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The present study was undertaken to test the hypothesis that NADPH oxidase-derived reactive oxygen species (ROS) are involved in isoliquiritigenin (ISL)-induced monocytic differentiation in human acute promyelocytic leukemia HL-60 cells. Morphological changes, cell surface markers CD11b/CD14 and NBT-reducing ability were used to determine the differentiation of HL-60 cells, and 2,7-dichlorofluorescein (DCFH-DA) was used to detect the level of intracellular ROS. ISL-induced HL-60 cell differentiation was accompanied by an increase in the intracellular ROS levels. L-Buthionine-(S,R)-sulfoximine (BSO), N-acetyl-L-cysteine (NAC), superoxide dismutase (SOD) and 4-hydroxy-2,2,6,6-tetramethylpiperidinoxyl (Tempol) were used to interfere with ROS production. NADPH oxidase inhibitors, apocynin (APO) and diphenyleneiodonium (DPI) were used to study the role of NADPH oxidase in ISL-induced HL-60 cell differentiation. The ISL-induced HL-60 cell differentiation and intracellular ROS generation were enhanced by the oxidant BSO and inhibited by the antioxidants NAC, SOD, and tempol, and were also inhibited by the NADPH oxidase inhibitors APO and DPI. The protein and mRNA expression of the NADPH oxidase subunits gp91phox and p47phox were determined by Western blotting and RT-PCR, respectively. The levels of translation and transcription of the NADPH oxidase subunits gp91phox and p47phox increased markedly in a concentration-dependent manner. These findings suggest that NADPH oxidase plays a critical role in HL-60 cell differentiation induced by ISL and that NADPH oxidase-derived ROS is involved in the differentiation mechanism. [ABSTRACT FROM AUTHOR]

The red coleoptile trait can help monocotyledonous plants withstand stresses, and key genes responsible for the trait have been isolated from Triticum aestivum, Triticum urartu, and Triticum monococcum, but no corresponding research has been reported for Aegilops tauschii. In this research, transcriptome analysis was performed to isolate the candidate gene controlling the white coleoptile trait in Ae. tauschii. There were 5348 upregulated, differentially-expressed genes (DEGs) and 4761 downregulated DEGs in red coleoptile vs. white coleoptile plants. Among these DEGs, 12 structural genes and two transcription factors involved in anthocyanin biosynthesis were identified. The majority of structural genes showed lower transcript abundance in the white coleoptile of accession 'As77' than in the red coleoptile of accession 'As60', which implied that transcription factors related to anthocyanin biosynthesis could be the candidate genes. The MYB and MYC transcription factors AetMYB7D and AetMYC1 were both isolated from Ae. tauschii accessions 'As60' and 'As77', and their transcript levels analyzed. The coding sequence and transcript level of AetMYB7D showed no difference between 'As60' and 'As77'. AetMYC1p encoded a 567-amino acid polypeptide in 'As60' containing the entire characteristic domains, bHLH-MYC_N, HLH, and ACT-like, belonging to the gene family involved in regulating anthocyanin biosynthesis. AetMYC1w encoded a 436-amino acid polypeptide in 'As77' without the ACT-like domain because a single nucleotide mutation at 1310 bp caused premature termination. Transient expression of AetMYC1p induced anthocyanin biosynthesis in 'As77' with the co-expression of AetMYB7D, while AetMYC1w could not cause induced anthocyanin biosynthesis under the same circumstances. Moreover, the transcript abundance of AetMYC1w was lower than that of AetMYC1p. AetMYC1 appears to be the candidate gene controlling the white coleoptile trait in Ae. tauschii, which can be used for potential biotech applications, such as producing new synthetic hexaploid wheat lines with different coleoptile colors. [ABSTRACT FROM AUTHOR]