Project description:To analyze the molecular function of HDAC inhibitors in salt stress responses in Arabidopsis, we conducted microarray analysis using 4-day-old plants, which were treated with 1 μM Ky-9 or Ky-72 or water for 24 h, and then treated with or without 100 mM NaCl for 2 h
Project description:Study of the secretome of Cellvibrio japonicus after growth on different chitins. Utilization of a novel plate method to enrich truly secreted proteins.
Project description:Plant mannans are a component of lignocellulose that may possess diverse compositions changing both in terms of its backbone and side-chain substitutions. Consequently, the degradation of mannan substrates requires a cadre of enzymes for complete reduction to substituent monosaccharides, specifically mannose, galactose, and/or glucose. One bacterium that possesses this suite of enzymes is the Gram-negative saprophyte Cellvibrio japonicus, which has ten predicted mannanases from the Glycoside Hydrolase (GH) families 5, 26, and 27. Here we describe a systems biology approach to identify and characterize the essential components of the mannan degradation apparatus in this bacterium. Transcriptomic analysis uncovered significant changes in gene expression for most mannanases, as well as many genes that encode Carbohydrate Active Enzymes (CAZymes) when mannan substrates were actively being degraded. A comprehensive mutational analysis characterized 54 CAZyme genes in the context of mannan utilization. Growth analysis of the mutant strains indicated that the man26C, aga27A, and man5D genes, which encode a mannobiohydrolase, α- galactosidase, and mannosidase, respectively, were influential to the deconstruction of galactomannan. Furthermore, our updated model of mannan degradation in C. japonicus proposes that the removal of galactose sidechains from substituted mannans constitutes a crucial step for the efficient and complete degradation of this hemicellulose by bacteria.