Effects of simultaneous arsenic and iron toxicities on rice (Oryza sativa L.) development, yield-related parameters and As and Fe accumulation in relation to As speciation in the grains
Background and aim
In numerous areas, rice cultivated under flooded conditions is exposed simultaneously to iron excess and arsenic contamination. The impact of these combined stresses on yield-related parameters and As distribution and speciation in various plant parts remains poorly documented.
Rice (cv I Kong Pao) was exposed to iron excess (125 mg L−1 Fe2SO4), arsenic (50 and 100 μM Na2HAsO4.7H2O) or a combination of those stressing agents in hydroponic culture until harvest. Plant growth, yield-related parameters, non protein thiols concentration and mineral nutrition were studied in roots and shoots. Arsenic speciation was determined by high-performance liquid chromatography-hydride generation-atomic fluorescence spectrometry.
Iron excess increased As retention by the roots in relation to the development of the root iron plaque but decreased As accumulation in the shoot. Arsenic concentration was lower in the grains than in the shoots. Iron stress reduced As accumulation in the husk but not in the dehusked grains. Iron excess decreased the proportion of extractable As(III) and As(V) in the grain while it increased the proportion of extractable As(III) in the shoot. Combined stresses (Fe+As) affected plant nutrition and significantly reduced the plant yield by limiting the number of grains per plant and the grain filling.
Fe excess had an antagonist impact on shoot As concentration but an additive negative impact on several yield-related parameters. Iron stress influences both As distribution and As speciation in rice.
KeywordsIron plaque Iron stress Arsenic Oryza sativa Rice Rice grain arsenic
The authors are grateful to the Fonds National de la Recherche Scientifique (FNRS—FRFC; Convention 2.4599.12) for financial support. The authors would like to thank anonymous referees for their valuable help in improving the quality of the manuscript.
- Garnier J-M, Travassac F, Lenoble V, Rose J, Zheng Y, Hossain MS, Chowdhury SH, Biswas AK, Ahmed KM, Cheng Z, van Geen A (2010) Temporal variations in arsenic uptake by rice plants in Bangladesh; the role of iron plaque in paddy fields irrigated with groundwater. Sci Total Environ 408:4185–4193PubMedCrossRefGoogle Scholar
- Ghanem ME, van Elteren J, Albacete A, Quinet M, Martinéz-Andújar C, Kinet JM, Perez-Alfocea F, Lutts S (2009) Impact of salinity on early reproductive physiology of tomato (Solanum lycopersicum) in relation to a heterogeneous distribution of toxic ions in flowers organs. Funct Plant Biol 36:125–136CrossRefGoogle Scholar
- Moore KL, Schröder M, Wu ZC, Martin BGH, Hawes CR, McGrath SP, Hawkesford MJ, Ma JF, Zhao FJ, Grovenor CRM (2011) High-resolution secondary ion mass spectrometry reveals the contrasting subcellular distribution of arsenic and silicon in roce roots. Plant Physiol 156:913–924PubMedCrossRefGoogle Scholar
- Quinet M, Vromman D, Clippe A, Bertin P, Lequeux H, Dufey I, Lutts S, Lefèvre I (2012) Combined transcriptomic and physiological approaches reveal strong differences between short and long term response of rice (Oryza sativa) to iron toxicity. Plant Cell Environ 35:1837–1859PubMedCrossRefGoogle Scholar
- Yoshida S, Forno D, Cock J, Gomez K (1976) Laboratory manual for physiological studies of rice. IRRI, PhilippinesGoogle Scholar