Illumina HiSeq 2000 sequencing; Drought treatment of Populus tremula × tremuloides with suppressed PICKLE or FDL2 gene expression
Drought treatment of Populus tremula × tremuloides with suppressed PICKLE or FDL2 gene expression
A piece of stem was collected during the harvest and the bark was removed. The woody material was shock frozen in liquid nitrogen and kept at -80 °C. Plants were multiplied by in vitro propagation and kept on 1/2 MS-medium for four weeks. Afterwards, rooted plants were potted in 1.5 l pots and kept in a glass chamber at a temperature of 22 °C, relative humidity of 60% and additional light (16 h, PAR of 100 μmol photons m-2 s-1). The plants were grown there for eight weeks and well irrigated before the treatment started. Well-watered and drought treatments were applied. Control plants were well-watered exhibiting soil moistures around 0.4 m3 m-3. The drought treatment was achieved by stopping irrigation until the soil moisture decreased to 0.1 m3 m-3. Then small amounts of water were applied to each plant to keep soil moisture at this level until the end of the treatment. Nucleic acid was extracted according to CTAB extraction protocol (Chang et al., 1993). TruSeq mRNA Sample Prep kit v2 (Illumina, San Diego, CA, USA) according to manufacturer's instructions.