Dr Bill Finch-Savage
Newly-shed seeds of many temperate broad-leaved tree species require lengthy low-temperature treatments to overcome physiological embryo dormancy before germination can occur. In cherry (Prunus avium), these treatments are well characterised, but none of the molecular events underlying this phenomenon are known.
Rapid amplification of cDNA ends (RACE), differential display (DD) and quantitative PCR were used to recover and monitor expression of cDNAs. We isolated cDNAs similar to two dormancy-imposing genes; a serine/threonine protein-phosphatase 2C homologous to ABSCISIC ACID INSENSITIVE 1 and 2, (Pa-PP2C1), and the transcription factor ABSCISIC ACID INSENSITIVE 3 (Pa-ABI3). Two germination-associated cDNAs were also recovered; aconitase, (Pa-ACO1) and eukaryotic translation initiation factor 3 subunit 8, (Pa-eIF3 SUBUNIT 8). Low-temperature treatment reduced expression of Pa-PP2C1 and Pa-ABI3, consistent with roles in establishing primary dormancy; neither was induced by imposition of secondary dormancy. Expression of these genes was distinct from expression of Pa-ACO1 and Pa-eIF3-SUBUNIT 8.
Germinating cherry seed with Northern analysis of Prunus avium eif3c gene expression
Results were consistent with a role for ABI1/ABI2 and ABI3 homologues in primary dormancy of P. avium embryonic axes, but not secondary dormancy as control of germination appeared overridden by the tissues surrounding the embryo.
Stephen, J.R., Dent, K.C. and Finch-Savage, W.E. 2004 Molecular responses of Prunus avium embryonic axis to temperatures affecting dormancy. New Phytologist 161, 401-413.
Stephen, J.R., Dent, K.C. and Finch-Savage, W.E. 2003 A cDNA encoding a cold-induced glycine-rich RNA binding protein from Prunus avium expressed in embryonic axes. Gene 320, 177-83.