Transcriptome Differences in Response Mechanisms to Low-Nitrogen Stress in Two Wheat Varieties

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.

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SiMYB3 in Foxtail Millet (Setaria italica) Confers Tolerance to Low-Nitrogen Stress by Regulating Root Growth in Transgenic Plants

International Journal of Molecular Sciences ◽

10.3390/ijms20225741 ◽

2019 ◽

Vol 20 (22) ◽

pp. 5741 ◽

Cited By ~ 5

Author(s):

Linhao Ge ◽

Yining Dou ◽

Maomao Li ◽

Pengju Qu ◽

Zhang He ◽

...

Keyword(s):

Root Development ◽

Plant Root ◽

Expression Patterns ◽

Protein Structures ◽

Foxtail Millet ◽

Setaria Italica ◽

Nitrogen Stress ◽

Auxin Synthesis ◽

Low Nitrogen Stress ◽

Low Nitrogen

Foxtail millet (Setaria italica), which originated in China, has a strong tolerance to low nutrition stresses. However, the mechanism of foxtail millet tolerance to low-nitrogen stress is still unknown. In this study, the transcriptome of foxtail millet under low-nitrogen stress was systematically analyzed. Expression of 1891 genes was altered, including 1318 up-regulated genes and 573 down-regulated genes. KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis revealed that 3% of these genes were involved in membrane transport and 5% were involved in redox processes. There were 74 total transcription factor (TF) genes in the DEGs (differentially expressed genes), and MYB-like transcription factors accounted for one-third (25) of the TF genes. We systematically analyzed the characteristics, expression patterns, chromosome locations, and protein structures of 25 MYB-like genes. The analysis of gene function showed that Arabidopsis and rice overexpressing SiMYB3 had better root development than WT under low-nitrogen stress. Moreover, EMSA results showed that SiMYB3 protein could specifically bind MYB elements in the promoter region of TAR2, an auxin synthesis related gene and MYB3-TAR2 regulate pair conserved in rice and foxtail millet. These results suggested that SiMYB3 can regulate root development by regulating plant root auxin synthesis under low-nitrogen conditions.

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