Integrated transcriptomic and CGAs analysis revealed IbGLK1 is a key transcription factor for chlorogenic acid accumulation in sweetpotato (Ipomoea batatas [L.] Lam.) blades.

Sweetpotato blades are rich in the functional secondary metabolite chlorogenic acid (CGA), which deepen potential for effective utilization of the blade in industry. In this study, we evaluated the type and content of CGA in the blades of 16 sweetpotato genotypes and analyzed the correlation between CGA content and antioxidant capacity. Then we isolated and characterized IbGLK1, a GARP-type transcription factor, by comparative transcriptome analysis. A subcellular localization assay indicated that IbGLK1 is located in the nucleus. Overexpression and silencing of IbGLK1 in sweetpotato blade resulted in a 0.90-fold increase and 1.84-fold decrease, respectively, in CGA content compared to the control. Yeast one-hybrid and dual-luciferase assays showed that IbGLK1 binds and activates the promoters of IbHCT, IbHQT, IbC4H, and IbUGCT, resulting in the promotion of CGA biosynthesis. In conclusion, our study provides insights into a high-quality gene for the regulation of CGA metabolism and germplasm resources for breeding sweetpotato.

Assembly and comparative analysis of the first complete mitochondrial genome of a traditional Chinese medicine Angelica biserrata (Shan et Yuan) Yuan et Shan.

Duhuo, a member of the Angelica family, is widely used to treat ailments such as rheumatic pain. It possesses a diverse array of bioactivities, including anti-tumor, anti-inflammatory, and analgesic properties, as recent pharmacological research has revealed. Nevertheless, the mtDNA of Angelica species remains relatively unexplored. To address this gap, we sequenced and assembled the mtDNA of A. biserrata to shed light on its genetic mechanisms and evolutionary pathways. Our investigation indicated a distinctive multi-branched conformation in the A. biserrata mtDNA. A comprehensive analysis of protein-coding sequences (PCGs) across six closely related species revealed the presence of 11 shared genes in their mitochondrial genomes. Intriguingly, positive selection emerged as a significant factor in the evolution of the atp4, matR, nad3, and nad7 genes. In addition, our data highlighted a recurring trend of homologous fragment migration between chloroplast and mitochondrial organelles. We identified 13 homologous fragments spanning both chloroplast and mitochondrial genomes. The phylogenetic tree established a close relationship between A. biserrata and Saposhnikovia divaricata. To sum up, our research would contribute to the application of population genetics and evolutionary studies in the genus Acanthopanax and other genera in the Araliaceae family.

Comparative and phylogenetic analysis of Asparagus meioclados Levl. and Asparagus munitus Wang et S. C. Chen plastomes and utility of plastomes mutational hotspots.

Tiandong is a vital traditional Chinese herbal medicine. It is derived from the tuber root of the Asparagus cochinchinensis according to the Pharmacopoeia of the people's republic of China (2020 Edition). On account of the similar morphology, Asparagus meioclados and Asparagus munitus were used as Tian-Dong in southwest China. Chloroplast (cp) genomes are highly active genetic components of plants and play an extremely important role in improving the efficiency of the identification of plant species. To differentiate the medicinal plants belonging to the genus Asparagus, we sequenced and analyzed the complete plastomes (plastid genomes) of A. meioclados and A. munitus and obtained two plastomes whose length changed to 156,515 bp and 156,381 bp, respectively. A total of 111 unique genes have been detected in plastome, which included 78 protein-coding genes, 29 tRNA genes and 4 rRNA genes. In plastomes of A. meioclados and A. munitus, 14,685 and 14,987 codons were detected, among which 9942 and 10,207 had the relative synonymous codon usage (RSCU) values higher than 1, respectively. A. meioclados and A. munitus have 26 SSRs patterns, among which A. meioclados was 25 and A. munitus 21. The average Ka/Ks value was 0.36, and positive selection was detected in genes of the photosynthetic system (ndhF and rbcL) in Asparagus species. To perform the comparative analysis of plastomes, the two newly sequenced plastomes of the A. meioclados and A. munitus species were compared with that of A. cochinchinensis, and 12 hotspots, including 5 coding regions and 7 inter-genomic regions, were identified. Based on the whole plastome of Asparagus, 2 divergent hotspots (accD and rpl32-trnL-UAG) and 1 international barcode fragment (rbcL) were screened, which may be used as particular molecular markers for the identification of Asparagus species. In addition, we determined the phylogenetic relationship between A. meioclados and A. munitus in the genus Asparagus. This study enriches our knowledge of the molecular evolutionary relationships of the Asparagus genus and provides treasured data records for species identification, molecular breeding, and evolutionary analysis of this genus.

The seed oil of Paeonia ludlowii ameliorates Aß25-35-induced Alzheimer's disease in rats.

Paeonia ludlowii, a plant of the Paeoniaceae family, has abundant genetic diversity in different populations, and the seed oil can be used in a diverse number of activities. However, its neuroprotective effect is not clear. We investigated the memory-improving effects and associated mechanisms of Paeonia ludlowii seed oil (PLSO) on amyloid beta (Aß)25-35-induced Alzheimer's disease (AD) in rats. The Morris water maze test was undertaken, and subsequently, the content of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), and acetylcholinesterase (ACHE) in the hippocampus was detected by biochemical analyses. To further study PLSO, we examined the pathologic structure and apoptosis of hippocampal tissue by staining. Immunohistochemical analysis was used to detect expression of IBA-1 and GFAP in the hippocampus. Detection of proinflammatory factors was achieved by reverse transcription-quantitative polymerase chain reaction and Western blotting. High-dose PLSO inhibited expression of GFAP and IBA-1. We demonstrated that high-dose PLSO can regulate activation of glial cells and mediate apoptosis of hippocampal cells, and significantly improve learning and memory deficits in AD rats. PLSO could be developed as a nutritional supplement and sold as a drug for AD prevention and/or treatment.

Study on the Fatty Acids, Aromatic Compounds and Shelf Life of Paeonia ludlowii Kernel Oil.

To determine the food potential of Paeonia ludlowii D.Y.Hong (P. ludlowii) kernel oil, in this study, we analysed the fatty acid composition and volatile components of this oil, compared the antioxidant effects of two natural antioxidants on it, and then predicted its shelf life at room temperature (25°C). The results showed that P. ludlowii kernel oil mainly contained 20 fatty acids, of which linoleic acid, oleic acid and other unsaturated fatty acid contents together made up 86.99%. The aromatic composition of the crude P. ludlowii kernel oil was analysed, and 34 aromatic compounds were obtained, including 5 lipids (2.30%), 9 alcohols (12.64%), 6 aldehydes (14.67%), 2 alkanes (1.30%), 5 acids (2.70%), 1 ketone (0.41), 2 alkenes (39.12%) and 4 other substances (26.85%). The effects of the antioxidants were ranked as follows: 0.04% tea polyphenols + crude oil > 0.04% bamboo flavonoids + crude oil > crude oil. In addition, the shelf lives at room temperature (25℃) of each kernel oil-antioxidant mixture were 200.73 d, 134.90 d and 131.61 d, respectively. Overall, these results reveal that P. ludlowii kernel oil is a potential candidate for a new high-grade edible oil, and its development has broad application prospects.

Complete Chloroplast Genome Sequencing and Phylogenetic Analysis of Two Dracocephalum Plants.

Dracocephalum tanguticum and Dracocephalum moldavica are important herbs from Lamiaceae and have great medicinal value. We used the Illumina sequencing technology to sequence the complete chloroplast genome of D. tanguticum and D. moldavica and then conducted de novo assembly. The two chloroplast genomes have a typical quadripartite structure, with the gene's lengths of 82,221 bp and 81,450 bp, large single-copy region's (LSC) lengths of 82,221 bp and 81,450 bp, and small single-copy region's (SSC) lengths of 17,363 bp and 17,066 bp, inverted repeat region's (IR) lengths of 51,370 bp and 51,352 bp, respectively. The GC content of the two chloroplast genomes was 37.80% and 37.83%, respectively. The chloroplast genomes of the two plants encode 133 and 132 genes, respectively, among which there are 88 and 87 protein-coding genes, respectively, as well as 37 tRNA genes and 8 rRNA genes. Among them, the rps2 gene is unique to D. tanguticum, which is not found in D. moldavica. Through SSR analysis, we also found 6 mutation hotspot regions, which can be used as molecular markers for taxonomic studies. Phylogenetic analysis showed that Dracocephalum was more closely related to Mentha.

Characterization of the complete chloroplast genome sequence of the medicinal plant Mirabilis himalaica.

Mirabilis himalaica is an old and popular medicinal plant used in traditional Tibetan folk medicine. Here, we reported the complete chloroplast genome sequence of Mirabilis himalaica. The assembled chloroplast genome was 154,348 bp long, containing a large single-copy region of 85,809 bp, a small single-copy region of 17,935 bp, and a pair of inverted repeat regions of 25,302 bp. It had 36% GC content and encoded 131 genes including 86 protein-coding genes, eight rRNA genes, and 37 tRNA. Fifteen and two genes contained one and two introns, respectively. Phylogenetic analysis revealed that Mirabilis himalaica was sister to Nyctaginia capitata.

[New records of medicinal plants in Tibet].

By the fourth survey of Chinese medicinal resources, new medicinal plants records of 2 genera and 5 species were reported in Tibet. They are two genera Rhynchoglossum and Asteropyrum, and five species including Rh. obliquum, A. peltatum, Urena repanda, Schefflera khasiana and Mimulus tenellus. All the voucher specimens are preserved in Herbarium of Tibet Agriculture and Animal Husbandry University.

The complete chloroplast genome sequence of Rhodiola sacra (Prain ex Hamet) S. H. Fu.

Rhodiola sacra (Prain ex Hamet) S. H. Fu is a traditional natural plant pharmaceutical with anti-hypoxia effect and mainly distributed in Yunnan and Tibet (China). The complete chloroplast sequence of R. sacra was determined in our study. The cpDNA was 150,941 bp in length, containing a pair of inverted repeats (IRs) of 25,873 bp each separated by a large and small single copy (LSC and SSC) regions of 82,161 bp and 17,034 bp, respectively. The genome contained 84 protein coding genes, eight rRNA genes and 36 tRNA genes. Phylogenetic tree revealed that R. sacra closely related to Rhodiola kirilowii and Rhodiola crenulata.

Integrated analysis of transcriptomic and metabolomic data reveals critical metabolic pathways involved in rotenoid biosynthesis in the medicinal plant Mirabilis himalaica.

Mirabilis himalaica (Edgew.) Heimerl is among the most important genuine medicinal plants in Tibet. However, the biosynthesis mechanisms of the active compounds in this species are unclear, severely limiting its application. To clarify the molecular biosynthesis mechanism of the key representative active compounds, specifically rotenoid, which is of special medicinal value for M. himalaica, RNA sequencing and TOF-MS technologies were used to construct transcriptomic and metabolomic libraries from the roots, stems, and leaves of M. himalaica plants collected from their natural habitat. As a result, each of the transcriptomic libraries from the different tissues was sequenced, generating more than 10 Gb of clean data ultimately assembled into 147,142 unigenes. In the three tissues, metabolomic analysis identified 522 candidate compounds, of which 170 metabolites involved in 114 metabolic pathways were mapped to the KEGG. Of these genes, 61 encoding enzymes were identified to function at key steps of the pathways related to rotenoid biosynthesis, where 14 intermediate metabolites were also located. An integrated analysis of metabolic and transcriptomic data revealed that most of the intermediate metabolites and enzymes related to rotenoid biosynthesis were synthesized in the roots, stems and leaves of M. himalaica, which suggested that the use of non-medicinal tissues to extract compounds was feasible. In addition, the CHS and CHI genes were found to play important roles in rotenoid biosynthesis, especially, since CHS might be an important rate-limiting enzyme. This study provides a hypothetical basis for the screening of new active metabolites and the metabolic engineering of rotenoid in M. himalaica.

Tcf3 represses Wnt-ß-catenin signaling and maintains neural stem cell population during neocortical development.

During mouse neocortical development, the Wnt-ß-catenin signaling pathway plays essential roles in various phenomena including neuronal differentiation and proliferation of neural precursor cells (NPCs). Production of the appropriate number of neurons without depletion of the NPC population requires precise regulation of the balance between differentiation and maintenance of NPCs. However, the mechanism that suppresses Wnt signaling to prevent premature neuronal differentiation of NPCs is poorly understood. We now show that the HMG box transcription factor Tcf3 (also known as Tcf7l1) contributes to this mechanism. Tcf3 is highly expressed in undifferentiated NPCs in the mouse neocortex, and its expression is reduced in intermediate neuronal progenitors (INPs) committed to the neuronal fate. We found Tcf3 to be a repressor of Wnt signaling in neocortical NPCs in a reporter gene assay. Tcf3 bound to the promoter of the proneural bHLH gene Neurogenin1 (Neurog1) and repressed its expression. Consistent with this, Tcf3 repressed neuronal differentiation and increased the self-renewal activity of NPCs. We also found that Wnt signal stimulation reduces the level of Tcf3, and increases those of Tcf1 (also known as Tcf7) and Lef1, positive mediators of Wnt signaling, in NPCs. Together, these results suggest that Tcf3 antagonizes Wnt signaling in NPCs, thereby maintaining their undifferentiated state in the neocortex and that Wnt signaling promotes the transition from Tcf3-mediated repression to Tcf1/Lef1-mediated enhancement of Wnt signaling, constituting a positive feedback loop that facilitates neuronal differentiation.