by American Phytopathological Society
Scientists have long known that the plant hormone auxin controls many aspects of plant growth, development, and responses to the environment. Only more recently have they begun to understand that there is also a link between auxin and leaf spotting diseases.
Several years ago scientists, including Barbara Kunkel, discovered an increased concentration of auxin in leaves inoculated by the bacterial pathogen, Pseudomonas syringae, that causes bacterial spot and speck diseases on many plants.
"We previously demonstrated that auxin promotes disease caused by P. syringae on Arabidopsis thaliana plants, which means that auxin is not acting as a classic plant defense hormone," Kunkel explained. "We were also one group to demonstrate that auxin also suppresses salicylic acid (SA)-mediated plant defense responses."
Read on: https://phys.org/news/2020-10-hormone-auxin-disease-virulence-gene.html