A poplar tree proteinase inhibitor-like gene promoter is responsive to wounding in transgenic tobacco

Abstract

Wounding of poplar trees leads to the accumulation of several mRNA species that encode proteins with putative defensive function. One class of wound-induced poplar RNA (win3) has amino acid sequence similarity to Kunitz-type trypsin inhibitors. Northern blots and cDNA sequencing show that several win3 mRNAs accumulate in the uninjured leaves of wounded trees. We report further characterization of the win3 family including sequence comparisons, gene family organization, and the identification of one win3 member that is transcriptionally activated in response to mechanical wounding. We also show that 1.5 kb of 5'-flanking sequence of one win3 member (win3.12) is sufficient to confer wound-regulated expression of a beta-D-glucuronidase (GUS) reporter gene in transgenic tobacco. Annual herbaceous plants such as tobacco can thus be used to study the expression of genes from a perennial woody angiosperm.