Search Results (32)

Populus euphratica Oliv. serves as a keystone species in desert riparian ecosystems. Owing to its pronounced tolerance to drought and salinity, as well as its robust reproductive capacity, it has become a pioneer species in desert oases. The xyloglucan endotransglucosylase (XET)/hydrolase (XTH) gene family plays a critical role in the remodeling of plant cell walls; however, its potential biological functions in poplar remain poorly understood. In this study, we identified the XTH gene family in P. euphratica and conducted a preliminary functional analysis. A total of 33 PeXTH genes were identified, which were unevenly distributed across the chromosomes, with the highest density observed on chromosome 6. Conserved domain analysis indicated that most members contain the typical GH16 domain associated with xyloglucan endotransglucosylase activity. Phylogenetic analysis classified them into four distinct subgroups, exhibiting evolutionary conservation with the model dicot plant of Arabidopsis thaliana. Notably, the promoter analysis revealed an abundance of ABA-responsive and stress-related cis-elements, suggesting their potential involvement in response to multiple stresses. Under drought stress, PeXTH7 (PeuTF07G00088.1) exhibited a distinct expression pattern, with transcript levels significantly increasing with persistent treatment. RT-qPCR results confirmed that PeXTH7 is highly expressed in both roots and leaves. Furthermore, subcellular localization assays demonstrated that the PeXTH7 protein localizes to the secretory pathway and the cell wall, implying a role in cell wall dynamic remodeling through the regulation of xyloglucan metabolism. The PeXTH7-overexpressing transgenic lines exhibited a significant increase in root length compared to the wild-type controls. As the first systematic analysis of the XTH gene family in P. euphratica, this study fills an important knowledge gap and provides new insights into the adaptive mechanisms of desert tree species. Full article

Banana (Musa spp.) is a typical climacteric fruit. Xyloglucan endotransglucosylase/hydrolase (XTH) is a key factor regulating plant cell wall dynamic remodeling and participates in fruit ripening. To clarify the core physiological traits of banana ripening, four ripening stages of banana cultivar (Musa AAA ‘Minai No. 1’) fruits in the fully green stage (S1), green-yellow stage (S2), fully yellow stage (S3), and yellow with brown spots stage (S4) were used in this study’s experimental materials, to examine dynamic changes in key physiological–biochemical properties. The results showed that fruit firmness decreased continuously, starch content first increased then decreased, and soluble protein and total soluble solids (TSS) accumulated gradually during the ripening stages of banana fruits. Transcriptome analysis of the four stages found that there were 14,315 differentially expressed genes (DEGs) in S1 versus S4, the GO enrichment pathway is enriched in “protein dephosphorylation”, and the KEGG enrichment pathway is enriched in the “Protein processing in endoplasmic reticulum” and “Ubiquitin mediated proteolysis” pathways. The fruit ripening process involves the processing of numerous proteins. The heatmap revealed that MaXTH32.5 was significantly up-regulated during banana ripening and the result of RT-qPCR is consistent with the transcriptome data. A total of 989 XTH members across 16 Musa varieties of the XTH gene family were further identified. Among them, MaXTH32.5 localized at the chloroplast, and transient overexpression of MaXTH32.5 significantly reduced banana fruit firmness and may be involved in regulating ripening in banana fruits. This study indicated that the differential expression of XTH gene family members may regulate ripening-related processes in banana and MaXTH32.5 as a key candidate, providing insights into banana ripening mechanisms and a foundation for subsequent Musa XTH research. Full article

Xyloglucan endotransglucosylase/hydrolase (XTH) plays a significant role in plant responses and adaptation to abiotic stresses. However, the XTH gene family in Camellia oleifera remains largely unknown. Herein, 31 CoXTH genes from the C. oleifera genome, which were clustered into four evolutionary groups, were identified. Notably, CoXTH1, CoXTH6, CoXTH14, CoXTH28, and CoXTH31 showed significant upregulation under drought stress, suggesting their importance in stress responses. Furthermore, heterologous expression of CoXTH1, CoXTH14, and CoXTH28 in yeast improved yeast survival under drought stress. Overexpressing CoXTH1 in Arabidopsis thaliana significantly enhanced drought tolerance, characterized by improved seedling growth, increased antioxidant enzyme activity, and reduced reactive oxygen species (ROS) levels. Notably, transgenic expression of CoXTH1 significantly elevated the contents of xyloglucan, leading to increased cellulose, and hemicellulose contents in the plants. The elevated hemicellulose and cellulose strengthen the cell wall structure, maintaining cellular integrity and stability, and improving plant drought tolerance. These findings lay a foundation for understanding the functional roles of CoXTH genes and highlight CoXTH1 as a potential candidate gene for improving drought tolerance in C. oleifera and other woody crops. Full article

Tomato (Solanum lycopersicum L.) seedlings are prone to excessive growth in summer, especially severe overgrowth of the embryo axis. Paclobutrazol is a plant growth inhibitor that regulates the balance of hormones in plants and delays their growth. In this study, 200 mg·L⁻¹ paclobutrazol was sprayed onto highly homozygous inbred strain DH tomato seedlings at the two-leaf stage, which led to a significant reduction in the length of the epicotyl, an increase in the number of cells, a close cell arrangement, and a reduction in cell size. To study the mechanism by which paclobutrazol dwarfs the epicotyl of tomatoes, we utilized a combined analysis of the transcriptome and metabolome to identify potential candidate genes and regulatory pathways. The results revealed that after paclobutrazol treatment, both the flavonoid and phenylpropanoid biosynthesis pathways were jointly annotated. In addition, plant hormones and sucrose metabolism pathways were also discovered using transcriptome analysis. Xyloglucan endotransglucosylase/hydrolases (XTHs), small auxin-up RNAs (SAURs) and invertase family-related genes were detected, which can serve as key candidate genes for the subsequent analysis of epicotyl dwarfism in tomato plants. These results provide a framework for understanding the metabolic processes underlying epicotyl dwarfism and a foundation for preventing tomato seedling overgrowth. Full article

Xyloglucan endotransglucosylases/hydrolases (XTHs) are key enzymes involved in cell wall remodeling that play roles in plant responses to environmental stress. Despite their importance, a comprehensive investigation of the XTH gene family in cassava (Manihot esculenta Crantz), a crucial drought-tolerant crop in tropical and subtropical regions, has not yet been conducted. In the present study, we identified 37 XTH genes (MeXTH1-37) within the cassava genome, and most of them contain two conserved structures (Glyco_hydro_16 and XET_C domain). Phylogenetic analysis grouped 37 MeXTH genes into three distinct clades, a classification further supported by exon–intron organizations and the conserved protein motif architectures. Duplication events, particularly segmental duplication, were identified as the main driving force for MeXTH gene expansion in cassava. Comparative synteny analysis revealed orthologous relationships between MeXTH genes and XTH-related genes in seven other plant species, including soybean, poplar, tomato, Arabidopsis, maize, wheat, and rice. Global expression analysis revealed that MeXTH genes display different expression patterns in various cassava tissues, shedding light on their potential biological functions. Furthermore, quantitative real-time PCR (qRT-PCR) analysis of 12 representative MeXTH genes under salt and osmotic stress, as well as salicylic acid (SA) and methyl jasmonate (MeJA) treatments, demonstrated their differential responses to these stimuli. These results provide novel insights into the role of the MeXTH gene family in enhancing cassava’s tolerance to abiotic stress. Full article

Xyloglucan endotransglucosylase/hydrolases (XTHs) are a class of cell wall-associated enzymes involved in the construction and remodeling of cellulose/xyloglucan crosslinks. However, knowledge of this gene family in the model monocot Brachypodium distachyon is limited. A total of 29 BdXTH genes were identified from the whole genome, and these were further divided into three subgroups (Group I/II, Group III, and the Ancestral Group) through evolutionary analysis. Gene structure and protein motif analyses indicate that closely clustered BdXTH genes are relatively conserved within each group. A highly conserved amino acid domain (DEIDFEFLG) responsible for catalytic activity was identified in all BdXTH proteins. We detected three pairs of segmentally duplicated BdXTH genes and five groups of tandemly duplicated BdXTH genes, which played vital roles in the expansion of the BdXTH gene family. Cis-elements related to hormones, growth, and abiotic stress responses were identified in the promoters of each BdXTH gene, and when roots were treated with two abiotic stresses (salinity and drought) and four plant hormones (IAA, auxin; GA3, gibberellin; ABA, abscisic acid; and BR, brassinolide), the expression levels of many BdXTH genes changed significantly. Transcriptional analyses of the BdXTH genes in 38 tissue samples from the publicly available RNA-seq data indicated that most BdXTH genes have distinct expression patterns in different tissues and at different growth stages. Overexpressing the BdXTH27 gene in Brachypodium led to reduced root length in transgenic plants, which exhibited higher cellulose levels but lower hemicellulose levels compared to wild-type plants. Our results provide valuable information for further elucidation of the biological functions of BdXTH genes in the model grass B. distachyon. Full article

Aluminum (Al) dissolves from soil at low pH and is absorbed by plants, inhibiting their growth. Since most of the Al absorbed by plants is present in the cell wall, it is thought that the binding of Al to cell wall polysaccharides alters the properties of the cell wall and inhibits cell elongation. However, it remains unclear in which component of the cell wall Al accumulates. In this study, we determined the distribution of Al in rice root cell wall fractions under Al stress conditions. The results show that Al accumulates predominantly in the hemicellulose fraction, with star1 mutants accumulating significantly more Al than WT plants. An analysis of cell wall sugars revealed an increase in xyloglucan content under Al stress, which influenced the inhibition of root elongation. OsXTH19, a member of the xyloglucan endotransglucosylase/hydrolase (XTH) family, exhibits only xyloglucan endohydrolase (XEH) activity and lacks endotransglucosylase (XET) activity. OsXTH19 overexpressor rice (OsXTH19-OX) enhances the degradation of xyloglucan. Furthermore, OsXTH19-OX rice with reduced xyloglucan levels exhibited reduced Al accumulation and enhanced root growth under Al stress. Full article

Xyloglucan endotransglucosylase/hydrolase (XTH) is a crucial enzyme in plant cell wall remodeling, which contributes to plant growth, development, and stress response. Based on the transcriptome data of Larix kaempferi, this study identified and analyzed 16 XTH genes. Sequence alignment and phylogenetic analysis indicated that the LkXTH gene family can be divided into three subfamilies, namely the Early Diverging Group, Group I/II, and Group III, all of which share highly conserved motifs and structural features. Expression profiling demonstrated that LkXTH genes are actively expressed in the roots, stems, and leaves of L. kaempferi. Under drought stress, the expression of LkXTH1, LkXTH2, LkXTH3, LkXTH4, LkXTH6, LkXTH14, LkXTH15, LkXTH17, and LkXTH18 increased rapidly in roots. Meanwhile, the expression levels of LkXTH5, LkXTH7, LkXTH8, and LkXTH13 exhibited significant upregulation in leaves. Notably, LkXTH11 and LkXTH16 significantly increased in both roots and leaves, with a more pronounced increase in leaves, but LkXTH10 displayed significant upregulation in the stems. Furthermore, the heterologous expression of LkXTH1 and LkXTH17 in yeast significantly enhances drought tolerance. These findings indicate that individual LkXTH genes exhibit distinct organ-specific responses to drought stress, thereby advancing our understanding of their functional roles in larch drought response. Full article

The cell wall, acting as the first line of defense against aluminum (Al) toxicity, is the primary cellular structure that encounters and perceives Al³⁺. Xyloglucan endotransglucosylase/hydrolase (XTH) plays a pivotal role in mediating cell wall remodeling, a critical mechanism for Al toxicity tolerance. In our previous studies, the candidate gene BnaXTH22 was identified through GWAS and RNA-seq analyses. Under Al toxicity stress, overexpression lines (OEs) exhibited a significant increase in the relative elongation of taproots (9.44–13.32%) and total root length (8.15–12.89%) compared to the wild type (WT). Following Al treatment, OEs displayed reduced MDA content and lower relative electrical conductivity, alongside a significantly higher root activity than WT. Transcriptomic analysis revealed that differentially expressed genes in OE under Al toxicity were predominantly enriched in stress-related biological processes, including phenylpropanoid metabolism, fatty acid biosynthesis, and lignin biosynthesis. These results suggest that BnaXTH22 overexpression could enhance Al toxicity tolerance in rapeseed, potentially by modulating cell wall synthesis to bolster plant resistance. 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

Mexico is the center of origin and the leading exporter of papaya (Carica papaya) to the United States of America and Canada. The changes in the fruit’s firmness during ripening result from the action of several enzymes implicated in the synthesis/hydrolysis of cell wall polysaccharides. A vast family of genes encodes xyloglucan endotransglucosylase/hydrolase (XTH) enzymes, which act on cellulose-bound xyloglucan bonds. There are few reports on the action of the XTH6 and XTH23 genes; therefore, their participation in the fruit development and maturity processes has yet to be fully known. The expression levels of the CpXTH6 and CpXTH23 genes, and their correlation with firmness, at different stages of development and ripening of the C. papaya fruit were determined in this work. The CpXTH6 and CpXTH23 genes reached their highest expression level during fruit development. These results suggest that these genes are activated in papaya mainly during fruit development to encode the enzymes that allow cell growth and maintain fruit firmness. These findings could be used to target papaya breeding texture quality and the speed of fruit growth. Full article

As key enzymes in the gibberellin (GA) biosynthesis pathway, GAoxs function as regulators of bioactive GA levels and plant architecture, yet little is understood about GAoxs in Gossypium. In this study, 78 GAox genes identified in four cotton species were divided into three subgroups: GA2ox, GA3ox, and GA20ox. Syntenic relationships of GAoxs in Gossypium suggested that divergencies in gene function may be attributed to whole-genome duplication during evolution. Cis-acting element analysis suggested that the GbGAox genes might participate in plant growth, development, and hormone responses. Moreover, transcriptome analysis was performed to characterize the molecular response of the exogenous GA₃ application. It was found that DEGs (differentially expressed genes) are widely involved in cell division and cell wall modification, in which the most XTH (xyloglucan endotransglucosylase/hydrolase) and GAox genes responded actively to the exogenous GA₃ treatment. Some transcription factors and protein kinases cooperated with those GbGAoxs in response to GA₃. These findings underlie the biological function of GAox genes and their responses to GA₃ in regulating plant growth in Gossypium barbadense. Full article

Plant height represents a pivotal agronomic trait for the genetic enhancement of crops. The plant cell wall, being a dynamic entity, is crucial in determining plant stature; however, the regulatory mechanisms underlying cell wall remodeling remain inadequately elucidated. This study demonstrates that the application of gibberellin 3 (GA3) enhances both plant height and cell wall remodeling in tomato (Solanum lycopersicum L.) plants. RNA sequencing (RNA-seq) results of GA3 treatment showed that the DEGs were mostly enriched for cell wall-related pathways; specifically, GA3 treatment elicited the expression of the cell wall-associated gene XYLOGLUCAN ENDOTRANSGLUCOSYLASE/HYDROLASE 19 (SlXTH19), whose overexpression resulted in increased plant height. Comparative analyses revealed that SlXTH19-overexpressing lines exhibited larger cell dimensions and increased XTH activity, along with higher contents of lignin, cellulose, and hemicellulose, thereby underscoring the gene’s role in maintaining cell wall integrity. Conversely, treatments with ethephon (ETH) and 1-Naphthaleneacetic acid (NAA) led to suppressed plant height and reduced SlXTH19 expression. Collectively, these findings illuminate a competitive interplay between GA and ethylene/auxin signaling pathways in regulating cell wall remodeling via SlXTH19 activation, ultimately influencing tomato plant height. Full article

The Xyloglucan endotransglucosylase/hydrolase (XTH) family, a group of cell wall-modifying enzymes, plays crucial roles in plant growth, development, and stress adaptation. The quality and yield of Chinese jujube (Ziziphus jujuba) fruit are significantly impacted by environmental stresses, including excessive salinity, drought, freezing, and disease. However, there has been no report of the XTH encoding genes present in the Chinese jujube genome and their response transcription level under various stresses. This study provides an in-depth analysis of ZjXTH genes in the genome of Chinese jujube and elucidates their structural motifs, regulatory networks, and expression patterns under various stresses. A total of 29 ZjXTH genes were identified from the Ziziphus jujuba genome. Phylogenetic analysis classifies ZjXTH genes into four distinct groups, while conserved motifs and domain analyses reveal coordinated xyloglucan modifications, highlighting key shared motifs and domains. Interaction network predictions suggest that ZjXTHs may interact with proteins such as Expansin-B1 (EXPB1) and Pectin Methylesterase 22 (PME22). Additionally, cis-regulatory element analysis enhances our understanding of Chinese jujube plant’s defensive systems, where TCA- and TGACG-motifs process environmental cues and orchestrate stress responses. Expression profiling revealed that ZjXTH1 and ZjXTH5 were significantly upregulated under salt, drought, freezing, and phytoplasma infection, indicating their involvement in biotic and abiotic stress responses. Collectively, these findings deepen our understanding of the functional roles of Chinese jujube XTHs, emphasizing their regulatory function in adaptive responses in Chinese jujube plants. Full article

The xyloglucan endotransglucosylase/hydrolase (XTH) family is an important multigene family in plants that plays a key role in cell wall reconstruction and stress tolerance. However, the specific traits of XTH genes and their expression patterns under different stresses have not been systematically studied in melon. In this study, based on the genomic data of Cucumis melon, 29 XTH genes were identified; most of these genes contain two conserved domains (Glyco_hydro_16 and XET_C domains). Based on neighbor-joining phylogenetic analysis, the CmXTHs were divided into four subfamilies, I/II, IIIA, and IIIB, which are distributed across nine chromosomes of melon. Collinearity analysis showed that the melon XTH genes have an evolutionary history consistent with three species: Arabidopsis, tomato, and cucumber. The promoter regions of the CmXTH genes contain numerous cis-acting elements, which are associated with plant growth, hormonal response, and stress responses. RNA-Seq analysis indicated that CmXTH genes exhibit different expression patterns under drought and salt stress treatments, suggesting that this gene family plays an important role under abiotic stress. This study provides a theoretical basis for further studies on the molecular function of XTH genes in melon. Full article