Inhibition of germination gene expression by Viviparous-1 and ABA during maize kernel development.
Two maize glyoxysomal genes expressed during germination, malate synthase (MS) and isocitrate lyase (ICL), were used to characterize the regulatory roles of the Viviparous-1 (Vp1) regulatory gene and abscisic aicd (ABA) in the induction of embryo quiescence during kernel development. In wild-type maize embryo, MS and ICL transcripts were first detected at 2 (MS) or 3 (ICL) days after germination (DAG), peaked at 5 DAG, and decreased thereafter. By reverse transcriptase-polymerase chain reaction (RT-PCR), the germination-specific genes were amplified in both ABA-insensitive (vp1) and ABA-deficient (vp7 and vp10) mutant embryos at 26 and 33 days after pollination (DAP), but not in wild-type embryos. The repression of these germination-specific genes thus requires the Vp1 gene product and normal levels of ABA to induce embryo quiescence during kernel development. This suggests that a genetic regulatory system exists to prevent vivipary in developing maize embryos. The involvement of the Vp1 gene product and ABA in repressing germination-specific genes complements their previously defined roles in the induction of seed-specific genes such as C1.
Paek
N C
NC
Department of Biology, Chonnam National University, Kwangju, Korea.
Lee
B M
BM
Gyu Bai
D
D
Smith
J D
JD
D000040:Abscisic Acid / Q000235:genetics / Q000502:physiology*; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology*; D015870:Gene Expression / Q000235:genetics; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant / Q000235:genetics; D018525:Germination / Q000235:genetics*; D007522:Isocitrate Lyase / Q000235:genetics; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics / Q000502:physiology; D012097:Repressor Proteins / Q000235:genetics / Q000502:physiology; D012639:Seeds / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D017386:Sequence Homology, Amino Acid; D015534:Trans-Activators; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*; D014158:Transcription, Genetic / Q000235:genetics; D003313:Zea mays / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development
D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D010940:Plant Proteins; D012097:Repressor Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D000040:Abscisic Acid; D007522:Isocitrate Lyase