Phosphoinositide 3-Kinase Promotes Oxidative Burst, Stomatal Closure and Plant Immunity in Bacterial Invasion.

Phosphoinositide 3-kinase (PI3K) plays a vital role in plant response to abiotic stress. However, the role of PI3K in plant immunity is largely unknown. This study showed that PI3K enhanced resistance to pv DC3000 ( DC3000) and DC3000 (). Overexpression of promoted stomatal closure while PI3K inhibitors blocked that after spray inoculation. Additionally, gene expression of was increased upon infection by DC3000 (), and SA upregulated gene expression in this process. Furthermore, overexpression of enhanced gene expression after syringe infiltration with DC3000 (), while PI3K inhibitors inhibited that. The production of hydrogen peroxide and the expression of gene encoding antioxidant enzyme were both enhanced in overexpressing lines after spray inoculation or syringe infiltration with DC3000 (). Collectively, these results unraveled a novel and broad role of PI3K in plant immunity which promoted stomatal closure and gene expression possibly regulating ROS production.