Search Results (112)

Chilli veinal mottle virus (ChiVMV) severely compromises the quality and yield of solanaceous crops. The helper component protease (HCPro) of ChiVMV functions as a multifunctional RNA silencing suppressor that subverts host antiviral defenses through diverse strategies, However, the underlying mechanisms remain mechanistically unresolved. In this study, HCPro-overexpressing (HCPro-OX) and wild-type (WT) plants were inoculated with ChiVMV to monitor the physiological and molecular changes. Transcriptome analysis identified 11,815 differentially expressed genes (DEGs) under viral infection, among which 1115 genes were specifically regulated by HCPro. KEGG enrichment analysis revealed that the DEGs were significantly associated with plant hormone signal transduction pathways, indicating their crucial role in host–virus interactions. Furthermore, functional clustering of HCPro-regulated DEGs specifically identified key components in ethylene biosynthesis pathways. GO analysis of DEGs between virus-inoculated WT and HCPro-OX plants annotated ethylene biosynthesis-related genes NtACO and NtACS. qPCR validation confirmed that the expression of ethylene biosynthesis-related genes was suppressed by HCPro. Exogenous treatments with the ethylene precursor ACC demonstrated that ethylene suppressed viral accumulation, enhanced POD activity, and reduced the ROS accumulation induced by viral infection. In conclusion, our results demonstrate that HCPro promotes viral infection by suppressing ethylene biosynthesis, which in turn attenuates peroxidase activity, leading to ROS accumulation. Full article

Angelica biserrata (Shan et Yuan) Yuan et Shan (A. biserrata) roots, a widely distributed medicinal crop with intraspecific diversity, exhibits significant variability in coumarin content across habitats. This study integrated metabolomics and transcriptomics to dissect the spatial heterogeneity in metabolite profiles and gene expression, revealing the mechanisms driving coumarin biosynthesis divergence. By synthesizing climate-related big data with machine learning and Bayesian-optimized deep learning models, we identified key environmental drivers and predicted optimal cultivation conditions. The key findings were as follows: (1) differential regions most strongly influenced coumarin; (2) upstream genes (such as PAL-1, PAL-2, BGLU44, etc.) modulated downstream coumarin metabolites; (3) elevation (Elev) and warmest quarter temperature (Bio10) dominated coumarin variation, whereas May solar radiation (Srad5) and precipitation seasonality (Bio15) controlled transcriptomic reprogramming; (4) the optimized environment for bioactive compounds included mean annual temperature (Bio1) = 9.99 °C, annual precipitation (Bio12) = 1493 mm, Elev = 1728 m, cumulative solar radiation = 152,643 kJ·m⁻²·day⁻¹, and soil organic carbon = 11,883 g·kg⁻¹. This study aimed to clarify the biological characteristics and differential regulatory mechanisms of A. biserrata roots in different habitats, establish a theoretical framework for understanding the molecular mechanisms controlling metabolic changes under various habitats, and contribute to elucidating the formation of active constituents while facilitating their effective utilization. Full article

Callose plays an important role in plant development and in response to a wide range of biotic and abiotic stresses. However, the systematic identification of callose synthase (CalS), the major enzyme for callose biosynthesis, has been delayed in crops, especially in Solanaceae. In the current research, 18 CalS genes (NtCalS1–NtCalS18) were identified in Nicotiana tabacum and classified into four subfamilies. A comprehensive analysis of their physicochemical properties, gene structure, and evolutionary history highlighted their evolutionary conservation. We also identified a number of NtCalSs that responded to the infection with Phytophthora nicotianae and Ralstonia solanacearum, as well as to drought and cold treatments, by analyzing RNA-seq data. NtCalS1 and NtCalS12, a highly homologous gene pair, were selected to create mutants using the CRISPR-Cas9 technology for their drastic response to Phytophthora nicotianae infection as well as the strong expression levels in roots. The mutants with the simultaneous knockout of NtCalS1 and NtCalS12, compared with the control plants, displayed more resistance to tobacco black shank caused by Phytophthora nicotianae. Furthermore, the real-time quantitative PCR (qRT-PCR) assay showed that the knockout of NtCalS1 and NtCalS12 activated the signaling pathways mediated by plant hormones salicylic acid (SA), jasmonic acid (JA), and ethylene (ET) before and after the infection of Phytophthora nicotianae and thus may have contributed to tobacco immunity against black shank. These findings contribute valuable information for further understanding the roles of CalS genes in tobacco stress responses and provide alternative genes for resistance improvement. Full article

The objectives of this study were to investigate the effects of extended and constant ethanol and hexanal exposure on ‘Gala’ apples’ production of aroma compounds after long-term CA storage. ‘Gala’ apples were stored in a CA under 2 kPa O₂ and 98 kPa N2 at 1.0 ± 0.1 °C with a constant ethanol (CA-et) or hexanal (CA-he) concentration maintained at 50 µgL⁻¹ throughout a six-month storage period. A total of 25 volatile compounds (VOCs) were identified. The odor activity value (OAV) results show that nine VOCs were key aroma compounds. Among them, hexyl acetate, 2-methylbutyl acetate, and 1-butanol were the highest. Hexanal increased the production of hexyl acetate, while ethanol increased the production of 2-methylbutyl acetate and ethyl 2-methylbutanoate. Both precursors promoted the production of 1-butanol after two months of storage and 1 day of shelf life. Overall, the impact of the precursors on aroma production was more pronounced after two months than after six months of storage. Different storage atmospheres significantly influenced VOC correlations, suggesting that ethanol and hexanal addition altered aroma biosynthesis pathways in the ‘Gala’ apples. For varieties like ‘Gala’ that rapidly lose their aroma during CA storage, CA-et and CA-he treatments may be beneficial for short-term storage, enhancing key aroma compounds and improving sensory quality. Full article

Fruit dropping represents a concern in many fruit species, including Vitis vinifera L. This research investigated the role of two plant growth regulators (PGRs), naphthaleneacetic acid (NAA) and 1-methylcyclopropene (1-MCP), in mitigating preharvest berry dropping (PHBD) through affecting ethylene (ET) and auxin (AUX) metabolism and interactions, key hormones involved in abscission. The experiment was carried out on cv. Dolcetto, with PGR treatments applied at 43, 53, and 90 days after anthesis (DAA) for NAA and at 56 DAA for 1-MCP. Berry dropping incidence, yield parameters, and transcript levels of genes related to ET and AUX pathways were analyzed, including VIT_212s0059g01380, VIT_211s0016g02380, VIT_207s0005g00820, VIT_216s0013g00980, VIT_203s0091g00310, and VIT_207s0104g00800. Both NAA and 1-MCP significantly reduced PHBD, with NAA achieving a 92% reduction and 1-MCP an 82% reduction compared to control vines. Transcript analysis revealed differential gene expression patterns, indicating that NAA affects the ET biosynthesis pathway, while 1-MCP interferes with ET receptor signaling. The results suggest that both PGRs effectively reduced berry dropping, providing a basis for integrated crop management strategies to mitigate PHBD in grapevine cultivars susceptible to this physiological disorder. Full article

Salt stress is an environmental factor that limits plant seed germination, growth, and survival. We performed a comparative RNA sequencing transcriptome analysis during germination of the seeds from two cultivars with contrasting salt tolerance responses. A transcriptomic comparison between salt-tolerant cotton cv Jin-mian 25 and salt-sensitive cotton cv Su-mian 3 revealed both similar and differential expression patterns between the two genotypes during salt stress. The expression of genes related to aquaporins, kinases, reactive oxygen species (ROS) scavenging, trehalose biosynthesis, and phytohormone biosynthesis and signaling that include ethylene (ET), gibberellin (GA), abscisic acid (ABA), jasmonic acid (JA), and brassinosteroid (BR) were systematically investigated between the cultivars. Despite the involvement of these genes in cotton’s response to salt stress in positive or negative ways, their expression levels were mostly similar in both genotypes. Interestingly, a PXC2 gene (Ghir_D08G025150) was identified, which encodes a leucine-rich repeat receptor-like protein kinase (LRR-RLK). This gene showed an induced expression pattern after salt stress treatment in salt-tolerant cv Jin-mian 25 but not salt-sensitive cv Su-mian 3. Our multifaceted transcriptome approach illustrated a differential response to salt stress between salt-tolerant and salt-sensitive cotton. Full article

Five new non-holostane di- and trisulfated triterpene pentaosides, conicospermiumosides A₃-1 (1), A₃-2 (2), A₃-3 (3), A₇-1 (4), and A₇-2 (5) were isolated from the Far Eastern sea cucumber Cucumaria conicospermium Levin et Stepanov (Cucumariidae, Dendrochirotida). Twelve known glycosides found earlier in other Cucumaria species were also obtained and identified. The structures of new compounds were established on the basis of extensive analysis of the 1D and 2D NMR spectra, as well as by the HR-ESI-MS data. The aglycones of 1–5 differed by side chains structures. Additionally, conicospermiumoside A₇-1 (4) had a 9(11)-double bond in the aglycone, while the remaining glycosides contained a 7(8)-intranuclear double bond. Eight types of carbohydrate chains known earlier from the glycosides of the sea cucumbers of the Cucumaria genus were found as part of the glycosides of C. conicospermium. The set of sugar chains of the glycosides from C. conicospermium was similar to that from C. okhotensis. The raw biogenetic series of aglycones, leading to the formation of hexa-nor-lanostane derivatives in the process of biosynthesis and a sort of functionally-structural division that was realized due to separation of biosynthetic pathways of holostane and lanostane derivatives, can be traced when the structures of the glycosides isolated from C. conicospermium are compared. The cytotoxic action against three human breast cancer cell lines (MCF-7, T-47D, MDA-MB-231), and non-tumor MCF-10A and hemolytic activity of compounds 1–5, as well as seven known glycosides were tested. Conicospermiumosides A₃-3 (3) and A₇-1 (4), having a 22-oxo-23(24)-en fragment, were strongly hemolytic despite lacking a lactone in their aglycones. Moreover, both compounds demonstrated a promising suppressing action against triple negative breast cancer cells. The cells of the MDA-MB-231 line were most sensitive to the cytotoxic action of the glycosides, while the MCF-7 cell line was most sustainable. Six glycosides were selected for further study of some aspects of anticancer action against MDA-MB-231. The selective action of the compounds 4 and 8 on the MDA-MB-231 cells without significant toxicity against the MCF-10A cells was noticeable. More importantly, the selectivity of the compounds was changed over time and maximal selectivity to cancer cells was demonstrated by glycoside 1 at 48 h of exposition. The glycosides 1, 3 and the desulfated derivative 7a strongly inhibited colony formation and growth of the TNBC cells until the process stops completely. Okhotoside B₁ (8), DS-okhotoside A₁-1 (7a), and conicospermiumoside A₃-3 (3) showed a potent cell migration-inhibiting capacity. Quantitative structure–activity relationships (QSARs) calculated on the basis of a correlational analysis of the physicochemical properties and structural features of the glycosides and their cytotoxic activity against different cell lines showed some structural features influenced differently, sometimes even in opposite ways, on the activity of glycosides toward diverse cells (erythrocytes, MCF-10A, and TNBC MDA-MB-231 cells). This observation indicated that glycosides obviously target different membrane components, such as lipids of erythrocytes and some receptors on the surface of mammary normal or tumor cells. Full article

The immune response in plants is regulated by several phytohormones and involves the overexpression of defense genes, including the pathogenesis-related (PR-) genes. The data reported in this paper indicate that nematodes can suppress the immune response by inhibiting the expression of defense genes. Transcripts from nine defense genes were detected by qRT-PCR in the roots of tomato plants at three and seven days post-inoculation (dpi) with living juveniles (J2s) of Meloidogyne incognita (root-knot nematodes, RKNs). All the salicylic acid (SA)-responsive genes tested (PR-1, PR-2, PR-4b, PR-5) were down-regulated in response to nematode infection. On the contrary, the expression of jasmonic acid (JA)-responsive genes, including ACO (encoding the enzyme 1-aminocyclopropane-1-carboxylic acid oxidase, which catalyzes the last step of ethylene (ET) biosynthesis) and JERF3 (Jasmonate Ethylene Response Factor 3), was unaffected by the infection. Conversely, the effect of nematode attack on the activities of the defense enzymes endoglucanase and endochitinase, encoded by PR-2 and PR-3, respectively, changed depending on the tested dpi. At 5 dpi, both enzymes were inhibited in inoculated plants compared to healthy controls. The genes encoding glutathione peroxidase (GPX) and catalase (CAT), both part of the antioxidant plant system, were highly overexpressed. Additionally, the activity of the antioxidant enzymes superoxide dismutase (SOD), CAT, and ascorbate peroxidase (APX) was enhanced in infected roots. Isoelectrofocusing of root extracts revealed novel SOD isoforms in samples from inoculated plants. Furthermore, plants were pre-treated with an array of key compounds, including hormone generators, inhibitors of SA or JA-mediated defense pathways, reactive oxygen species (ROS) scavengers and generators, inhibitors of ROS generation, and compounds that interfere with calcium-mediated metabolism. After treatments, plants were inoculated with RKNs, and nematodes were allowed to complete their life cycle. Factors of plant growth and infection level in treated plants were compared with those from untreated inoculated plants. Generally, compounds that decreased SA and/or ROS levels increased infection severity, while those that reduced JA/ET levels did not affect infection rates. ROS generators induced resistance against the pests. Compounds that silence calcium signaling by preventing its intake augmented infection symptoms. The data shown in this paper indicate that SA-mediated plant immune responses are consistently suppressed during the early stages of nematode infection, and this restriction is associated with the activation of the antioxidant ROS-scavenging system. Full article

Arabidopsis LIM proteins are named after the initials of three proteins Lin-11, Isl-1, and MEC-3, which belong to a class of transcription factors that play an important role in the developmental regulation of eukaryotes and are also involved in a variety of life processes, including gene transcription, the construction of the cytoskeleton, signal transduction, and metabolic regulation. Plant LIM proteins have been shown to regulate actin bundling in different cells, but their role in immunity remains elusive. Mitogen-activated protein kinases (MAPKs) are a family of conserved serine/threonine protein kinases that link upstream receptors to their downstream targets. Pathogens produce pathogen-associated molecular patterns (PAMPs) that trigger the activation of MAPK cascades in plants. Recently, we conducted a large-scale phosphoproteomic analysis of PAMP-induced Arabidopsis plants to identify putative MAPK targets. One of the identified phospho-proteins was WLIM2A, an Arabidopsis LIM protein. In this study, we investigated the role of WLIM2A in plant immunity. We employed a reverse-genetics approach and generated wlim2a knockout lines using CRISPR-Cas9 technology. We also generated complementation and phosphosite-mutated WLIM2A expression lines in the wlim2a background. The wlim2a lines were compromised in their response to Pseudomonas syringae Pst DC3000 but showed enhanced resistance to the necrotrophic fungus Botrytis cinereae. Transcriptome analyses of wlim2a mutants revealed the deregulation of immune hormone biosynthesis and signaling of salicylic acid (SA), jasmonic acid (JA), and ethylene (ET) pathways. The wlim2a mutants also exhibited altered stomatal phenotypes. Analysis of plants expressing WLIM2A variants of the phospho-dead or phospho-mimicking MAPK phosphorylation site showed opposing stomatal behavior and resistance phenotypes in response to Pst DC3000 infection, proving that phosphorylation of WLIM2A plays a crucial role in plant immunity. Overall, these data demonstrate that phosphorylation of WLIM2A by MAPKs regulates Arabidopsis responses to plant pathogens. Full article

Tricholoma are significant medicinal and edible mushrooms within Basidiomycota. Known for their various medicinal properties such as anti-tumor, immune regulation, and antioxidant effects, they are regarded worldwide as health foods of the 21st century. Tricholoma species produce various types of secondary metabolites, which have been extensively studied by the scientific community. In 2018, Clericuzio et al. summarized the structures, biosynthesis, and biological activities of over one hundred different secondary metabolites isolated from the fruiting bodies of 25 Tricholoma species. Building on this, the present article reviews the research progress on Tricholoma secondary metabolites from 2018 to 2023, identifying a total of 101 compounds, 46 of which were newly discovered. These secondary metabolites include a wide range of chemical categories such as terpenoids, steroids, and alkaloids, demonstrating broad biological activities. This article aims to provide in-depth scientific insights and guidance for researchers in this field by summarizing the chemical and biological properties of these secondary metabolites, promoting further applications and development of Tricholoma fungi in the pharmaceutical and food industries. Full article

ADP-glucose pyrophosphorylase (AGPase), which is a key enzyme in the starch biosynthesis pathway, plays a critical role in barley grain development. Despite its importance, the regulatory mechanisms governing AGPase expression, particularly the influence of plant hormones, remain poorly understood in barley. To address this, we identified and characterized the HvAGPS2b gene, which encodes the AGPase small subunit. The full-length HvAGPS2b gene was cloned from the barley database and expressed as a recombinant protein using the pET-30a system. Polyclonal antibodies were prepared against HvAGPS2b to facilitate detailed analysis. Our findings revealed that HvAGPS2b, as a small subunit of the rate-limiting enzyme AGPase, is integral to the later stages of grain development. Furthermore, RT-qPCR and Western blotting analyses showed that the phytohormones ABA, GA, ETH, and BR significantly upregulated the expression of AGPase small subunits. These results underscore the vital role of plant hormones in modulating AGPS2b expression, thereby influencing grain development. This study provides significant insights into the hormonal regulation of starch biosynthesis and establishes a foundation for further investigation into the functional dynamics of AGPase in barley. Full article

The occurrence and spread of Verticillium dahliae (V. dahliae) in cotton depends on the combined effects of pathogens, host plants, and the environment, among which temperature is one of the most important environmental factors. Studying how temperature impacts the occurrence of V. dahliae in cotton and the mechanisms governing host defense responses is crucial for disease prevention and control. Understanding the dual effects of temperature on both pathogens and hosts can provide valuable insights for developing effective strategies to manage this destructive fungal infection in cotton. This study was based on the deciduous V. dahliae Vd-3. Through cultivation at different temperatures, Vd-3 formed the most microsclerotia and had the largest colony diameter at 25 °C. Endospore toxins were extracted, and 48 h was determined to be the best pathogenic time point for endotoxins to infect cotton leaves through a chlorophyll fluorescence imaging system and phenotypic evaluation. Transcriptome sequencing was performed on cotton leaves infected with Vd-3 endotoxins for 48 h at different culture temperatures. A total of 34,955 differentially expressed genes (DEGs) were identified between each temperature and CK (no pathogen inoculation), including 17,422 common DEGs. The results of the enrichment analysis revealed that all the DEGs were involved mainly in photosynthesis and sugar metabolism. Among the 34,955 DEGs, genes in the biosynthesis and signal transduction pathways of jasmonic acid (JA), salicylic acid (SA), and ethylene (ET) were identified, and their expression patterns were determined. A total of 5652 unique DEGs were clustered into six clusters using the k-means clustering algorithm, and the functions and main transcription factors (TFs) of each cluster were subsequently annotated. In addition, we constructed a gene regulatory network via weighted correlation network analysis (WGCNA) and identified twelve key genes related to cotton defense against V. dahliae at different temperatures, including four genes encoding transcription factors. These findings provide a theoretical foundation for investigating temperature regulation in V. dahliae infecting cotton and introduce novel genetic resources for enhancing resistance to this disease in cotton plants. Full article