J Integr Plant Biol ›› 2009, Vol. 51 ›› Issue (7): 689-697.DOI: 10.1111/j.1744-7909.2009.00843.x

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Growth, and Nitrogen Uptake and Flow in Maize Plants Affected by Root Growth Restriction

Liangzheng Xu1,2, Junfang Niu3, Chunjian Li1* and Fusuo Zhang1   

  • 收稿日期:2009-02-07 接受日期:2009-04-09 出版日期:2009-07-10 发布日期:2009-06-25

Growth, and Nitrogen Uptake and Flow in Maize Plants Affected by Root Growth Restriction

Liangzheng Xu1,2, Junfang Niu3, Chunjian Li1* and Fusuo Zhang1   

  1. 1 The Key Laboratory of Plant Nutrition, Ministry of Agriculture, Department of Plant Nutrition, China Agricultural University, Beijing 100193, China
    2 School of Life Sciences, Jiaying University, Meizhou 514015, China
    3 Centre of Agricultural Resources, Institute of Genetics and Developmental Biology, the Chinese Academy of Sciences, Shijiazhuang 050021, China
  • Received:2009-02-07 Accepted:2009-04-09 Online:2009-07-10 Published:2009-06-25
  • About author: *Author for correspondence Tel: +86 10 6273 3886; Fax: +86 10 6273 1016; E-mail: lichj@cau.edu.cn

Abstract:

The objective of the present study was to investigate the influence of a reduced maize root-system size on root growth and nitrogen (N) uptake and flow within plants. Restriction of shoot-borne root growth caused a strong decrease in the absorption of root: shoot dry weight ratio and a reduction in shoot growth. On the other hand, compensatory growth and an increased N uptake rate in the remaining roots were observed. Despite the limited long-distance transport pathway in the mesocotyl with restriction of shoot-borne root growth, N cycling within these plants was higher than those in control plants, implying that xylem and phloem flow velocities via the mesocotyl were considerably higher than in plants with an intact root system. The removal of the seminal roots in addition to restricting shoot-borne root development did not affect whole plant growth and N uptake, except for the stronger compensatory growth of the primary roots. Our results suggest that an adequate N supply to maize plant is maintained by compensatory growth of the remaining roots, increased N uptake rate and flow velocities within the xylem and phloem via the mesocotyl, and reduction in the shoot growth rate.

Xu L, Niu J, Li C, Zhang F (2009). Growth, and nitrogen uptake and flow in maize plants affected by root growth restriction. J.Integr.Plant Biol. 51(7),689-697.

Key words: Root system components, nitrogen uptake, nitrogen flow, Zea mays.

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