title: NextSeq 500 sequencing; Transcription profiling of leaves of four Poplar clones growing in monoculture and stands mixed with Robinia at poor and rich soil sites
design: Transcription profiling of leaves of four Poplar clones growing in monoculture and stands mixed with Robinia at poor and rich soil sites
library_construction_protocol: Fresh young leaves from the middle part of single trees were collected and immediately frozen in liquid nitrogen. Poplars were planted with stem cuttings at two field sites: Deppoldshausen (51.581째N/9.967째E) and Reinshof (51.484째N/9.923째E), Germany. Planting took place during April 2014. After growing for 2 years under ambient weather conditions, plants were harvested in 2016. Treatment conditions:a) The two field sites Deppoldshausen and Reinshof differ in soil nutrient levels. b) All poplar clones were planted in blocks, either as monoculture or in mixture with Robinia. mRNA was extracted using the QIAGEN RNeasy Plant Mini Kit (QIAGEN GmbH, Hilden, Germany) according to manufacturer's protocol. cDNA libraries were prepared using the NEBNext Ultra RNA Library Prep Kit for Illumina (New England BioLabs, Frankfurt am Main, Germany) according to manufacturer's protocol.