Fig. 3: ABRE cis-elements in the promoter region of the MdNRT1.5 gene are required for ABA-mediated expression.

a MdNRT1.5 transcription levels in apple (“Royal Gala”) treated with 20 μM ABA. b GUS staining experiment of pMdNRT1.5-GUS and pMdNRT1.5-GUS (m) transgenic apple calli with or without 20 μM ABA treatment. c GUS activity assays of pMdNRT1.5-GUS and pMdNRT1.5-GUS (m) transgenic apple calli