A novel role for the TIR domain in association with pathogen-derived elicitors

Plant innate immunity is mediated by Resistance (R) proteins, which bear a striking resemblance to animal molecules of similar function. Tobacco N is a TIR-NB-LRR R gene that confers resistance to Tobacco mosaic virus, specifically the p50 helicase domain. An intriguing question is how plant R proteins recognize the presence of pathogen-derived Avirulence (Avr) elicitor proteins. We have used biochemical cell fraction and immunoprecipitation in addition to confocal fluorescence microscopy of living tissue to examine the association between N and p50. Surprisingly, both N and p50 are cytoplasmic and nuclear proteins, and N's nuclear localization is required for its function. We also demonstrate an in planta association between N and p50. Further, we show that N's TIR domain is critical for this association, and indeed, it alone can associate with p50. Our results differ from current models for plant innate immunity that propose detection is mediated solely through the LRR domains of these molecules. The data we present support an intricate process of pathogen elicitor recognition by R proteins involving multiple subcellular compartments and the formation of multiple protein complexes. © 2007 Burch-Smith et al

New Evidence on Household Valuation of Curbside Recycling

This paper looks at the willingness to pay for and participate in a curbside recycling program based on a survey of 401 residents in Ogden, Utah. Modifying the Cameron and James ( Efficient Estimation Methods for \u27Close-Ended\u27 Contingent Valuation Surveys, The Review a/Economics and Statistics 69(1987):269-76) econometric model to fit ordered-interval data, we estimate that the mean willingness to pay for curbside recycling is $2.05 per month, and that 72% of the residents would willingly participate in such a program. Furthermore, females, young people, college-educated, those currently recycling without monetary reward, those regarding recycling as beneficial to the community and nation, and those with relatively high incomes are willing to pay the most for curbside recycling. Based on projected costs and estimates of mean willingness to pay, mandatory curbside recycling appears to be a fiscally feasible method for reducing waste disposal