Analysis of the Thinopyrum elongatum transcriptome under water deficit stress
Seeds of Thinopyrum elongatum were pre-germinated on wet filter paper in the dark at 25°C. Once the coleoptiles were approximately 1 cm, uniform seedlings were selected and transplanted to plastic pot, which were filled with mixture of surface soil collected from infield and washed sand. For the 16 weeks after transplant, each pot was supplied with 50 mL of water and 50 mL of half strength Hoagland solution twice weekly (irrigated four times per week). After 16 weeks, the plants were randomly divided into two groups. One was control group, which was watered normally as above description. Another was water deficit group, which was just supplied 50 mL of half strength Hoagland solution twice weekly. With eight weeks treatment, plant materials were collected for both control and water deficit groups. The root and shoot tissue samples were separated, cleaned quickly, and frozen in liquid nitrogen, and stored at -80°C for RNA isolation. Total RNA was extracted using One Step RNA Reagent as per manufacturer’s protocol and purified using RNeasy Plant Mini Kit. The whole transcriptome cDNA library was prepared using Ion Total RNA-Seq kit. Double stranded cDNA was ligated to barcoded adapters and was sequenced using Ion torrent through BGI-Shenzhen. Ltd. (Shenzhen, China).