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Triphenyl phosphate (TPHP) is an organophosphorus flame retardant, but its cardiac toxicity has not been adequately investigated. Therefore, in the current study, the effect of TPHP on the heart and the underlying mechanism involved was evaluated. C57BL/6 J mice were administered TPHP (0, 5, and 50 mg/kg/day) for 30 days. In addition, H9c2 cells were treated with three various concentrations (0, 50, and 150 μM) of TPHP, with and without the reactive oxygen species (ROS) scavenger N-acetyl-L-cysteine or the mitochondrial fusion promoter M1. TPHP caused cardiac fibrosis and increased the levels of CK-MB and LDH in the serum. TPHP increased the levels of ROS, malondialdehyde (MDA), and decreased the level of superoxide dismutase (SOD) and Glutathione peroxidase (GSH-Px). Furthermore, TPHP caused mitochondrial damage, and induced fusion and fission disorders that contributed to mitophagy in both the heart of C57BL/6 J mice and H9c2 cells. Transcriptome analysis showed that TPHP induced up- or down-regulated expression of various genes in myocardial tissue and revealed enriched apoptosis pathways. It was also found that TPHP could remarkably increase the expression levels of Bax, cleaved Caspase-9, cleaved Caspase-3, and decreased Bcl-2, thereby causing apoptosis in H9c2 cells. Taken together, the results suggested that TPHP promoted mitophagy through mitochondria fusion dysfunction resulting from oxidative stress, leading to fibrosis by inducing myocardial apoptosis. [Display omitted] • Triphenyl phosphate could cause cardiac fibrosis and dysfunction in mice. • Triphenyl phosphate could induce apoptosis and mitophagy of cardiomyocyte. • Triphenyl phosphate lead to dysfunction of mitochondria fusion and fission. [ABSTRACT FROM AUTHOR]

GROWTH-REGULATING FACTORs (GRFs) play a pivotal role in the regulation of leaf size in plants and have been widely reported in plants. However, their specific functions in leaf size regulation in Liriodendron chinense remains unclear. Therefore, in this study, we identified GRF genes on a genome-wide scale in L. chinense to characterize the roles of LcGRFs in regulating leaf size. A total of nine LcGRF genes were identified, and these genes exhibited weak expression in mature leaves but strong expression in shoot apex. Notably, LcGRF2 exhibited the highest expression level in the shoot apex of L. chinense. Further RT-qPCR assay revealed that the expression level of LcGRF2 gradually decreased along with the leaf development process, and also displayed a gradient along the leaf proximo-distal and medio-lateral axes. Furthermore, overexpression of LcGRF2 in Arabidopsis thaliana resulted in increased leaf size, and significantly up-regulated the expression of genes involved in cell division like AtCYCD3;1 , AtKNOLLE , and AtCYCB1;1 , indicating that LcGRF2 may influence leaf size by promoting cell proliferation. This work contributes to a better understanding of the roles and molecular mechanisms of LcGRFs in the regulation of leaf size in L. chinense. • LcGRF2 exhibited a gradient expression pattern along both the proximal-distal axis (from high to low) and medio-lateral axis (from low to high) of leaves. • Overexpression of LcGRF2 in A. thaliana enlarged leaf size. • LcGRF2 regulated leaf size through the regulation of cell proliferation. [ABSTRACT FROM AUTHOR]

Basic region/leucine zipper (bZIP) transcription factors function as critical regulators in numerous abiotic stress responses. Massive bZIPs have been systematically identified in plants, but not in sweetpotato. In this study, 87 sweetpotato IbbZIPs unevenly distributed onto 15 chromosomes were identified, and segmental duplications were shown to play dominant roles in the diversity of IbbZIPs. The collinearity between IbbZIPs and the related orthologs from nine plants depicted evolutionary insights into bZIP gene family. Additionally, IbbZIP proteins were clustered into 11 subfamilies while no members were found in the M subfamily, and the regularity of gene structures and conserved motifs was consistent with the subgroup classification. Evidence from transcriptome data and qRT-PCR analysis of 12 selected IbbZIPs revealed that they were significantly and varyingly induced under multiple abiotic stresses (salt, drought, heat and cold) and hormone treatments (ABA, ACC, JA and SA). Consistently, the promoters of IbbZIPs harbored multiple stress- and hormone-related cis-acting elements. Besides, IbbZIP17 and IbbZIP61 exhibited transactivation activity in yeasts, while IbbZIP-14/-69/-84 did not. These findings supply worthy foundations for further functional investigation of IbbZIPs , and multiple members may serve as promising regulators to enhance the abiotic stress tolerance of transgenic plants. [ABSTRACT FROM AUTHOR]