Expression stability of the reference genes calculated by BestKeeper software.

Notes: SR, roots exposed to high-salt treatment; SL, leaves exposed to high-salt treatment; PR, roots exposed to PEG treatment; PL, leaves exposed to PEG treatment; HL, leaves exposed to heat treatment; CL, leaves exposed to cold treatment. Descriptive statistics of 10 candidate genes based on the coefficient of variance (CV) and standard deviation (SD) of their Cq values were determined using the whole data set. Reference genes were identified as the most stable genes, i.e. those with the lowest coefficient of variance and standard deviation (CV ± SD).