Use of a new tetrazolium-based assay to study the production of superoxide radicals by tobacco cell cultures challenged with avirulent zoospores of phytophthora parasitica var nicotianae
نویسندگان
چکیده
The relationship between the production of reactive oxygen species and the hypersensitive response (HR) of tobacco (Nicotiana tabacum L. ) toward an incompatible race of the Oomycete Phytophthora parasitica var nicotianae has been investigated. A new assay for superoxide radical (O2-) production based on reduction of the tetrazolium dye sodium,3'-(1-[phenylamino-carbonyl]-3, 4-tetrazolium)-bis(4-methoxy-6-nitro) benzene-sulfonic acid hydrate (XTT) has enabled the quantitative estimation of perhydroxyl/superoxide radical acid-base pair (HO2./O2-) production during the resistant response. Tobacco suspension cells were inoculated with zoospores from compatible or incompatible races of the pathogen. Subsequent HO2./O2- production was monitored by following the formation of XTT formazan. In the incompatible interaction only, HO2./O2- was produced in a minor burst between 0 and 2 h and then in a major burst between 8 and 10 h postinoculation. During this second burst, rates of XTT reduction equivalent to a radical flux of 9.9 x 10(-15) mol min-1 cell-1 were observed. The HO2./O2- scavengers O2- dismutase and Mn(III)desferal each inhibited dye reduction. An HR was observed in challenged, resistant cells immediately following the second burst of radical production. Both scavengers inhibited the HR when added prior to the occurrence of either radical burst, indicating that O2- production is a necessary precursor to the HR.
منابع مشابه
Tobacco Rotated with Rapeseed for Soil-Borne Phytophthora Pathogen Biocontrol: Mediated by Rapeseed Root Exudates
Black shank, caused by Phytophthora parasitica var. nicotianae, is a widespread and destructive disease of tobacco. Crop rotation is essential in controlling black shank. Here, we confirmed that rotating black shank-infested fields with rapeseed (Brassica napus) suppressed the incidence this disease. Further study demonstrated that rapeseed roots have a strong ability to attract zoospores and s...
متن کاملLipoxygenase gene expression in the tobacco-Phytophthora parasitica nicotianae interaction.
A recently isolated cDNA clone of tobacco (Nicotiana tabacum L.) lipoxygenase (LOX) was used to study LOX gene expression in tobacco cell-suspension cultures and intact plants in response to infection with Phytophthora parasitica nicotianae (Ppn). Southern blot analysis of tobacco DNA indicated that only a small number of LOX genes hybridize to this probe. These genes were not constitutively ex...
متن کاملSynergistic biosynthesis of biphasic ethylene and reactive oxygen species in response to hemibiotrophic Phytophthora parasitica in tobacco plants.
We observed the biphasic production of ethylene and reactive oxygen species (ROS) in susceptible tobacco (Nicotiana tabacum 'Wisconsin 38') plants after shoot inoculation with Phytophthora parasitica var nicotianae. The initial transient increase in ROS and ethylene at 1 and 3 h (phase I), respectively, was followed by a second massive increase at 48 and 72 h (phase II), respectively, after pat...
متن کاملModification of disease resistance of tobacco callus tissues by cytokinins.
The effects of differing cytokinin and auxin concentrations on resistance of tobacco (Nicotiana tabacum L.) tissue cultures to race 0 of Phytophthora parasitica var. nicotianae were examined. With 1 micromolar kinetin and either 11.5 micromolar indoleacetic acid or 1 micromolar 2,4-dichlorophen-oxyacetic acid, tissues from resistant cultivars exhibited a "hypersensitive" reaction to zoospores o...
متن کاملRandom amplified polymorphic DNA analysis of China isolates of Phytophthora parasitica var. nicotianae from different districts
China isolates of Phytophthora parasitica var. Nicotianae have been divided into three large pathogenic groups (PGS) (Hv(A), Iv(B), Wv(C)) which came from Yunnan, Shandong and Liaoning. These three districts belong to main tobacco regions in China: 15 isolates derived from Yunnan of the southwest, 13 isolates from Shandong of the east and 20 isolates from Liaoning of the northeast. PGS were det...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Plant physiology
دوره 117 2 شماره
صفحات -
تاریخ انتشار 1998