Cellulose Synthase Genes Research Articles

Unveiling the secrets of lotus seed longevity: insights into adaptive strategies for extended storage.

Seed longevity is crucial for long-term storage, but prolonged unfavorable conditions can lead to viability loss. This study integrated theoretical and experimental techniques to elucidate the inherent mechanisms underlying the unique ability of lotus seed capacity to maintain stable viability even after enduring years. Transcriptome analysis and microscopy revealed the sturdy structure of the lotus seed pericarp, which predominantly expressed cellulose synthase genes involved in cell wall biogenesis. The cotyledon serves as a nutrient source for seeds during long-term storage. Additionally, the inactivation of chlorophyll degradation pathways may allow for the retention of chlorophyll in the lotus seed plumule, potentially enhancing the environmental adaptability of lotus seedlings. While the reduced abundance of transcripts corresponding to heat shock protein genes could impact protein processing and consequently diminish the vitality of aging lotus seeds. Moreover, an expansion in the number of seed maturation and defense response genes was observed in the lotus genome compared to other 11 species, which might represent an adaptive strategy against long-term adverse storage conditions. Overall, these findings are crucial for understanding the mechanisms underlying lotus seed longevity and may inform future improvements in the extended storage periods of seed crops.

Genome-wide analysis of cellulose synthase (CesA) and cellulose synthase-like (Csl) proteins in Cannabis sativa L

The cellulose and hemicellulose components of plant cell walls are synthesized by the cellulose synthase (CESA) and cellulose synthase-like (CSL) gene families and regulated in response to growth, development, and environmental stimuli. In this study, a total of 29 CESA/CSL family members were identified in Cannabis sativa and were grouped into seven subfamilies (CESA, CSLA, CSLB, CSLC, CSLD, CSLE and CSLG) according to phylogenetic relationships. The CESA/CESA proteins of C. sativa were closely related phylogenetically to the members of the subfamily of other species. The CESA/CSL subfamily members of C. sativa have unique gene structures. In addition, the expressions of four CESA and 10 CsCSL genes in flower, leaf, root, and stem organs of cannabis were detected using RT-qPCR. The results showed that CESA and CSL genes are expressed at varying levels in several organs. This detailed knowledge of the structural, evolutionary, and functional properties of cannabis CESA/CSL genes will provide a basis for designing advanced experiments for genetic manipulation of cell wall biogenesis to improve bast fibers and biofuel production.

Study of the expression of cellulose synthase genes during plant growth of flax

Study of the expression of cellulose synthase genes during plant growth of flax

Transcriptomic analysis of the response of Avena sativa to Bacillus amyloliquefaciens DGL1.

Bacillus amyloliquefaciens DGL1, isolated from the arid sandy areas in Dagler, Qinghai Province, China, promotes the growth of Avena sativa variety "Qing Yan 1". To elucidate the transcriptomic changes in the oat root system following interaction with DGL1 and to reveal the molecular mechanism by which DGL1 promotes oat growth, treatment and control groups of oat roots at 2, 4, 8, and 12 h after inoculation with a suspension of strain DGL1 were analyzed using Illumina high-throughput transcriptome sequencing technology. The differentially expressed genes were determined through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses, and the metabolic pathways and key genes were analyzed. The results showed that 7874, 13,392, 13,169, and 19,026 differentially expressed genes were significantly enriched in the glycolysis/gluconeogenesis pathway, amino acid metabolism, nitrogen metabolism, plant hormone signal transduction, and other related metabolic pathways in the oat roots at 2, 4, 8, and 12 h after inoculation with a DGL1 suspension. The GO and KEGG enrichment analyses revealed that the genes encoding plasma membrane ATPase, phosphoglycerate kinase gene PGK, ammonium transporter protein gene AMT, cellulose synthase gene CSLF6, and growth hormone response family gene IAA18 were significantly upregulated. It is hypothesized that the pro-growth mechanism of strain DGL1 in oats is the result of the coordination of multiple pathways through the promotion of oat energy metabolism, phytohormone signaling, secondary metabolite synthesis, and amino acid metabolism.

Cloning and functional mechanism of the dwarf gene gba affecting stem elongation and cellulose biosynthesis in jute (Corchorus olitorius).

Plant height (PH) is an important factor affecting bast fiber yield in jute. Here, we report the mechanism of dwarfism in the 'Guangbaai' (gba) of jute. The mutant gba had shorter internode length and cell length compared to the standard cultivar 'TaiZi 4' (TZ4). Exogenous GA3 treatment indicated that gba is a GA-insensitive dwarf mutant. Quantitative trait locus (QTL) analysis of three PH-related traits via a high-density genetic linkage map according to re-seq showed that a total of 25 QTLs were identified, including 13 QTLs for PH, with phenotypic variation explained ranging from 2.42 to 74.16%. Notably, the functional mechanism of the candidate gene CoGID1a, the gibberellic acid receptor, of the major locus qPHIL5 was evaluated by transgenic analysis and virus-induced gene silencing. A dwarf phenotype-related single nucleotide mutation in CoGID1a was identified in gba, which was also unique to the dwarf phenotype of gba among 57 cultivars. Cogid1a was unable to interact with the growth-repressor DELLA even in the presence of highly accumulated gibberellins in gba. Differentially expressed genes between transcriptomes of gba and TZ4 after GA3 treatment indicated up-regulation of genes involved in gibberellin and cellulose synthesis in gba. Interestingly, it was found that up-regulation of CoMYB46, a key transcription factor in the secondary cell wall, by the highly accumulated gibberellins in gba promoted the expression of cellulose synthase genes CoCesA4 and CoCesA7. These findings provide valuable insights into fiber development affected by endogenous gibberellin accumulation in plants.

Genome-wide analysis of cellulose synthase gene superfamily in Tectona grandis L.f.

The online version contains supplementary material available at 10.1007/s13205-024-03927-6.

High-quality genomes of Bombax ceiba and Ceiba pentandra provide insights into the evolution of Malvaceae species and differences in their natural fiber development

Members of the Malvaceae family, including Corchorus spp., Gossypium spp., Bombax spp., and Ceiba spp., are important sources of natural fibers. In the past decade, the genomes of several Malvaceae species have been assembled; however, the evolutionary history of Malvaceae species and the differences in their fiber development remain to be clarified. Here, we report the genome assembly and annotation of two natural fiber plants from the Malvaceae, Bombax ceiba and Ceiba pentandra, whose assembled genome sizes are 783.56 Mb and 1575.47 Mb, respectively. Comparative analysis revealed that whole-genome duplication and Gypsy long terminal repeat retroelements have been the major causes of differences in chromosome number (2n = 14 to 2n = 96) and genome size (234 Mb to 2676 Mb) among Malvaceae species. We also used comparative genomic analyses to reconstruct the ancestral Malvaceae karyotype with 11 proto-chromosomes, providing new insights into the evolutionary trajectories of Malvaceae species. MYB-MIXTA-like 3 is relatively conserved among the Malvaceae and functions in fiber cell-fate determination in the epidermis. It appears to perform this function in any tissue where it is expressed, i.e. in fibers on the endocarp of B. ceiba and in ovule fibers of cotton. We identified a structural variation in a cellulose synthase gene and a higher copy number of cellulose synthase-like genes as possible causes of the finer, less spinnable, weaker fibers of B. ceiba. Our study provides two high-quality genomes of natural fiber plants and offers insights into the evolution of Malvaceae species and differences in their natural fiber formation and development through multi-omics analysis.

Exogenous applications of brassinosteroids promote secondary xylem differentiation in Eucalyptus grandis.

Brassinosteroids (BRs) play many pivotal roles in plant growth and development, especially in cell elongation and vascular development. Although its biosynthetic and signal transduction pathway have been well characterized in model plants, their biological roles in Eucalyptus grandis, a major hardwood tree providing fiber and energy worldwide, remain unclear. Here, we treated E. grandis plantlets with 24-epibrassinolide (EBL), the most active BR and/or BR biosynthesis inhibitor brassinazole. We recorded the plant growth and analyzed the cell structure of the root and stem with histochemical methods; then, we performed a secondary growth, BR synthesis, and signaling-related gene expression analysis. The results showed that the BRs dramatically increased the shoot length and diameter, and the exogenous BR increased the xylem area of the stem and root. In this process, EgrBRI1, EgrBZR1, and EgrBZR2 expression were induced by the BR treatment, and the expressions of HD-ZIPIII and cellulose synthase genes were also altered. To further verify the effect of BRs in secondary xylem development in Eucalyptus, we used six-month-old plants as the material and directly applied EBL to the xylem and cambium of the vertical stems. The xylem area, fiber cell length, and cell numbers showed considerable increases. Several key BR-signaling genes, secondary xylem development-related transcription factor genes, and cellulose and lignin biosynthetic genes were also considerably altered. Thus, BR had regulatory roles in secondary xylem development and differentiation via the BR-signaling pathway in this woody plant.

Wall-associated kinase GhWAK13 mediates arbuscular mycorrhizal symbiosis and Verticillium wilt resistance in cotton.

The cell wall is the major interface for arbuscular mycorrhizal (AM) symbiosis. However, the roles of cell wall proteins and cell wall synthesis in AM symbiosis remain unclear. We reported that a novel wall-associated kinase 13 (GhWAK13) positively regulates AM symbiosis and negatively regulates Verticillium wilt resistance in cotton. GhWAK13 transcription was induced by AM symbiosis and Verticillium dahliae (VD) infection. GhWAK13 is located in the plasma membrane and expressed in the arbuscule-containing cortical cells of mycorrhizal cotton roots. GhWAK13 silencing inhibited AM colonization and repressed gene expression of the mycorrhizal pathway. Moreover, GhWAK13 silencing improved Verticillium wilt resistance and triggered the expression of immunity genes. Therefore, GhWAK13 is considered an immune suppressor required for AM symbiosis and disease resistance. GhWAK7A, a positive regulator of Verticillium wilt resistance, was upregulated in GhWAK13-silenced cotton plants. Silencing GhWAK7A improved AM symbiosis. Oligogalacturonides application also suppressed AM symbiosis. Finally, GhWAK13 negatively affected the cellulose content by regulating the transcription of cellulose synthase genes. The results of this study suggest that immunity suppresses AM symbiosis in cotton. GhWAK13 affects AM symbiosis by suppressing immune responses.

Physiology and Gene Expression Analysis of Tomato (Solanum lycopersicum L.) Exposed to Combined-Virus and Drought Stresses.

Crop productivity can be obstructed by various biotic and abiotic stresses and thus these stresses are a threat to universal food security. The information on the use of viruses providing efficacy to plants facing growth challenges owing to stress is lacking. The role of induction of pathogen-related genes by microbes is also colossal in drought-endurance acquisition. Studies put forward the importance of viruses as sustainable means for defending plants against dual stress. A fundamental part of research focuses on a positive interplay between viruses and plants. Notably, the tomato yellow leaf curl virus (TYLCV) and tomato chlorosis virus (ToCV) possess the capacity to safeguard tomato host plants against severe drought conditions. This study aims to explore the combined effects of TYLCV, ToCV, and drought stress on two tomato cultivars, Money Maker (MK, UK) and Shalala (SH, Azerbaijan). The expression of pathogen-related four cellulose synthase gene families (CesA/Csl) which have been implicated in drought and virus resistance based on gene expression analysis, was assessed using the quantitative real-time polymerase chain reaction method. The molecular tests revealed significant upregulation of Ces-A2, Csl-D3,2, and Csl-D3,1 genes in TYLCV and ToCV-infected tomato plants. CesA/Csl genes, responsible for biosynthesis within the MK and SH tomato cultivars, play a role in defending against TYLCV and ToCV. Additionally, physiological parameters such as "relative water content," "specific leaf weight," "leaf area," and "dry biomass" were measured in dual-stressed tomatoes. Using these features, it might be possible to cultivate TYLCV-resistant plants during seasons characterized by water scarcity.

Expression and possible functions of a horizontally transferred glycosyl hydrolase gene, GH6-1, in Ciona embryogenesis

BackgroundThe Tunicata or Urochordata is the only animal group with the ability to synthesize cellulose directly and cellulose is a component of the tunic that covers the entire tunicate body. The genome of Ciona intestinalis type A contains a cellulose synthase gene, CesA, that it acquired via an ancient, horizontal gene transfer. CesA is expressed in embryonic epidermal cells and functions in cellulose production. Ciona CesA is composed of both a glycosyltransferase domain, GT2, and a glycosyl hydrolase domain, GH6, which shows a mutation at a key position and seems functionless. Interestingly, the Ciona genome contains a glycosyl hydrolase gene, GH6-1, in which the GH6 domain seems intact. This suggests expression and possible functions of GH6-1 during Ciona embryogenesis. Is GH6-1 expressed during embryogenesis? If so, in what tissues is the gene expressed? Does GH6-1 serve a function? If so, what is it? Answers to these questions may advance our understanding of evolution of this unique animal group.ResultsQuantitative reverse transcription PCR and in situ hybridization revealed that GH6-1 is expressed in epidermis of tailbud embryos and in early swimming larvae, a pattern similar to that of CesA. Expression is downregulated at later stages and becomes undetectable in metamorphosed juveniles. The GH6-1 expression level is higher in the anterior-trunk region and caudal-tip regions of late embryos. Single-cell RNA sequencing analysis of the late tailbud stage showed that cells of three clusters with epidermal identity express GH6-1, and that some of them co-express CesA. TALEN-mediated genome editing was used to generate GH6-1 knockout Ciona larvae. Around half of TALEN-electroporated larvae showed abnormal development of adhesive papillae and altered distribution of surface cellulose. In addition, three-fourths of TALEN-electroporated animals failed to complete larval metamorphosis.ConclusionsThis study showed that tunicate GH6-1, a gene that originated by horizontal gene transfer of a prokaryote gene, is recruited into the ascidian genome, and that it is expressed and functions in epidermal cells of ascidian embryos. Although further research is required, this observation demonstrates that both CesA and GH6-1 are involved in tunicate cellulose metabolism, impacting tunicate morphology and ecology.

Galactosylation of xyloglucan is essential for the stabilization of the actin cytoskeleton and endomembrane system through the proper assembly of cell walls.

Xyloglucan, a major hemicellulose, interacts with cellulose and pectin to assemble primary cell walls in plants. Loss of the xyloglucan galactosyltransferase MURUS3 (MUR3) leads to the deficiency of galactosylated xyloglucan and perturbs plant growth. However, it is unclear whether defects in xyloglucan galactosylation influence the synthesis of other wall polysaccharides, cell wall integrity, cytoskeleton behaviour, and endomembrane homeostasis. Here, we found that in mur3-7 etiolated seedlings cellulose was reduced, CELLULOSE SYNTHASE (CESA) genes were down-regulated, the density and mobility of cellulose synthase complexes (CSCs) were decreased, and cellulose microfibrils become discontinuous. Pectin, rhamnogalacturonan II (RGII), and boron contents were reduced in mur3-7 plants, and B-RGII cross-linking was abnormal. Wall porosity and thickness were significantly increased in mur3-7 seedlings. Endomembrane aggregation was also apparent in the mur3-7 mutant. Furthermore, mutant seedlings and their actin filaments were more sensitive to Latrunculin A (LatA) treatment. However, all defects in mur3-7 mutants were substantially restored by exogenous boric acid application. Our study reveals the importance of MUR3-mediated xyloglucan galactosylation for cell wall structural assembly and homeostasis, which is required for the stabilization of the actin cytoskeleton and the endomembrane system.

Sucrose metabolism analysis in a high sucrose sugarcane mutant clone at a mature stage in contrast to low sucrose parental clone through the transcriptomic approach

BackgroundThe significance of sugarcane as a major crop is due to the production of sucrose and a significant source of ethanol. Sucrose phosphate synthase (SPS), Sucrose synthase (SuSy), and cell wall invertase (CWIN) genes regulate sucrose metabolism and accumulation in high sucrose sugarcane; such genes are significant for manipulating sucrose content. The current study explored the genes associated with sucrose metabolism and accumulation in a high sucrose sugarcane mutant clone GXB9 compared to its low sucrose parental clone B9.ResultsA total of 100, 262 differentially expressed genes were obtained, and 69, 637 (69.46%) got annotation in public databases COG, GO, KEGG, KOG, Pfam, eggNOG, NR, and Swiss-Prot. The SPS5 gene was significantly up-regulated in the maturing internodes of GXB9 and downregulated in B9. The SuSy and CWIN genes were up-regulated in the immature internodes; however, no expression was found in the maturing internodes of GXB9. The genes involved in trehalose synthesis were downregulated in GXB9 while up-regulated in B9. The cellulose synthase (CeS) genes were significantly up-regulated in the immature internodes than in maturing internodes of GXB9.ConclusionsThe key finding of this research suggests that the SPS5 gene has a predominant role in enhancing the sucrose accumulation ability of GXB9. No expression of SuSy and CWIN genes in maturing internodes and downregulation of trehalose genes in GXB9 may also have contributed to the higher sucrose accumulation in the stalk of high sucrose mutant. The current finding is a source for sugarcane breeding, particularly improving sucrose content.Graphical

The RLCK–VND6 module coordinates secondary cell wall formation and adaptive growth in rice

The orderly deposition of secondary cell wall (SCW) in plants is implicated in various biological programs and is precisely controlled. Although many positive and negative regulators of SCW have been documented, the molecular mechanisms underlying SCW formation coordinated with distinct cellular physiological processes during plant adaptive growth remain largely unclear. Here, we report the identification of Cellulose Synthase co-expressed Kinase1 (CSK1), which encodes a receptor-like cytoplasmic kinase, as a negative regulator of SCW formation and its signaling cascade in rice. Transcriptome deep sequencing of developing internodes and genome-wide co-expression assays revealed that CSK1 is co-expressed with cellulose synthase genes and is responsive to various stress stimuli. The increased SCW thickness and vigorous vessel transport in csk1 indicate that CSK1 functions as a negative regulator of SCW biosynthesis. Through observation of green fluorescent protein-tagged CSK1 in rice protoplasts and stable transgenic plants, we found that CSK1 is localized in the nucleus and cytoplasm adjacent to the plasma membrane. Biochemical and molecular assays demonstrated that CSK1 phosphorylates VASCULAR-RELATED NAC-DOMAIN 6 (VND6), a master SCW-associated transcription factor, in the nucleus, which reduces the transcription of a suite of SCW-related genes, thereby attenuating SCW accumulation. Consistently, genetic analyses show that CSK1 functions upstream of VND6 in regulating SCW formation. Interestingly, our physiological analyses revealed that CSK1 and VND6 are involved in abscisic acid-mediated regulation of cell growth and SCW deposition. Taken together, these results indicate that the CSK1–VND6 module is an important component of the SCW biosynthesis machinery, which coordinates SCW accumulation and adaptive growth in rice. Our study not only identifies a new regulator of SCW biosynthesis but also reveals a fine-tuned mechanism for precise control of SCW deposition, offering tools for rationally tailoring agronomic traits.

Genome-wide characterization of the cellulose synthase gene family in Ziziphus jujuba reveals its function in cellulose biosynthesis during fruit development

The cellulose synthase (Ces/Csl) is a key enzyme in plant cellulose synthesis. Jujube fruits are rich in cellulose. 29 ZjCesA/Csl genes were identified in jujube genome and showed tissue-specific expression. 13 genes highly expressed in jujube fruit exhibited obviously sequential expressions during the fruit development, indicating that they might play distinct roles during the process. Meanwhile, the correlation analysis showed the expressions of ZjCesA1 and ZjCslA1 were significant positive related to the cellulose synthase activities. Furthermore, transient overexpressions of ZjCesA1 or ZjCslA1 in jujube fruits significantly increased cellulose synthase activities and contents, whereas silencing of ZjCesA1 or ZjCslA1 in jujube seedlings obviously reduced cellulose levels. Moreover, the Y2H assays verified that ZjCesA1 and ZjCslA1 may participate in cellulose synthesis by forming protein complexes. The study not only reveals the bioinformatics characteristics and functions of cellulose synthase genes in jujube, but also provides clues for studying cellulose synthesis in other fruits.

Comparative physiological and transcriptome analysis in cultivated and wild sugarcane species in response to hydrogen peroxide-induced oxidative stress

BackgroundSugarcane is an important energy crop grown worldwide,supplementing various renewable energy sources. Cultivated and wild sugarcane species respond differently to biotic and abiotic stresses. Generally, wild species are tolerant to various abiotic stresses. In the present study, the physiological and molecular responses of cultivated and wild sugarcane species to oxidative stress at the transcriptional levels were compared. Transcriptional responses were determined using RNAseq. The representative RNA-seq transcript values were validated by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) and confirmed through physiological responses.ResultsOxidative stress causes leaf-rolling and -tip drying in cultivated sugarcane, but the wild species are tolerant. Higher chlorophyll fluorescence was observed in the wild species than that in the cultivated varieties under stress. Wild species can maintain a higher chlorophyll stability index than the cultivated species, which was confirmed by the lower transcripts of the chlorophyllase gene in the wild species than that in the cultivated variety. Transcription factor genes (NAC, MYB, and WRKY) were markedly expressed in response to oxidative stress, revealing their involvement in stress tolerance. The analysis revealed synchronized expression of acetyl-transferase, histone2A, cellulose synthase, and secondary cell wall biosynthetic genes in the wild species. The validation of selected genes and 15 NAC transcription factors using RT-qPCR revealed that their expression profiles were strongly correlated with RNA-seq. To the best of our knowledge, this is the first report on the oxidative stress response in cultivated and wild sugarcane species.ConclusionPhysiological and biochemical changes in response to oxidative stress markedly differ between cultivated and wild sugarcane species. The differentially expressed stress-responsive genes are grouped intothe response to oxidative stress, heme-binding, peroxidase activity, and metal ion binding categories. Chlorophyll maintenance is a stress tolerance response enhanced by the differential regulation of the chlorophyllase gene.There is a considerable difference in the chlorophyll stability index between wild and cultivated varieties. We observed a substantial regulation of secondary wall biosynthesis genes in the wild species compared with that in the cultivated variety, suggesting differences in stress tolerance mechanisms.

Integrated analysis of transcriptome and microRNAs associated with exogenous calcium-mediated enhancement of hypoxic tolerance in cucumber seedlings (Cucumis sativus L.).

Plants often suffer from hypoxic stress due to flooding caused by extreme weather. Hypoxia usually leads to restricted oxygen supply and alters metabolic patterns from aerobic to anaerobic. Cucumber roots are fragile and highly sensitive to damage from hypoxic stress. The purpose of this study was to investigate the regulatory mechanism of exogenous calcium alleviating hypoxic stress in cucumber through transcriptome and small RNAs analysis. Three treatments were performed in this paper, including untreated-control (CK), hypoxic stress (H), and hypoxic stress + exogenous calcium treatment (H + Ca2+). A large number of differentially expressed genes (DEGs) were identified, 1,463 DEGs between CK vs H, 3,399 DEGs between H vs H + Ca2+, and 5,072 DEGs between CK vs H + Ca2+, respectively. KEGG analysis of DEGs showed that exogenous calcium could activate hormone signaling pathways (ethylene, ABA, IAA and cytokinin), transcription factors (MYB, MYB-related, bHLH, bZIP, and WRKY), calcium signaling and glycolysis pathway to mitigating hypoxic stress in cucumber seedlings. Additionally, miRNA and their target genes were detected and predicted between treatments. The target genes of these miRNAs revealed that auxin, cellulose synthase, and mitochondrial ribosomal related genes (Csa2G315390, Csa6G141390, Csa4G053280, and Csa6G310480) probably play in the improvement of the hypoxic tolerance of cucumber seedlings through exogenous calcium application. In short, our data adds new information to the mechanism of exogenous calcium mitigation of hypoxic stress injury in cucumber seedlings at transcriptional and post-transcriptional levels.

Tissue specific expression of bacterial cellulose synthase (Bcs) genes improves cotton fiber length and strength

Fiber growing inside the cotton bolls is a highly demandable product and its quality is key to the success of the textile industry. Despite the various efforts to improve cotton fiber staple length Pakistan has to import millions of bales to sustain its industrial needs. To improve cotton fiber quality Bacterial cellulose synthase (Bcs) genes (acsA, acsB) were expressed in a local cotton variety CEMB-00. In silico studies revealed a number of conserved domains both in the cotton-derived and bacterial cellulose synthases which are essential for the cellulose synthesis. Transformation efficiency of 1.27% was achieved by using Agrobacterium shoot apex cut method of transformation. The quantitative mRNA expression analysis of the Bcs genes in transgenic cotton fiber was found to be many folds higher during secondary cell wall synthesis stage (35 DPA) than the expression during elongation phase (10 DPA). Average fiber length of the transgenic cotton plant lines S-00–07, S-00–11, S-00–16 and S-00–23 was calculated to be 13.02% higher than that of the non-transgenic control plants. Likewise, the average fiber strength was found to be 20.92% higher with an enhanced cellulose content of 22.45%. The mutated indigenous cellulose synthase genes of cotton generated through application of CRISPR/Cas9 resulted in 6.03% and 12.10% decrease in fiber length and strength respectively. Furthermore, mature cotton fibers of transgenic cotton plants were found to have increased number of twists with smooth surface as compared to non-transgenic control when analyzed under scanning electron microscope. XRD analysis of cotton fibers revealed less cellulose crystallinity index in transgenic cotton fibers as compared to control fibers due to deposition of more amorphous cellulose in transgenic fibers as a result of Bcs gene expression. This study paved the way towards unraveling the fact that Bcs genes influence cellulose synthase activity and this enzyme helps in determining the fate of cotton fiber length and strength.

Brittle culm 3, encoding a cellulose synthase subunit 5, is required for cell wall biosynthesis in barley (Hordeum vulgare L.).

The cell wall plays an important role in plant mechanical strength. Cellulose is the major component of plant cell walls and provides the most abundant renewable biomass resource for biofuels on earth. Mutational analysis showed that cellulose synthase (CESA) genes are critical in cell wall biosynthesis in cereal crops like rice. However, their role has not been fully elucidated in barley. In this study, we isolated a brittle culm mutant brittle culm 3 (bc3) derived from Yangnongpi 5 ethyl methanesulfonate (EMS) mutagenesis in barley. The bc3 mutants exhibited reduced mechanical strength of the culms due to impaired thickening of the sclerenchyma cell wall and reduced cellulose and hemicellulose content in the culms. Genetic analysis and map-based cloning revealed that the bc3 mutant was controlled by a single recessive gene and harbored a point mutation in the HvCESA5 gene, generating a premature stop codon near the N-terminal of the protein. Quantitative real-time PCR (qRT-PCR) analysis showed that the HvCESA5 gene is predominantly expressed in the culms and co-expressed with HvCESA4 and HvCESA8, consistent with the brittle culm phenotype of the bc3 mutant. These results indicate that the truncated HvCESA5 affects cell wall biosynthesis leading to a brittle culm phenotype. Our findings provide evidence for the important role of HvCESA5 in cell wall biosynthesis pathway and could be a potential target to modify cell wall in barley.

Genome-wide identification and functional analysis of Cellulose synthase gene superfamily in Fragaria vesca.

The Cellulose synthase (CesA) and Cellulose synthase-like (Csl) gene superfamilies encode key enzymes involved in the synthesis of cellulose and hemicellulose, which are major components of plant cell walls, and play important roles in the regulation of fruit ripening. However, genome-wide identification and functional analysis of the CesA and Csl gene families in strawberry remain limited. In this study, eight CesA genes and 25 Csl genes were identified in the genome of diploid woodland strawberry (Fragaria vesca). The protein structures, evolutionary relationships, and cis-acting elements of the promoter for each gene were investigated. Transcriptome analysis and quantitative real-time PCR (qRT-PCR) results showed that the transcript levels of many FveCesA and FveCsl genes were significantly decreased during fruit ripening. Moreover, based on the transcriptome analysis, we found that the expression levels of many FveCesA/Csl genes were changed after nordihydroguaiaretic acid (NDGA) treatment. Transient overexpression of FveCesA4 in immature strawberry fruit increased fruit firmness and reduced fresh fruit weight, thereby delaying ripening. In contrast, transient expression of FveCesA4-RNAi resulted in the opposite phenotypes. These findings provide fundamental information on strawberry CesA and Csl genes and may contribute to the elucidation of the molecular mechanism by which FveCesA/Csl-mediated cell wall synthesis regulates fruit ripening. In addition, these results may be useful in strawberry breeding programs focused on the development of new cultivars with increased fruit shelf-life.