Clarke H R, Davis J M, Wilbert S M, Bradshaw H D, Gordon M P
Department of Biochemistry, University of Washington, Seattle 98195.
Plant Mol Biol. 1994 Aug;25(5):799-815. doi: 10.1007/BF00028875.
Wounding hybrid poplar (Populus trichocarpa x P. deltoides) trees results in the expression of novel wound-inducible (win) mRNAs thought to encode proteins involved in defense against pests and pathogens. Members of the win6 gene family encode acidic multi-domain chitinases, with combined structure and charge characteristics that differ from previously described chitinases. Win6 expression has been shown to occur in pooled unwounded leaves of a wounded (on multiple leaves) poplar plant. Here we demonstrate that wounding a single leaf induces win6 expression locally, in the wounded leaf, and remotely, in specific unwounded leaves with strong vascular connections to the wounded leaf. We also demonstrate that a win6 promoter-beta-glucuronidase (GUS) gene fusion (win6-GUS) responds to wounding locally and remotely in transgenic tobacco. These data indicate that the poplar win6 promoter has regulatory elements that are responsive to 'wound signals' in the heterologous host. In addition, win6-GUS is developmentally activated in unwounded young leaves and floral tissues of transgenic tobacco. Similar developmental expression patterns are found to occur for win6 in poplar trees, demonstrating that a herbaceous plant can serve as a host for woody tree transgene analysis and can accurately predict expression patterns in tree tissues (e.g. flowers) that would be difficult to study in free-living trees.
对杂种杨树（毛果杨×美洲黑杨）进行创伤处理会导致新的创伤诱导型（win）mRNA的表达，这些mRNA被认为编码参与抵御害虫和病原体的蛋白质。win6基因家族的成员编码酸性多结构域几丁质酶，其结构和电荷特征与先前描述的几丁质酶不同。已证明win6在受伤（多片叶子）杨树植株的未受伤叶片集合中表达。在此我们证明，对一片叶子进行创伤处理会在受伤叶片中局部诱导win6表达，并在与受伤叶片有强维管连接的特定未受伤叶片中远程诱导win6表达。我们还证明，win6启动子-β-葡萄糖醛酸酶（GUS）基因融合体（win6-GUS）在转基因烟草中对创伤处理产生局部和远程响应。这些数据表明杨树win6启动子具有对异源宿主中的“创伤信号”作出响应的调控元件。此外，win6-GUS在转基因烟草的未受伤幼叶和花组织中被发育激活。在杨树中发现win6也有类似的发育表达模式，这表明草本植物可作为木本植物转基因分析的宿主，并能准确预测在自由生长的树木中难以研究的树木组织（如花朵）中的表达模式。
