Transcription profiling of leaves of Populus nigra × P. maximowiczii growing in monoculture and stands mixed with Robinia at poor and rich soil sites

P. nigra × P. maximowiczii plants were grown in the field, each in monoculture and in stands mixed with Robinia pseudoacacia, at two locations differing in soil nutrient levels. After 3 years of growing under ambient weather conditions, leaf samples were harvested and analyzed by RNA-seq.