The response to cabbage looper infestation in Arabidopsis is altered by lowering levels of Zat18 a Q-type C2H2 zinc finger protein

ABSTRACT Q-type C2H2 zinc finger proteins (ZFPs) play a role in plant stress response. Overexpression of individual ZFPs enhances tolerance to abiotic stresses such as drought or salt. Overexpression of ZFP, Zat18 enhances tolerance to drought, whereas plants with lower amounts are less resilient. The effect of Zat18 loss on gene expression has not been characterized. Overexpression of an ortholog of Zat18 in potato, StZFP2 enhances tolerance to infestation by Manduca sexta. This work focuses on two Zat18 mutant lines, a knockout and knockdown. The two lines differ in response to infestation. Typically, a chewing insect induces the jasmonic acid (JA) pathway. While infestation induces JA pathway genes, Zat18 mutant lines downregulate abscisic acid signaling and induce ethylene signaling genes ERF1 and EBF2 as well as salicylic acid response gene NPR3. Knockdown Zat18, cause far more changes in the infestation response compared with Col-0 or the Zat18 knockout line.