Visualization by comprehensive microarray analysis of gene expression programs during transdifferentiation of mesophyll cells into xylem cells.
Plants have a unique transdifferentiation mechanism by which differentiated cells can initiate a new program of differentiation. We used a comprehensive analysis of gene expression in an in vitro zinnia (Zinnia elegans L.) culture model system to gather fundamental information about the gene regulation underlying the transdifferentiation of plant cells. In this model, photosynthetic mesophyll cells isolated from zinnia leaves transdifferentiate into xylem cells in a morphogenic process characterized by features such as secondary-wall formation and programmed cell death. More than 8,000 zinnia cDNA clones were isolated from an equalized cDNA library prepared from cultured cells transdifferentiating into xylem cells. Microarray analysis using these cDNAs revealed several types of unique gene regulation patterns, including: the transient expression of a set of genes during cell isolation, presumably induced by wounding; a rapid reduction in the expression of photosynthetic genes and the rapid induction of protein synthesis-associated genes during the first stage; the preferential induction of auxin-related genes during the subsequent stage; and the transient induction of genes closely associated with particular morphogenetic events, including cell-wall formation and degradation and programmed cell death during the final stage. This analysis also revealed a number of previously uncharacterized genes encoding proteins that function in signal transduction, such as protein kinases and transcription factors that are expressed in a stage-specific manner. These findings provide new clues to the molecular mechanisms of both plant transdifferentiation and wood formation.
Demura
Taku
T
Plant Science Center, RIKEN, 230-0045 Yokohama, Japan. demura@psc.riken.go.jp
Tashiro
Gen
G
Horiguchi
Gorou
G
Kishimoto
Naoki
N
Kubo
Minoru
M
Matsuoka
Naoko
N
Minami
Atsushi
A
Nagata-Hiwatashi
Miyo
M
Nakamura
Keiko
K
Okamura
Yoshimichi
Y
Sassa
Naomi
N
Suzuki
Shinsuke
S
Yazaki
Junshi
J
Kikuchi
Shoshi
S
Fukuda
Hiroo
H
D019659:Asteraceae / Q000166:cytology / Q000235:genetics*; D015415:Biomarkers; D002454:Cell Differentiation; D002473:Cell Wall / Q000378:metabolism; D002478:Cells, Cultured; D003583:Cytokinins / Q000494:pharmacology; D018076:DNA, Complementary / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D015723:Gene Library; D008031:Lignin / Q000096:biosynthesis; D008969:Molecular Sequence Data; D009280:Naphthaleneacetic Acids / Q000494:pharmacology; D020411:Oligonucleotide Array Sequence Analysis; D010788:Photosynthesis / Q000235:genetics; D018515:Plant Leaves / Q000166:cytology; D010940:Plant Proteins / Q000096:biosynthesis / Q000235:genetics*; D011494:Protein Kinases / Q000096:biosynthesis / Q000235:genetics; D015398:Signal Transduction
D015415:Biomarkers; D003583:Cytokinins; D018076:DNA, Complementary; D018744:DNA, Plant; D009280:Naphthaleneacetic Acids; D010940:Plant Proteins; D008031:Lignin; D011494:Protein Kinases