Integrative genome, transcriptome, microRNA, and degradome analysis of water dropwort (Oenanthe javanica) in response to water stress

Water dropwort (Liyang Baiqin, Oenanthe javanica (BI.) DC.) is an aquatic perennial plant from the Apiaceae family with abundant protein, dietary fiber, vitamins, and minerals. It usually grows in wet soils and can even grow in water. Here, whole-genome sequencing of O. javanica via HiSeq 2000 sequencing technology was reported for the first time. The genome size was 1.28 Gb, including 42,270 genes, of which 93.92% could be functionally annotated. An online database of the whole-genome sequences of water dropwort, Water dropwortDB, was established to share the results and facilitate further research on O. javanica (database homepage: http://apiaceae.njau.edu.cn/waterdropwortdb). Water dropwortDB offers whole-genome and transcriptome sequences and a Basic Local Alignment Search Tool. Comparative analysis with other species showed that the evolutionary relationship between O. javanica and Daucus carota was the closest. Twenty-five gene families of O. javanica were found to be expanded, and some genetic factors (such as genes and miRNAs) related to phenotypic and anatomic differentiation in O. javanica under different water conditions were further investigated. Two miRNA and target gene pairs (miR408 and Oja15472, miR171 and Oja47040) were remarkably regulated by water stress. The obtained reference genome of O. javanica provides important information for future work, thus making in-depth genetic breeding and gene editing possible. The present study also provides a foundation for the understanding of the O. javanica response to water stress, including morphological, anatomical, and genetic differentiation.

COMPARISON OF ANTIOXIDANT ACTIVITIES OF TESPONG HERBAL (OENANTHE JAVANICA DC.) EXTRACT AND NANOEXTRACT USING DPPH METHOD

Background: Tespong herbs (O. Javanica DC.) contain numerous chemical compounds considered beneficial for medications, including flavonoids, phenols, and tannins, which can function as antioxidants. Nanoparticles are materials with a size range of 1-1000 nanometers which can increase the bioavailability of drugs, thus accelerating the drug delivery system in the body. Objective: The aim of this study is to identify the characteristics of herbal extract and nanoextract of Tespong and to compare their antioxidant activity. Methods: Extraction of tespong herbs was done using maceration for three days, nanoextract was formulated using the ionic gelation method with herbal extract of tespong, chitosan, and Na-TPP. Antioxidant activity testing was carried out using the DPPH method. Results: The water content of tespong herbal extract was 1.78%, and the total ash content was 4.95%. The tespong herbal nanoextract was 148.1nm in diameter with a polydispersity index of 0.362 and a zeta potential value of -39.16 mV. The IC50 values of tespong herbal extract and nanoextract were 65.424 ppm and 97.106 ppm, respectively, which fell into the strong category. Conclusion: Tespong herbal extract had a higher antioxidant activity compared to its nanoextract. Keywords: Tespong herb, nanoextract, chitosan, Na-TPP

Effect of Salt Stress on Growth, Physiological Parameters, and Ionic Concentration of Water Dropwort (Oenanthe javanica) Cultivars

Salt stress is an important environmental limiting factor. Water dropwort (Oenanthe javanica) is an important vegetable in East Asia; however, its phenotypic and physiological response is poorly explored. For this purpose, 48 cultivars of water dropwort were grown hydroponically and treated with 0, 50, 100, and 200 mm NaCl for 14 days. Than their phenotypic responses were evaluated, afterward, physiological studies were carried out in selected sensitive and tolerant cultivars. In the present study, the potential tolerant (V11E0022) and sensitive (V11E0135) cultivars were selected by screening 48 cultivars based on their phenotype under four different levels of salt concentrations (0, 50, 100, and 200 mm). The results depicted that plant height, number of branches and leaves were less effected in V11E0022, and most severe reduction was observed in V11E0135 in comparison with others. Than the changes in biomass, ion contents, accumulation of reactive oxygen species, and activities of antioxidant enzymes and non-enzymatic antioxidants were determined in the leaves and roots of the selected cultivars. The potential tolerant cultivar (V11E0022) showed less reduction of water content and demonstrated low levels of Na+ uptake, malondialdehyde, and hydrogen peroxide (H2O2) in both leaves and roots. Moreover, the tolerant cultivar (V11E0022) showed high antioxidant activities of ascorbate peroxidase (APX), superoxide dismutase, peroxidase, catalase (CAT), reduced glutathione (GSH), and high accumulation of proline and soluble sugars compared to the sensitive cultivar (V11E0135). These results suggest the potential tolerance of V11E0022 cultivar against salt stress with low detrimental effects and a good antioxidant defense system. The observations also suggest good antioxidant capacity of water dropwort against salt stress. The findings of the present study also suggest that the number of branches and leaves, GSH, proline, soluble sugars, APX, and CAT could serve as the efficient markers for understanding the defense mechanisms of water dropwort under the conditions of salt stress.

Flavonolignan 2, 3-dehydroderivatives from Oenanthe javanica and their anti inflammatory activities

Flavonolignans, for example, silymarin and silybin, have interesting biological activities. For the first time, three new flavonolignans named oenanthenoid A-C (1–3) and nine known flavonolignan derivatives (4–12) were isolated from Oenanthe javanica. Comprehensive spectroscopic data analysis and references were used to identify all of the compounds. The anti inflammatory activities of these isolates (1–12) on RAW264.7 macrophage cells were investigated. Three new compounds (1–3) demonstrated anti inflammatory activity with IC50 values ranging from 6.5 ± 0.6 to 14.7 ± 1.6 µM. Furthermore, two compounds (11 and 12) demonstrated moderate anti inflammatory activity, with IC50 values ranging from 24.1 ± 1.2 to 62.5 ± 1.9 µM.

Purification Efficiency of Eight Aquatic Plant Species in an Artificial Floating Island System in Relation to Extracellular Enzyme Activity and Microbial Community

An artificial floating island is an ecological restoration technology that aims to create sustainable ecosystems and improve biodiversity. Aquatic plants play an important role in wastewater purification. The floating island system exploits the combination of aquatic plants, microorganisms, and extracellular enzymes to purify wastewater. We investigated the purification efficiency of eight aquatic plant species (Ceratophyllum demersum, Elodea nuttallii, Eichhornia crassipes, lris pseudacorus, lris sibirica, Myriophyllum verticillatum, Thalia dealbata and Oenanthe javanica) cultured in wastewater. The relationships of plant purification capacity with extracellular enzyme activity and microbial community were analyzed to explore the crucial factors that affect the plant purification capacity and the mechanism of pollutants removal in different plant systems. Three plant species, namely Oenanthe javanica, Thalia dealbata, and lris pseudacorus, were the most effective for purification of ammonium-nitrogen (NH4+-N), total phosphate (TP), and chemical oxygen demand (COD) with maximum efficiencies of 76.09%, 85.87%, and 89.10%, respectively. Urease, alkaline phosphatase (AP), and β-glucosidase activities were significantly and positively correlated with root system development (P < 0.05). Activities of urease and AP were positively correlated with NH4+-N and TP removal, respectively. The magnitude of urease and AP activity was generally consistent with the plant’s capacity to remove NH4+-N and TP. β-Glucosidase activity and COD removal were not significantly correlated. The dominant microbial phylum in each species treatment was Proteobacteria. Alphaproteobacteria and Bacteroidia showed > 1% relative abundance and greater involvement in degradation of pollutants in the experimental system. The results provide a scientific and theoretical basis for improvement of the plant purification efficiency of artificial floating island systems.

Phenotypic, Nutritional, and Antioxidant Characterization of Blanched Oenanthe javanica for Preferable Cultivar

Blanching is a technique used in blocking sunlight for the production of tender, sweet, and delicious stems in the field. This technique is also used in water dropwort (Oenanthe javanica), an important vegetable in East Asia. In China, the steamed stems of water dropwort are prepared with boiled rice. However, the effect of blanching on the nutritional level and antioxidant capacity of water dropwort has not been explored yet. The current study aims to determine the nutrient contents and antioxidant capacities of five cultivars and select the best cultivar. They were mainly compared in terms of phenotypic, physiological, nutritional, and antioxidant levels after blanch cultivation. Results indicate that blanching significantly influenced the phenotype, physiology, and nutritional level of water dropwort in all cultivars. Although few parameters decreased with blanching, starch, sugars, vitamins, minerals, and antioxidant activities increased significantly in the blanched stems in mid- and post-blanching periods. The most noticeable changes were detected in post-blanching samples. Furthermore, the best cultivar (V11E0012) was identified among them. Therefore, blanched water dropwort could be consumed for achieving more nutraceuticals and antioxidants, and cultivar V11E0012 could be recommend for blanching cultivation.

Hyaluronidase and degranulation inhibitors from the edible roots of Oenanthe javanica including seric acids F and G that were obtained by heating

ABSTRACT Oenanthe javanica is a vegetable grown in East Asia and Australia in which the roots and aerial parts are boiled together to make certain traditional dishes. Nineteen compounds (1-19) were isolated from O. javanica roots and the chemical structures of 2 new norlignans were determined. The inhibitory effects of the compounds on hyaluronidase and degranulation in RBL-2H3 cells were evaluated to determine antiallergic and antiinflammation activities. Saponins (2-4) and the new norlignan seric acid G (12) were among the active compounds identified. Seric acid G (12), a methoxy derivative of seric acid F (11), was obtained as an interconverting mixture of 3:1 trans-cis isomers. Seric acids F and G (11, 12) were derived from seric acids C (10) and E, respectively, by decarboxylation and dehydration reactions that occurred during heating. It was confirmed by HPLC analysis that all eleven of the O. javanica cultivars contained seric acid C (10).