A research team at University of California, Riverside (UCR) led by plant
pathologist Hailing Jin has identified a regulatory, genetic mechanism in
plants that could help fight bacterial infection.
Using Arabidopsis thaliana, Jin's research team found that Argonaute
protein, a major core protein in the RNA interference machinery, is
controlled by "post-translational modification," a process that occurs
during bacterial infection. This process controls the level of Argonaute
protein and its associated small RNAs.
In normal conditions, the Argonaute protein and its associated small RNAs
are well controlled by arginine methylation, a type of post-translational
modification of the Argonaute protein. This regulates the Argonaute protein
and prevents it and the associated small RNAs from accumulating to high
levels, which allows plants to save energy for growth.
During bacterial infection, however, arginine methylation of the Argonaute
protein is suppressed, leading to the accumulation of the protein and its
associated small RNAs that contribute to plant immunity. Together, these two
changes allow the plant to both survive and defend itself.