Development and Assessment of Reference Genes for qPCR of Malus transitoria under Drought Stress

The use of a stable reference gene is fundamental for achieving reliable quantitative qRT-PCR (qPCR) results. Developing and evaluating the stability of reference genes is necessary for studying the molecular mechanisms of M. transitoria in response to drought stress. In this study, 18 candidate reference genes were selected from transcriptome sequencing data of M. transitoria according to their FPKM values under different drought stress degrees. Cluster23533.34641 was identified as the most stable reference gene for M. transitoria under drought stress based on qPCR results and combined analysis of Genorm, NormFinder, BestKeeper, and Delta Ct algorithms. The reference genes identified in this research offer improved accuracy for quantifying target gene expression in both M. transitoria and Malus species under drought stress. This study could provide insights into the drought stress-related functional gene or factor in M. transitoria, even in Malus species.