Habituation to thaxtomin A in hybrid poplar cell suspensions provides enhanced and durable resistance to inhibitors of cellulose synthesis

BMC Plant Biology

Research Article

Sylvain Lerat¹  Olivier Domingue¹  Gilles Grondin¹  Nathalie Beaudoin¹  Viviane Brochu¹  Carole Beaulieu¹  Isabelle Duval²  Marie Girard-Martel³ 

[1] Centre SÈVE, Département de biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada J1K 2R1;Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Québec, QC, Canada G1V 4C7;Natural Resources Canada, Canadian Forest Service, Pacific Forestry Centre, Victoria, BC, Canada V8Z 1M5;

关键词: Pectin;    Cell Wall Composition;    Cellulose Synthesis;    Dichlobenil;    Poplar Cell;   

DOI  :  10.1186/1471-2229-10-272

 received in 2010-07-16, accepted in 2010-12-10,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundThaxtomin 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.ResultsHabituation 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 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.ConclusionsWe have shown that habituation to TA induced durable resistance to the bacterial toxin in poplar cells. TA-habituation also enhanced resistance to two other structurally different inhibitors of cellulose synthesis that were found to target different proteins. Enhanced resistance was associated with major changes in the expression of numerous genes, including some genes that are involved in DNA and chromatin modifications, suggesting that epigenetic changes might be involved in this process.

【 授权许可】

Unknown   
© Brochu et al; licensee BioMed Central Ltd. 2010. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.