Transcriptome of sunflower (Helianthus annuus) nectaries and leaf

Comparative RNA-Seq study of expression in sunflower nectaries from different lines. Interspecific crosses of Helianthus annuus displaying differing nectar secretion phenotypes were grown on Sun Gro LC8 soil under a 16 hr day/8 hr night cycle (with supplemental lighting) and a temperature of 23°C in a greenhouse at the University of Minnesota Plant Growth Facility in March-April 2016. Floral nectaries were isolated from mature, secretory florets from each interspecific cross displaying ‘low’ (lines 412 and 441), ‘medium’ (lines 452 and 456) and ‘high’ (lines 434 and 467) levels of nectar production. Nectary and leaf tissue was also harvested from a maintainer line (ER). All nectary tissues were separately dissected by hand from the flowers of primary inflorescences of ca. 40 day-old plants. Due to the small size of nectaries, dissections took place over several days from 4–8 hours after dawn (h.a.d.). Isolated nectaries were pooled in RNAlater™ solution (Ambion, Austin, TX) on ice, and stored at 4°C prior to RNA extraction. Approximately 50 nectaries were processed as a single RNA sample. Each biological replicate was represented by nectaries pooled from different individual plants.