Author:
Huang Wei-Tao,Zheng Zhi-Chao,Hua Dan,Chen Xu-Feng,Zhang Jiang,Chen Huan-Huan,Ye Xin,Guo Jiu-Xin,Yang Lin-Tong,Chen Li-Song
Abstract
Abstract
Background
In China, nitrogen (N)-deficiency often occurs in Citrus orchards, which is one of the main causes of yield loss and fruit quality decline. Little information is known about the adaptive responses of Citrus carbon (C) and N metabolisms to N-deficiency. Seedlings of ‘Xuegan’ (Citrus sinensis (L.) Osbeck) were supplied with nutrient solution at an N concentration of 0 (N-deficiency), 5, 10, 15 or 20 mM for 10 weeks. Thereafter, we examined the effects of N supply on the levels of C and N in roots, stems and leaves, and the levels of organic acids, nonstructural carbohydrates, NH4+-N, NO3−-N, total soluble proteins, free amino acids (FAAs) and derivatives (FAADs), and the activities of key enzymes related to N assimilation and organic acid metabolism in roots and leaves.
Results
N-deficiency elevated sucrose export from leaves to roots, C and N distributions in roots and C/N ratio in roots, stems and leaves, thus enhancing root dry weight/shoot dry weight ratio and N use efficiency. N-deficient leaves displayed decreased accumulation of starch and total nonstructural carbohydrates (TNC) and increased sucrose/starch ratio as well as a partitioning trend of assimilated C toward to sucrose, but N-deficient roots displayed elevated accumulation of starch and TNC and reduced sucrose/starch ratio as well as a partitioning trend of assimilated C toward to starch. N-deficiency reduced the concentrations of most FAADs and the ratios of total FAADs (TFAADs)/N in leaves and roots. N-deficiency reduced the demand for C skeleton precursors for amino acid biosynthesis, thus lowering TFAADs/C ratio in leaves and roots. N-deficiency increased (decreased) the relative amounts of C-rich (N-rich) FAADs, thus increasing the molar ratio of C/N in TFAADs in leaves and roots.
Conclusions
Our findings corroborated our hypothesis that C and N metabolisms displayed adaptive responses to N-deficiency in C. sinensis seedlings, and that some differences existed between roots and leaves in N-deficiency-induced alterations of and C and N metabolisms.
Publisher
Springer Science and Business Media LLC
Reference65 articles.
1. Yang JB, Zhang J, Li JJ, Zheng YQ, Lü Q, Xie RJ, et al. Effects of nitrogen application levels on nutrient, yield and quality of Tarocco blood orange and soil physicochemical properties in the three gorges area of Chongqing. Sci Agric Sin. 2019;52:893–908.
2. Chen G, Wang L, Fabrice MR, Tian Y, Qi K, Chen Q, et al. Physiological and nutritional responses of pear seedlings to nitrate concentrations. Front Plant Sci. 2018;9:1679.
3. Huang WT, Xie YZ, Chen XF, Zhang J, Chen HH, Ye X, et al. Growth, mineral nutrients, photosynthesis and related physiological parameters of Citrus in response to nitrogen-deficiency. Agronomy. 2012;11:1859.
4. Luo J, Zhou JJ, Masclaux-Daubresse C, Wang N, Wang H, Zheng B. Morphological and physiological responses to contrasting nitrogen regimes in Populus cathayana is linked to resources allocation and carbon/nitrogen partition. Environ Exp Bot. 2019;162:247–55.
5. Masclaux-Daubresse C, Daniel-Vedele F, Dechorgnat J, Chardon F, Gaufichon L, Suzuki A. Nitrogen uptake, assimilation and remobilization in plants: challenges for sustainable and productive agriculture. Ann Bot. 2010;105:1141–57.
Cited by
21 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献