Antioxidant Activity of Phenolic Extraction from Different Sweetpotato (Ipomoea batatas (L.) Lam.) Blades and Comparative Transcriptome Analysis Reveals Differentially Expressed Genes of Phenolic Metabolism in Two Genotypes

Transcriptome-Based WGCNA Analysis Reveals the Mechanism of Drought Resistance Differences in Sweetpotato (Ipomoea batatas (L.) Lam.)

Sweetpotato (Ipomoea batatas (L.) Lam.) is a globally significant storage root crop, but it is highly susceptible to yield reduction under severe drought conditions. Therefore, understanding the mechanism of sweetpotato resistance to drought stress is helpful for the creation of outstanding germplasm and the selection of varieties with strong drought resistance. In this study, we conducted a comprehensive analysis of the phenotypic and physiological traits of 17 sweetpotato breeding lines and 10 varieties under drought stress through a 48 h treatment in a Hoagland culture medium containing 20% PEG6000. The results showed that the relative water content (RWC) and vine-tip fresh-weight reduction (VTFWR) in XS161819 were 1.17 and 1.14 times higher than those for the recognized drought-resistant variety Chaoshu 1. We conducted RNA-seq analysis and weighted gene co-expression network analysis (WGCNA) on two genotypes, XS161819 and 18-12-3, which exhibited significant differences in drought resistance. The transcriptome analysis revealed that the hormone signaling pathway may play a crucial role in determining the drought resistance in sweetpotato. By applying WGCNA, we identified twenty-two differential expression modules, and the midnight blue module showed a strong positive correlation with drought resistance characteristics. Moreover, twenty candidate Hub genes were identified, including g47370 (AFP2), g14296 (CDKF), and g60091 (SPBC2A9), which are potentially involved in the regulation of drought resistance in sweetpotato. These findings provide important insights into the molecular mechanisms underlying drought resistance in sweetpotato and offer valuable genetic resources for the development of drought-resistant sweetpotato varieties in the future.

Phytochemical Profile and Biological Activities of Different Extracts of Three Parts of Paliurus spina-christi: A Linkage between Structure and Ability

Paliurus spina-christi Mill., a member of the Rhamnaceae family, is a traditionally used medicinal plant in the management of a panoply of human ailments. The current research focused on its phytochemical profile and biological properties evaluated by its antioxidant and enzyme inhibitory properties. The methanol extract was found to be the most effective antioxidant as evidenced by its DPPH and ABTS scavenging activities, cupric and ferric reducing power (CUPRAC and FRAP), and high activity in phosphomolybdenum (PBD) assay, and also displayed the highest anti-tyrosinase activity. The n-hexane extract was the most effective AChE inhibitor (8.89 ± 0.08 mg GALAE/g) followed by the methanol (8.64 ± 0.01 mg GALAE/g) while the latter showed the highest BChE inhibition (2.50 ± 0.05 mg GALAE/g). Among the different solvent extracts of the stem, the methanolic extract showed highest antioxidant activity in the following assays: DPPH (909.88 ± 4.25 mg TE/g), ABTS (3358.33 ± 51.14 mg TE/g), CUPRAC (781.88 ± 16.37 mg TE/g), FRAP (996.70 ± 47.28 mg TE/g), and PBD (4.96 ± 0.26 mmol TE/g), while the dichloromethane extract showed the highest MCA (28.80 ± 0.32 mg EDTAE/g). The methanol extracts revealed the highest TPC and TFC among the different solvents used, and as for plant part, the stem extracts had the highest TPC ranging from 22.36 ± 0.26 to 121.78 ± 1.41 (mg GAE/g), while the leaf extracts showed the highest TFC ranging from 8.43 ± 0.03 to 75.36 ± 0.92 (mg RE/g). Our findings tend to provide additional scientific evidence on the biological and chemical activities of P. spina-christi, which may serve as a source of naturally occurring bioactive chemicals with potential biomedical applications.