Sugarcane (Saccharum spp.) is an important sugar crop. Biotic and abiotic stresses such as diseases, cold, and drought are major factors limiting sugarcane production. β-1,3-glucanase (EC 3.2.1.39), a member of the pathogenesis-related protein family, plays an essential role not only in the plant defenses against pathogens but also in plant growth, development, and abiotic stress responses. To systematically investigate the sugarcane β-1,3-glucanase gene family, 132 glycoside hydrolase (GH) 17 family members were identified in the genomes of the sugarcane wild species Saccharum spontaneum 'Np-X', the tropical species S. officinarum 'LA-Purple', and the Saccharum spp. hybrid cultivar 'R570'. The results of the phylogenetic analysis categorized them into four subfamilies, of which subfamily Ⅳ had the largest proportion of members (102). The members of the sugarcane GH17 gene family contained five conserved motifs and 0-16 introns. The majority of the GH17 genes exhibited a genome-wide replication pattern, with 89.50% originating from S. spontaneum 'Np-X' and S. officinarum 'LA-Purple', while 58.10% of them in the Saccharum spp. hybrid cultivar 'R570' belonged to the discrete replication type. Four major classes of cis-acting elements were identified in the promoters, including the elements related to plant growth, development, and tissue-specific expression (14.21%), light-responsive elements (38.24%), biotic or abiotic stress-responsive elements (9.18%), and hormone-responsive elements (38.37%), which suggested that this gene family was involved in plant growth, development, hormone responses, and stress responses. Transcriptome and quantitative real-time PCR (RT-qPCR) analyses showed that the sugarcane GH17 genes exhibited tissue-specific expression and were differentially expressed under low temperature, drought, and hormone treatments, as well as during the interactions between different sugarcane genotypes and Sporisorium scitamineum, suggesting their potential roles in plant defenses. In addition, some SsGlu genes (SsGlu5, SsGlu20, SsGlu21, SsGlu25, SsGlu28, and SsGlu39) were expected to serve as candidate stress-related genes. This study lays a foundation for further revealing the molecular mechanisms of the stress resistance of sugarcane via β-1,3-glucanase genes.
Saccharum/physiology* ; Stress, Physiological/genetics* ; Glucan 1,3-beta-Glucosidase/metabolism* ; Multigene Family ; Phylogeny ; Gene Expression Regulation, Plant ; Plant Proteins/genetics*

In order to explore the influence of reaction temperature on the product composition, the effect of continuous temperature change (22 degrees C-60 degrees C, +/-0.1 degree C) on hydrolysis of yeast beta-glucan by endo-beta-1,3-glucanase was determined by using self-developed Biochem-temperature Characteristic Apparatus. The activation energy of enzymatic hydrolysis of yeast beta-glucan was 84.17 kJ/mol. The optimum temperature represented by accumulation of products decreased exponentially within a certain period of time. The components of the products were changed with reaction temperature. The length of oligosaccharides decreased with the increase of temperature. The main products were laminaribiose and laminaritriose at the temperature higher than 46 degrees C, while the main products were laminaripentaose and larger molecular weight components at the temperature lower than 30 degrees C. The results can provide precise parameters to control the reaction temperature of the production of 1,3-beta-D-glucooligosaccharides.
Enzyme Activation ; Glucan Endo-1,3-beta-D-Glucosidase ; chemistry ; metabolism ; Hydrolysis ; Oligosaccharides ; chemistry ; metabolism ; Temperature ; Yeasts ; metabolism ; beta-Glucans ; metabolism

OBJECTIVETo obtain transgenic Pinellia ternata plants resistant to fungus by transfer Chitinase and beta-1,3-Glucanase gene from Trichoderma harzianum.

METHODUsing hygromycin phosphotransferase as the selection marker, the Chitinase gene (ech42), beta-1,3-Glucanase gene (gluc78) and both gene pCAMBIA(ech42 + gluc78) driven by CaMV35S promoter were transferred into P. ternata callus via Agrobacterium-mediated transformation.

RESULTPCR results confirmed that the regenerants were identified to be transgenic lines and the RT-PCR results confirmed that foreign genes construction were transfer to mRNA. Two foreign genes were inherited stably to T5 generation according to PCR results of the lines.

CONCLUSIONThe results showed that chitinase gene ech42 and beta-1, 3-glucanase gene gluc78 respectively or together introducing and co-integrating into P. ternata

Agrobacterium tumefaciens ; genetics ; metabolism ; Chitinases ; genetics ; metabolism ; Fungal Proteins ; genetics ; metabolism ; Gene Expression Regulation, Plant ; Gene Transfer Techniques ; Genetic Vectors ; genetics ; metabolism ; Glucan 1,3-beta-Glucosidase ; genetics ; metabolism ; Pinellia ; genetics ; metabolism ; Transformation, Genetic ; Trichoderma ; enzymology