WRKY18 and WRKY53 Coordinate with HISTONE ACETYLTRANSFERASE1 to Regulate Rapid Responses to Sugar.

Sugars provide a source of energy; they also function as signaling molecules that regulate gene expression, affect metabolism, and alter growth in plants. Rapid responses to sugar signaling and metabolism are essential for optimal growth and fitness, but the regulatory mechanisms underlying these are largely unknown. In this study, we found that the rapid induction of sugar responses in Arabidopsis (Arabidopsis thaliana) requires the W-box cis-elements in the promoter region of GLC 6-PHOSPHATE/PHOSPHATE TRANSLOCATOR2, a well-studied sugar response marker gene. The transcription factors WRKY18 and WRKY53 directly bind to the W-Box cis-elements in the promoter region of sugar response genes and activate their expression. In addition, HISTONE ACETYLTRANSFERASE 1 (HAC1) is recruited to the WRKY18 and WRKY53 complex that resides on the promoters. In this complex, HAC1 facilitates the acetylation of histone 3 Lys 27 (H3K27ac) on the sugar-responsive genes. Taken together, our findings demonstrate a mechanism by which sugar regulates chromatin modification and gene expression, thus helping plants to adjust their growth in response to environmental changes.