Author(s)

Hongyu Yang, Xiaodan Zhao, Jia Wu, Min Hu, Shaolei Xia

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Botrytis cinerea is a necrotrophic fungal pathogen that impacts a wide range of hosts, including Arabidopsis. Pretreatment with nitric oxide (NO) donor sodium nitroprusside (SNP) on Arabidopsis leaves suppressed Botrytis cinerea infection development. Additionally, in this study the dosage levels of SNP applied to the leaves had no direct, toxic impact on the development of the pathogen. The relationship between NO and reactive oxidant species (ROS) was studied by using both spectrophotometrical methods and staining leaf material with fluorescent dyes, nitro blue tetrazolium (NBT), and with 3,3-diaminobenzidine (DAB). The results showed that exogenous NO restrained the generation of ROS, especially H₂O₂, as the pathogen interacted with the Arabidopsis plant. And this inhibition of reactive oxidant burst coincided with delay infection development in NO-supplied leaves. The influence of elevated level of NO on antioxidant enzymes was investigated in this study. The activities of catalase (CAT) and guaiacol peroxidase (POD) were increased to different degrees in both: 1) SNP treated only leaves, and 2) SNP pretreated leaves that were subsequently inoculateted with pathogens. However, the activity of superoxide dismutase (SOD) was unchanged in the leaves studied. The decrease in H₂O₂ content probably resulted from the increase in activities of POD and CAT. Our study suggests that NO might trigger some metabolic reactions, i.e. enhanced enzyme activity that restrains H₂O₂ which ultimately results in resistance to B. cinerea infection.

Arabidopsis, Botrytis cinerea, Nitric Oxide, Antioxidant Enzyme, Disease Resistance

Yang, H. , Zhao, X. , Wu, J. , Hu, M. and Xia, S. (2011) The Benefits of Exogenous NO: Enhancing Arabidopsis to Resist Botrytis cinerea. American Journal of Plant Sciences, 2, 511-519. doi: 10.4236/ajps.2011.23060.