Abstract
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 (Hattori et al., 1992; Paek et al., 1997), Em (McCarty et al., 1991), and Gln1 (Kriz et al., 1990; Rivin and Grudt, 1991).
Original language | English |
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Pages (from-to) | 336-342 |
Number of pages | 7 |
Journal | Molecules and Cells |
Volume | 8 |
Issue number | 3 |
State | Published - 30 Jun 1998 |
Keywords
- ABA
- Germination
- Isocitrate Lyase
- Maize
- Malate Synthase
- Viviparous-1