Project description:Plants have developed a complicated resistance system, and they exhibit various defense patterns in response to different attackers. However, the determine factors of plant defense patterns are still not clear. Here, we hypothesized that damage patterns of plant attackers play an important role in determining the plant defense patterns. To test this hypothesis, we selected leafminer, which has a special feeding pattern more similar to pathogen damage than chewing insects, as our model insect, and Arabidopsis thaliana as the response plants. The local and systemic responses of Arabidopsis thaliana to leafminer feeding were investigated using the Affymetrix ATH1 genome array.
Project description:The plant innate immunity consists of the two interconnected mechanisms, pattern-triggered immunity (PTI) and effector-triggered immunity (ETI). Although much is known about how plants trigger immune responses upon pathogen recognition, the genetic program by which plants avoid an overshoot in pathogen-triggered immune responses remains largely unknown. Here, we discovered a trihelix transcription factor, GT-3a, as an immune-inducible negative regulator of bacterial resistance in Arabidopsis thaliana. Analysis of public RNA-seq data revealed that GT-3a is specifically induced by ETI activation not by PTI activation. Overexpression of GT-3a suppressed resistance against the bacterial pathogen Pseudomonas syringae pv. tomato DC3000 (Pto) and Pto-elicited expression of salicylic acid (SA)-responsive genes. Our results suggest that transcriptional induction of GT-3a circumvents the overshooting of SA-mediated defense responses during ETI.
