Transcriptional Response of Ziziphus xanthoxylum to Abiotic Stresses

Three-week-old Z. xanthoxylum plants were used for different treatment for 6 h as follows. (i) Control: seedlings were irrigated with modified Hoagland solution; (ii) Salt treatment: seedlings were irrigated with modified Hoagland solution containing 50 mM NaCl; (iii) Osmotic stress: seedlings were irrigated with modified Hoagland solutions supplemented with sorbitol to adjust osmotic potential to -0.5 MPa. Roots of seedlings in each condition were collected and frozen by liquid nitrogen immediately.
Total RNA was extracted by using an RNAprep Pure Plant Plus Kit (Polysaccharides & Polyphenolics-rich) (TIANGEN, Beijing, China), and cDNA was synthesized from DNase-pretreated RNA using a PrimeScript™ RT reagent Kit with gDNA Eraser (TaKaRa Biotechnology, Beijing, China). qRT-PCR was performed in triplicate on three bio-replicates with a StepOne Real-Time PCR Thermocylcer (Applied Biosystems, Foster City, CA, USA) using the Power SYBR™ Green Master Mix (TaKaRa Biotechnology, Beijing, China). ZxACTIN (GenBank accession no. EU019550) was used as the internal control gene [15 (link),19 (link),20 (link),21 (link)]. Sequences of primers are listed in Table S1. The 2^−ΔΔCt method was used to determine the relative expression level [48 (link)].