External Nitrogen and Carbon Source-Mediated Response on Modulation of Root System Architecture and Nitrate Uptake in Wheat Seedlings
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Nitrogen uptake efficiency is an important component trait that could be targeted for improving nitrogen use efficiency of crop plants. To understand the responses of different nitrate transport systems and the influence of root system architecture on nitrate uptake under limited nitrate conditions in wheat (Triticum aestivum L.) at the seedling stage, we studied nitrate uptake, root system architecture, and expression of different nitrate transporter genes in induced and non-induced wheat seedlings. Further, effects of inclusion of sucrose and two amino acids (glutamine and asparagine) in induction medium on these parameters were also studied. We observed that the induced wheat root system took up more nitrate as compared to non-induced root system in a dose-dependent manner. Gene expression of both high- and low-affinity nitrate transporter gene showed differential expression in the induced root tissues, as compared to non-induced tissues, depending on the concentration of nitrate present in induction medium. External nutrient media containing sucrose, glutamine, and asparagine reduce nitrate concentration in both root and shoot tissues and also influence the gene expression of these transporters. Our observations indicate that upon induction with milder external nitrate concentrations, the root architecture is modulated by changing overall lateral root size and 1st order lateral root numbers along with activation of nitrate transporters which acquire and transport nitrate in roots and shoots, respectively, depending on the carbon and nitrogen source available to seedlings.
KeywordsNitrate transporter Nitrate starvation Root system architecture Nitrate uptake efficiency Wheat
The present work was financially supported by ICAR-NRCPB institutional fund. Authors would like to acknowledge the Project Director of ICAR-NRCPB, New Delhi for his support and encouragement at various levels to execute this work. We are thankful to Dr. Anju M. Singh, Division of Genetics, Indian Agricultural Research Institute, New Delhi, for providing HD-2967 seeds.
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Conflict of interest
The authors declare no conflicts of interest.
- Agren GI, Ingestad T (1987) Root: shoot ratio as a balance between nitrogen productivity and photosynthesis. Plant Cell Environ 10:579–586Google Scholar
- Crawford NM, Glass ADM (1998) Molecular and physiological aspects of nitrate uptake in plants. Trends Plant Sci 3:395–398Google Scholar
- Goyal SS, Huffaker RC (1986) A novel approach and a fully automated microcomputer-based system to study kinetics of NO3; NO2 – and NW transport simultaneously by intact wheat seedlings. Plant Cell Environ 9:209–215Google Scholar
- Masclaux-Daubresse C, Daniel-Vedele F, Dechorgnat J, Chardon F, Gaufichon L, Suzuki A (2010) Nitrogen uptake, assimilation and remobilization in plants: challenges for sustainable and productive agriculture. AnnBot 105:1141–1157Google Scholar
- Meyer C, Stitt M (2001) Nitrate reductase and signallin. In: Lea PJ, Morot-Gaudry JF (Eds) Plant nitrogen. Springer, New YorkGoogle Scholar
- MSTATC (1990) A microcomputer program for the design, management, and analysis of research agronomic experiments. Michigan State University, East LansingGoogle Scholar
- Negi M, Sanagala R, Rai V, Jain A (2016) Deciphering phosphate deficiency-mediated temporal effects on different root traits in rice grown in a modified hydroponic system. Front Plant Sci 7:550Google Scholar