Journal of Integrative Agriculture ›› 2014, Vol. 13 ›› Issue (11): 2508-2517.DOI: 10.1016/S2095-3119(13)60523-7

• 论文 • 上一篇    下一篇

Cell Production and Expansion in the Primary Root of Maize in Response to Low-Nitrogen Stress

 GAO Kun, CHEN Fan-jun, YUAN Li-xing , MI Guo-hua   

  1. Key Laboratory of Plant-Soil Interaction, Ministry of Agriculture/Center for Resources, Environment and Food Security, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, P.R.China
  • 收稿日期:2013-04-08 出版日期:2014-11-06 发布日期:2014-11-14
  • 通讯作者: MI Guo-hua, E-mail: miguohua@cau.edu.cn
  • 作者简介:GAO Kun, Mobile: 15810536392, E-mail: happycreek@126.com
  • 基金资助:

    This work was financially supported by the National Natural Science Foundation of China (31071852 and 31121062). We thank Professor Tobias I Baskin (University of Massachusetts Amherst, USA) for the critical comments on the kinematic analysis and great assistance in manuscript preparation.

Cell Production and Expansion in the Primary Root of Maize in Response to Low-Nitrogen Stress

 GAO Kun, CHEN Fan-jun, YUAN Li-xing , MI Guo-hua   

  1. Key Laboratory of Plant-Soil Interaction, Ministry of Agriculture/Center for Resources, Environment and Food Security, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, P.R.China
  • Received:2013-04-08 Online:2014-11-06 Published:2014-11-14
  • Contact: MI Guo-hua, E-mail: miguohua@cau.edu.cn
  • About author:GAO Kun, Mobile: 15810536392, E-mail: happycreek@126.com
  • Supported by:

    This work was financially supported by the National Natural Science Foundation of China (31071852 and 31121062). We thank Professor Tobias I Baskin (University of Massachusetts Amherst, USA) for the critical comments on the kinematic analysis and great assistance in manuscript preparation.

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摘要： Maize plants respond to low-nitrogen stress by enhancing root elongation. The underlying physiological mechanism remains unknown. Seedlings of maize (Zea mays L., cv. Zhengdan 958) were grown in hydroponics with the control (4 mmol L-1) or low-nitrogen (40 μmol L-1) for 12 d, supplied as nitrate. Low nitrogen enhanced root elongation rate by 4.1-fold, accompanied by increases in cell production rate by 2.2-fold, maximal elemental elongation rate (by 2.5-fold), the length of elongation zone (by 1.5-fold), and final cell length by 1.8-fold. On low nitrogen, the higher cell production rate resulted from a higher cell division rate and in fact the number of dividing cells was reduced. Consequently, the residence time of a cell in the division zone tended to be shorter under low nitrogen. In addition, low nitrogen increased root diameter, an increase that occurred specifically in the cortex and was accompanied by an increase in cell number. It is concluded that roots elongates in response to low-nitrogen stress by accelerating cell production and expansion.

关键词: cell length , elemental expansion , kinematic analysis , root diameter , root elongation , Zea mays L.

Abstract: Maize plants respond to low-nitrogen stress by enhancing root elongation. The underlying physiological mechanism remains unknown. Seedlings of maize (Zea mays L., cv. Zhengdan 958) were grown in hydroponics with the control (4 mmol L-1) or low-nitrogen (40 μmol L-1) for 12 d, supplied as nitrate. Low nitrogen enhanced root elongation rate by 4.1-fold, accompanied by increases in cell production rate by 2.2-fold, maximal elemental elongation rate (by 2.5-fold), the length of elongation zone (by 1.5-fold), and final cell length by 1.8-fold. On low nitrogen, the higher cell production rate resulted from a higher cell division rate and in fact the number of dividing cells was reduced. Consequently, the residence time of a cell in the division zone tended to be shorter under low nitrogen. In addition, low nitrogen increased root diameter, an increase that occurred specifically in the cortex and was accompanied by an increase in cell number. It is concluded that roots elongates in response to low-nitrogen stress by accelerating cell production and expansion.

Key words: cell length , elemental expansion , kinematic analysis , root diameter , root elongation , Zea mays L.