Figure 2.

The regulation of transcriptional regulators in defense. Diagram illustrates the regulation of defense transcription factor (TF) family members at different levels. At the transcriptional level, auto- and cross-regulation among members of the same TF family or between members of different TF families forms a regulatory node for their expression (1). Epigenetic changes, such as histone modification and DNA methylation can also direct the genetic regulation and priming of the TF gene expression in response to stress (2). At the post-transcriptional level, many defense regulators are targeted by small RNAs (e.g., miRNA) for precise control of the transcript accumulation (3). In addition, the presence of a characteristic DNA binding domain (Figure 1) and various conserved domains among the TFs mediate various post-translational controls of these regulators through different mechanisms, including protein localization in intracellular membranes (4), interaction and modification with other cellular proteins in the cytoplasm (5), or ubiquitination (6). Regulation and interactions among these TF families control expression of their downstream targets involved in primary and secondary metabolisms, as well as phytohormone production, thereby mediating growth and defense in plants. ER: endoplasmic reticulum.