Journal of Integrative Agriculture ›› 2018, Vol. 17 ›› Issue (04): 837-846.DOI: 10.1016/S2095-3119(17)61759-3

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  • 收稿日期:2017-03-18 出版日期:2018-04-20 发布日期:2018-04-16

The positive function of selenium supplementation on reducing nitrate accumulation in hydroponic lettuce (Lactuca sativa L.)

LEI Bo1*, BIAN Zhong-hua2*, YANG Qi-chang1, WANG Jun1, CHENG Rui-feng1, LI Kun1, LIU Wen-ke1, ZHANG Yi1, FANG Hui1, TONG Yun-xin1   

  1. 1 Key Laboratory of Energy Conservation and Waste Treatment of Agricultural Structures, Ministry of Agriculture/Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, P.R.China
    2 Nottingham Trent University, Brackenhurst Campus, Nottingham NG25 0QF, UK
  • Received:2017-03-18 Online:2018-04-20 Published:2018-04-16
  • Contact: Correspondence YANG Qi-chang, Tel: +86-10-82105983, Fax: +86-10-82106021, E-mail: yangqichang@caas.cn; CHENG Rui-feng, Tel: +86-10-82106015, Fax: +86-10-82106021, E-mail: chengruifeng@caas.cn
  • About author:LEI Bo, E-mail: bl198356@126.com; BIAN Zhong-hua, E-mail: zhonghua.bian@ntu.ac.uk; * These authors contributed equally to this study.
  • Supported by:

    This work was supported by the National High-Tech R&D Program of China (863 Program, 2013AA103004), the International S&T Cooperation Program of China (2014DFG32110), the National Key Research and Development Program of China (2014BAD08B020106). 

Abstract: High nitrate (NO3) in vegetables, especially in leaf vegetables poses threaten to human health.  Selenium (Se) is an important element for maintaining human health, and exogenous Se application during vegetable and crop production is an effective way to prevent Se deficiency in human bodies.  Exogenous Se shows positive function on plant growth and nutrition uptake under abiotic and/or biotic stresses.  However, the influence of exogenous Se on NO3 accumulation in hydroponic vegetables is still not clear.  In the present study, hydroponic lettuce plants were subjected to six different concentrations (0, 0.1, 0.5, 5, 10 and 50 µmol L–1) of Se as Na2SeO3.  The effects of Se on NO3 content, plant growth, and photosynthetic capacity of lettuce (Lactuca sativa L.) were investigated.  The results showed that exogenous Se positively decreased NO3 content and this effect was concentration-dependent.  The lowest NO3 content was obtained under 0.5 µmol L–1 Se treatment.  The application of Se enhanced photosynthetic capacity by increasing the photosynthesis rate (Pn), stomatal conductance (Cs) and the transpiration efficiency (Tr) of lettuce.  The transportation and assimilation of NO3 and activities of nitrogen metabolism enzymes in lettuce were also analysed.  The NO3 efflux in the lettuce roots was markedly increased, but the efflux of NO3 from the root to the shoot was decreased after treated with exogenous Se.  Moreover, Se application stimulated NO3 assimilation by enhancing nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS) and glutamate synthase enzyme (GOGAT) activities.  These results provide direct evidence that exogenous Se shows positive function on decreasing NO3 accumulation via regulating the transport and enhancing activities of nitrogen metabolism enzyme in lettuce.  We suggested that 0.5 µmol L–1 Se can be used to reduce NO3 content and increase hydroponic lettuce yield. 

Key words: selenium ,  NO3&minus, , nitrogen metabolism enzyme ,  SIET ,  photosynthetic performance ,  lettuce