Transcriptional regulation mechanism of wheat varieties with different nitrogen use efficiencies in response to nitrogen deficiency stress

Abstract

Background As one of the microelements, nitrogen play essential roles in cereal production. Although the use of chemical fertilizers has significantly improved the yield of wheat, it has also caused increasingly adverse environmental pollution. Revealing the molecular mechanism manipulating wheat nitrogen use efficiency (NUE), and cultivating wheat germplasms with high nitrogen use efficiency has become important goals for wheat researchers. In this study, we investigated the physiological and transcriptional differences of three wheat cultivars with different NUE under low nitrogen stress. Results The results showed that, under low nitrogen conditions, the activities of nitrogen metabolism-related enzymes (GS, NR, GDH), antioxidant enzymes (SOD, POD, CAT) and soluble protein contents of ZM366 (high NUE cultivar) were higher than those of JD8 (low NUE cultivar). The hybrid cultivar of ZM366 and JD8 showed mid-parent or over-parent heterosis. Transcriptome analysis revealed that ‘alanine, aspartate and glutamate metabolism’, ‘terpenoid backbone biosynthesis’ and ‘vitamin B6 metabolism’ pathways play key roles in nitrogen use efficiency in wheat. The significant enhancement of the ‘Calvin cycle’ and ‘photorespiration’ in ZM366 contributed to its higher level of carbon metabolism under low nitrogen stress, which is an important attribute differs from the other two varieties. In addition, the activation of ABA signal transduction and biosynthesis pathways also helps to maintain NUE under low- nitrogen conditions. Moreover, bHLH transcription factors were also found to play a positive role in wheat NUE. Conclusions In conclusion, these results enriched our knowledge of the mechanism of wheat NUE, and provided a theoretical basis for improving wheat NUE and breeding new cultivars.

Effects of a dark septate endophyte and extracellular metabolites on alfalfa root exudates: a non‐targeted metabolomics analysis

“…Terpenoid backbone biosynthesis can increase plant nitrogen use efficiency (Wang et al, 2022a). The terpenoid skeleton biosynthesis of farnesyl diphosphate was used as a synthetic substrate for steroid biosynthesis.…”

“…Interestingly, the main metabolic cycles of alfalfa are upregulated, including glycolysis and carbon fixation. In particular, we predicted that DSE mycelium and metabolites would increase the Terpenoid backbone biosynthesis can increase plant nitrogen use efficiency (Wang et al, 2022a). The terpenoid skeleton biosynthesis of farnesyl diphosphate was used as a synthetic substrate for steroid biosynthesis.…”

Transcriptome Profiling Reveals the Gene Network Responding to Low Nitrogen Stress in Wheat

“…With the development of biotechnology, transcriptomic data have become an important tool for understanding the potential mechanisms of gene expression [38,39]. Over the past decades, a large amount of N-related transcriptomic data has been analyzed in crops to understand the N response mechanisms [40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58]. In rice, the expression of genes related to energy metabolism, amino acid metabolism, and carbohydrate metabolism was reduced under LN stress [40].…”

“…Although several transcriptomic datasets of wheat LN tolerance are available, this research has rarely focused on the signaling transduction mechanism in wheat [51][52][53][54][55][56][57][58]. Therefore, we aimed to understand the LN response and N signaling transduction mechanisms in wheat.…”