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báo cáo khoa học: " Habituation to thaxtomin A in hybrid poplar cell suspensions provides enhanced and durable resistance to inhibitors of cellulose synthesis"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Habituation to thaxtomin A in hybrid poplar cell suspensions provides enhanced and durable resistance to inhibitors of cellulose synthesis | Brochu et al. BMC Plant Biology 2010 10 272 http www.biomedcentral.com 1471-2229 10 272 BMC Plant Biology RESEARCH ARTICLE Open Access Habituation to thaxtomin A in hybrid poplar cell suspensions provides enhanced and durable resistance to inhibitors of cellulose synthesis 3 t 1t 2 3 3 3 Viviane Brochu Marie Girard-Martel Isabelle Duval Sylvain Lerat Gilles Grondin Olivier Domingue Carole Beaulieu 3 Nathalie Beaudoin3 Abstract Background Thaxtomin A TA a phytotoxin produced by the phytopathogen Streptomyces scabies is essential for the development of potato common scab disease. TA inhibits cellulose synthesis but its actual mode of action is unknown. Addition of TA to hybrid poplar Populus trichocarpa x Populus deltoides cell suspensions can activate a cellular program leading to cell death. In contrast it is possible to habituate hybrid poplar cell cultures to grow in the presence of TA levels that would normally induce cell death. The purpose of this study is to characterize TA-habituated cells and the mechanisms that may be involved in enhancing resistance to TA. Results Habituation to TA was performed by adding increasing levels of TA to cell cultures at the time of subculture over a period of 12 months. TA-habituated cells were then cultured in the absence of TA for more than three years. These cells displayed a reduced size and growth compared to control cells and had fragmented vacuoles filled with electron-dense material. Habituation to TA was associated with changes in the cell wall composition with a reduction in cellulose and an increase in pectin levels. Remarkably high level of resistance to TA was maintained in TA-habituated cells even after being cultured in the absence of TA. Moreover these cells exhibited enhanced resistance to two other inhibitors of cellulose biosynthesis dichlobenil and isoxaben. Analysis of gene expression in TA-habituated cells using an Affymetrix GeneChip Poplar Genome Array revealed that durable resistance to TA is .