|Bell, Alois - Al|
Submitted to: Transgenic Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/1/2010
Publication Date: 2/12/2010
Citation: Parkhi, V., Kumar, V., Campbell, L.M., Bell, A.A., Shah, J., Rathore, K.S. 2010. Resistance against various fungal pathogens and reniform nematode in transgenic cotton plants expressing Arabidopsis NPR1. Transgenic Research. 19:959-975. Interpretive Summary: Soil borne diseases cause loss of about 10 percent of the potential yield of cotton in the USA. A gene from Arabidopsis that controls active pest resistance responses in plants was introduced into cotton to effect resistance to diseases caused by fungi and nematodes. Plants carrying this foreign gene were more resistant to several fungal pathogens and the reniform nematode. The increased resistance was shown to be due to more rapid responses to attempted invasions by the pests. The germplasm has potential to reduce losses from several major diseases in cotton.
Technical Abstract: Cotton is an economically important crop worldwide that suffers severe losses due to a wide range of fungal/bacterial pathogens and nematodes. Given its susceptibility to various pathogens, it is important to obtain broad-spectrum resistance in cotton. Resistance to several fungal and bacterial diseases has been obtained by over expressing the Non-expressor of Pathogenesis-Related genes-1 (NPR1) in various plant species with apparently minimal or no pleiotropic effects. We examined the efficacy of this approach in cotton by constitutive expression of the Arabidopsis NPR1 gene. The results show that NPR1-expressing lines exhibited significant resistance to Verticillium dahliae isolate TS2 and Fusarium oxysporum f. sp. vasinfectum, Rhizoctonia solani, and Alternaria alternata. Interestingly, the transformants showed significant tolerance to reniform nematodes. Analysis of defense-related, biochemical and molecular responses showed that when challenged with pathogens or certain systemic acquired resistance-inducing chemicals, the transgenic lines respond to a greater degree compared to the wild-type. Importantly, the basal activities of the defense-related genes and enzymes in uninduced transformants were no different than those in non-transgenic counterparts. The results provide additional evidence supporting the role of NPR1 as an important part of the plant defense system and suggest a means to achieve broad-spectrum resistance to pathogens via genetic engineering.