Generation Of Broad-Spectrum Disease Resistant Rice By Overexpression Of Arabidopsis Thaliana NPR1 Gene In Rice

The NPR1 gene was isolated by positional cloning from Arabidopsis thaliana by Cao et al in 1997. It is a key regulator for systemic acquired resistance (SAR) of Arabidopsis thaliana. Upon induction, NPRl expression is elevated and the NPRl protein is activated, in turn inducing expression of a battery of downstream defense-related genes. Overexpression of NPRl gene in Arabidopsis thaliana leads to enhanced broad-spectrum disease resistance with no obvious detrimental effect on the plant.In this work, one rice expression plasmid for Arabidopsis thaliana NPRl gene was constructed by using plant expression vector pJFNPTII-UbiN as vector. The widely cultivated Indica rice Gui 99 and 253 were transformed with the NPRl gene by Agrobacterium tumefaciens-mediated transformation. Eighty five Gui 99 and thirteen 253 G418-resistant plants were regenerated, respectively. PCR, RT-PCR, DNA dot blotting and Northern blotting analysis of G418-resistant plants and their progenies revealed that we had obtained 75 Gui 99 and thirteen 253 transgenic plants. Gui 99 transgenic plants were assayed for resistance to rice bacterial blight and rice blast and 253 transgenic plants were assayed for resistance to rice blast. It turned out that Gui 99 transgenic plants expressed significantly enhanced resistance to both rice bacterial blight and rice blast and 253 transgenic plants expressed significantly enhanced resistance to rice blast. These data indicates that overexpression of Arabidopsis thaliana NPRl gene in rice can lead to enhanced broad-spectrum disease resistance and the introduction of Arabidopsis thaliana NPRl gene into widely cultivated rice can creat new rice germplasm for broad spectrum disease resistance.