Influence of new effective allelochemicals on the distribution of Cleome arabica L. community in nature

Analysis Transcriptome and Phytohormone Changes Associated with the Allelopathic Effects of Ginseng Hairy Roots Induced by Different-Polarity Ginsenoside Components

The allelopathic autotoxicity of ginsenosides is an important cause of continuous cropping obstacles in ginseng planting. There is no report on the potential molecular mechanism of the correlation between polarity of ginsenoside components and their allelopathic autotoxicity. This study applied a combination of metabolomics and transcriptomics analysis techniques, combined with apparent morphology, physiological indexes, and cell vitality detection of the ginseng hairy roots, through which the molecular mechanism of correlation between polarity and allelopathic autotoxicity of ginsenosides were comprehensively studied. The hairy roots of ginseng presented more severe cell apoptosis under the stress of low-polarity ginsenoside components (ZG70). ZG70 exerted allelopathic autotoxicity by regulating the key enzyme genes of cis-zeatin (cZ) synthesis pathway, indole-3-acetic acid (IAA) synthesis pathway, and jasmonates (JAs) signaling transduction pathway. The common pathway for high-polarity ginsenoside components (ZG50) and ZG70 to induce the development of allelopathic autotoxicity was through the expression of key enzymes in the gibberellin (GA) signal transduction pathway, thereby inhibiting the growth of ginseng hairy roots. cZ, indole-3-acetamid (IAM), gibberellin A1 (GA1), and jasmonoyl-L-isoleucine (JA-ILE) were the key response factors in this process. It could be concluded that the polarity of ginsenoside components were negatively correlated with their allelopathic autotoxicity.

Desert Endemic Plants in Algeria: A Review on Traditional Uses, Phytochemistry, Polyphenolic Compounds and Pharmacological Activities

Due to their robust antioxidant capabilities, potential health benefits, wide variety of biological activities, and strong antioxidant qualities, phenolic compounds are substances that have drawn considerable attention in recent years. The main goal of the review is to draw attention to saharian Algerian medicinal plants and the determination of their bioactivity (antioxidant, anti-cancer, and anti-inflammatory importance), and to present their chemical composition as well as in vivo and in vitro studies, clinical studies, and other studies confirming their real impact on human health. Research results have revealed a rich variety of medicinal plants used to treat various disease states in this region. Based on in vivo and in vitro studies, biological activity, and clinical studies, a list of 34 species of desert plants, belonging to 20 botanical families, useful both in preventive actions and in the treatment of neoplastic diseases has been established, and polyphenolic compounds have been identified as key to the health potential of endemic diseases and desert plants. It has been shown that people who follow a diet rich in polyphenols are less prone to the risk of many cancers and chronic diseases, such as obesity and diabetes. In view of the increasing antioxidant potential of these plant species, as well as the increasing trade in herbal products from the Sahara region, phytosanitary and pharmaceutical regulations must change in this respect and should be in line with Trade Related Aspects of Intellectual Property Rights (TRIPS), and the sustainable use and development of plant products must be addressed at the same time.

Regulatory network of ginsenoside biosynthesis under Ro stress in the hairy roots of Panax ginseng revealed by RNA sequencing

P. ginseng C.A. Meyer is a valuable Chinese herbal medicine that belongs to the Araliaceae family. Major obstacles to the continuous cropping of ginseng have severely restricted the sustainable development of the ginseng industry. The allelopathic effects of triterpenoid saponins play an important role in disorders related to continuous cropping; however, the mechanisms underlying the allelopathic autotoxicity of triterpenoid ginsenosides remain unknown. In this study, we performed mRNA and miRNA sequencing analyses to identify candidate genes and miRNAs that respond differentially to ginsenoside Ro stress in ginseng and their targets. The growth of the ginseng hairy roots was significantly inhibited under Ro stress (0.5 mg/L, Ro-0.5). The inhibition of root growth and injury to root-tip cells promoted the accumulation of the endogenous hormones indole-3-acetic acid and salicylic acid and inhibited the accumulation of abscisic acid and jasmonate acid. The accumulation of ginsenosides, except Rg3, was significantly inhibited under Ro-0.5 stress. An mRNA analysis of the Ro-0.5 and control groups showed that differentially expressed genes were mostly concentrated in the hormone signal transduction pathway. ARF7 and EFM were upregulated, whereas XTH23 and ZOX1 were downregulated. These genes represent important potential candidates for hormone-responsive continuous cropping diseases. In total, 74 differentially expressed miRNAs were identified based on the miRNA sequencing analysis, of which 22 were upregulated and 52 were downregulated. The target genes of ptc-miR156k_L + 1, mtr-miR156b-5p, gma-miR156a_R + 1, and mtr-miR156e all belonged to TRINITY_DN14567_c0_g4, which is a gene in the plant hormone signal transduction pathway. These four miRNAs were all negatively correlated with mRNA, indicating their likely involvement in the response of ginseng to continuous cropping disorders and the regulation of ginsenoside synthesis. Our findings provide useful insights for removing the barriers to continuous ginseng cropping and have important implications in the genetic engineering of plant stress responses.

Elshamy A. Chemical Composition, Allelopathic, Antioxidant, and Anti-Inflammatory Activities of Sesquiterpenes Rich Essential Oil of Cleome amblyocarpa Barratte & Murb

The integration of green natural chemical resources in agricultural, industrial, and pharmaceutical applications allures researchers and scientistic worldwide. Cleome amblyocarpa has been reported as an important medicinal plant. However, its essential oil (EO) has not been well studied; therefore, the present study aimed to characterize the chemical composition of the C. amblyocarpa, collected from Egypt, and assess the allelopathic, antioxidant, and anti-inflammatory activities of its EO. The EO of C. amblyocarpa was extracted by hydrodistillation and characterized via gas chromatography–mass spectrometry (GC-MS). The chemometric analysis of the EO composition of the present studied ecospecies and the other reported ecospecies was studied. The allelopathic activity of the EO was evaluated against the weed Dactyloctenium aegyptium. Additionally, antioxidant and anti-inflammatory activities were determined. Forty-eight compounds, with a prespondence of sesquiterpenes, were recorded. The major compounds were caryophyllene oxide (36.01%), hexahydrofarnesyl acetone (7.92%), alloaromadendrene epoxide (6.17%), myrtenyl acetate (5.73%), isoshyobunone (4.52%), shyobunol (4.19%), and trans-caryophyllene (3.45%). The chemometric analysis revealed inconsistency in the EO composition among various studied ecospecies, where it could be ascribed to the environmental and climatic conditions. The EO showed substantial allelopathic inhibitory activity against the germination, seedling root, and shoot growth of D. aegyptium, with IC₅₀ values of 54.78, 57.10, and 74.07 mg L⁻¹. Additionally, the EO showed strong antioxidant potentiality based on the IC₅₀ values of 4.52 mg mL⁻¹ compared to 2.11 mg mL⁻¹ of the ascorbic acid as standard. Moreover, this oil showed significant anti-inflammation via the suppression of lipoxygenase (LOX) and cyclooxygenases (COX1, and COX2), along with membrane stabilization. Further study is recommended for analysis of the activity of pure authentic materials of the major compounds either singularly or in combination, as well as for evaluation of their mechanism(s) and modes of action as antioxidants or allelochemicals.

Unravelling triterpene biosynthesis through functional characterization of an oxidosqualene cyclase (OSC) from Cleome arabica L

Cleome arabica is a medicinal plant contains diverse bioactive compounds and terpenoids are the major components. However, the isolation and purification of the active triterpenes from this plant involve long and complicated procedures. The present work investigates the triterpenes profiles of different tissues, besides that, describes the isolation, heterologous expression and functional characterization of C. arabica gene coding for triterpenes synthases. The phytochemical investigation through GC-MS revealed significant accumulation of pentacyclic triterpenes in leaves and siliques at mature stage compared to the stems and roots of C. arabica. Among the pentacyclic triterpenes, the lupeol reached the highest level of 320 μg/g DW in leaves at maturity stage compared to the other tissues. The biosynthesis of a pentacyclic triterpene was investigated through isolation and cloning of a full-length oxidosqualene cyclase cDNA (CaOSC) from mature leaves of C. arabica. The bioinformatic analyses revealed that CaOSC was highly homologous with the characterized lupeol synthases and shared 79.3% identity to camelliol C synthase from A. thaliana. Heterologous expression of CaOSC gene in Saccharomyces cerevisiae synthesized lupeol as a single product. The lupeol biosynthesis was exponentially increased after induction through the fermentation process reaching the maximum of 2.33 μg/ml for 240 h. Furthermore, organ-specific expression of lupeol gene was exactly matched the accumulation pattern in different tissues of C. arabica during phenological cycle. Thus, the identified CaOSC will be useful in enhancing triterpene yield for industrial purposes.