Study of the Multiple Roles of Phosphatidylinositol-4-Kinases Betas in Morphogenesis and Defense Responses of Arabidopsis Thaliana

The study investigated the role of phosphatidylinositol-4-kinases beta (PI4Kβ) in Arabidopsis thaliana, focusing on morphogenesis and defense responses. Using a pi4kβ1β2 double mutant, it was found that these plants exhibited impaired root growth, altered auxin responses, and a less stable actin cytoskeleton. The mutant also showed increased susceptibility to the fungus Blumeria graminis, suggesting PI4Kβ's role in forming defensive papillae. Additionally, the mutant displayed constitutively active immunity with salicylic acid (SA) accumulation, leading to dwarfism. The study suggested that the transcription factor WRKY70 might be involved in this SA accumulation, highlighting PI4Kβ's importance in plant defense and development.