Bulbil initiation: a comprehensive review on resources, development, and utilisation, with emphasis on molecular mechanisms, advanced technologies, and future prospects.

Bulbil is an important asexual reproductive structure of bulbil plants. It mainly grows in leaf axils, leaf forks, tubers and the upper and near ground ends of flower stems of plants. They play a significant role in the reproduction of numerous herbaceous plant species by serving as agents of plant propagation, energy reserves, and survival mechanisms in adverse environmental conditions. Despite extensive research on bulbil-plants regarding their resources, development mechanisms, and utilisation, a comprehensive review of bulbil is lacking, hindering progress in exploiting bulbil resources. This paper provides a systematic overview of bulbil research, including bulbil-plant resources, identification of development stages and maturity of bulbils, cellular and molecular mechanisms of bulbil development, factors influencing bulbil development, gene research related to bulbil development, multi-bulbil phenomenon and its significance, medicinal value of bulbils, breeding value of bulbils, and the application of plant tissue culture technology in bulbil production. The application value of the Temporary Immersion Bioreactor System (TIBS) and Terahertz (THz) in bulbil breeding is also discussed, offering a comprehensive blueprint for further bulbil resource development. Additionally, additive, seven areas that require attention are proposed: (1) Utilization of modern network technologies, such as plant recognition apps or websites, to collect and identify bulbous plant resources efficiently and extensively; (2) Further research on cell and tissue structures that influence bulb cell development; (3) Investigation of the network regulatory relationship between genes, proteins, metabolites, and epigenetics in bulbil development; (4) Exploration of the potential utilization value of multiple sprouts, including medicinal, ecological, and horticultural applications; (5) Innovation and optimization of the plant tissue culture system for bulbils; (6) Comprehensive application research of TIBS for large-scale expansion of bulbil production; (7) To find out the common share genetics between bulbils and flowers.

First Report of Brown Leaf Rot Disease on Dendrobium nobile Caused by Xylaria flabelliformis in Guizhou Province, China.

Dendrobium nobile is the largest species of the Orchidaceae family and produces dendrobine, a compound with medicinal properties (Sarsaiya et al., 2020a; Sarsaiya et al., 2024; Qian et al., 2024). The accumulation of dendrobine in D. nobile is regulated by various pathogenic fungi, which directly and indirectly influence dendrobine biosynthesis (Sarsaiya et al., 2019a; Sarsaiya et al., 2019b). In a field planted with D. nobile in Guizhou Province, China, small lesions were initially observed on the upper part of the leaves from May to June 2019, which later developed into larger brown necrotic leaf lesions. Over time, these lesions greatly impacted the medicinal value (dendrobine) and productivity of the plant. A pure culture of Xylaria flabelliformis from infected wild D. nobile leaves was recovered and subsequently cultured on potato dextrose agar (PDA) at 25 °C for 5 days. Xylaria flabelliformis grew slowly and was composed of white mycelia. Colonies were initially white, with a regular margin, and formed stromata that consisted of mycelia sterilia without ascospores. We identified the strain as Xylaria flabelliformis based on its morphological characteristics (Liu et al., 2007) and by sequencing elongation factor-1α (EF-1α). The length of the DNA sequence of EF-1α that was used for the analysis of Xylaria flabelliformis was 1188 bp. BLASTx (nucleotide 6-frame translation-protein) analysis using the National Center for Biotechnology Information database showed that the obtained protein sequence (BLASTx protein accession no.: UTS95822.1, BLASTn nucleotide sequence accession no.: MW508334.1) had the highest similarity (98.21%) with the X. flabelliformis hypothetical protein (TRX95197.1) based on a thorough phylogenetic comparison with other Xylaria species. Healthy D. nobile seedlings were planted in pots and sterilized. The terminal leaves were excised from all pre-sterilised D. nobile seedlings and inoculated with Xylaria flabelliformis mycelial plugs, whereas sterile PDA plugs and moist cotton plugs were used as controls. All seedlings were maintained under optimum temperature and humidity conditions (25 °C and 80%, respectively) for seven days for observation and analysis. All experiments were performed in triplicate. After the incubation period, brown leaf rot lesions were observed for the first time on the inoculated D. nobile leaves, but no symptoms were observed on the leaves of the two control groups (sterile PDA plugs and moist cotton plugs). To complete Koch's postulates, Xylaria flabelliformis was re-isolated and identified from all diseased tissues by DNA sequencing of the EF-1α. It was determined for the first time that Xylaria flabelliformis can cause brown leaf lesions in D. nobile. Moreover, the pathogenicity of Xylaria flabelliformis in D. nobile has not been previously reported (Mead et al., 2019; Meng et al., 2019; Sarsaiya et al., 2019a; Sarsaiya et al., 2020b; Chen et al., 2023; Rinchen, 2023; Cao et al., 2024). To the best of our knowledge, this is the first report of BLRS lesions in D. nobile leaves caused by Xylaria flabelliformis in Guizhou Province, China. Identification of Xylaria flabelliformis as a pathogen of D. nobile is crucial for advancing effective management and control practices against brown leaf rot disease. This discovery provides valuable insights into the development of targeted strategies to mitigate the impact of Xylaria flabelliformis on D. nobile, safeguard medicinal properties such as dendrobine, and enhance overall productivity.

Enhancing dendrobine production in Dendrobium nobile through mono-culturing of endophytic fungi, Trichoderma longibrachiatum (MD33) in a temporary immersion bioreactor system.

Introduction: Dendrobine, a valuable alkaloid found in Dendrobium nobile, possesses significant pharmaceutical potential. Methods: In this study, we explored innovative approaches to enhance dendrobine production by utilizing endophytic fungi in a Temporary Immersion Bioreactor System (TIBS, Nanjing BioFunction Co. Ltd., China) and traditional test bottles. Dendrobine was unequivocally identified and characterised in D. nobile co-culture seedlings through UHPLC analysis and LC-MS qTOF analysis, supported by reference standards. Results: The CGTB (control group) and EGTB (experimental group) 12-month-old D. nobile seedlings exhibited similar peak retention times at 7.6±0.1 minutes, with dendrobine identified as C16H25NO2 (molecular weight 264.195). The EGTB, co-cultured with Trichoderma longibrachiatum (MD33), displayed a 2.6-fold dendrobine increase (1804.23 ng/ml) compared to the CGTB (685.95 ng/ml). Furthermore, a bioanalytical approach was applied to investigate the mono-culture of T. longibrachiatum MD33 with or without D. nobile seedlings in test bottles. The newly developed UHPLC-MS method allowed for dendrobine identification at a retention time of 7.6±0.1 minutes for control and 7.6±0.1 minutes for co-culture. Additionally, we explored TIBS to enhance dendrobine production. Co-culturing D. nobile seedlings with Trichoderma longibrachiatum (MD33) in the TIBS system led to a substantial 9.7-fold dendrobine increase (4415.77 ng/ml) compared to the control (454.01 ng/ml) after just 7 days. The comparative analysis of dendrobine concentration between EGTB and EGTIBS highlighted the remarkable potential of TIBS for optimizing dendrobine production. Future research may focus on scaling up the TIBS approach for commercial dendrobine production and investigating the underlying mechanisms for enhanced dendrobine biosynthesis in D. nobile. The structural elucidation of dendrobine was achieved through 1H and 13C NMR spectroscopy, revealing a complex array of proton environments and distinct carbon environments, providing essential insights for the comprehensive characterization of the compound. Discussion: These findings hold promise for pharmaceutical and industrial applications of dendrobine and underline the role of endophytic fungi in enhancing secondary metabolite production in medicinal plants.

Unveiling terahertz wave stress effects and mechanisms in Pinellia ternata: Challenges, insights, and future directions.

This review aims to elucidate the intricate effects and mechanisms of terahertz (THz) wave stress on Pinellia ternata, providing valuable insights into plant responses. The primary objective is to highlight the imperative for future research dedicated to comprehending THz wave impacts across plant structures, with a specific focus on the molecular intricacies governing root system structure and function, from shoots to roots. Notably, this review highlights the accelerated plant growth induced by THz waves, especially in conjunction with other environmental stressors, and the subsequent alterations in cellular homeostasis, resulting in the generation of reactive oxygen species (ROS) and an increase in brassinosteroids. Brassinosteroids are explored for their dual role as toxic by-products of stress metabolism and vital signal transduction molecules in plant responses to abiotic stresses. The paper further investigates the spatio-temporal regulation and long-distance transport of phytohormones, including growth hormone, cytokinin, and abscisic acid (ABA), which significantly influence the growth and development of P. ternata under THz wave stress. With a comprehensive review of Reactive oxygen species (ROS) and Brassinosteroid Insensitive (BRI) homeostasis and signalling under THz wave stress, the article elucidates the current understanding of BRI involvement in stress perception, stress signalling, and domestication response regulation. Additionally, it underscores the importance of spatio-temporal regulation and long-distance transport of key plant hormones, such as growth hormone, cytokinin, and ABA, in determining root growth and development under THz wave stress. The study of how plants perceive and respond to environmental stresses holds fundamental biological significance, and enhancing plant stress tolerance is crucial for promoting sustainable agricultural practices and mitigating the environmental burdens associated with low-tolerance crop cultivation.

Transcriptomic profiling of adding cobalt chloride to improve dendrobine-type total alkaloid production.

Trichoderma longibrachiatum UN32 is known for its efficient production of dendrobine-type total alkaloids (DTTAs). This study aimed to determine the optimal medium composition for the UN32 strain using response surface methodology. Key factors, including glucose, beef extract, and CoCl2, were selected through the Plackett-Burman design. Subsequently, a factorial optimization approach was employed using the steepest ascent design, and 17 trial sets were completed via the Box-Behnken design. The optimal medium composition was found to consist of 29.4 g/L of glucose, 17.3 g/L of beef extract, and 0.28 mmol/L of CoCl2. This optimized medium resulted in an impressive 80.8% increase in mycelial dry weight (reaching 12.303 g/L) and a substantial 76.4% boost in DTTA production (reaching 541.63 ± 46.95 µg). Furthermore, the fermentation process was scaled up to a 5-L bioreactor, leading to a DTTA production approximately 1.95 times than the control. Transcriptome analysis of strain UN32 in response to CoCl2 supplementation revealed significant changes in the expression of critical genes associated with the TCA cycle and L-valine, L-leucine, and L-isoleucine biosynthesis changed. These alterations resulted in a heightened influx of acetyl-CoA into DTTA production. Additionally, the expression of genes related to antioxidant enzymes was modified to maintain homeostasis of reactive oxygen species (ROS). A potential mechanism for the accumulation of DTTAs based on ROS as a signal transduction was proposed. These findings provide valuable insights into the regulatory mechanisms of DTTA biosynthesis, potentially offering a method to enhance the production of secondary metabolites in the UN32 strain. KEY POINTS: • After the RSM optimization, there is a substantial increase of 80.8% in biomass production and a significant 76.4% rise in DTTA production. • Transcriptome analysis revealed that the inclusion of CoCl2 supplements resulted in an enhanced influx of acetyl-CoA. • Proposed a mechanism for the accumulation of DTTAs for the role of ROS as a signal transduction pathway.

Analysis of the response mechanisms of Pinellia ternata to terahertz wave stresses using transcriptome and metabolic data.

Pinellia ternata (Thunb.) Breit. (Araceae), a significant medicinal plant, has been used to treat various diseases for centuries. Terahertz radiation (THZ) is located between microwaves and infrared rays on the electromagnetic spectrum. THZ possesses low single-photon energy and a spectral fingerprint, but its effects on plant growth have not yet been investigated. The study's primary objective was to examine the transcriptome and metabolome databases of the SY line to provide a new perspective for identifying genes associated with resistance and growth promotion and comprehending the underlying molecular mechanism. Variations in the biological characteristics of P. ternata grown under control and experimental conditions were analyzed to determine the effect of THZ. Compared with the control group, phenotypic variables such as leaf length, petiole length, number of leaves, leaf petiole diameter, and proliferation coefficient exhibited significant differences. P. ternata response to THZ was analyzed regarding the effects of various coercions on root exudation. The experimental group contained considerably more sugar alcohol than the control group. The transcriptome analysis revealed 1,695 differentially expressed genes (DEGs), including 509 upregulated and 1,186 downregulated genes. In the KEGG-enriched plant hormone signaling pathway, there were 19 differentially expressed genes, 13 of which were downregulated and six of which were upregulated. In the metabolomic analysis, approximately 416 metabolites were uncovered. There were 112 DEMs that were downregulated, whereas 148 were upregulated. The P. ternata leaves displayed significant differences in phytohormone metabolites, specifically in brassinolide (BR) and abscisic acid (ABA). The rise in BR triggers alterations in internal plant hormones, resulting in faster growth and development of P. ternata. Our findings demonstrated a link between THZ and several metabolic pathway processes, which will enhance our understanding of P. ternata mechanisms.

Study on the preparation and properties of CaCO3 ultrafine powder derived from waste eggshell.

In this study, eggshell-derived CaCO3 ultrafine powder was prepared from waste eggshell with the method of omnidirectional planetary ball mill. The particle size distribution was measured by laser particle size analyzer. Then, the parameters of grinding kinetic equation of eggshell powder were obtained by software fitting, and the grinding model and characteristic equation of particle-size distribution of the eggshell-derived CaCO3 powder were discussed. The results showed that the best grinding conditions were as follows: using 3 mm zirconia grinding ball, 400 rpm, 50% filling rate, 50% slurry concentration, and ball-milling time of 30 min. The grinding kinetic equation can well simulate the eggshell crushing process. The equation showed that with the prolongation of milling time, the large particle size of the eggshell powder gradually decreased, and the milling efficiency was 0 after 60 min. The Rosin-Rammler-Bennet distribution model could be used to describe the distribution characteristics of the cumulative particle size of the eggshell powder, and the fitting degree of particle size distribution at each milling time could reach R2 > 0.99. No chemical change occurred in the eggshell powder before and after grinding. However, the calcite crystal structure of eggshell-derived CaCO3 ultrafine powder becomes incomplete.

First Report of Blight Caused by Rhizoctonia solani AG4-HGI on Pinellia ternata in Guizhou, China.

Pinellia ternata (Thumb.) has been used for over 1000 years as a traditional Chinese herbal medicine (Ying et al. 2007) and is widely cultivated in Guizhou Province, China. It is cultivated over an area of 2000 hectares, and is of great value to underdeveloped regions. In April 2020, blight was observed in a field of P. ternatain Bijie County, Guizhou Province, China (27°30'N, 105°28'E). Around 20 hectares of P. ternata were surveyed and the disease incidence ranged from 10 to 12%. The disease symptoms included light brown lesions formed on the stems near the soil line. The color of the lesions became darker, and the stems became constricted around the lesions and broke, associated with the leaf blight. To identify the causal agent of this blight, 22 diseased plants (about 30 d-old） were collected, the margins of the infected parts were cut into small pieces (5 mm) and surface disinfested with 1% NaOCl for 10 min, 75% ethanol for 30 s, and rinsed three times in sterile distilled water. The pieces were blotted dry with sterile filter paper and placed on potato dextrose agar (PDA, Hopebio, China), incubated at 28℃ in darkness until fungal hyphae growth was visible. Sixteen cultures with different morphologies were recovered from the samples. When representative isolates of each culture type were inoculated onto plants, one produced similar blight symptoms. The representative isolate was called CD-1. The colony color was first white but turned light brown after grown on PDA for 6-7 d, and produced dark brown sclerotia. The hyphae were branched at right angles, with a slight constriction at the base of the branches and a septum near the junction where the branch separates from the main hyphae. Hyphal cells were stained with 0.5% Safranin O and 3% KOH and were observed to be multinucleate. These morphological features indicated that CD-1 likely is R. solani (Sneh et al. 1991). When paired with tester strains AG1 and AG4(provided by Dr. Genhua Yang, Yunnan Agricultural University). CD-1 showed anastomosis with isolate of AG4 (Fenille et al. 2002). Genomic DNA was extracted from the isolate (Thangaraj et al. 2018) using a fungal genomic DNA extraction kit (Tiangen, China). The internal transcribed spacer (ITS) regions were amplified using the primers ITS1/ITS4 (White et al. 1990). A 535 bp fragment was amplified that showed 99% coverage and 99.4% identity with an isolate of R. solani AG4-HGI (GenBank: HG934417). The gene sequence was deposited in GenBank as accession #OL518945. Pathogenicity tests were performed using 30 d-old plants planted in sterilized soil in pots. Cut mycelial discs (diameter 6 mm) from 3-day-old PDA cultures and placed beside stems of 21 healthy plants. Nine plants treated with agar plugs were control samples. Inoculated plants were maintained at 24 ± 5℃ in a green house and watered every two days with sterilized water. Typical blight symptoms developed on the inoculated plants at d 3-5 post inoculation, whereas the control plants remained healthy. The experiments were repeated three times, and the isolates was re-isolated from the inoculated plants and identified as R. solaniAG4 by morphological features and molecular method. R. solani has been reported to cause blight of many plants such as coffee (Ren et al. 2018) and sesame (Cochran et al. 2018). To the best of our knowledge, this is the first report of R. solani AG4-HGI causing disease on P. ternate, both in China and worldwide. This finding suggests that this pathogen may cause a threat to cultivation and production of P. terenata.

Transcriptome Analysis of Dendrobine Biosynthesis in Trichoderma longibrachiatum MD33.

Dendrobine is a representative component of Dendrobium nobile, and its pharmacological effects have been extensively studied. Trichoderma longibrachiatum MD33 was isolated from the stem of Dendrobium nobile which can produce dendrobine. In order to understand the effect of Methyl Jasmonate (MeJA) on the production of dendrobine, transcriptome analysis was performed after MeJA treatment in the MD33 and control groups. The dendrobine production of MeJA (20 µmol/L) treatment group was 44.6% higher than that of control. In this study, the RNA sequencing technology was applied, a total of 444 differentially expressed genes (DEGs) in the control and MeJA treatment groups, including 226 up-regulated genes and 218 down-regulated genes. The Kyoto Encyclopedia of Genes and Genomes annotation showed that numbers of DEGs were associated with the putative alkaloid biosynthetic pathway in T Trichoderma longibrachiatum MD33. Several MVA pathway enzyme-coding genes (isopentenyl-diphosphate Delta-isomerase, iphosphomevalonate decarboxylase and farnesyl diphosphate synthase) were found to be differentially expressed, suggesting an active precursor supply for alkaloid biosynthesis after MeJA treatment, in other wise, dendrobine may synthesis through the MVA pathway in MD33. Numerous MeJA-induced P450 family genes, aminotransferase genes and methyltransferase genes were identified, providing several important candidates to further elucidate the dendrobine biosynthetic pathway of T. longibrachiatum MD33. Furthermore, several MeJA-induced transcription factors (TFs) encoding genes were identified, suggesting a complex genetic network affecting the dendrobine in T. longibrachiatum MD33. These findings reveal the regulation mechanism underlying the MeJA-induced accumulation of dendrobine in T. longibrachiatum MD33.

Effect of Polyaniline and Graphene Oxide Modified Carbon Felt on Adsorption and Immobilization of Acidithiobacillus ferrooxidans.

Biological desulfurization plays an increasingly important role in desulfurization industry. A strain of Acidithiobacillus ferrooxidans ZJ-2 with high Fe2+ oxidizing efficiency was in this study isolated and screened to remove hydrogen sulfide from biogas. To further improve its oxidation efficiency, A. ferrooxidans ZJ-2 was immobilized using carbon felt (CF), modified with graphene oxide (GO) and polyaniline (PANI), as immobilized carrier. The effects of immobilization on strain's Fe2+ oxidation efficiency and impact of PANI and GO on CF were also investigated. Raman spectra and atomic force microscopy showed that CF was successfully modified using GO and PANI. Cyclic voltammetry and electrochemical impedance spectroscopy measurements revealed that the electrochemical properties of modified CF were improved, presenting the following trend in conductivity: CF< GO-modified CF (GO-CF) < PANI-modified CF (PANI-CF) < PANI/GO-modified CF (PANI/GO-CF). The resistance of modified CF was lower than that of unmodified CF, and exhibited the following trend: CF > GO-CF > PANI-CF > GO/PANI-CF. While PANI-CF inhibited growth of free and immobilized A. ferrooxidans ZJ-2, GO-CF was conducive to microbial growth and increased cell density and oxidation ability of A. ferrooxidans ZJ-2. Thus, the present study developed an immobilized bacterial carrier that had better conductivity and lower resistance and was efficient in immobilizing A. ferrooxidans and could be used for biogas desulfurization in biological and biochemical combined reactors.

Development and mechanical properties of straw-polyethylene imitation rattan material with wheat straw fibre.

A new type of imitation rattan was developed via a two-step method that used modified wheat straw as the raw materials and low-density polyethylene to make up wood plastic composite. Post-modification, a graft condensation reaction was carried out between silane as a coupling agent and wheat straw powder, which improved the thermal stability of the composite. A high level of contact and interaction at the fibre-matrix interface was observed. The optimum formula for the first step was 80% wheat straw powder, 4% silane coupling agent, and 16% calcium carbonate, with a modification temperature of 120 °C sustained for 10 min. For the second step, the mechanical properties had been greatly improved with the addition of modified wheat straw fibre and maleic anhydride grafted polypropylene (MA-g-PP). The use of 10% modified straw fibre and 5% MA-g-PP exhibited the highest tensile strength (8.75 MPa) and highest melt index (2.86 g/10 min). In particular, the MA-g-PP had an extremely advantage to the elastic modulus of wheat straw imitation rattan. The elastic modulus reached the maximum value of 2761.70 MPa at the amount of MA-g-PP added reached 5%. Our present study indicated the innovation of a new type of imitation rattan, which provides a new choice for utilizing wheat straw as industrial raw material, and other agricultural by-products containing liginocellulose could be used in a similar way.

Illumina Sequencing Reveals Conserved and Novel MicroRNAs of Dendrobium nobile Protocorm Involved in Synthesizing Dendrobine, a Potential Nanodrug.

Emergency of nanoparticulate drug delivery systems has improved the target, bioavailability, and curative effect of traditional Chinese medicine (TCM). However, the application of nano-preparation has been limited owing to the low content of active ingredients in part TCM. MicroRNAs (miRNAs) regulate plant growth, development, and response to environmental stresses at post-transcriptional regulation level by cleavage or translational inhibition. The molecular functions of miRNAs playing a role in synthesizing active comportments at medicinal plants have been widely researched. Dendrobium nobile is a perennial herb in the orchidaceae family. D. nobile protocorm can produce plant-specific metabolites at a short period. Therefore, it is a good substitute for producing metabolites. To understand the functions of miRNAs in D. nobile protocorm, Illumina sequencing of D. nobile protocorm (Dnp), D. officinale protocorm (Dcp), and D. nobile leaf (Dnl) were carried out. A total of 439, 412, and 432 miRNAs were identified from Dnp, Dcp, and Dnl, respectively. Some specific miRNAs were identified among them. Through combing GO and KEGG function annotation, miRNAs mainly involved metabolic pathways, plant hormone signal transduction, biological regulation, and protein binding. Acetyl-CoA acetyltransferase (AACT), mevalonate kinase (MK), 1-deoxy-D-xylulose 5-phosphate reductoisomerase (DXR), and 2-C-methyl-D-erythritol 4-phosphate cytidylyltransferase (HDS), synthesizing basic precursor isoprene pyrophosphate (IPP) in terpenoid backbone biosynthesis pathway, were predicted as potential targets of 6 different miRNAs. Twenty-six miRNAs participated in auxin, cytokinin, abscisic acid, jasmonic acid, and salicylic acid signal transduction pathway. This report provided valuable candidate genes in Dnp involved in terpenoid biosynthesis and plant hormone signal transduction pathway. At the same time, it can help accelerate the use of dendrobine into nano preparation.

Transcriptomic analysis of Pinellia ternata (Thunb.) Breit T2 plus line provides insights in host responses resist Pectobacterium carotovorum infection.

Transcriptome is used to determine the induction response of Pinellia ternata (Thunb.) Breit T2 plus line (abbreviated as PT2P line) infected with Pectobacterium carotovorum. The main objective of the study was to deal with the transcriptome database of PT2P line resistance to soft rot pathogens to provide a new perspective for identifying the resistance-related genes and understanding the molecular mechanism. Results indicated that water soaking and tissue collapse started at 20 h after PT2P line was infected by P. carotovorum. A total of 1360 and 5768 differentially expressed genes (DEGs) were identified at 0 h and 20 h, respectively. After 20 h of infection, growth and development-related pathways were inhibited. Meanwhile, DEGs were promoted the colonization of P. carotovorum pathogens in specific cell wall modification processes at the early infected stage. A shift to a defensive response was triggered at 0 h. A large number of DEGs were mainly up-controlled at 20 h and were substantially used in the pathogen recognition and the introduction of signal transformation cascades, secondary metabolites biosynthesis, pathogenic proteins activation, transcription aspects and numerous transporters. Furthermore, our data provided novel insights into the transcript reprogramming of PT2P line in response to P. carotovorum infestation.

Comparative Transcriptome Analysis of Genes Involved in Sesquiterpene Alkaloid Biosynthesis in Trichoderma longibrachiatum MD33 and UN32.

Trichoderma longibrachiatum MD33, a sesquiterpene alkaloid-producing endophyte isolated from Dendrobium nobile, shows potential medical and industrial applications. To understand the molecular mechanisms of sesquiterpene alkaloids production, a comparative transcriptome analysis was performed on strain MD33 and its positive mutant UN32, which was created using Ultraviolet (UV) mutagenesis and nitrogen ion (N+) implantation. The alkaloid production of UN32 was 2.62 times more than that of MD33. One thousand twenty-four differentially expressed genes (DEGs), including 519 up-regulated and 505 down-regulated genes, were identified. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed 139 GO terms and 87 biosynthesis pathways. Dendrobine, arguably the main sesquiterpene alkaloid the strain MD33 produced, might start synthesis through the mevalonate (MVA) pathway. Several MVA pathway enzyme-coding genes (hydroxy-methylglutaryl-CoA synthase, mevalonate kinase, and farnesyl diphosphate synthase) were found to be differentially expressed, suggesting that physical mutagenesis can disrupt genome integrity and gene expression. Some backbone post-modification enzymes and transcript factors were either discovered, suggesting the sesquiterpene alkaloid metabolism in T. longibrachiatum is a complex genetic network. Our findings help to shed light on the underlying molecular regulatory mechanism of sesquiterpene alkaloids production in T. longibrachiatum.

Carbon availability shifts the nitrogen removal pathway and microbial community in biofilm airlift reactor.

This study investigated the response of nitrogen removal performance and microbial community to different carbon composites in biofilm airlift reactors for wastewater treatment. Three reactors were filled with poly (butylene succinate) and bamboo powder composite at the blending ratio of 9:1, 1:1 and 1:9. Increasing the component of bamboo powder in the carrier reduced the carbon availability and had an adverse effect on nitrate removal efficiency. However, bamboo powder improved the ammonia removal rate which mainly through autotrophic nitrification. Three reactors exhibited distinct microbial compositions in both bacterial and fungal diversity. High inclusion of bamboo power decreased the relative abundance of denitrifiers Denitromonas and increased the relative abundance of nitrifiers, including Nitromonas, Nitrospina and Nitrospira. Moreover, correlation network revealed a competitive interaction between the taxa responsible for ammonia removal and nitrate removal processes. Those results indicated the feasibility of steering nitrogen removal pathway through carrier formulation in wastewater treatment.

Changes in global Orchidaceae disease geographical research trends: recent incidences, distributions, treatment, and challenges.

Many of the Orchidaceae species are threatened due to environmental changes and over exploitation for full fill global demands. The main objective of this article was critically analyzed the recent global distribution of Orchidaceae diversity, its disease patterns, microbial disease identification, detection, along with prevention and challenges. Critical analysis findings revealed that Orchidaceae growth and developments were affected indirectly or directly as a result of complex microbial ecological interactions. Studies have identified many species associated with orchids, some are pathogenic and cause symptoms such as soft rot, brown rot, brown spot, black rot, wilt, foliar, root rot, anthracnose, leaf spot. The review was provided the comprehensive data to evaluate the identification and detection of microbial disease, which is the most important challenge for sustainable cultivation of Orchidaceae diversity. Furthermore, this article is the foremost of disease triggering microbes, orchid relations, and assimilates various consequences that both promoted the considerate and facts of such disease multipart, and will permit the development of best operative disease management practices.

New Insights into Detection of a Dendrobine Compound From a Novel Endophytic Trichoderma longibrachiatum Strain and Its Toxicity Against Phytopathogenic Bacteria.

Dendrobium nobile is the only plant that could produce the natural bioactive dendrobine. No other source of dendrobine has been found to date except from D. nobile and via chemical synthesis. In this study, we aimed to examine the potential fungal endophyte isolated from D. nobile stem segments using the molecular method and to detect dendrobine compound through high-performance liquid chromatography (HPLC), gas chromatography-mass spectrometry (GC-MS), and liquid chromatography with tandem mass spectrometry (LC-MS/MS) and their metabolite for their antibacterial activity. The potential dendrobine producer strain was recognized as Trichoderma longibrachiatum based on molecular DNA sequencing and GenBank databases. The T. longibrachiatum MD33 produced dendrobine and other compounds in a potato dextrose medium (PDM), as confirmed by HPLC retention time peak analysis. The HPLC results revealed that T. longibrachiatum MD33 biomass showed a peak retention time of 5.28 ± 0.2 min, similar to wild D. nobile stem dendrobine (5.32 ± 0.2 min) and standard chemical reference dendrobine (5.30 ± 0.2 min), indicating the presence of dendrobine in the fungal biomass. Results of GC-MS and LC-MS analysis revealed that T. longibrachiatum MD33 produced the same molecular weight (263 in GC-MS and 264.195 in LC-MS) of dendrobine as compared with standard chemical reference dendrobine and D. nobile dendrobine. Antibacterial activity data revealed that T. longibrachiatum MD33 produced the strongest bactericidal activity against Bacillus subtilis, Bacillus mycoides, and Staphylococcus species, and the diameter of the bacterial growth inhibition zone was 12 ± 0.2, 9 ± 0.2, and 8 ± 0.2 mm, respectively. To the best of our knowledge, this was the first study to investigate T. longibrachiatum as a dendrobine producer, and the results revealed that T. longibrachiatum was directly involved in the potential production of a similar bioactive compound to D. nobile (dendrobine). In addition, the T. longibrachiatum metabolite exhibited potent antibacterial activity and can be a potential strain for medical and industrial purposes.

Phenotypic and Transcriptomic Analysis of Two Pinellia ternata Varieties T2 line and T2Plus line.

Pinellia (Pinellia ternata (Thunb.) Breit.), as important medicinal plant, has been used to treat various ailments for a long time. The sixteen ploid plant (2n = 16 * 13 = 208) Pinellia T2Plus line was obtained from an octoploid (2n = 8 * 13 = 104) T2 line by chromosome-doubling technique. Compared with T2 line, the content of various medicinal components (polysaccharide, guanosine, adenosine and ephedrine) was increased in T2Plus line. In this study, the transcriptome of T2 line and T2Plus line were characterized by RNA sequencing (RNA-seq) technology. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways enrichment analysis on differential expressed unigenes (DEGs) revealed that multiple metabolic pathway were enriched significantly, such as 'Starch and sucrose metabolism', 'Purine metabolism', 'Photosynthesis' and six transcription factors (MYB, WRKY, bHLH, lateral organ boundaries domain (LBD), homeodomain-zipper (HD-ZIP) and Ethylene-responsive factor (ERF)) play a key role in difference of transcriptome between T2 line and T2Plus line. These metabolic pathways and transcription factors may play an important role in the difference of medicinal components and epigenetic features between these two Pinellia cultivars. This conclusion provides a robust theoretical basis for the mechanism of the formation of medicinal ingredients in Pinellia cultivars.

Rapid propagation in vitro and accumulation of active substances of endangered Dendrobium cariniferum Rchb. f.

Dendrobium cariniferum is a valuable ornamental and medicinal plant rich with polysaccharides, alkaloid, and other bioactive compounds, which are potential raw materials for pharmacological utilization. In this study, an efficient protocol for the rapid propagation of D. cariniferum was developed. By using the tissue culture protocol, the effects of pH, hormone combinations, temperatures, light intensity, culture time protocorm proliferation, seedlings rooting, and accumulation of biomass with bioactive compounds were investigated. The experiments showed that the medium [1/2 MS + activated carbon1.0 g/L+ agar strip 7.5 g/L + sucrose 25 g/L] effectively promoted the germination of D. cariniferum seeds. The optimal culture conditions were found at pH 5.7, temperature 23 ± 2°C, and light intensity of 1000 Lx in the protocorm proliferation stage. Adding 1.5 g/L peptone in the medium effectively promoted the seedling rooting. The optimal culture conditions for accumulation of bioactive compounds (polysaccharides and alkaloids) of seedlings were found at temperature of 25 ± 2°C, light intensity of 1500-2000 Lx after the 60-day (d). Our study constructed a rapid propagation system in vitro for D. cariniferum, as well as the methods for efficient accumulation of active substances in seedling culture, which will serve as guidance for industrial production of D. cariniferum seedlings for both medicinal raw materials and ornamental plants. In addition, our study provided a new idea that we can directly use the high bioactive compound seedlings to extract medicinal components in industry conditions without transferring to the field.