"The connection between SRFR1 and SNC1 was somewhat surprising," said Gassmann. "We identified SRFR1 based on its effect on the plant immune response to the bacterial effector protein AvrRps4, which is usually detected by the resistance protein RPS4, not SNC1."
This class of plant resistance proteins has been thought to be highly specific detectors, meaning each member responds to a different effector protein.
"Based on our work, we think part of the answer is that both SNC1 and RPS4 physically associate with SRFR1. In other words, SRFR1 is where the SNC1 and RPS4 telephone wires get crossed."
The researchers tapped into this cross talk while studying temperature effects on resistance. They found that both proteins, SNC1 and RPS4, contribute to detection of AvrRps4 at 22 degrees Celsius, but only RPS4 does so at 24 degrees Celsius. Gassmann speculated that the temperature dependence may explain why this cross talk had not been previously observed.
"The discovery adds important new knowledge about the underlying mechanism of how plants fight off bacterial infection," said Gassmann, who is also a member of the University's Interdisciplinary Plant Group.
|Contact: Melody Kroll|
University of Missouri-Columbia