Welcome to Chinese Agricultural Science Bulletin,

Chinese Agricultural Science Bulletin ›› 2020, Vol. 36 ›› Issue (32): 23-29.doi: 10.11924/j.issn.1000-6850.casb2020-0044

Special Issue: 生物技术 园艺

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Nitrogen Stress: Effect on Physiology and Relative NRTs Genes Expression in Beta vulgaris Seedlings

Liu Dali1,2(), Wei Duo1,2, Gao Zhuo1,3, Wang Qiuhong1,2, Ma Longbiao1,2, Zhou Jianchao1,2()   

  1. 1Key Laboratory of Sugarbeet Genetics and Breeding, Heilongjiang University/College of Advanced Agriculture and Ecological Environment, Harbin 150080
    2Sugar Beet Engineering Research Center of Heilongjiang Province, Heilongjiang University/College of Advanced Agriculture and Ecological Environment, Harbin 150080
    3Key Laboratory of Biochemistry and Molecular Biology/College of Life Sciences, Heilongjiang University, Harbin 150080
  • Received:2020-04-25 Revised:2020-06-28 Online:2020-11-15 Published:2020-11-19
  • Contact: Zhou Jianchao E-mail:383739479@qq.com;zhou88767@126.com

Abstract:

This research aims at further studying the regulatory mechanism of N utilization in sugar beet (Beta vulgaris L.) in N deficient environment, and laying a foundation for improving plants for NUE by molecular breeding and genetic engineering approaches. In this study, sugar beet seedlings of ‘780016b/12you’ were used as material, the physiological and molecular response mechanism was studied under low nitrogen and nitrogen deficiency stress, through observation of phenotype, determination of chlorophyll content and responsive changes of related genes and enzyme activity. The results showed that sugar beet leaves turned yellow partially due to nitrogen deficiency, and the SPAD value exhibited decreased chlorophyll content with the increase of stress time. qPCR showed that both BvNRT2.1 and BvNRT3.2 were induced by low N or N deficiency, and the expression of the two genes in roots was higher than that in leaves, and BvNRT2.1 responded to stress more obviously. Meanwhile, with the increase of stress time, nitrate reductase (NR) activity in beet decreased gradually, but the activity of NR in leaves was always higher than that in roots. Hence, it is concluded that low nitrogen or nitrogen deficiency stress could cause a serious impact on the photosynthesis and nitrate reductases activity of sugar beet seedlings, and lead to the inhibition of growth to some extent. It is inferred that, in order to adapt to the N stress environment, sugar beet itself might compensate for the lack of nutrition caused by N deficiency or low nitrogen through up regulating the expression of nitrate transporter genes directly or indirectly.

Key words: Beta vulgaris, nitrogen stress, NRTs, NR activity, chlorophyll

CLC Number: