Comprehensive analysis of glucan elicitor-regulated gene expression in tobacco BY-2 cells reveals a novel MYB transcription factor involved in the regulation of phenylpropanoid metabolism.
We previously demonstrated that a beta-1,3-, 1,6-oligoglucan (AaGlucan) from the fungus Alternaria alternata 102 shows strong elicitor activity in tobacco BY-2 cells. We have used cDNA microarray analysis to monitor global changes in gene expression in tobacco cells treated with this A. alternata fraction or with laminarin. In total, we identified 265 genes that were induced 1 h after treatment with an AaGlucan-enriched fraction or laminarin. Among them, we characterized in detail a novel tobacco R2R3 MYB-type transcription factor homolog (NtMYBGR1) and two DC1 domain-containing genes (NtDC1A and NtDC1B). Microarray data, together with overexpression and metabolic analyses, indicated that NtMYBGR1, but not the NtDC1 proteins, primarily targets the phenylpropanoid synthesis-related genes PAL and 4CL. These results suggest that NtMYBGR1 specifically regulates defense responses in BY-2 cells by enhancing phenylpropanoid metabolism in response to AaGlucan and laminarin elicitors.
Shinya
Tomonori
T
Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-16, Naka-cho, Koganei, Tokyo, 184-8588 Japan. shinya@isc.meiji.ac.jp
Gális
Ivan
I
Narisawa
Tomoko
T
Sasaki
Mami
M
Fukuda
Hiroo
H
Matsuoka
Hideaki
H
Saito
Mikako
M
Matsuoka
Ken
K
D000528:Alternaria / Q000737:chemistry; D002460:Cell Line; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D005936:Glucans / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D011134:Polysaccharides / Q000494:pharmacology; D020005:Propanols / Q000378:metabolism*; D014026:Nicotiana / Q000166:cytology*; D014157:Transcription Factors / Q000378:metabolism*
D005936:Glucans; D010940:Plant Proteins; D011134:Polysaccharides; D020005:Propanols; D014157:Transcription Factors; C439395:1-phenylpropanol; C008247:laminaran