In this study, polysaccharides were extracted at a rate of 87.5% ± 1.5% from native dandelion roots, and the dandelion root polysaccharides (DRPs) were then chemically modified to obtain sulfated polysaccharides (SDRPs) with a degree of substitution of 1.49 ± 0.07. The effects of modification conditions, physicochemical characterizations, structural characteristics, antioxidant properties, hypoglycemic activity, and proliferative effects on probiotics of DRP derivatives were further investigated. Results showed that the optimum conditions for sulfation of DRPs included esterification reagents (concentrated sulfuric acid: n-butanol) ratio of 3:1, a reaction temperature of 0 °C, a reaction time of 1.5 h, and the involvement of 0.154 g of ammonium sulfate. The DRPs and SDRPs were composed of six monosaccharides, including mannose, glucosamine, rhamnose, glucose, galactose, and arabinose. Based on infrared spectra, the peaks of the characteristic absorption bands of S=O and C-O-S appeared at 1263 cm⁻¹ and 836 cm⁻¹. Compared with DRPs, SDRPs had a significantly lower relative molecular mass and a three-stranded helical structure. NMR analysis showed that sulfated modification mainly occurred on the hydroxyl group at C6. SDRPs underwent a chemical shift to higher field strength, with their characteristic signal peaking in the region of 1.00–1.62 ppm. Scanning electron microscopy (SEM) analysis indicated that the surface morphology of SDRPs was significantly changed. The structure of SDRPs was finer and more fragmented than DRPs. Compared with DRPs, SDRPs showed better free radical scavenging ability, higher Fe²⁺chelating ability, and stronger inhibition of α-glucosidase and α-amylase. In addition, SDRPs had an excellent promotional effect on the growth of Lactobacillus plantarum 10665 and Lactobacillus acidophilus. Therefore, this study could provide a theoretical basis for the development and utilization of DRPs.

The extraction of total flavonoids from Hylotelephium spectabile (Boreau) H. Ohba (H. spectabile) leaves was studied through the use of a double enzyme-assisted ultrasonic method, and the extraction process was optimized using the Box–Behnken design. Eight different macroporous resins were screened for purification in single-factorial experiments, and the flavonoid compounds in the extract of H. spectabile leaves were identified using HPLC-MS. Through the evaluation of the total reducing capacity and capacity for reducing 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH), hydroxyl radicals (·OH), and 2,2’-biazobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), the in vitro antioxidant activities of the crude extracts of the total flavonoids and purified total flavonoids of H. spectabile leaves were investigated. The results showed that the most efficient conditions for flavonoid extraction were an ultrasonic extraction time of 60 min, an ethanol concentration of 35%, a liquid-to-material ratio of 20:1 mL/g, and an amount of enzyme (cellulose/pectinase = 1:1) of 1.5%, forming H. spectabile powder. Under these conditions, the total flavonoid extraction rate in the H. spectabile leaf extract was 4.22%. AB-8 resin showed superior performance in terms of purification, and the optimal adsorption and desorption times were 1.5 h and 3 h, respectively. The recommended parameters for purification included a liquid volume of 5.5 BV, a flow rate of 1.2 BV/min, a pH of 5, and a concentration of 0.8 mg/mL. The observed order for reducing capacity was ascorbic acid (VC) > rutin > purified total flavonoids > crude extract of total flavonoids. The purified total flavonoid extract from H. spectabile showed a good scavenging ability against DPPH, ·OH, and ABTS^·+, suggesting strong antioxidant activity. Therefore, this study can serve as technical support and reference data for the further development and utilization of H. spectabile resources.

Salt stress is a significant environmental factor influencing plant growth and development. Anoectochilus roxburghii is a valuable medicinal plant, but it is still unclear how it responds to salinity. In this study, A. roxburghii was used as experimental material to investigate its physiological mechanisms underlying salt stress resistance. Seedlings were subjected to various NaCl concentrations (0, 50, 100, 150, and 200 mmol/L), and changes in key physiological parameters were subsequently analyzed. The results indicated that under NaCl-induced salt stress, the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), as well as soluble protein content, initially increased and then decreased, with peak levels observed between 100 and 150 mmol/L. Malondialdehyde (MDA) content exhibited a steady increase with rising salt concentration. Total chlorophyll content declined progressively, while anthocyanin content increased initially but decreased significantly when NaCl concentration exceeded 100 mmol/L. Additionally, the contents of total flavonoids and total phenolics decreased markedly at salt concentrations above 100 mmol/L. These findings suggest that A. roxburghii can tolerate salt stress up to 100 mmol/L for 24 h without exhibiting substantial physiological or morphological damage. This study provides a theoretical basis for analyzing the salt tolerance mechanism of A. roxburghii.

Using the current method to screen and analyze the resistant mutant of Arabidopsis thaliana, there is a problem that the antioxidant capacity is poor. In this paper, an efficient algorithm for screening resistant mutants of Arabidopsis thaliana in vitro is proposed. In this study, the Arabidopsis thaliana selenium-resistant mutants are extracted and by combining the in vitro extraction, the in vitro screening method is used to screen the Selenium-resistant mutants of Arabidopsis thaliana, so as to realize the in vitro screening method research and analysis for Arabidopsis thaliana. The experimental results show that the algorithm can effectively improve the selenium resistant of Arabidopsis thaliana.

Using Sedum spectabile boreau flowers as raw material, single factor and Box-Behnken response surface test were used to optimize the extraction conditions of Sedum spectabile boreau flavone assisted by ultrasonic enzymatic method, and the antioxidant activity of Sedum spectabile boreau flavone was analyzed in vitro. The results showed that the optimal extraction conditions of total Sedum spectabile boreau flavonoids were ultrasonic action time of 60 min, ethanol concentration of 35%, liquid-solid ratio (ml /g) was 20:1, and the amount of enzyme (cellulase: pectinase =1:1) was 3.2g.The study on the antioxidant activity of total flavonoids of Sedum spectabile boreau flower showed that its antioxidant capacity was gradually enhanced with the increase of the mass concentration of the test, which had a certain dose-effect relationship.

Although previous studies have indicated that heme oxygenase 1 (HO1/HY1) regulates the flowering time via the photoperiod pathway, the specific mechanism is still elusive. Here, we found that the Arabidopsis hy1-100 mutant displayed early flowering, and the characteristic expression patterns of several master genes involved in the autonomous pathway were altered. Notably, the transcript levels of FLOWERING LOCUS C (AtFLC) gene declined developmentally in both wild-type and hy1-100 mutant, with a more pronounced fold reduction observed in the mutant. Genetic evidence further underlined that hy1-100/FLCOE plants partially reversed the early flowering phenomenon of hy1-100 mutant, suggesting that AtHO1 regulated flowering at least partially through the AtFLC-involved autonomous pathway, as supported by changes in FLOWERING LOCUS T (AtFT) and SUPPRESSOR OF OVEREXPRESSION OF CO1 (AtSOC1) transcripts. Further analysis of hy1-100/ft mutants revealed that hy1-100/ft and ft mutants displayed similar late flowering phenotypes, accompanied by downregulated APETALA1 (AtAP1) and AtSOC1, indicating that AtFT played a crucial role in AtHO1-regulated flowering. Two key conclusions are drawn: first, the loss of AtHO1 function promotes early flowering in Arabidopsis, which was genetically linked to the autonomous pathway regulating AtFLC expression; second, AtFT was an essential downstream factor mediating AtHO1-regulated flowering.