snd2, a nac transcription factor gene, regulates genes involved in secondary cell wall development in arabidopsis fibres and increases fibre cell area in eucalyptussnd2,nac转录因子基因,调节拟南芥基因参与次生细胞壁发展纤维,提高纤维细胞地区桉树.pdf

Hussey et al. BMC Plant Biology 2011, 11:173 /1471-2229/11/173 RESEARCH ARTICLE Open Access SND2, a NAC transcription factor gene, regulates genes involved in secondary cell wall development in Arabidopsis fibres and increases fibre cell area in Eucalyptus 1 1 2 2 3 Steven G Hussey , Eshchar Mizrachi , Antanas V Spokevicius , Gerd Bossinger , Dave K Berger and Alexander A Myburg1* Abstract Background: NAC domain transcription factors initiate secondary cell wall biosynthesis in Arabidopsis fibres and vessels by activating numerous transcriptional regulators and biosynthetic genes. NAC family member SND2 is an indirect target of a principal regulator of fibre secondary cell wall formation, SND1. A previous study showed that overexpression of SND2 produced a fibre cell-specific increase in secondary cell wall thickness in Arabidopsis stems, and that the protein was able to transactivate the cellulose synthase8 (CesA8) promoter. However, the full repertoire of genes regulated by SND2 is unknown, and the effect of its overexpression on cell wall chemistry remains unexplored. Results: We overexpressed SND2 in Arabidopsis and analyzed homozygous lines with regards to stem chemistry, biomass and fibre secondary cell wall thickness. A line showing upregulation of CesA8 was selected for transcriptome-wide gene expression profiling. We found evidence for upregulation of biosynthetic genes associated with cellulose, xylan, mannan and lignin polymerization in this line, in agreement with significant co- expression of these genes with native SND2 transcripts according to public microarray repositories. Only minor alterations in cell wall chemistry were detected. Transcription factor MYB103,