16 May 2012
As a collaborator of the laboratory of Dr. Xinnian Dong at Duke University, we helped identify and characterize receptors of the plant immune hormone salicylic acid (SA). Until now SA was the only major plant hormone for which bona vide receptors remained elusive. We now show that the BTB domain-containing proteins NPR3 and NPR4 bind SA with high affinity. NPR3 and NPR4 are substrate adaptors for an ubiquitin ligase that targets the master immune coactivator NPR1 for degradation. Strikingly, SA binding to NPR3 and NPR4 differentially regulates their ability to recruit NPR1 to this ubiquitin ligase, thereby regulating the transcriptional activity of NPR1 in an SA-dependent manner. Moreover, this mechanism of SA perception may determine cell death and survival responses upon pathogen infection.
These findings are now published in NATURE:
"NPR3 and NPR4 are receptors for the immune signal salicylic acid in plants"
Fu ZQ, Yan S, Saleh A, Wang W, Ruble J, Oka N, Mohan R, Spoel SH, Tada Y, Zheng N, Dong X.
NATURE (2012), doi:10.1038/nature11162.