Fig. 5: DELLA proteins GmRGAa and GmRGAb associate with the promoter of GmWRKY100 and suppress its transcription.
From: The mechanism of low blue light-induced leaf senescence mediated by GmCRY1s in soybean
a Relative expression levels of GmWRKY100 in the unifoliate leaves of wild-type TL1 cultivar and Gmrgas-dm plants under long-day conditions for indicated days. Values are relative to the control gene GmACT and represent means ± SD (n = 3 biological replicates). b Relative expression levels of GmWRKY100 in the unifoliate leaves of 14-day-old seedlings treated with 10 μM GA3 for the indicated time. Values are means ± SD (n = 3 biological replicates), **P < 0.01. c Relative expression levels of GmWRKY100 in the indicated lines grown under continuous light conditions for 15 days. Values are means ± SD (n = 3 biological replicates). d Constructs of GmCRY1b, GmRGAa, and GmRGAb were used for transient dual-luciferase reporter assay in soybean protoplast. e LUC and REN activity were measured after culturing the protoplasts under continuous white light or LBL conditions for 4 h. Values are means ± SD (n = 3 biological replicates). All above P values were calculated by unpaired two-tailed t-test. f Schematic diagram of GmWRKY100 gene and regions tested for enrichment by ChIP assay. The filled red arrowhead represents the AE-box (part of a module for light response). g ChIP analysis of the interaction between GmRGAb and the GmWRKY100 chromatin regions. Values are means ± SD (n = 3 biological replicates). h A working model of GmCRY1s-GmDELLAs-GmWRKY100 signaling pathway in regulating leaf senescence in soybean. Under LBL conditions, GA triggers the degradation of DELLA proteins through the 26S proteasome pathway, and the expression of GmWRKY100 is released from the repression of DELLA proteins, which further promotes the expression of GmSAGs and leaf senescence. Upon blue light illumination, GmCRY1s were activated and physically interacted with GmRGAa and GmRGAb and to enhance their protein stability. Meanwhile, DELLA proteins could bind to the promoter of GmWRKY100 with unknown factors and repress its expression and the process of leaf senescence. Thick and thin blue arrows denote the expression of GmWRKY100 being induced and repressed, respectively. Source data are provided as a Source Data file.
