Search Results (275)

Huanglongbing (HLB), caused by Candidatus Liberibacter asiaticus (CLas), is the most devastating disease threatening global citrus production. Although no commercial citrus varieties exhibit complete HLB resistance, genotype-specific tolerance variations remain underexplored. This study conducted a comparative transcriptomic profiling of six commercially citrus cultivars in South China, four susceptible cultivars (C. reticulata cv. Tankan, Gongkan, Shatangju, and C. sinensis Osbeck cv. Newhall), and two tolerant cultivars (C. limon cv. Eureka; C. maxima cv Guanxi Yu) to dissect molecular mechanisms underlying HLB responses. Comparative transcriptomic analyses revealed extensive transcriptional reprogramming, with tolerant cultivars exhibiting fewer differentially expressed genes (DEGs) and targeted defense activation compared to susceptible genotypes. The key findings highlighted the genotype-specific regulation of starch metabolism, where β-amylase 3 (BAM3) was uniquely upregulated in tolerant varieties, potentially mitigating starch accumulation. Immune signaling diverged significantly: tolerant cultivars activated pattern-triggered immunity (PTI) via receptor-like kinases (FLS2) and suppressed ROS-associated RBOH genes, while susceptible genotypes showed the hyperactivation of ethylene signaling and oxidative stress pathways. Cell wall remodeling in susceptible cultivars involved upregulated xyloglucan endotransglucosylases (XTH), contrasting with pectin methylesterase induction in tolerant Eureka lemon for structural reinforcement. Phytohormonal dynamics revealed SA-mediated defense and NPR3/4 suppression in Eureka lemon, whereas susceptible cultivars prioritized ethylene/JA pathways. These findings delineate genotype-specific strategies in citrus–CLas interactions, identifying BAM3, FLS2, and cell wall modifiers as critical targets for breeding HLB-resistant cultivars through molecular-assisted selection. This study provides a foundational framework for understanding host–pathogen dynamics and advancing citrus immunity engineering. Full article

Mannoproteins are structural components of the yeast cell wall exhibiting extensive functionality applicable to the food, feed, and medical industries. They are characterized mostly by immunostimulatory, prebiotic, antimicrobial, antibiofilm, antioxidant, and emulsifying properties. The bioactive properties of mannoproteins underscore their significance in functional food production, therapy, and animal husbandry. This review critically examines the literature on yeast mannoproteins, focusing on their chemical characteristics, biological activity, and potential applications. Considering gaps in the literature data regarding detailed chemical characterization and mechanisms of action of mannoproteins, future research should aim at precise structural analysis, particularly of mannoproteins derived from nonconventional yeast, to uncover new potential industrial and health applications. Full article

Xyloglucan endotransglucosylases/hydrolases (XTHs) are key enzymes involved in cell wall remodeling by modifying xyloglucan–cellulose networks, thereby influencing plant growth, development, and secondary cell wall formation. While the roles of XTHs have been extensively studied in primary and secondary growth, their functions in the formation and thickening of lignified nut shells remain largely unknown. Pecan (Carya illinoinensis), an economically important nut crop, develops a hard, lignified shell that protects the seed during fruit maturation. In this study, we performed a comprehensive genome-wide characterization of the XTH gene family in pecan and identified 38 XTH genes, which were categorized into four distinct phylogenetic groups. Structural analyses of the deduced proteins revealed conserved catalytic residues alongside divergent loop regions, suggesting functional diversification. Expression profiling across various tissues and among pecan cultivars with contrasting shell phenotypes indicated that specific XTH genes may play critical roles in shell structure formation. Moreover, gene regulatory networks in thin- and thick-shelled pecans provided new insights into the molecular mechanisms underlying shell development and thickness regulation. These findings lay a foundation for future genetic improvement strategies targeting nut shell traits in woody perennials. Full article

Background: Deinococcus radiodurans, renowned for its exceptional resistance to radiation, provides a robust model for elucidating cellular stress responses and DNA repair mechanisms. Previous studies have established PprI as a key regulator contributing to radiation resistance through its involvement in DNA damage repair pathways, oxidative stress response, and metabolic regulation. Methods: Building upon these foundations, our study employs label-free quantitative (LFQ) proteomics coupled with high-resolution mass spectrometry to systematically map pprI deletion protein networks by comparing the global proteomic profiles of pprI knockout and wild-type D. radiodurans strains. Results: Under stringent screening criteria, we identified 719 significantly higher and 281 significantly lower abundant proteins in the knockout strain compared to wild-type strains. Functional analysis revealed that PprI deficiency disrupts homologous recombination (HR) repair, activates nucleotide excision repair (NER) and base excision repair (BER) as a compensatory mechanism, and impairs Mn/Fe homeostasis and carotenoid biosynthesis, leading to increased oxidative stress. Furthermore, PprI deficiency induces significant metabolic reprogramming, including impaired purine synthesis, compromised cell wall integrity, etc. Conclusions: These proteomic findings delineate the extensive regulatory network influenced by PprI, revealing coordinated perturbations across multiple stress response systems when PprI is absent. Full article

The agro-industrial sector generates large volumes of fruit waste each year, leading to environmental concerns and sustainability challenges. In this study, we evaluate the potential of fruit residues—apple, pear, blueberry, tomato, papaya, and a mixed fruit juice blend—as alternative sources of high-value polysaccharides, including pectins, hemicelluloses, and cellulose. Additionally, white strawberry, included as a reference from fresh fruit rather than agro-industrial waste, was analyzed to expand the comparative framework. These biopolymers, naturally derived from the plant cell wall, are renewable and biodegradable, and they possess physicochemical properties suitable for applications in food, pharmaceutical, cosmetic, textile, and bioenergy industries. Using a combination of cell wall fractionation, biochemical characterization, and immunodetection of specific structural domains, we identified significant variability in polysaccharide composition and structure among the samples. Blueberry, pear, and apple residues showed high levels of rhamnogalacturonan-I (RG-I) with extensive branching, while variations in rhamnogalacturonan-II (RG-II) dimerization and the degree of methylesterification of homogalacturonan were also observed. These structural differences are key to determining the gelling properties and functional potential of pectins. In the hemicellulose fractions, xylans and xyloglucans with distinct substitution patterns were especially abundant in apple and pear waste. Our findings demonstrate that fruit processing waste holds significant promise as a sustainable source of structurally diverse polysaccharides. These results support the reintegration of agro-industrial residues into production chains and emphasize the need for environmentally friendly extraction methods to enable industrial recovery and application. Overall, this study contributes to advancing a circular bioeconomy by transforming underutilized plant waste into valuable functional materials. Full article

Hydroxyproline O-arabinosyltransferase (HPAT), a critical enzyme in plant glycosylation pathways, catalyzes the transfer of arabinose to the hydroxyl group of hydroxyproline residues. This enzyme contains a canonical GT95 glycosyltransferase, a structural hallmark of this carbohydrate-active enzyme family. HPAT mediates arabinosylation of diverse cellular targets, including cell wall extension and small signaling peptides. Emerging evidence has shown that HPAT orthologs regulate plant development and symbiotic interactions through post-translational modification of CLV1/LRR Extracellular (CLE) peptides. Although the molecular functions of HPAT genes have been characterized in model plants such as Arabidopsis thaliana and Lotus japonicus, their roles remain unexplored in Zea mays L. In this study, we used ZmHPAT2 homozygous mutants to explore the function of the maize HPAT gene. Sequence analysis identified a N-terminal signal peptide targeting the Golgi apparatus and promoter elements responsive to AM fungal colonization. Phenotypic analysis revealed its negative regulatory role: zmhpat2 promotes vegetative growth (increased plant height and accelerated flowering) and enhances AM symbiosis (increased colonization rate). Mechanistic studies demonstrated that ZmHPAT2 possesses dual regulatory functions—the activation of auxin signaling and repression of ZmMYB1-mediated arbuscular degradation pathways. In addition, overexpression of ZmHPAT2 in Lotus japonicus inhibits growth (reduced plant height) and impairs symbiotic interactions. Our findings establish ZmHPAT2 as a critical node to regulate auxin and symbiotic signaling, providing novel insights into plant glycosylation-mediated development. This work not only advances our understanding of maize growth regulation but also identifies potential targets for crop improvement through arabinosylation pathway manipulation. Full article

Common in Fungal Extracellular Membrane (CFEM) effectors, a unique class of fungal-specific proteins, play critical roles in host-pathogen interactions. While CFEM proteins have been extensively characterized in phytopathogens, their presence and functions in Fusarium verticillioides remained unexplored. Here, we systematically identified 19 CFEM-containing proteins in F. verticillioides, among which FvCFEM12 exhibited secretory activity and plant infection-induced expression. Functional characterization revealed that FvCFEM12 suppressed Bax- and INF1-triggered cell death in Nicotiana benthamiana leaves. Furthermore, heterologous expression of FvCFEM12 in maize leaves using P. syringae strain D36E can compromise immune responses against bacterial pathogens. Deletion of FvCFEM12 impaired fungal virulence, altered hyphal morphology, and reduced cell wall stress tolerance. Interestingly, FvCFEM12 physically interacted with the maize wall-associated receptor kinase ZmWAK17ET, and targeted silencing of ZmWAK17 in maize enhanced susceptibility to F. verticillioides. Our findings revealed that FvCFEM12 is a dual-function effector that suppresses plant immunity and maintains fungal cell wall integrity, thereby orchestrating fungal pathogenicity at the host–pathogen interface. Full article

In a previous Arabidopsis investigation, three ovule-specific cell-wall peroxidases decreased seed abortion rates. These peroxidases were expressed in soybean plants. Because cell wall peroxidases alter extensibility, possible effects on seed size and plant yield were evaluated. Since the effects of these peroxidases in Arabidopsis were dependent on environmental stress, soybean plants were grown in controlled environment greenhouse rooms under four temperature treatments; the daily temperature averages were 26, 30, 34, and 38 °C. In this experiment in vivo oxygen levels during seed growth were 25-fold below ambient, which could affect peroxidase activities. Consequently, soybeans were grown at atmospheric (21%) and elevated (32%) O₂ to evaluate peroxidase activities at higher O₂. Chambers were maintained at 700 ppm CO₂ in an attempt to minimize photorespiration in elevated O_2. Individual seed weight decreased with increasing temperature to zero at 38 °C. In elevated O₂ rooms, the oxygen concentration in developing seeds increased, but, due to leaf photorespiration, plant biomass and seed yield decreased. Seed size and shelling percentage declined equally with temperature at both O₂ concentrations. Expression of all three cell-wall peroxidases reduced seed abortion; however, that did not increase yields at ambient or elevated O₂. While O₂ concentration is less than 1% in developing seeds, increased O₂ levels in seeds were not beneficial for soybean reproduction. Full article

Yeasts have been extensively recognized as a type of model microorganism due to their facile cultivation, short growth cycle, and genetic stability. Different yeast strains, such as Saccharomyces cerevisiae and Rhodotorula mucilaginosa, have exhibited notable sorption capacities for heavy metals and metalloids. Yeast employs diverse pathways for detoxifying heavy metals via its cell walls, intracellular organelles, and extracellular polymeric substances (EPSs). The cell wall has many functional groups to adsorb metals, decreasing their concentrations in the environment. In intracellular regions, some proteins are capable of transporting metals into biological metabolic processes for detoxification. In extracellular regions, electrostatic as well as complexation mechanisms between protein in EPSs and heavy metals is well accepted. Meanwhile, mannose and glucose within EPSs are target sugars for complexation with metals. Many yeasts can hence work as excellent biomaterials for the bioremediation of metal pollution. Meanwhile, they can be combined with other materials to enhance remediation efficiency. This study reviews underlying mechanisms and cases of yeast-mediated metal detoxification, alongside highlighting yeasts’ industrial applications as bioremediation materials. Full article

The emergence of multidrug-resistant and extensively drug-resistant Mycobacterium tuberculosis strains poses serious challenges to global tuberculosis control, highlighting the urgent need to elucidate the mechanisms underlying multidrug resistance. In this study, we screened for spontaneous bortezomib (BTZ)-resistant Mycobacterium smegmatis (Msm) mutants and identified a strain, Msm-R1-2, exhibiting 16- and 64-fold increases in minimum inhibitory concentrations (MICs) to BTZ and linezolid (LZD), respectively, compared to the parental strain. Whole-genome sequencing revealed resistance-associated mutations in two functionally distinct genes: MSMEG_1380, encoding a transcriptional regulator involved in efflux pump expression, and MSMEG_0965, encoding a porin protein. CRISPR-Cpf1-assisted gene knockout and editing experiments confirmed that single mutations in either MSMEG_1380 or MSMEG_0965 caused low-level resistance (4-fold MIC increase) to BTZ and LZD, while dual mutations conferred resistance levels comparable to Msm-R1-2, with 16- and 64-fold increases in MICs for BTZ and LZD, respectively. An ethidium bromide accumulation assay demonstrated that mutations in MSMEG_0965 reduce cell wall permeability, contributing to multidrug resistance. Furthermore, quantitative real-time PCR showed that mutations in MSMEG_1380 upregulate the mmpS5-mmpL5 efflux system. Together, these dual mechanisms function synergistically: restricted drug entry combined with enhanced drug efflux confers robust multidrug resistance. These findings provide novel insights into the evolutionary mechanisms of resistance in mycobacteria. Full article

The seeds of 121 species belonging to 38 genera of the subtribe Angraecinae (Orchidaceae) were studied in terms of their morphological characteristics under a scanning electron microscope (SEM). This study provided new data about the seed micromorphology of 17 genera and 100 species. Ten qualitative traits of the seed coat were analyzed, of which four were common for all the examined samples: elongated testa cells, anticlinal zone, curved transverse anticlinal walls, and sunken and narrow-to-not visible periclinal walls. These features are consistent with the epiphytic life-form of the genera studied. However, variation among genera was observed with reference to the seed shape, the morphology of the apical and the basal poles, the arrangement of the medial cells, the morphology of the longitudinal anticlinal walls, and the presence of testa extensions. A cluster analysis was performed, and two large groups were segregated according to the seed shape. Within a genus, all the examined species showed the same pattern of seed coat, except in Diaphananthe, Mystacidium, and Rhipidoglossum. On the other hand, the variation in the seed coat observed in Angraecum sensu lato supported its segregation into different genera. Our results perfectly fitted with recent taxonomic proposals. Full article

Tomato (Solanum lycopersicum), a leading vegetable crop of significant economic importance, is a valuable source of nutrients and minerals in the human diet. Consumer and breeder interest focuses extensively on tomato quality attributes, including appearance, texture, flavor, and nutritional value. While moderate low temperatures are generally beneficial for preserving tomato quality during transportation and storage, the precise effects of storage temperature on these qualities remain to be fully elucidated. This study investigated the changes in quality attributes of tomato (cv. Shangjiao No.2) fruit stored at different temperatures (4 °C, 14 °C, and 24 °C) for varying durations (0, 1, 5, 9, and 15 days postharvest, dph). Results showed that low temperatures (4 °C and 14 °C) were beneficial for maintaining fruit appearance and total soluble solids (TSS) content. Furthermore, 4 °C storage effectively delayed ascorbic acid (Vitamin C) loss. Storage at both 4 °C and 14 °C similarly and significantly reduced fruit softening and water loss rate (WLR). This reduction was associated with the temperature-regulated expression of cell wall-related genes, including SlCESA6, SlCEL2, SlEXP1, and SlPL. The activities of cell wall-degrading enzymes, such as polygalacturonase (PG), β-galactosidase (β-Gal), and cellulase, were also significantly inhibited at lower storage temperatures. Additionally, storage at 24 °C caused considerable damage to plastid ultrastructure. Although temperature had a minor effect on carotenoid, the reduction in carotenoid levels was less pronounced at 4 °C. While low-temperature storage suppressed the release of some aroma compounds, it also reduced the levels of undesirable volatiles. This study provides insights for optimizing storage temperature and duration to maintain tomato fruit quality. Full article

Transcription factors are extensively found in fungi and are involved in the regulation of multiple biological processes, including growth, development, conidiation, morphology, stresses tolerance, and virulence, as well as the production of secondary metabolites. Biocontrol is a complex biological process through which several biocontrol behaviors, such as the secretion of cell wall-degrading enzymes and the production of secondary metabolites, are regulated by transcription factors. To date, biocontrol-related transcription factors have been reported in several biocontrol fungi, such as Beauveria bassiana, Clonostachys rosea, Coniothyrium minitans, and different species in the genera Metarhizium, Trichoderma, and Arthrobotrys. However, comprehensive reviews summarizing and analyzing transcription factors with biocontrol potential in these fungi are scarce. This review begins by giving a basic overview of transcription factors and their functions. Then, the role of biocontrol-related transcription factors in biocontrol fungi is discussed. Lastly, possible approaches for further work on transcription factors in biocontrol fungi are suggested. This review provides a basis for further elaborating the molecular mechanisms of transcription factors in the context of biocontrol. Full article

Invertase (INV, EC3.2.1.26) is widely recognized as an indispensable enzyme for catalyzing sucrose degradation and plays a central role in plant growth as well as fruit quality improvement. However, no systematic study has been performed in kiwifruit. Here, we identified 102 AaINV genes in the Actinidia arguta “M1” genome. Their physical and chemical properties, subcellular localizations, phylogenetic relationships and expression profiles were characterized. Phylogenetic analysis showed that the INV members were clustered into three groups (vacuole invertases (VINVs) and cell wall invertases (CWINVs) in Group I, alkaline/neutral invertase (NINVs) in Group II and Group III), demonstrating evolutionary conservation in the INV family across Arabidopsis and Actinidia species. Gene replication analysis revealed that many AaINV genes were derived from gene duplication events. Molecular evolution analysis based on Ka/Ks ratios indicated that the INV members have experienced extensive purifying selection during evolution. To explore the potential gene functions, we integrated RNA-seq and metabolomics to analyze AaINV gene expression patterns and sugar accumulation in three A. arguta varieties (“Kukuwa”, “Qinhuang”, “Xianziguang”), respectively. The expression analysis of the 102 genes showed that the expression patterns varied among the three kiwifruit varieties at fruit maturity stage. The expression levels of AaINVs were also investigated via qRT-PCR in these varieties. Specifically, we constructed a complex regulatory network that regulates sugar metabolism in kiwifruit based on the correlation between 42 AaINV genes and 14 sugar metabolites. These findings provide insights into physiological functions of AaINVs in kiwifruit, especially roles in governing sugars accumulation in fruits. Full article

Thin-walled structures are extensively utilized in construction because of their lightweight nature and excellent energy absorption efficiency, especially under dynamic loads. Improving the energy-absorbing performance of thin-walled structures by inspiring natural multi-cell designs is a sufficient approach. This paper investigates the energy-absorbing characteristics of variable novel cross-section designs of thin-walled structures subjected to oblique impact loading. Straight and tapered types with seven cross-sectional designs of novel thin-walled structures were studied. The nonlinear ABAQUS/Explicit software 6.13 version was implemented to analyze the crashworthiness behaviors for the proposed variable cross-section designs under different loading angles. The crushing behaviors of the proposed thin-walled structures were examined for various wall thicknesses of 0.5 mm, 1.5 mm, and 2.5 mm and impact loading angles of 0°, 15°, 30°, and 45°. It was determined that the energy-absorbing characteristics of novel thin-walled structures can be efficiently controlled by varying two geometries and seven cross-section designs. A multi-criteria decision-making method (MCDM) using a complex proportional assessment method (COPRAS) was performed to select the optimum thin-walled structures with cross-section designs. It was shown that a tapered square thin-walled structure with 2.5 mm thickness had the best crashworthiness performances with energy absorption (EA) of 11.01 kJ and specific energy absorption (SEA) of 20.32 kJ/kg under a 30° impact angle. Moreover, the results indicated that the EA of the thin-walled structure decreased with the increase in the impact loading angle. In addition, with the increase in the impact loading angle, the peak crushing force (PCF) decreased and reflected the reduction in energy absorbed at a larger angle. The MCDM method in conjunction with the COPRAS method is proposed, it provides valuable insights for safer and more resilient building construction. Full article