Xin Liu, Chengmiao Yin, Li Xiang, Weitao Jiang, Shaozhuo Xu & Zhiquan Mao

BMC Plant Biology October 2020; volume 20, Article number: 448 (2020)

Abstract

Background

Agricultural yield is closely associated with nitrogen application. Thus, reducing the application of nitrogen without affecting agricultural production remains a challenging task. To understand the metabolic, physiological, and morphological response of wheat (Triticum aestivum) to nitrogen deficiency, it is crucial to identify the genes involved in the activated signaling pathways.

Results

We conducted a hydroponic experiment using a complete nutrient solution (N1) and a nutrient solution without nitrogen (N0). Wheat plants under nitrogen-deficient conditions (NDC) showed decreased crop height, leaf area, root volume, photosynthetic rate, crop weight, and increased root length, root surface area, root/shoot ratio. It indicates that nitrogen deficiency altered the phenotype of wheat plants. Furthermore, we performed a comprehensive analysis of the phenotype, transcriptome, GO pathways, and KEGG pathways of DEGs identified in wheat grown under NDC. It showed up-regulation of Exp (24), and Nrt (9) gene family members, which increased the nitrogen absorption and down-regulation of Pet (3), Psb (8), Nar (3), and Nir (1) gene family members hampered photosynthesis and nitrogen metabolism.

Conclusions

We identified 48 candidate genes that were involved in improved photosynthesis and nitrogen metabolism in wheat plants grown under NDC. These genes may serve as molecular markers for genetic breeding of crops.

See https://bmcplantbiol.biomedcentral.com/articles/10.1186/s12870-020-02662-3

Figure 1: Effects of nitrogen content on winter wheat crop. a The shoot morphology, including crop height, leaf area per plant, specific leaf area, shoot fresh weight; b root morphology, including root length per plant, root surface area, root volume per plant, root fresh weight per plant; c root/shoot ratio; d net photosynthetic rate; e phenotypes, under normal nitrogen (N1) and nitrogen-deficient (N0) conditions. The root length per plant, root surface area, root volume per plant, root fresh weight per plant were the sum of all roots of one plant. Significance levels of differences between N0 and N1 group were estimated using the two-tailed t-test method. Different lowercase letters represent significant differences.