Abstract: The responses of rice roots to 1,2,4-trichlorobenzene (TCB) stress were investigated by proteomic analysis, electron micrograph observation, and lipid peroxide estimation. The results showed that TCB stress inhibited root growth, led to water deficit in rice seedlings, affected cell structure and caused lipid peroxidation in rice roots. Moreover, TCB stress had significant effect on global proteome in rice roots. The analysis of the category and function of TCB stress inducible proteins showed that different groups of proteins were induced by 5 mg L^-1 TCB stress. They are detoxification enzymes (including esterase, aldo/keto reductases, and glutathione S-transferase), cell wall compound metabolism related enzymes (including UDP-glucose protein transglucosylase and GDP-mannose 3,5-epimerase 1), phytohormone metabolism and regulation related enzymes or proteins (including aci-reductone dioxygenase 4, beta-glucosidase, two members of pathogenesis-related proteins from family 10), primary and secondary metabolism regulative enzymes (including translational elongation factor Tu, cytosolic orthophosphate dikinase, triosephosphate isomerases, alanine aminotransferase, and isoflavone reductase). Compared the TCB stress inducible proteins between two cultivars, β-glucosidase and PR10 proteins were particularly induced in Aizizhan roots, and glutathione S-transferase and aci-reductone dioxygenase 4 were induced in Shanyou 63 roots. This might be one of the important mechanisms for Shanyou 63 having higher tolerance to TCB stress than Aizizhan.

Key words: Rice, 4-Trichlorobenzene, Proteome, Stress response