Selection of suitable reference genes for real-time PCR in wheat flag leaves under drought stress

Many studies on the defence and stress mechanisms in plants are based on gene expression. The stability of the reference genes expression used in real-time PCR is a further major step in data normalization. For validation of reference genes as internal control in wheat flag leaves under drought stress , the expression stability of eight candidate genes, including ribosomal RNA subunit (18S rRNA), ubiquitin (UBQ and WUB), Actin (ACT), glyseraldehyd-3-phosphate dehydrogenase (GAPDH), RNase L inhibitor-like protein (RLI), beta-tubulin 4 (bTUB) and ATP-dependent 26s proteasome regulatory subunit (Ta.22845), was evaluated using NormFinder and BestKeeper softwaresResults indicated that RLI and UBQ were the most stable genes, whereas 18S rRNA was least stable gene among the eight tested genes for the normalization of gene expression in wheat flag leaf under drought and normal conditions.