Abstract
Nitrogen plays a crucial role in wheat growth and development. Here, we analyzed the tolerance of wheat strains XM26 and LM23 to low-nitrogen stress using a chlorate sensitivity experiment. Subsequently, we performed transcriptome analyses of both varieties exposed to low-nitrogen (LN) and normal (CK) treatments. Compared with those under CK treatment, 3534 differentially expressed genes (DEGs) were detected in XM26 in roots and shoots under LN treatment (p < 0.05, and |log2FC| > 1). A total of 3584 DEGs were detected in LM23. A total of 3306 DEGs, including 863 DEGs in roots and 2443 DEGs in shoots, were specifically expressed in XM26 or showed huge differences between XM26 and LM23 (log2FC ratio > 3). These were selected for gene ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses. The calcium-mediated plant–pathogen interaction, MAPK signaling, and phosphatidylinositol signaling pathways were enriched in XM26 but not in LM23. We also verified the expression of important genes involved in these pathways in the two varieties using qRT-PCR. A total of 156 transcription factors were identified among the DEGs, and their expression patterns were different between the two varieties. Our findings suggest that calcium-related pathways play different roles in the two varieties, eliciting different tolerances to low-nitrogen stress.
Highlights
Nitrogen (N) and nitrogen fertilizers play key roles in the growth and development of crops and crop yield, respectively [1]
The results showed that pathways such as plant hormone signal transduction, plant–pathogen interaction, mitogen-activated protein kinases (MAPK) signaling pathway–plant, alpha-Linolenic acid metabolism, and phenyl orchid metabolism were significantly enriched in shoots
We found that the expression profiles of many genes belonging to pathways including the plant–pathogen interaction pathway; mitogen-activated protein kinases (MAPK) signaling pathway; phosphatidylinositol signaling pathway; fatty acid degradation pathway; flavonoid biosynthesis; alpha-linolenic acid metabolism; glyoxylate and dicarboxylate metabolism; glycerolipid metabolism; and cutin, suberine, and wax biosynthesis were significantly different between XM26 and LM23, suggesting that these genes may be related to different tolerances to low-nitrogen stress for the two wheat varieties (Figure 5)
Summary
Nitrogen (N) and nitrogen fertilizers play key roles in the growth and development of crops and crop yield, respectively [1]. Four NRT2-like transporters including NRT2.1, NRT2.2, NRT2.4, and NRT2.5, and two NRT1/NPF-like transporters, including NRT1.1 and NRT1.2, are of greater importance for root nitrate uptake than the other members [13,14] Both NRT2-like genes TaNRT2.1 and TaNRT2.2 are regulated by the transcription factor TaWRKY20 in wheat [15]. The re-application of nitrate to nitrogen-deprived Arabidopsis significantly changes the expression of pathway genes in primary and secondary metabolism, cell growth, hormone response, protein synthesis, signal transduction, and transcriptional regulation [25]. A transcriptome analysis of low-nitrogen-treated wheat seedlings revealed that carbon and nitrogen metabolism, antioxidant processes, and environmental adaptation-related pathways are involved in the low-nitrogen stress response [26]. We identified three pathways that may be important in response to low-nitrogen stress in wheat, namely the calcium-mediated plant–pathogen interaction, MAPK signaling, and phosphatidylinositol signaling pathways
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
