Search Results (4)

Cellulose synthase (CESA) is a key enzyme in the synthesis of cellulose, which plays an important role in cell wall construction and plant growth and development. In this study, seven CesA genes of P. massoniana were identified by searching the transcriptome data. Bioinformatics analysis showed that the putative CESA proteins were composed of 984–1101 amino acids, each containing the typical motifs of CESA proteins. Phylogenetic analysis showed that Transcript4609, Tran-script2643 and Transcript1263 were clustered into three groups with proteins related to regulating secondary wall synthesis, while Transcript691, Transcript1283, Transcript418 and Transcript556 were categorized into three clades with those associated with the formation of the primary cell walls. RT-qPCR analysis showed that the CesA genes were differentially expressed in different tissues, and most of the genes were induced by different abiotic stress and hormones. Transcript4609, Tran-script2643 and Transcript1263 were mainly expressed in the xylem and could respond to drought and salt stress induced by ABA, MeJA, ETH and SA hormones, indicating that these three CesA genes may play an important role in the response to abiotic stress in P. massoniana. This study revealed the possible biochemical and physiological functions of the CesA gene in P. massoniana, which can provide a basis for further exploration of the function of the CesA gene in cell wall formation and the response to external stress. Full article

Improved cellulose biosynthesis and plant biomass represent important economic targets for several biotechnological applications including bioenergy and biofuel production. The attempts to increase the biosynthesis of cellulose by overexpressing CesAs proteins, components of the cellulose synthase complex, has not always produced consistent results. Analyses of morphological and molecular data and of the chemical composition of cell walls showed that tobacco plants (F₃1 line), stably expressing the Arabidopsis CesA6 fused to GFP, exhibits a “giant” phenotype with no apparent other morphological aberrations. In the F₃1 line, all evaluated growth parameters, such as stem and root length, leaf size, and lignified secondary xylem, were significantly higher than in wt. Furthermore, F₃1 line exhibited increased flower and seed number, and an advance of about 20 days in the anthesis. In the leaves of F₃1 seedlings, the expression of primary CesAs (NtCesA1, NtCesA3, and NtCesA6) was enhanced, as well as of proteins involved in the biosynthesis of non-cellulosic polysaccharides (xyloglucans and galacturonans, NtXyl4, NtGal10), cell wall remodeling (NtExp11 and XTHs), and cell expansion (NtPIP1.1 and NtPIP2.7). While in leaves the expression level of all secondary cell wall CesAs (NtCesA4, NtCesA7, and NtCesA8) did not change significantly, both primary and secondary CesAs were differentially expressed in the stem. The amount of cellulose and matrix polysaccharides significantly increased in the F₃1 seedlings with no differences in pectin and hemicellulose glycosyl composition. Our results highlight the potentiality to overexpress primary CesAs in tobacco plants to enhance cellulose synthesis and biomass production. Full article

Cellulose is the world’s most abundant renewable energy resource, and a variety of cellulose synthase genes are involved in the biosynthesis of cellulose. In the process of cellulose synthesis, all cellulose synthases are interrelated and act synergistically. In this study, we analyzed the contents of cellulose, hemicellulose, and lignin in the different parts and tissues of E. grandis. The results showed that the cellulose content had greater differences among three different heights. On this basis, we carried out the transcriptome-wide profiling of gene expression patterns using RNA sequencing. A total of 2066 differentially expressed genes were identified for three pairwise comparisons between three different heights, most of which were related to the programmed photosynthetic membrane and photosystem. A total of 100 transcripts of CSs (58 CesA and 42 Csl) were obtained from transcriptome libraries. The expression pattern of these genes indicated that different CS genes had a wide range of expression profiles. A phylogenetic analysis of 135 reference CS genes showed that the CSs of E. grandis were clustered into six major groups (CesA1-9, CslA, CslB/H, CslD, CslE, and CslG). Based on the weighted gene co-expression network analysis, a dual-directional regulation mechanism between Csl and CesA proteins in the cellulose biosynthesis was identified. The gene expression profile analysis, using qRT-PCR in different tissues of E. grandis, demonstrated that the CSs were highly expressed in xylem, and CesAs had a higher relative expression than Csls. The analysis of sequence similarity combined with the expression pattern indicated that the CesA1, 3, and 6 transcripts were associated with the biosynthesis of the secondary cell wall, and CesA4, 5, and 7 transcripts were more likely to associate with the biosynthesis of the primary cell wall. Finally, the qRT-PCR analysis confirmed the expression of 11 selected CSs in three different parts of E. grandis. Full article

Cellulose synthase (CESA), which is an essential catalyst for the generation of plant cell wall biomass, is mainly encoded by the CesA gene family that contains ten or more members. In this study; four full-length cDNAs encoding CESA were isolated from Betula platyphylla Suk., which is an important timber species, using RT-PCR combined with the RACE method and were named as BplCesA3, −4, −7 and −8. These deduced CESAs contained the same typical domains and regions as their Arabidopsis homologs. The cDNA lengths differed among these four genes, as did the locations of the various protein domains inferred from the deduced amino acid sequences, which shared amino acid sequence identities ranging from only 63.8% to 70.5%. Real-time RT-PCR showed that all four BplCesAs were expressed at different levels in diverse tissues. Results indicated that BplCESA8 might be involved in secondary cell wall biosynthesis and floral development. BplCESA3 appeared in a unique expression pattern and was possibly involved in primary cell wall biosynthesis and seed development; it might also be related to the homogalacturonan synthesis. BplCESA7 and BplCESA4 may be related to the formation of a cellulose synthase complex and participate mainly in secondary cell wall biosynthesis. The extremely low expression abundance of the four BplCESAs in mature pollen suggested very little involvement of them in mature pollen formation in Betula. The distinct expression pattern of the four BplCesAs suggested they might participate in developments of various tissues and that they are possibly controlled by distinct mechanisms in Betula. Full article