| Summary: | <i>Salsola ferganica</i> is a natural desert herbaceous plant in the arid area of western and northwestern China. Because of its salt tolerance and drought resistance, it is of great significance in desert afforestation and sand-fixing capacity. There has been much research on the genes involved in plants under desert stresses in recent years. The application of the best internal reference genes for standardization was a critical procedure in analyzing the gene expression under different types. Even so, the reference gene has not been reported in the application of gene expression normalization of <i>S. ferganica</i>. In this study, nine reference genes (<i>TUA-1726</i>, <i>TUA-1760</i>, <i>TUB</i>, <i>GAPDH</i>, <i>ACT</i>, <i>50S</i>, <i>HSC70</i>, <i>APT</i>, and <i>U-box</i>) in <i>S. ferganica</i> were adopted and analyzed under six different treatments (ABA, heat, cold, NaCl, methyl viologen (MV), and PEG). The applicability of candidate genes was evaluated by statistical software, including geNorm, NormFinder, BestKeeper, and RefFinder, based on their stability values in all the treatments. These results indicated that the simultaneous selection of two stable reference genes would fully standardize the optimization of the normalization research. To verify the feasibility of the above internal reference genes, the CT values of AP2/ERF transcription factor family genes were standardized using the most (<i>ACT</i>) and least (<i>GAPDH</i>) stable reference genes in <i>S. ferganica</i> seedlings under six abiotic stresses. The research showed that <i>HSC70</i> and <i>U-box</i> were the most appropriate reference genes in ABA stressed samples, and <i>ACT</i> and <i>U-box</i> genes were the optimal references for heat-stressed samples. <i>TUA-1726</i> and <i>U-box</i> showed the smallest value in gene expression levels of cold treatment. The internal reference groups of the best applicability for the other samples were <i>U-box</i> and <i>ACT</i> under NaCl treatment, <i>ACT</i> and <i>TUA-1726</i> under MV stress, <i>HSC70</i> and <i>TUB</i> under PEG treatment, and <i>ACT</i> in all samples. <i>ACT</i> and <i>U-box</i> showed higher stability than the other genes based on the comprehensive stability ranking of RefFinder, as determined by the geometric mean in this study. These results will contribute to later gene expression studies in other closely related species and provide an important foundation for gene expression analysis in <i>S. ferganica</i>.
|
|---|