Microarray analysis of gene expression patterns in Arabidopsis seedlings under trehalose, sucrose and sorbitol treatment

Trehalose is the non-reducing alpha-alpha-1, 1-linked glucose disaccharide. The biosynthesisprecursor of trehalose, trehalose-6-phosphate (T6P), is essential for plant development, growth,carbon utilization and alters photosynthetic capacity but its mode of action is not understood. In thecurrent research, 6 days old seedlings of Arabidopsis thaliana (Columbia ecotype) were grown inliquid culture containing 100 mM trehalose, sorbitol or sucrose for 24 hours. Changes in the genesexpression patterns were studied by cDNA microarray analysis. In sucrose treatment expression of1745 genes was significantly changed. But trehalose changed significantly the expression of only 162genes compared to sorbitol after 24h treatment. Gene expressions profiles revealed that 100 mMtrehalose altered 5% of the genes which are changed by 100 mM sucrose. Statistical analysis showedthat only 4 genes which are induced by trehalose repressed by sucrose. Exogenous trehalose treatmentdid not down-regulate the expression of carbon catabolite genes, but up-regulates a specificcombination of genes known from biotic stress responses. Trehalose induced gene expressionresponses related to ROS and secondary metabolism activation. The expression profile showsparticularly up-regulation (8-fold) of a glutathione transferase (GST22) under trehalose but notsucrose. Also, trehalose treatment induced expression of the JA and ethylene signaling pathwaysfactors. These findings revealed that trehalose or its precursor, T6P, are important in gene expressionregulation of plants.