Transcription profiling of Populus trichocarpa x Populus deltoides habituated to thaxtomin A

ABSTRACT: 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. This habituation 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 18 months. 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 Affymetrix GeneChip Poplar Genome Array revealed that durable resistance to TA is associated with a major and complex reprogramming of gene expression implicating processes such as cell wall synthesis and modification, lignin and flavonoid synthesis, as well as DNA and chromatin modifications. Experiment Overall Design: Each sample was taken from an individual flask of control cells or TA-habituated resistant cells grown without the toxin for 18 months (TA(-)hab cells) that had grown for 5 d after subculture. Six arrays were hybridized, representing 3 arrays per cell type.

ORGANISM(S): Populus trichocarpa x Populus deltoides

SUBMITTER: Nathalie Beaudoin 

PROVIDER: E-GEOD-17804 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress