Abstract Background: The characteristics of elephant grass, especially its stem lignocellulose, are of great significance for its quality as feed or other industrial raw materials. However, the research on lignocellulose biosynthesis pathway and key genes is limited because the genome of elephant grass has not been deciphered. Results: In this study, RNA sequencing (RNA-seq) combined with lignocellulose content analysis and cell wall morphology observation using elephant grass stems from different development stages as materials were applied to reveal the genes that regulate the synthesis of cellulose and lignin. A total of 3852 differentially expressed genes (DEGs) were identified in three periods of T1, T2, and T3 through RNA-seq analysis. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of all DEGs showed that the two most abundant metabolic pathways were phenylpropane metabolism, starch and sucrose metabolism, which were closely related to cell wall development, hemicellulose, lignin and cellulose synthesis. Through weighted gene co-expression network analysis (WGCNA) of DEGs, a ‘blue’ module highly associated with cellulose synthesis and a ‘turquoise’ module highly correlated with lignin synthesis were exhibited. A total of 43 candidate genes were screened, of which 17 had function annotations in other species. Besides, by analyzing the content of lignocellulose in the stem tissues of elephant grass at different developmental stages and the expression levels of genes such as CesA , PAL , CAD , C4H , COMT , CCoAMT , F5H and CCR , it was found that the content of lignocellulose was related to the expression level of these structural genes. Conclusions: This study provides a basis for further understanding the molecular mechanisms of cellulose and lignin synthesis pathways of elephant grass, and offers a unique and extensive list of candidate genes for future specialized functional studies which may promote the development of high-quality elephant grass varieties with high cellulose and low lignin content.
Abstract Background: The characteristics of elephant grass, especially its stem lignocellulose, are of great significance for its quality as feed or other industrial raw materials. However, the research on lignocellulose biosynthesis pathway and key genes is limited because the genome of elephant grass has not been deciphered. Results: In this study, RNA sequencing (RNA-seq) combined with lignocellulose content analysis and cell wall morphology observation using elephant grass stems from different development stages as materials were applied to reveal the genes that regulate the synthesis of cellulose and lignin. A total of 3852 differentially expressed genes (DEGs) were identified in three periods of T1, T2, and T3 through RNA-seq analysis. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of all DEGs showed that the two most abundant metabolic pathways were phenylpropane metabolism, starch and sucrose metabolism, which were closely related to cell wall development, hemicellulose, lignin and cellulose synthesis. Through weighted gene co-expression network analysis (WGCNA) of DEGs, a ‘blue’ module highly associated with cellulose synthesis and a ‘turquoise’ module highly correlated with lignin synthesis were exhibited. A total of 43 candidate genes were screened, of which 17 had function annotations in other species. Besides, by analyzing the content of lignocellulose in the stem tissues of elephant grass at different developmental stages and the expression levels of genes such as CesA , PAL , CAD , C4H , COMT , CCoAMT , F5H and CCR , it was found that the content of lignocellulose was related to the expression level of these structural genes. Conclusions: This study provides a basis for further understanding the molecular mechanisms of cellulose and lignin synthesis pathways of elephant grass, and offers a unique and extensive list of candidate genes for future specialized functional studies which may promote the development of high-quality elephant grass varieties with high cellulose and low lignin content.
Abstract Background: The characteristics of elephant grass, especially its stem lignocellulose, are of great significance for its quality as feed or other industrial raw materials. Because the genome of elephant grass has not been deciphered, the study of its lignocellulose synthesis pathway and key genes is limited. Results: In this study, RNA sequencing (RNA-seq) combining with lignocellulose content analysis and cell wall morphology observation using elephant grass stems from different development stages as materials, were applied to reveal the genes regulating cellulose and lignin synthesis. A total of 3852 differentially expressed genes (DEGs) were identified in three periods of T1, T2 and T3. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the two most abundant metabolic pathways were phenylpropanemetabolism, starch and sucrose metabolism, which closely related to cell wall development, hemicellulose, lignin and cellulose synthesis. Through weighted gene co-expression network analysis (WGCNA) of DEGs, a ‘blue’ module highly correlated with cellulose synthesis and a ‘turquoise’ module highly correlated with lignin synthesis were exhibited. A total of 43 candidate genes were screened, of which 17 had function annotations in other species. In addition, the expression of CesA , PAL , CAD , C4H , COMT , CCoAMT , F5H , CAD and CCR at different development stages were analyzed, and found that the content of lignocellulose was correlated with the expression levels of these structural genes. Conclusions: This study not only provides new insights into the molecular mechanisms of cellulose and lignin synthesis pathways in elephant grass, but also offers a new and extensive list of candidate genes for more specialized functional studies in the future which may promote the development of high-quality elephant grass varieties with high cellulose and low lignin content.
Wheat straw was treated by thermal plasma technology to prepare biochar. In this study, the effects of different preparation methods (thermal plasma and traditional pyrolysis) and plasma treatment time (3, 4, 5 and 10min) on the characterization of biochar and its adsorption of formaldehyde were studied. Results showed that for plasma treatment method, the treatment time played a leading role in the physicochemical and surface properties of biochar. When the plasma treatment time was 5 min and 10 min, biochar had a relatively high number of functional groups. The specific surface area of biochar treated by plasma for 4 min was increased to 256.17 m2/g. As well as, compared with the traditional pyrolysis method, the biochar prepared by thermal plasma got significantly improved adsorption capacity for formaldehyde, in which the concentration of formaldehyde decreased from 1.654 mg/L to 0.854 mg/L, 0.592 mg/L, 0.555 mg/L and 0.534 mg/L for biochar prepared by thermal plasma with 3 min, 4 min, 5 min and 10 min respectively. This study suggested that compared with pyrolysis method, the plasma treatment was an efficiency method to produce biochar from wheat straw in short time and the plasma treated biochar got high potential as the adsorbent to remove formaldehyde.
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