Abstract: 【Objective】The purpose of this study is to find a new gene resource for cotton Verticillium wilt-resistance genetic engineering. 【Method】G. barbadense var. 7124 was used as a starting material to clone the full-length cDNA of NPR1 (none expresser of PR gene)- GbNPR1 which is a key regulator in SA (salicylic acid)-mediated systemic acquired resistance (SAR) by homologous cloning and RACE techniques. 【Result】In the GbNPR1 molecule, there are two "W- boxes" in the upstream of ATG that are necessary for both induction of NPR1 transcription and NPR1-mediated activation of plant defense responses. The deduced amino acid sequence of GbNPR1 has low homology (39%-57%) to the other known NPR1 proteins; however, they have higher homology (79.2%) in the functional domain. GbNPR1 contains the BTB and ankyrin repeat domain that is known to be the molecular basis for NPR1 function in Arabidopsis. Plant expression vector harboring GbNPR1 gene was constructed and transferred into Nicotiana tabacum var. NC89 via Agrobaterium-mediated gene transfer. PCR and Southern-blot analysis indicated that the gene has been integrated into tobacco genome. In vitro leaf-disease challenge test of transgenic plants by inoculation of Alternaria alternata demonstrated that the transgenic plants over expressing GbNPR1 shown enhanced resistance compared with the non-transgenic plants. Genetic analysis of transgenic T1 indicated that inserted gene is one copy. 【Conclusion】All of the results indicated that the obtained gene is the homologous gene of NPR1 gene in G. barbadense.

Key words: Gossypium barbadense, NPR1 gene, Transgenic tobacco, Alternaria alternata, Disease resistance