Transcription profiling by array of leaf samples from wild-type Arabidopsis and knockout mutants in different insect-inducible transcription factors challenged or unchallenged with Spodoptera littoralis larvae
ABSTRACT: There is currently little information on which trancription factors control the expression of defence genes in response to herbivory in Arabidopsis thaliana. We performed a whole-genome analysis of Arabidopsis plants after feeding by Spodoptera littoralis larvae. Wild-type and knockout mutants in different insect-inducible transcription factors were either untreated (control plants) or challenged for 8 days with S. littoralis larvae (insect challenged plants).
In response to insect herbivory, Arabidopsis plants activate the synthesis of the phytohormone jasmonate-isoleucine, which binds to a complex consisting of the receptor COI1 and JAZ repressors. Upon proteasome-mediated JAZ degradation, basic helix-loop-helix transcription factors (TFs) MYC2, MYC3, and MYC4 become activated and this results in the expression of defense genes. Although the jasmonate (JA) pathway is known to be essential for the massive transcriptional reprogramming that follows he ...[more]
Project description:Arabidopsis thaliana plants fend off insect attack by constitutive and inducible production of toxic metabolites such as glucosinolates (GS). A triple mutant lacking MYC2, MYC3, and MYC4, three basic helix-loop-helix transcription factors that are known to additively control jasmonate-related defense responses, is highly susceptible to insect herbivory. In this study, we performed a whole-genome microarray analysis on three-week-old plants and compared wild-type (Col-0) and myc2myc3myc4 plants in control conditions (no treatment). Myc234 was shown to have a highly reduced expression of GS biosynthesis genes.