Background: Suitable reference genes can be used to calibrate the error in quantitative real‑time polymerase chain reaction (qRT-PCR) experiments and make the results more credible. However, reference genes suitable for different species and different experimental conditions do not exist. Nitraria tangutorum Bobr. is a typical plant in desert areas and desert plains, which is drought-resistant, saline-alkali resistant, barren-resistant, and has extremely strong adaptability. Due to insufficient understanding of the importance of this germplasm in the past, it is still unclear which genes can be used as reference genes to calibrate qRT-PCR data of N. tangutorum .Results: In this study, we analyzed the expression levels of 10 candidate reference genes (ACT, GAPDH, TUA, TUB, CYP, UBC, His, PP2A, HSP, and EF1-α) in three tissues (root, stem and leaf) and under five abiotic stresses (salt, drought, heat, cold, and ABA) of N. tangutorum seedlings by qRT-PCR. Three analysis software programs (geNorm, NormFinder, and BestKeeper) were used to evaluate expression stability of ten genes. Comprehensive analysis showed that EF1-α and His had the best expression stability, whereas HSP was the least suitable as a reference gene. The expression profile of NtCER7, a gene related to the regulation of the waxy synthesis of N. tangutorum, verified the accuracy of the experimental results.Conclusion: Based on this study, we recommend EF1-α and His as suitable reference genes for N. tangutorum. This study provides the first data on stable reference genes in N. tangutorum, which will be beneficial to study of the gene expression of N. tangutorum and other Nitraria species in the future.
