Heat shock transcription factors (HSFs) are critical regulators of plant responses to various abiotic and biotic stresses, including high temperature stress. HSFs are involved in regulating the expression of heat shock proteins (HSPs) by binding with heat stress elements (HSEs) to defend against high-temperature stress. The H. perforatum genome was recently fully sequenced; this provides a valuable resource for genetic and functional analysis. In this study, 23 putative HpHSF genes were identified and divided into three groups (A, B, and C) based on phylogeny and structural features. Gene structure and conserved motif analyses were performed on HpHSFs members; the DNA-binding domain (DBD), hydrophobic heptad repeat (HR-A/B), and exon-intron boundaries exhibited specific phylogenetic relationships. In addition, the presence of various cis -acting elements in the promoter regions of HpHSFs underscored their regulatory function in abiotic stress responses. RT-qPCR analyses showed that most HpHSF genes were expressed in response to heat conditions, suggesting that HpHSFs play potential roles in the heat stress resistance pathway. Our findings are advantageous for the analysis and research of the function of HpHSFs in high temperature stress tolerance in H. perforatum .
Hypericum perforatum , also known as “natural fluoxetine,” is a commonly used herbal remedy for treating depression. It is unclear whether melatonin in plants regulated by the endogenous circadian clock system is like in vertebrates. In this work, we found that the melatonin signal and melatonin biosynthesis gene, serotonin N -acetyltransferase HpSNAT1 , oscillates in a 24-hour cycle in H. perforatum . First, we constructed a yeast complementary DNA library of H. perforatum and found a clock protein HpLHY that can directly bind to the HpSNAT1 promoter. Second, it was confirmed that HpLHY inhibits the expression of HpSNAT1 by targeting the Evening Element. Last, it indicated that HpLHY -overexpressing plants had reduced levels of melatonin in 12-hour light/12-hour dark cycle photoperiod, while loss-of-function mutants exhibited high levels, but this rhythm seems to disappear as well. The results revealed the regulatory role of LHY in melatonin biosynthesis, which may make an important contribution to the field of melatonin synthesis regulation.
This paper describes newly discovered dinosaur and crocodylomorph egg fragments from the Upper Cretaceous Sanshui and Dalangshan formations of the Sanshui Basin of Guangdong Province, southern China. Despite the absence of macroscopic information, the eggshell specimens can be identified to the oofamilies Prismatoolithidae, Elongatoolithidae and Krokolithidae, and it is hypothesized that these three families of eggs correspond to troodontids, oviraptorids and crocodiloids, respectively. Comparison with egg fossils from Nanxiong Basin, Heyuan Basin and Ganzhou Basin highlights the similarity between these egg assemblages and those from Nanxiong Basin. The egg fossils found in the Sanshui and the Dalangshan formations enrich the known faunal types in the research area and facilitate further studies on the diversity of Late Cretaceous vertebrate assemblages in the Sanshui Basin.
In this study, semiquantitative reverse transcription–PCR analysis showed that estrogen receptor α (ERα) and β (ERβ) mRNAs are developmentally regulated in the rat heart. We found that ERα mRNA was low in all heart chambers of 4-day-old rats, but was elevated in the atria (6- to 18-fold) and ventricles (3- to 4-fold) of adult rats. Western blotting analysis confirmed that these differences were efficiently translated into 67-kDa ERα protein. ERβ mRNA was expressed at its highest level in the left atrium and was 3- to 4-fold lower in other heart chambers of 4-day-old animals. In adult rats ERβ was decreased dramatically in the left atrium (20-fold) and, to a lesser extent in the other heart chambers (2- to 4-fold). Significant ER changes occurred already in the first week after birth. Accordingly, estrogen regulation in cells from neonatal hearts, as reported in several studies, may not correspond to that occurring in fully differentiated adult hearts, because of an altered degree of ER expression. In adult rats, ovariectomy decreases atrial ERα, the atria/body weight ratio, and atrial natriuretic peptide (ANP) transcription. Treatment of ovariectomized rats with 17-β-estradiol (25 μg, 10 days, s.c.) reversed these changes. In addition, there was no effect of ovariectomy and 17-β-estradiol supplementation on systolic blood pressure, but in ovariectomized rats a decreased heart rate followed 17-β-estradiol administration. Similar to the effects on ERα in the atria, ovariectomy lowered plasma ANP levels, and 17-β-estradiol administration restored ANP in the plasma of ovariectomized rats. Changes in plasma ANP correlated with changes in ANP content in the right atrium, as demonstrated by RIA. Increased ANP expression and secretion in response to ERα activation may be a protective mechanism in the heart.
The eggs of fish, amphibians, and many invertebrates are soft, delicate structures that are only rarely preserved in the fossil record. Here we report egg masses preserved as inclusions in mid-Cretaceous amber deposits of Myanmar. Of five specimens recovered, three of the egg masses probably pertain to insects, but the other two appear different. One mass is composed of relatively stiff eggs that retain their shape throughout the mass and may be linked by mucoid strands. This morphology resembles that of some terrestrial molluscs. The second mass is composed of softer eggs that have compressed one another so that their shapes are strongly distorted within the mass. These eggs most closely resemble those of amphibians. Given the forest environment reconstructed for the amber locality, the eggs were presumably attached on or close to the resin producing tree.
Hypericum perforatum L. is a widely known medicinal herb used mostly as a remedy for depression because it contains high levels of naphthodianthrones, phloroglucinols, alkaloids, and some other secondary metabolites. Quantitative real-time PCR (qRT-PCR) is an optimized method for the efficient and reliable quantification of gene expression studies. In general, reference genes are used in qRT-PCR analysis because of their known or suspected housekeeping roles. However, their expression level cannot be assumed to remain stable under all possible experimental conditions. Thus, the identification of high quality reference genes is essential for the interpretation of qRT-PCR data. In this study, we investigated the expression of 14 candidate genes, including nine housekeeping genes (HKGs) (ACT2, ACT3, ACT7, CYP1, EF1-α, GAPDH, TUB-α, TUB-β, and UBC2) and five potential candidate genes (GSA, PKS1, PP2A, RPL13, and SAND). Three programs-GeNorm, NormFinder, and BestKeeper-were applied to evaluate the gene expression stability across four different plant tissues, four developmental stages and a set of abiotic stress and hormonal treatments. Integrating all of the algorithms and evaluations revealed that ACT2 and TUB-β were the most stable combination in different developmental stages samples and all of the experimental samples. ACT2, TUB-β, and EF1-α were identified as the three most applicable reference genes in different tissues and stress-treated samples. The majority of the conventional HKGs performed better than the potential reference genes. The obtained results will aid in improving the credibility of the standardization and quantification of transcription levels in future expression studies on H. perforatum.
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