Paeonol promotes longevity and fitness in Caenorhabditis elegans through activating the DAF-16/FOXO and SKN-1/Nrf2 transcription factors.

Paeonol, as one of the most abundant plant-derived polyphenols, has multiple bioactivities including anti-inflammatory, anti-tumor, and anti-cardiovascular diseases. Nevertheless, the anti-aging effects and related mechanisms of paeonol are rarely reported. In this study, we found that paeonol significantly prolonged the mean lifespan of Caenorhabditis elegans (C. elegans) by 28.49% at a dose of 200 µM. Moreover, paeonol promoted the health of C. elegans by increasing the body bending and pharyngeal pumping rates and reducing the lipofuscin accumulation level. Meanwhile, paeonol induced the expression of stress-related genes or proteins by activating the transcription factors DAF-16/FOXO, SKN-1/Nrf2, and HSF-1, which in turn enhanced oxidative and thermal stress tolerance. The mechanism behind the anti-aging effect of paeonol occurred by down-regulating the insulin/IGF-1 signaling (IIS) pathway. Our findings shed new light on the application of paeonol for longevity promotion and human health.

Identification and characterization of CYC2-like genes related to floral symmetric development in Tagetes erecta (Asteraceae).

Marigold (Tagetes erecta) is an annual herbaceous flower belonging to Asteraceae, whose capitulum is composed of bilateral symmetry ray florets on the outer periphery and radial symmetry disk florets on the inside. The flower symmetry evolution from radial symmetry to bilateral symmetry has changed the morphology, inflorescence architecture and function of florets among several lineages in Asteraceae. Several studies have identified that CYC2 genes in TCP transcription factor family are the key genes regulating the flower morphogenesis, such as corolla symmetry and stamen development. Here, seven TeCYC2 genes were cloned and phylogenetically grouped into the CYC2 branch of TCP transcription family. TeCYC2c and TeCYC2d were found to be expressed specifically in ray florets, TeCYC2b was strongly expressed in both ray and disk florets, TeCYC2g was significantly higher expressed in ray florets than in disk florets, while TeCYC2a, TeCYC2e1 and TeCYC2e2 were significantly expressed in disk florets, according to an examination of the expression profile. Among the ectopic expression lines of seven TeCYC2 genes in Arabidopsis thaliana, the flower symmetry of all transgenic lines was changed from radial symmetry to bilateral symmetry, and only the reproductive growth of TeCYC2c lines was affected. In TeCYC2c transgenic Arabidopsis, the pollen sac was difficult to crack, and the filaments were shorter than the pistils, resulting in a significant decrease in the seed setting rate. All TeCYC2 proteins were localized in the nucleus. Eight pairs of interactions between TeCYC2 proteins were validated by Y2H and BiFC assays, indicating the possibility of TeCYC2 proteins forming homodimers or heterodimers to improve functional specificity. Our findings verified the main regulatory role of TeCYC2c on the development of corollas and stamen in marigold, and analyzed the interaction network of the formation mechanism of floral symmetry in two florets, which provided more insights into the expansion of CYC2 genes in the evolution of Asteraceae inflorescence and contributed to elucidate the complex regulatory network, as well as the molecular breeding concerning flower form diversity in marigold.

A histone deacetylase inhibitor enhances rice immunity by derepressing the expression of defense-related genes.

Histone deacetylase (HDAC) inhibitors (HDACis) have been widely used in plants to investigate the role of histone acetylation, particularly the function of HDACs, in the regulation of development and stress response. However, how histone acetylation is involved in rice (Oryza sativa L.) disease resistance has hardly been studied. In this paper, four HDACis including Sodium butyrate (NaBT), Suberoylanilide Hydroxamic Acid (SAHA), LBH-589 and Trichostatin A (TSA) were used to treat rice seedlings at different concentrations before inoculation of Magnaporthe oryzae. We found that only 10mM NaBT treatment can significantly enhanced rice blast resistance. However, treatment of the four HDACis all increased global histone acetylation but at different sites, suggesting that the inhibition selectivity of these HDACis is different. Notably, the global H3K9ac level was dramatically elevated after both NaBT and LBH589 treatment although LBH589 could not enhance rice blast resistance. This indicates that the HDACs they inhibit target different genes. In accordance with the phenotype, transcriptomic analysis showed that many defense-related genes were up-regulated by NaBT treatment. Up-regulation of the four genes bsr-d1, PR10B, OsNAC4, OsKS4 were confirmed by RT-qPCR. ChIP-qPCR results revealed that H3K9ac level on these genes was increased after NaBT treatment, suggesting that these defense-related genes were repressed by HDACs. In addition, by promoter motif analysis of the genes that induced by both NaBT treatment and rice blast infection, we found that the motifs bound by ERF and AHL transcription factors (TFs) were the most abundant, which demonstrates that ERF and AHL proteins may act as the candidate TFs that recruit HDACs to defense-related genes to repress their expression when plants are not infected by rice blast.

Plant tannin immobilized Fe3O4@SiO2 microspheres: A novel and green magnetic bio-sorbent with superior adsorption capacities for gold and palladium.

In this paper, a new core-shell nanostructured magnetic bio-based composite was prepared by immobilizing persimmon tannin (PT) onto Fe3O4@SiO2 microspheres, and the as designed Fe3O4@SiO2@PT was utilized for adsorptive recovery of Au(III) and Pd(II). The preparation, morphology, composition and magnetic property of Fe3O4@SiO2@PT were characterized. Adsorption parameters of Fe3O4@SiO2@PT towards Au(III) and Pd(II) including initial pH, reaction time, initial concentration of metal ions, effect of acidity and interference of coexisting metal ions were investigated. It is sufficiently confirmed that silica was coated on Fe3O4 and persimmon tannin was immobilized on aminated Fe3O4@SiO2. The thickness of silica and loaded persimmon tannin are around 18 nm and 14 nm, respectively. With only 1.00 wt% of persimmon tannin, however, the maximum adsorption capacities of Fe3O4@SiO2@PT for Au(III) and Pd(II) were as high as 917.43 and 196.46 mg·g-1, respectively. In addition, after adsorption of Au(III) and Pd(II), the magnetization saturation values (Ms) of Fe3O4@SiO2@PT were high enough to guarantee efficient magnetic seperation. Metallic gold could be facilely recovered from wastewaters containing Au(III).

Analysis of rice Snf2 family proteins and their potential roles in epigenetic regulation.

Snf2 family proteins are ATP-dependent chromatin remodeling factors that control many aspects of DNA events such as transcription, replication, homologous recombination and DNA repair. In animals several members in this family have been revealed to control gene expression in concert with other epigenetic mechanisms including histone modification, histone variants and DNA methylation. Their function in regulating genome expression in plant has hardly been disclosed before except in Arabidopsis. Here we identified 40 members of this family in the rice (Oryza Sativa) genome and constructed a phylogenetic tree together with Arabidopsis 41 Snf2 proteins. Sequence alignment of the Snf2 helicase regions revealed conserved motifs and blocks in most proteins. Expression profile analysis indicates that many rice Snf2 family genes show a tissue-specific expression pattern and some of them respond to abiotic stresses including drought, salt and cold. The results provide a basis for further analysis of their roles in epigenetic regulation to control rice development.

[Comparison of Doppler examination and non-stress test in the prediction of intrauterine fetal hypoxia].

OBJECTIVE: To assess the predictive value of intrauterine fetal hypoxia by Doppler examination and non-stress test (NST). METHODS: The normal value of the peak-systolic and diastolic ratio (S/D), pulse index (PI), resistance index (RI), fast volume ratio (FVR) of different gestational age was created according to 4 326 normal pregnancy. S/D, PI, RI, FVR and NST was performed for 2 873 normal pregnancy at the last trimester. Fetal outcomes were recorded within 7 days of birth. RESULTS: (1) S/D, PI, and RI decreased with the gestational age advancing, but FVR didn't. When S/D, PI, RI, FVR or NST appeared abnormal, the ratio of intrauterine fetal hypoxia was 62.0%, 60.7%, 63.3%, 27.0% and 75.7% respectively, as these normal, the ratio of intrauterine fetal hypoxia was 12.8%, 13.9%, 13.0%, 15.7%, 7.5% respectively. There was significant difference (P < 0.01). (2) Logistic regression showed that the predictive value of RI and NST to intrauterine fetal hypoxia was significant (P < 0.05). CONCLUSIONS: The predictive value of NST and RI to intrauterine fetal hypoxia was stronger than other parameters. Multi-parameter may predict more accurately than any single index for intrauterine fetal hypoxia.