Determination of suitable housekeeping genes for normalization of quantitative real time PCR analysis of Avicennia marina under crude oil treatment

Gene expression studies could provide insight into the physiological mechanisms and strategies used by plants under stress conditions. Selection of suitable internal control gene(s) is essential to accurately assess gene expression levels. For the mangrove plant, Avicennia marina, reliable reference genes to normalize real-time quantitative PCR data has not been previously investigated. In this study, the expression stabilities of four candidate reference genes [Actin 2 (ACT2),Serine/threonine-protein phosphatase 2A subunit A3 (PP2AA3),TIP-Like (TIP), polyubiquitin 10 (UBQ)] were determined in leaves and roots of A. marina treated by different level of oils contamination . Three software programs (Bestkeeper, NormFinder and geNorm) were employed to analyze and rank the tested genes. Results showed that ACT2 was the most suitable reference gene in A. marina and the combination of two or three genes was recommended for greater accuracy. Identification of A. marina reference genes in a wide range of experimental samples will provide a useful reference in future gene expression studies in this species, particularly involving similar stresses.