YODA Kinase Controls a Novel Immune Pathway of Tomato Conferring Enhanced Disease Resistance to the Bacterium .

Mitogen-activated protein kinases (MAPK) play pivotal roles in transducing developmental cues and environmental signals into cellular responses through pathways initiated by MAPK kinase kinases (MAP3K). AtYODA is a MAP3K of that controls stomatal development and non-canonical immune responses. plants overexpressing a constitutively active YODA protein () show broad-spectrum disease resistance and constitutive expression of defensive genes. We tested YDA function in crops immunity by heterologously overexpressing in . We found that these tomato plants do not show developmental phenotypes and fitness alterations, except a reduction in stomatal index, as reported in plants. Notably, tomato plants show enhanced resistance to the bacterial pathogen pv. DC3000 and constitutive upregulation of defense-associated genes, corroborating the functionality of YDA in tomato immunity. This function was further supported by generating CRISPR/Cas9-edited tomato mutants impaired in the closest orthologs of [ () and ()]. and mutants are highly susceptible to pv. DC3000 in comparison to wild-type plants but only shows altered stomatal index. These results indicate that tomato orthologs have specialized functions and support that YDA also regulates immune responses in tomato and may be a trait for breeding disease resistance.