Characterization, Expression Profiling, and Functional Analysis of , a Defensin-Encoding Gene From .

PtDef cloned from contained eight cysteine domains specific to defensins. Quantitative reverse-transcription polymerase chain reaction (qRT-PCR) analysis showed that was expressed in all tissues tested, with lower expression in leaves and higher expression in petioles, stems, and roots. Purified fused PtDef inhibited , , , , sp., and . PtDef also inhibited the growth of by triggering autolysis. overexpression in Nanlin895 poplar ( × cv. Nanlin895) enhanced the level of resistance to qRT-PCR analysis also showed that the expression of 13 genes related to salicylic acid (SA) and jasmonic acid (JA) signal transduction differed between transgenic and wild-type (WT) poplars before and after inoculation, and that (12-72 h), , , and expression was higher in transgenic poplars than in WT. During the hypersensitivity response (HR), large amounts of HO were produced by the poplar lines, particularly 12-24 h after inoculation; the rate and magnitude of the HO concentration increase were greater in transgenic lines than in WT. Overall, our findings suggest that , a defensin-encoding gene of , could be used for genetic engineering of woody plants for enhanced disease resistance.