MYC2 differentially regulates GATA-box containing promoters during seedling development in Arabidopsis

Abstract

MY C2 is an important transcription factor, which modulates transcription by directly binding to Z-, G- and E-box elements present in the promoters of light and different stress responsive genes. Very recently, we have shown that MY C2 plays a role in the regulation of Z- and/or G-box containing promoters during both seedling and adult plant growth. Although, MY C2 does not bind to the GATA box light responsive element (LRE ) in vitro as shown in DNA binding assays, its involvement in the regulation of GATA -box containing promoter in planta, if any, is not known. Here, we report that the promoter activity of GATA-NOS101 in atmyc2 mutant was found to be similar to wild-type in BL and dark grown seedlings, whereas it was found to be lower compared with wild-type as revealed from GUS staining results. Further, we will discuss the consequences of MY C2 regulating GATA -box containing promoter in combination with G-box containing promoters.

Figure 1. MYC2/ZBF1 differentially regulates the expression of GATA-box containing promoter. In each panel of A, WT and atmyc2/zbf1 mutant seedlings carrying the transgene are shown on the left and right, respectively. Six-day-old WT and atmyc2 seedlings were stained for the similar length of time. (A) GUS staining patterns of 4GATA/NOS1O1-GUS transgenic seedlings grown under constant dark, BL (30 µmol m⁻² s⁻¹), RL (90 µmol m⁻² s⁻¹), and FR (60 µmol m⁻² s⁻¹). (B) GUS activities of 6-d-old wild-type and atmyc2/zbf1 seedlings carrying 4G/NOS101-GUS transgene grown in constant dark, BL (30 µmol m⁻² s⁻¹), RL (90 µmol m⁻² s⁻¹), and FR (60 µmol m⁻² s⁻¹). Error bars represent SD (n = 3). *P ≤ 0.05 and ** P ≤ 0.01 for values significantly differ from WT in respective light conditions. The experiment was performed at least twice with similar results.