Reference gene selection for RT-qPCR normalization of strawberry at various organs, different growing stages of fruits, and salt-stress treatment

Strawberry (Fragaria x ananassa Duch.) is a favorite fruit of high economic value due to its good taste and high nutrition ingredients. Strawberry is a fruit grown around the world that has distinct genetic structures and indicates diverse levels of precision to different environmental circumstances. Plants respond differently to diverse physiological processes, organizing of biological events, control of hormones, different individuals of the same species, and internal and external factors in developmental stages. Quantitative real-time polymerase chain reaction (RT-qPCR) has become a very useful tool for the determination of plant genetic and physiological changes in gene expression. To obtain more securable gene expression outcomes, RT-qPCR data should be standardized with a control gene that shows homogeneous expression at diverse stages of growth in plants, in different organs, or under various environmental circumstances. We evaluated the gene expression of 8 reference genes, including StRefHISTH4, StRefGAPDH, StRefDBP, StRefActin1, UBQ, aTUB, 18SrRNA, and EF1a in different sets of 2 cultivars, four different organs, various fruit growing stages, and development period samples treated with salt. The genes expressions are greatly dissimilar in various organ samples examined. The expressions of StRefHISH4 and StRefActin 1 were very steady in all the different organs, fruits at various growth stages, and samples treated with salt analyzed. Furthermore, StRefHISH4 and StRefActin 1 showed the steadiest expression in plants cultivated under different development states. The expression of these reference (housekeeping) genes can be utilized for the standardization of real-time PCR outcomes for gene expression examination in many types of samples in strawberries.