Gibberellin biosynthesis and response during Arabidopsis seed germination.
The hormone-mediated control of plant growth and development involves both synthesis and response. Previous studies have shown that gibberellin (GA) plays an essential role in Arabidopsis seed germination. To learn how GA stimulates seed germination, we performed comprehensive analyses of GA biosynthesis and response using gas chromatography-mass spectrometry and oligonucleotide-based DNA microarray analysis. In addition, spatial correlations between GA biosynthesis and response were assessed by in situ hybridization. We identified a number of transcripts, the abundance of which is modulated upon exposure to exogenous GA. A subset of these GA-regulated genes was expressed in accordance with an increase in endogenous active GA levels, which occurs just before radicle emergence. The GA-responsive genes identified include those responsible for synthesis, transport, and signaling of other hormones, suggesting the presence of uncharacterized crosstalk between GA and other hormones. In situ hybridization analysis demonstrated that the expression of GA-responsive genes is not restricted to the predicted site of GA biosynthesis, suggesting that GA itself, or GA signals, is transmitted across different cell types during Arabidopsis seed germination.
Ogawa
Mikihiro
M
Plant Science Center, RIKEN, Suehiro-cho 1-7-22, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan.
Hanada
Atsushi
A
Yamauchi
Yukika
Y
Kuwahara
Ayuko
A
Kamiya
Yuji
Y
Yamaguchi
Shinjiro
S
D000040:Abscisic Acid / Q000494:pharmacology; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D005030:Ethylenes / Q000494:pharmacology; D008401:Gas Chromatography-Mass Spectrometry; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D018525:Germination / Q000187:drug effects / Q000235:genetics; D005875:Gibberellins / Q000096:biosynthesis* / Q000494:pharmacology; D017403:In Situ Hybridization; D007210:Indoleacetic Acids / Q000494:pharmacology; D005810:Multigene Family / Q000235:genetics; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D010937:Plant Growth Regulators / Q000494:pharmacology; D012639:Seeds / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D014157:Transcription Factors / Q000235:genetics
D005030:Ethylenes; D005875:Gibberellins; D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; D014157:Transcription Factors; D000040:Abscisic Acid; C036216:ethylene; C007842:gibberellic acid