An Evolutionarily Conserved Mediator of Plant
Disease Resistance Gene Function Is
Required for Normal Arabidopsis Development
Developmental Cell, Vol. 2, 807–817, June, 2002
Ben F. Holt III, Douglas C. Boyes, Mats Ellerstrom, Nicholas Siefers,
Aaron Wiig, Scott Kauffman, Murray R. Grant, and Jeffery L. Dangl
Summary
Plants recognize many pathogens through the action of a diverse family of proteins called disease resistance (R) genes. The Arabidopsis R gene RPM1 enodes resistance to specific Pseudomonas syringae strains. We describe an RPM1-interacting protein that is an ortholog of TIP49a, previously shown to interact with the TATA binding protein (TBP) complex and to modulate c-myc- and -catenin-mediated signaling in animals. Reduction of Arabidopsis TIP49a (AtTIP49a) mRNA levels results in measurable increases of two R-dependent responses without constitutively activating defense responses, suggesting that AtTIP49a can act as a negative regulator of at least some R functions. Further, AtTIP49a is essential for both sporophyte and female gametophyte viability. Thus, regulators of R function overlap with essential modulators of plant development.