Expression and activity of intracellular immune receptors are tightly regulated in plants for effective defense responses as well as balance between growth and immunity.We are dissecting this fine regulation using an autoimmune mutant bonl with an upregulation of immune receptor gene SNC1 in Arabidopsis.Enhancer and suppressor screens of bonl revealed a role of cell cycle regulators OSD1 and MOS1 respectively in immunity modulation.OSD1 is negative regulator of anaphase promoting complex, and its overexpression leads to enhanced immune responses to a bacterial pathogen due to upregulation of SNC1.SNC1 expression is also positively regulated by MOS1 that is associated with MAD2, a component of mitotic spindle assembly checkpoint complex.These studies indicate that cell cycle progression could impact plant immunity and expression of immune receptors might be subject to multiple environmental and developmental controls.