BioProject

Plant homeodomain (PHD) finger proteins are ‘histone code readers’. They recognize and bind to epigenetically modified histone H3 ‘tail’. More...

Plant homeodomain (PHD) finger proteins are ‘histone code readers’. They recognize and bind to epigenetically modified histone H3 ‘tail’. Here we reported that an Alfin1-like soybean protein, GmPHD6, read H3K4me0/1/2 but not H3K4me3 with the N-terminal instead of the PHD finger. GmPHD6 does not possess transcriptional regulatory ability. Through the PHD finger, GmPHD6 interacts with its co-activator, LHP1-1/2. Using a transgenic hairy root system, we demonstrated that over-expression of GmPHD6 improved stress tolerance in transgenic soybean composites. Perhaps due to the excessive amount of LHP1 compared to that of GmPHD6, over-expression of LHP1-1/2 failed to do so. The integrity of the complex is essential in stress response, for the abrogation of DNA binding activity of GmPHD6 or the decrease of LHP1 content leads to stress sensitivity in soybean. GmPHD6 influences expression of dozens of stress-related genes to confer stress tolerance. Among these genes, we identified three direct targets of GmPHD6, ASR (ABA-stress-ripening induced), CYP71A22 (cytochrome P450) and CYP82C4. Our study reveals significant findings in stress response. GmPHD6 and LHP1 are recruited to H3K4me0/1/2 marks, where several stress-related genes may locate in, to form a transcriptional activation complex. GmPHD6 locates target sites through recognizing the G-rich elements in their promoters; LHP1 enhances expression levels of these targets. Genetically engineering of GmPHD6/LHP1 complex should improve stress tolerance in crop plants. Overall design: Three samples were chosen, GmPHD6 over-expression, GmPHD6 RNAi and the control sample (K599).Downstream genes are defined as the common genes that are up-regulated in GmPHD6-OE sample and down-regulated in RNAi sample. Less...