Arabidopsis Toxicos en Levadura 12 ( ATL12 ): A Gene Involved in Chitin-Induced, Hormone-Related and NADPH Oxidase-Mediated Defense Responses

Plants, as sessile organisms, have evolved complex systems to respond to changes in environmental conditions. Chitin is a Pathogen-Associated-Molecular Pattern (PAMP) that exists in the fungal cell walls, and can be recognized by plants and induce plant pattern-triggered immunity (PTI). Our previous studies showed that is highly induced in response to fungal infection and chitin treatment. We used the model organism to characterize and explore its role in fungal defense. Histochemical staining showed that -GUS was continually expressed in roots, leaves, stems, and flowers. Subcellular co-localization of the ATL12-GFP fusion protein with the plasma membrane-mcherry marker showed that ATL12 localizes to the plasma membrane. Mutants of are more susceptible to infection, while overexpression of increased plant resistance to the fungus. is highly induced by chitin after two hours of treatment and may act downstream of cascades. Additionally, 3,3'-diaminobenzidine (DAB) staining indicated that mutants generate less reactive oxygen species compared to wild-type Col-0 plants and RT-PCR indicated that regulated ROS production may be linked to the expression of ( ). Furthermore, we present evidence that expression is upregulated after treatment with both salicylic acid and jasmonic acid. Taken together, these results suggest a role for in crosstalk between hormonal, chitin-induced, and NADPH oxidase-mediated defense responses in Arabidopsis.