I, Greco G, Livraghi S, Fubini B (2009) Non-UV-induced radical reactions at the surface of TiO2 nanoparticles that may trigger toxic responses. Chemistry 15(18):4614–4621

    Article  CAS  PubMed  Google Scholar 

  9. Gao FQ, Hong FH, Liu C, Zheng L, Su M, Wu X, Yang F, Wu C, Yang P (2006) Mechanism of nano-anatase TiO2 on promoting photosynthetic carbon reaction of spinach - inducing complex of Rubisco-Rubisco activase. Biol Trace Elem Res 111(1–3):239–253

    Article  CAS  PubMed  Google Scholar 

  10. Gao F, Liu C, Qu C, Zheng L, Yang F, Su M, Hong F (2008) Was improvement of spinach growth by nano-TiO2 treatment related to the changes of Rubisco activase? Biometals 21(2):211–217

    Article  CAS  PubMed  Google Scholar 

  11. Gao J, Xu G, Qian H, Liu P, Zhao P, Hu Y (2013) Effects of nano-TiO2 on photosynthetic characteristics of Ulmus elongata seedlings. Environ Pollut 176:63–70

    Article  CAS  PubMed  Google Scholar 

  12. Hurum DC, Agrios AG, Gray KA, Rajh T, Thurnauer MC (2003) Explaining the enhanced photocatalytic activity of Degussa P25 mixed-phase TiO2 using EPR. J Phys Chem B 107(19):4545–4549

    Article  CAS  Google Scholar 

  13. Irigoyen JJ, Emerich DW, Sanchezdiaz M (1992) Water-stress induced changes in concentrations of proline and total soluble sugars in nodulated alfalfa (Medicago sativa) plants. Physiol Plantarum 84(1):55–60

    Article  CAS  Google Scholar 

  14. ISO- International Organization for Standardization (2008) Technical specification: nanotechnologies—terminology and definitions for nano-objects—nanoparticle, nanofibre and nanoplate. ISO/TS 80004-2:2008

    Google Scholar 

  15. Keller AA, McFerran S, Lazareva A, Suh S (2013) Global life cycle releases of engineered nanomaterials. J Nanopart Res 15(6):1692

  16. Li J, Naeem MS, Wang XP, Liu L, Chen C, Ma N, Zhang C (2015) Nano-TiO2 is not phytotoxic as revealed by the oilseed rape growth and photosynthetic apparatus ultra-structural response. PLoS One 10(12):e0143885

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  17. Linglan M, Chao L, Chunxiang Q, Sitao Y, Jie L, Fengqing G, Fashui H (2008) Rubisco activase mRNA expression in spinach: modulation by nanoanatase treatment. Biol Trace Elem Res 122(2):168–178

    Article  CAS  PubMed  Google Scholar 

  18. Lubick N (2009) Hunting for engineered nanomaterials in the environment. Environ Sci Technol 43(17):6446–6447

    Article  CAS  PubMed  Google Scholar 

  19. Luttrell T, Halpegamage S, Tao JG, Kramer A, Sutter E, Batzill M (2014) Why is anatase a better photocatalyst than rutile? – model studies on epitaxial TiO2 films. Sci Rep 4:4043. https://doi.org/10.1038/srep04043

  20. Mingyu S, Xiao W, Chao L, Chunxiang Q, Xiaoqing L, Liang C, Hao H, Fashui H (2007) Promotion of energy transfer and oxygen evolution in spinach photosystem II by nano-anatase TiO2. Biol Trace Elem Res 119(2):183–192

    Article  CAS  PubMed  Google Scholar 

  21. Murchie EH, Lawson T (2013) Chlorophyll fluorescence analysis: a guide to good practice and understanding some new applications. J Exp Bot 64(13):3983–3998

    Article  CAS  Google Scholar 

  22. Organization for Economic Co-operation and Development (OECD) (1984) Guidelines for the Testing of Chemicals, 208, Terrestrial Plants, Growth Test Organisation for Economic Co-operation and Development, Paris

  23. Osaki M, Shinano T, Tadano T (1991) Redistribution of carbon and nitrogen-compounds from the shoot to the harvesting organs during maturation in field crops. Soil Sci Plant Nutr 37(1):117–128

    Article  CAS  Google Scholar 

  24. Qi MF, Liu YF, Li TL (2013) Nano-TiO2 improve the photosynthesis of tomato leaves under mild heat stress. Biol Trace Elem Res 156(1–3):323–328

    Article  CAS  PubMed  Google Scholar 

  25. Raliya R, Nair R, Chavalmane S, Wang WN, Biswas P (2015) Mechanistic evaluation of translocation and physiological impact of titanium dioxide and zinc oxide nanoparticles on the tomato (Solanum lycopersicum L) plant. Metallomics 7(12):1584–1594

    Article  CAS  PubMed  Google Scholar 

  26. Reyes-Coronado D, Rodriguez-Gattorno G, Espinosa-Pesqueira ME et al (2008) Phase-pure TiO2 nanoparticles: anatase, brookite and rutile. Nanotechnology 19(14):145605

    Article  CAS  PubMed  Google Scholar 

  27. Schreiber U, Bilger W, Neubauer (1995) Chlorophyll flourescence as a non-destructive indicator for rapid assessment of in vivo photosynthesis. In: Schulze ED, Caldwell MM (eds) Ecophysiology of photosynthesis. Springer-Verlag, Berlin, pp 40–70

    Google Scholar 

  28. Servin AD, Morales MI, Castillo-Michel H, Hernandez-Viezcas JA, Munoz B, Zhao L, Nunez JE, Peralta-Videa JR, Gardea-Torresdey JL (2013) Synchrotron verification of TiO2 accumulation in cucumber fruit: a possible pathway of TiO2 nanoparticle transfer from soil into the food chain. Environ Sci Technol 47(20):11592–11598

    Article  CAS  PubMed  Google Scholar 

  29. Silva S, Oliveira H, Craveiro SC, Calado AJ, Santos C (2016) Pure anatase and rutile + anatase nanoparticles differently affect wheat seedlings. Chemosphere 151:68–75

    Article  CAS  PubMed  Google Scholar 

  30. Silva S, Oliveira H, Silva AMS, Santos C (2017a) The cytotoxic targets of anatase or rutile + anatase nanoparticles depend on the plant species. Biol Plant 61(4):717–725

    Article  CAS  Google Scholar 

  31. Silva S, Craveiro S, Oliveira H, Calado JA, Pinto RJB, Silva AMS, Santos C (2017b) Wheat chronic exposure to TiO2-nanoparticles: Cyto- and genotoxic approach. Plant Physiol Biochem 121:89–98

    Article  CAS  PubMed  Google Scholar 

  32. Silva S, Pinto G, Santos C (2017c) Low doses of Pb affected Lactuca sativa photosynthetic performance. Photosynthetica 55(1):50–57

    Article  CAS  Google Scholar 

  33. Sims DA, Gamon JA (2002) Relationships between leaf pigment content and spectral reflectance across a wide range of species, leaf structures and developmental stages. Remote Sens Environ 81:337–354

    Article  Google Scholar 

  34. Song U, Jun H, Waldman B, Roh J, Kim Y, Yi J, Lee EJ (2013a) Functional analyses of nanoparticle toxicity: a comparative study of the effects of TiO2 and ag on tomatoes (Lycopersicon esculentum). Ecotoxicol Environ Saf 93:60–67

    Article  CAS  PubMed  Google Scholar 

  35. Song U, Shin M, Lee G, Roh J, Kim Y, Lee EJ (2013b) Functional analysis of TiO2 nanoparticle toxicity in three plant species. Biol Trace Elem Res 155(1):93–103

    Article  CAS  PubMed  Google Scholar 

  36. Srivastava V, Gusain D, Sharma Y (2015) Critical review on the toxicity of some widely used engineered nanoparticles. Ind Eng Chem Res 54(24):6209–6233

    Article  CAS  Google Scholar 

  37. Stampoulis D, Sinha SK, White JC (2009) Assay-dependent phytotoxicity of nanoparticles to plants. Environ Sci Technol 43(24):9473–9479

    Article  CAS  PubMed  Google Scholar 

  38. Tassi E, Giorgetti L, Morelli E, Peralta-Videa JR, Gardea-Torresdey JL, Barbafieri M (2017) Physiological and biochemical responses of sunflower (Helianthus annuus L) exposed to nano-CeO2 and excess boron: modulation of boron phytotoxicity. Plant Physiol Biochem 110:50–58

    Article  CAS  PubMed  Google Scholar 

  39. Tripathi DK, Shweta, Singh S et al (2017) An overview on manufactured nanoparticles in plants: uptake, translocation, accumulation and phytotoxicity. Plant Physiol Biochem 110:2–12

    Article  CAS  PubMed  Google Scholar 

  40. Tumburu L, Andersen C, Rygiewicz P, Reichman J (2015) Phenotypic and genomic responses to titanium dioxide and cerium oxide nanoparticles in Arabidopsis germinants. Environ Toxicol Chem 34(1):70–83

    Article  CAS  PubMed  Google Scholar 

  41. van Kooten O, Snel JFH (1990) The use of chlorophyll fluorescence nomenclature in plant stress physiology. Photosynth Res 25(3):147–150

    Article  Google Scholar 

  42. Wang XP, Yang XY, Chen SY et al (2016) Zinc oxide nanoparticles affect biomass accumulation and photosynthesis in Arabidopsis. Front Plant Sci 12(6):1243. https://doi.org/10.3389/fpls.2015.01243

  43. Xue GP, McIntyre CL, Glassop D, Shorter R (2008) Use of expression analysis to dissect alterations in carbohydrate metabolism in wheat leaves during drought stress. Plant Mol Biol 67(3):197–214

    Article  CAS  Google Scholar 

  44. Yanik F, Vardar F (2015) Toxic effects of aluminum oxide (Al2O3) nanoparticles on root growth and development in Triticum aestivum. Water Air Soil Poll 226(9):296

  45. Zhang P, Cui HX, Zhang ZJ, Zhong RG (2008) Effects of nano-TiO2 photosemiconductor on photosynthesis of cucumber plants. Chi Agric Sci Bull 24:230–233

    Google Scholar 

  46. Zhang Z, He X, Zhang H, Ma Y, Zhang P, Ding Y, Zhao Y (2011) Uptake and distribution of ceria nanoparticles in cucumber plants. Metallomics 3(8):816–822

    Article  CAS  PubMed  Google Scholar 

  47. Zheng L, Hong F, Lu S, Liu C (2005) Effect of nano-TiO2 on strength of naturally aged seeds and growth of spinach. Biol Trace Elem Res 104:83–91

    Article  CAS  PubMed  Google Scholar 

Download references


The Fundação para a Ciência e Tecnologia (FCT/MCT) supported S. Silva (SFRH/BPD/74299/2010), M. C. Dias (SFRH/BPD/100865/2014), and G. Pinto (SFRH/BPD/101669/2014) grants from QREN–POPH/FSE—Tipologia 4.1—Formação Avançada. This work was financed by FCT/MEC through national founds, and the co-funding by the FEDER, within the PT2020 Partnership Agreement and Compete 2020, within the projects CEF (UID/BIA/04004/2013), CESAM (UID/AMB/50017), QOPNA (UID/QUI/00062/2013), and LAQV/REQUIMTE (PT2020 UID/QUI/50006/2013, POCI/01/0145/FEDER/007265).

Author information



Corresponding author

Correspondence to Sónia Silva.

Ethics declarations

Conflict of interest

The authors declare that they have no conflict of interest.

Additional information

Handling Editor: Néstor Carrillo

Electronic supplementary material


(DOCX 88 kb)

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Dias, M.C., Santos, C., Pinto, G. et al. Titanium dioxide nanoparticles impaired both photochemical and non-photochemical phases of photosynthesis in wheat. Protoplasma 256, 69–78 (2019). https://doi.org/10.1007/s00709-018-1281-6

Download citation


  • Net photosynthetic rate
  • PSII photochemical efficiency
  • Phytotoxicity
  • TiO2 nanoparticles