SSR identification and phylogenetic analysis in four plant species based on complete chloroplast genome sequences.

The effective utilization of traditional Chinese medicine (TCM) has been challenged by the difficulty to accurately distinguish between similar plant varieties. The stability and conservation of the chloroplast genome can aid in resolving genotypes. Previous studies using nuclear sequences and molecular markers have not effectively differentiated the species from related taxa, such as Machilus leptophylla, Hanceola exserta, Rubus bambusarum, and Rubus henryi. This study aimed to characterize the chloroplast genomes of these four plant species, and analyze their simple sequence repeats (SSRs) and phylogenetic positions. The results demonstrated the four chloroplast genomes consisted of 152.624 kb, 153.296 kb, 156.309 kb, and 158.953 kb in length, involving 124, 130, 129, and 131 genes, respectively. They also contained four specific regions with mononucleotide being the class with the most members. Moreover, these repeating types of SSR were various in individual class. Phylogenetic analysis showed that M. leptophylla was clustered with M. yunnanensis, and H. exserta was confirmed as belonging to the family Ocimeae. Additionally, R. bambusarum and R. henryi were grouped together but differed in their SSR features, indicating that they were not the same species. This research provides evidence for resolving species and contributes new genetic information for further studies.

Sijunzi decoction enhances sensitivity of colon cancer cells to NK cell destruction by modulating P53 expression.

ETHNOPHARMACOLOGICAL RELEVANCE: Sijunzi Decoction (SJZD), a traditional Chinese herbal remedy, is frequently employed in the treatment of various cancers, including colon cancer. Previous research suggests that SJZD plays a pivotal role in modulating the immune system and enhancing immunity against tumors. However, the precise role of SJZD in combating colon cancer and its potential molecular functions in regulating natural killer cells remain elusive. AIMS OF THE STUDY: To elucidate the potential mechanism underlying the anticolon cancer effects of SJZD in synergy with natural killer (NK) cells through both in vivo and in vitro experiments. MATERIALS AND METHODS: In vivo experiments: A subcutaneous tumor mouse model of colon cancer and in vivo NK cell depletion experiments were conducted to observe the anticolon cancer effects of SJZD. Flow cytometry assessed immune cell depletion in mouse spleens, while immunohistochemical (IHC) staining detected the expression of apoptotic genes in tumor tissues. In vitro experiments: The mechanism by which SJZD regulates the sensitization of colon cancer cells to NK cells was investigated using real-time polymerase chain reaction (RT-PCR), western blotting (WB), and co-culture experiments with NK cells. RESULTS: Sijunzi Decoction (SJZD) significantly impeded tumor growth in mice; however, NK cell depletion markedly attenuated the tumor-suppressive effect of SJZD. Immunohistochemical (IHC) results indicated that SJZD increased the expression of P53, death receptor 4 (DR4), and death receptor 5 (DR5) in tumor tissues. In vitro experiments, 24 h SJZD-pretreated colon cancer cells showed a substantial elevation in P53, DR4, and DR5 levels, and the activity of colon cancer cells significantly diminished after co-culture with NK cells. These effects of SJZD were reversed with the addition of the P53 inhibitor pifithrin-α (PFT-α), resulting in reduced inhibition of colon cancer cells by NK cells. CONCLUSION: SJZD enhances the levels of DR4 and DR5 through the modulation of P53 expression, consequently increasing the sensitivity of colon cancer cells to NK cell-mediated killing. These findings provide a theoretical foundation for the clinical application of SJZD in patients with colon cancer. In this study, we first investigated the effect of SJZD on subcutaneous tumor growth in mice with colon cancer using in vivo assays and assessed the impact of NK cells on the anticolon cancer effect of SJZD in vivo through NK cell depletion. In vitro experiments were conducted to explore the potential mechanism of action of SJZD in NK cell-mediated anticolon cancer effects.

The complete chloroplast genome sequence of Gynura cusimbua (D. Don) S. Moore.

Gynura cusimbua (D. Don) S. Moore is a favorite food vegetable and traditional folk medicine. The chloroplast genome information, of G. cusimbua, was introduced and released in this study. The complete chloroplast genome was characterized as 156, 684 base pairs (bp) in length. The circle gDNA contained four segments, namely LSC (large single copy), SSC (small single copy) and two IRs (inverted repeats), which was 86, 834 bp and 18, 414 bp and 25, 718 bp in length separately. The total GC content was 36.88%. A total of 125 genes were characterized in the chloroplast genome, where 84, 33 and 8 genes were for coding-proteins, tRNA and rRNA respectively. The phylogeny tree demonstrated that G. cusimbua was clustered with Jacobaea valgaris and Senecio valgaris. This study would fill a vacancy of chloroplast genome information involving G. cusimbua, and provide new genetic resources for the study on Senecioninae.

A Comparative Study of Flavonoids and Carotenoids Revealed Metabolite Responses for Various Flower Colorations Between Nicotiana tabacum L. and Nicotiana rustica L.

Tobacco is a model plant for studying flower coloration. Flavonoids and carotenoids were reported to contribute to the flower color in many plants. We investigated the mechanism underlying flower color formation in tobacco by comparing the profiling flavonoids and carotenoids between various species Nicotiana tabacum L. and Nicotiana rustica L., as their flowers commonly presented red (pink) and yellow (orange), respectively. The metabolomes were conducted by UPLC-ESI-MS/MS system. The main findings were as follows: (1) A total of 31 flavonoids and 36 carotenoids were identified in all four cultivars involved in N. tabacum and N. rustica. (2) Flavonoids and carotenoids tended to concentrate in the red flowers (N. tabacum) and yellow flowers (N. rustica), respectively. (3) About eight flavonoids and 12 carotenoids were primarily screened out for metabolic biomarkers, such as the robust biomarker involving kaempferol-3-o-rut, quercetin-glu, rutin, lutein, and ß-carotene. This is the first research of systematic metabolome involving both flavonoids and carotenoids in tobacco flower coloration. The metabolic mechanism concluded that flavonoids and carotenoids mainly contributed to red (pink) and yellow (orange) colors of the tobacco flowers, respectively. Our finding will provide essential insights into characterizing species and modifying flower color in tobacco breeding through genetic improvement or regulation of featured metabolic synthesis.

Genome-wide characterization on MT family and their expression in response to environmental cues in upland cotton (Gossypium hirsutum L.).

Metallothioneins (MTs) are believed as key metal chelators and scavengers of reactive oxygen species (ROS), which are involved in tolerance and de-toxicity to multiple environmental stresses in plants. The MT gene family was characterized from upland cotton (Gossypium hirsutum L.), compared with its putative genome donors G. arboretum and raimondii. Subsequently, gene functions were predicted by promoter analysis. Moreover, gene expressions subjecting to exogenous stimuli, as well as in terms of developments, were studied. The main findings were shown as follows: 1) 19 GhMTs were identified from G. hirsutum, and the family completely included all four sub-types, namely p1, p2, p3, and pec. Sub-type p2 GhMTs were most conservative in protein motif compositions, gene structures, phylogenic relationships, and group numbers, while p3 GhMTs demonstrated much more diversiform and distant genetic relationships. 2) The GhMT family experienced apparent gene expansion, and the members from the D sub-genome were subjected to stronger environmental selection. 3) GhMTs played differential and overlapped roles in response to environmental cues. 4) GhMT6, GhMT8, and GhMT14 were involved in both vegetative and reproductive developments. These findings must provide valuable insights into understanding the plant MT gene family and novel gene resources for cotton breeding for environmental stresses, phytoremediation, and beyond.

Mercury-Induced Phytotoxicity and Responses in Upland Cotton (Gossypium hirsutum L.) Seedlings.

Cotton is a potential and excellent candidate to balance both agricultural production and remediation of mercury-contained soil, as its main production fiber hardly involves into food chains. However, in cotton, there is known rarely about the tolerance and response to mercury (Hg) environments. In this study, the biochemical and physiological damages, in response to Hg concentrations (0, 1, 10, 50 and 100 µM), were investigated in upland cotton seedlings. The results on germination of cottonseeds indicated the germination rates were suppressed by high Hg levels, as the decrease of percentage was more than 10% at 1000 µM Hg. Shoots and roots' growth were significantly inhibited over 10 µM Hg. The inhibitor rates (IR) in fresh weight were close in values between shoots and roots, whereas those in dry weight the root growth were more obviously influenced by Hg. In comparison of organs, the growth inhibition ranked as root > leaf > stem. The declining of translocation factor (TF) opposed the Hg level as even low to 0.05 at 50 µM Hg. The assimilation in terms of photosynthesis, of cotton plants, was affected negatively by Hg, as evidenced from the performances on pigments (chlorophyll a and b) and gas exchange (Intercellular CO2 concentration (Ci), CO2 assimilation rate (Pn) and stomatal conductance (Gs)). Sick phenotypes on leaf surface included small white zone, shrinking and necrosis. Membrane lipid peroxidation and leakage were Hg dose-dependent as indicated by malondialdehyde (MDA) content and relative conductivity (RC) values in leaves and roots. More than 10 µM Hg damaged antioxidant enzyme system in both leaves and roots (p < 0.05). Concludingly, 10 µM Hg post negative consequences to upland cotton plants in growth, physiology and biochemistry, whereas high phytotoxicity and damage appeared at more than 50 µM Hg concentration.