Do you already have candidate genes ni a particular species (Arabidopsis for instance)? You can easily obtain upstream sequences for a particular gene at Phytozome (www.phytozome.net). This database contains sequence information of all plant genomes completely sequence to date ( which also allows you to perform analysis of regulatory sequences among homologous promoters).

I see the NCR promoter derived from soybean chlorotic mottle virus is good also. best wishes

PHT1 (AT5G43350) (Ref: Plant Physiol. 2014 Apr;164(4):2020-9 and PNAS June 24, 1997 vol. 94 no. 13 pp. 7098–7102.) that encodes a high-affinity phosphate transporter is regulated by AtWRKY41 and its promoter sequence along with ATG (start site) is below...

AAGAGATGACCAAGACGGACGAAGGATACCCACATGGCTTTGGAGTCAAGAACTCACTGGTCATGCTTGG

TGTCATTAACTTTGTCGGTATTCTCTTCACCTTCCTTGTTCCTTAGCCCAAGGGCAGAGCCGGCCATGAG

CACAAGCGGGCCAAGCCCATGCTTGCAGCCGATTATTCAATAATTACATTTTCGGCCTCCAAATACTGAA

GTTGTTCTATGGTCCAATGTTCGCGTCAGGGAAAACTTGGTCCTTGTTTTGTTTAACTTCTTAAGTTCGA

ATCTCCCAAATGCCGATATTATTACAGTTTTTCTTCTTCCGTTTTTGTCAAAAAAAAATTAGTTACTAAA

TTATAAATAATTAACCTCAATTGCAATTAATCTTTTGGTTCCTTTTCTTCCTCTAGCATTGTGTGGTTTA

TTGGTCCTTAAACTGTCAGCTTTTTAGTTCAAATCCATCCATTTTGTCTATTTTGTCTCTGTATCTCATA

CTTATTCTATAATTCATTAGTGGTTTAACTGTAACAAATTCATGTTTTATTCTGATAAGTTTTTTTTCTT

TACTTCTTAATCATTGTTTCTTCATAAAAACAACATATGAAGGATATGATAGAAATTTGACTAAAAAAAA

CTTGATGGATGAGTCTACGTACATATATAAATGCAAGGAATATCATATATAAAAATTGCATTGATCTTTG

ATGCTTTAATACTTTTAGTGCTTTTTTTAAACATAACCAATTTTATATTTTGTTTGATCACACTTTTTTA

TACTATGAACATGTGTAAAGAGGCTTTTTTTATATTATGAACATGTGTAAAATATCCTCTCTTTTTTTTT

TACTATAAGCATGTGTTAAGTGGCCTTTTCTTTTTCTTTGCTTGTAGCCTTGTAAATAATAGGAATGCCC

AAGGGCAAGTCCCTTGAAGAGCTCTCCGGTGAGGCTGAGGTTGAGAAATGATTACGCCATAATATTTTCA

AATTCTTAATTGGTTCGATGAATTACATCTTCTATTACGATTTACTTTATTTTTGCGATGCGTAATGTGA

TATTTCATGTTCGTAATGGTGGATCTCTACATTTATTTTTTTGTGTGACAAAATGTAATCAATCGATATT

TAGTGGTCATTTATGATATTTATTTGACTGCTTATCTCTACTACACAGCTACTATCAAATTCCTAATCTT

TGTTGTTATTATGGTTATATTTAATTTATGCATGTAATACCTCTCGTATAACAACAAAACATTCAAACCA

TTTAAAACATTAACGTGTACATATCGAAGTCCAGAAAACCCGTCATTTAAAACAAATACAATCCTCACAT

TTATATATATATATGGTCTGAGCTGGATTGGTTGATATTAAATCCTTATTTATGTATATGTAATGGCAAC

TAAGTCCACTAAGGCATGAATTATCTGTTAAAATGAATTTATATGCTTATGTTCTCGCGAATATCCTATG

TTTTTCGAATATGCTTTTTTAAAATAATGATTTTGACTTTGCTAAATGATAATTAATCTTCATGACTATA

TGTATCCTGATTGTCACTCCTCAAATGTCAACTATTAGAGTTGAATAACTCGACTGCAAAAAACAAAACA

AAGAAAACGAGGAAGATGGAGAAATTTAAAACCTTTCGACTTATATTGGCTCTAAAATAACTTGTAGTTC

AGATTTACACGAAACAATAAATAAATGATTAGAGCTTGCAACTCTCCTTATTTAATTTTAGAAATGCATT

TTATATTGCGAATAATATAATTGCAAAGTTGGAATCAAACATAAATATATATAACTGGTCAACGATTACA

AGTAATGCCAACAAGATTAACTACAAACTGAATTCGTGTCTACACTACTTCTTTTTGATTTTATTTTATT

CTTTTTTTGTGTGTGTACAACGTCTAAATTAGCTACTTCTATTTATAGAAATTTACATGGAATGCATATC

TATAGTAATGCTCATATATCAATCTGTCTCCATATAGTAATTGAGATGGTTAAACAGAAATTTTTGCTAA

AACTTCGTTTCCTGCTTCAAAATAATAATCAGAATCCGTAACTATCATACAATAAAAAAATCATCCCATC

TCACGTATCCTAGAGAGATTTATTGTATAAGGTGTTCATATTCTGGAAGGCGTATCGTCCAGCTTAGATG

ATGTTTTATACTTTTCAATATAAAATAGACTGTAAATAATATTTTACTTCAGAAACAAATGGTGTTCAAA

AATCTTAAACATCAACTATAAACATACGGAGGGAGTATTGATGACTAAAATTCTAAAATCCAAAATGAAA

TTACAAAATAAATAATAACTATGAAGAAAGAGGCGATCACGTTGCTTACATATCTTTCCTTTTCAAAAAG

CATTTTTTTATTACATTTAACGTGCTTCTCTTTCTTCTTCTCTATAAATGGCCAGCATAATTGTTCATTT

CTAATG

Good Luck

Last two weeks were hectic, anywys Thanks all for your inputs. will see it next week and get back to you guys if further needed any help.

Thanks once again.